Reflecting sun's rays would cause crops to fail, scientists warn

Research shows geoengineering method intended to combat climate change would have adverse effect on agriculture
Fiona Harvey The Guardian 8 Aug 18;

Proposals to combat climate change by reflecting the sun’s rays back into space would cause widespread crop failure, cancelling out any benefits to farming from the reduction in warming, according to new research.

By examining the effects of volcanic eruptions on agriculture – which has a similar effect to proposed artificial methods of scattering solar radiation through aerosols – scientists have concluded that such methods could have unintended consequences.

“[The research was to] find a way to examine the side effects of geoengineering without experimenting on the climate,” said Jonathan Proctor of University of California, Berkeley, lead author of the published in the peer review journal Nature. “[We found] potential adverse effect on agricultural production.”

But he said there could be other positive effects that were less easy to capture.

The findings deal another blow to proposals to use to reduce or delay global warming, which some scientists think may be necessary to stave off the worst effects of rising greenhouse gas emissions.

Spraying or injecting tiny airborne particles into the stratosphere has been regarded as one of the prime possibilities for geoengineering, by reflecting some of the sun’s rays back into space before they can warm the Earth.

Facebook Twitter Pinterest Solar geoengineering aims to cool the Earth by injecting reflective particles, shown in blue, into the high atmosphere. Photograph: Jonathan Proctor and Solomon Hsiang/Nature
The scientists studied the eruption of El Chichón in Mexico in 1982 and the eruption of Mount Pinatubo in the Philippines, both of which caused large quantities of sulphate particles to enter the stratosphere. This created a “veil” which reduced the amount of sunlight reaching the Earth’s surface.

In the study, the researchers examined the aerosol levels, solar radiation and crop yields. The deflection of sunlight had a negative effect on the yields of many staple crops, including rice, wheat and maize. They concluded that the impacts on crops of sending particles deliberately into the stratosphere would probably be similar, and that the beneficial effects on crop yields from the resulting cooling would be “essentially negated” by the loss in crops due to the reduction in sunlight, failing to remove the threat climate change poses to agriculture and food security.

Hugh Hunt, reader in engineering at Cambridge University, who was not involved in the research, said solar radiation management [SRM] was “no magic bullet”, but the effects should be compared with doing nothing. “We may well decide to use SRM to slow or reverse the melting of Arctic sea ice and to preserve the Greenland ice sheet. We will then be glad to have saved valuable land and the homes of millions of people from rising sea levels. Moreover, in an SRM world, agriculture will be sustained by a more stable and predictable climate,” he told the Guardian.

“SRM, rather like chemotherapy, is not something one would wish on a healthy planet. The Earth is sick and it is likely that any cure such as SRM will have unpleasant side effects. What we really ought to be doing is to halt the rise of atmospheric greenhouse gases, not just sometime in the future but now.”

Matthew Watson, of the school of Earth sciences at Bristol University, added: “It’s worth noting that this research only states that SRM would not necessarily improve crop yields and that there are other potential co-benefits and risks that must be carefully considered.”

Previous research has shown that the use of aerosols for geoengineering could have a substantial impact on weather patterns, for instance on the frequency and intensity of hurricanes, or could cause changes in rainfall such as droughts in vulnerable regions.

In the UK, the Spice (stratospheric particle injection for climate engineering) project was set up as a government-funded university collaboration in 2010 to examine the possibilities of aerosol-based geoengineering. It ended in 2015 and is understood to have queried the potential positive impacts of geoengineering, though findings have not yet been published. An experiment to mimic the effects of such a programme was abandoned.

Durwood Zaelke, president of the Institute for Governance and Sustainable Development in the US, who was not involved in the research, pointed out that the effects of sulphate particles can already be seen, as many coal plants which emit sulphates have been closed down. Cutting sulphates can produce a short-term warming effect, because the sulphates can deflect the sun’s rays, while cutting carbon dioxide emissions takes longer to have an effect.

He said: “There are other strategies for managing short-lived climate pollutants we should start with [including] cutting black carbon [soot, from fossil fuel burning], methane and HFC refrigerants. We need to think of climate change mitigation like a staggered race, where short-lived pollutants get a fast start and CO2 reductions eventually catch up and provide more and more cooling.” If these measures were taken, it could reduce temperature rises by up to 0.6C by 2050 and by 1.2C by the end of this century.

The research showed, he concluded, that “maybe we can keep geoengineering on the bench a bit longer while we figure out how to manage it safely”.

Stephen Salter, emeritus professor of engineering design at Edinburgh University, and an advocate of an alternative geoengineering method spraying the air to whiten clouds and increase their reflectivity, said: “The message is that we should not expect great agricultural improvements from stratospheric sulphur but negative results will be moderate. People who are hostile to geoengineering – there are lots of them – will argue that we are stuck with the results of stratospheric sulphur for a year or more and that there might be another Pinatubo or even something like the 1815 Tambora event, which gave the year without a summer.”

Read more!

India’s grand plan to create world’s longest river set to go

TV Padma New Scientist 28 Nov 16;

Engineering projects don’t come any bigger than this. If India’s prime minister, Narendra Modi, gets his way, work could soon begin on a project to link large rivers in the Himalayas and Deccan Peninsula via 30 mega-canals and 3000 dams.

When the work is finished the water network will be twice the length of the Nile, the world longest river, and it will be able to divert water from flood-prone areas to those vulnerable to drought.

But geologists and ecologists in India question the science behind the Inter Linking of Rivers (ILR) scheme. If it goes ahead it might lead to ecological disasters and coastal erosion that would threaten livelihoods and endanger wildlife.

And yet New Scientist has learned from the officials close to the project that work on the pilot link is likely to “start any time soon”, with final clearance from the ministry of environment and forests expected imminently.

Water network

Versions of the ILR scheme date back more than 60 years to the days of British rule in India. In its latest incarnation the plan is to link 14 rivers in north India and 16 in the western, central and southern parts of the country, creating a water network some 12,500 kilometres long. The idea is to reduce droughts and floods and create 35 million hectares of arable land in the process, as well as the means to generate 34,000 megawatts of hydropower.

This project is backed by Narendra Modi, who became the country’s prime minister in 2014. Since then India’s National Water Development Agency has completed detailed project reports for three key initial river links – the pilot link between Ken and Betwa rivers in northern and central India; Daman Ganga and Pinjal rivers in western India; and Par and Tapti rivers in western and central India. A feasibility report of a fourth link between three Himalayan rivers – Manas, Teesta and Ganges – is in the final stages of preparation.

But many researchers question the science behind the scheme. They say there isn’t a simple division between river basins that carry too little and too much water – and that climate change has triggered changes in rainfall patterns with unpredictable knock-on effects on water flow.

They argue that it would be unwise to set in stone a vast new canal network at a time of dramatic environmental change.

Changing climate

A study published in July builds on this. Climate modelling once predicted that India’s dry areas will become drier and its wet areas wetter, but this is no longer the case.

A team of scientists from the Indian Institute of Technology in Bombay and Madras found a significant decrease in the monsoon rainfall over major water surplus river basins in India. The team’s computer simulations showed that the water yield in surplus river basins is decreasing but it is increasing in deficit basins.”What may appear as water deficient today may become water surplus in the future due to climate change,” says study author Sachin Gunthe at Indian Institute of Technology, Madras. “So, how do you justify inter-linking?”

Geologists are concerned, too. Over the millennia India’s landscape has gradually evolved with the natural flow of water. “Most rivers are fed by monsoon rains and have built large floodplains and deltas over the years,” says Vedharaman Rajamani at the Jawaharlal Nehru University in New Delhi. “Pushing rivers around through ILR disrupts the supply of sediments and nutrients downstream.”

This could negatively affect agriculture, as farmlands have been built over centuries in floodplains and near river deltas. “Rivers recharge aquifers near farmland,” Rajamani says. “Besides, rivers are critical to freshwater biodiversity, including fish, and carry nutrients to marine life.”

Good side of floods
What’s more, a central target of the ILR scheme – to make flooding in some parts of India a thing of the past – ignores the very real value of flooding. For one thing, it carries huge volumes of silt that can reduce coastal erosion.

“A river is not just a natural pipe through which water flows,” says geologist Chittenipattu Rajendran at the Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore. “It carries deposits and sediments. Dams trap sediments that are critical to habitats downstream.”

Natural flooding also helps recharge supplies of freshwater below India’s floodplains and deltas. Without that sporadic influx from floods, salt water gradually intrudes into groundwater supplies in land. “Desiccation and desertification follow,” says Rajamani. Decreased sedimentation also leads to coastal erosion, he adds.

Rajamani says the presence of excess fresh water in the Bay of Bengal delta is especially crucial, as it helps create and maintain a layer of low salinity in the bay, which is one of the several complex, interlinked factors that influence the onset of the Indian summer monsoon. Artificially manipulating the natural system could disrupt the monsoon rainfall in the region, he says.

Rajendran says that the huge amount of water in dams would increase the water pressure in the cracks and push on crust below, possibly increasing the risk of earthquakes in the already quake-prone Himalayas.

A grand distraction?
Sunita Narain, director of Delhi-based NGO, the Centre for Science and Environment, has in the past described river linking as a “grand distraction” from other pressing problems, including environment degradation.

She thinks the ILR scheme will mean building vast reservoirs to control and store water. Those reservoirs will displace hundreds of thousands of people, she says – claiming the Indian government’s track record in resettling people displaced by such projects has been poor.

Ecologists are concerned too. A pilot project in the ILR scheme – the Ken-Betwa link – would be built at the cost of destroying an estimated 4100 hectares of forest. This might include 58 square kilometres of the Panna Tiger Reserve – 10 per cent of the reserve’s area. And yet it got the official approval in September.

The government, however, has stayed dedicated to the idea. Interlinking rivers is an attempt to boost water supply to the needy states, says Vijay Goel, junior minister for water resources.

But while the project looks grand on paper whether it turns out to be a success or a disaster remains to be seen.

Read more!

Geo-engineering unlikely to work, conservation group says

Attempts to limit climate change by using the novel technologies known as geo-engineering are very unlikely to work, leading biologists say.
Alex Kirby Climate News Network 1 Nov 16;

LONDON, 1 November, 2016 – The global watchdog responsible for protecting the world’s wealth of species, the UN’s Convention on Biological Diversity (CBD), has looked at the hopes for reining in climate change through geo-engineering. Its bleak conclusion, echoing that reached by many independent scientists, is that the chances are “highly uncertain”.

“Novel means”, in this context, describes trying to reduce greenhouse gas (GHG) emissions by removing them from the atmosphere, and altering the amount of heat from the Sun that reaches the Earth.

Some scientists and policymakers say geo-engineering, as these strategies are collectively known, is essential if the world is to meet the goals of the Paris Agreement. This is because current attempts to reduce emissions cannot make big enough cuts fast enough to keep global average temperatures from rising more than 2°C above their pre-industrial levels, the Agreement’s basic goal.

But the CBD says in a report that geo-engineering, while it could possibly help to prevent the world overheating, might endanger global biodiversity and have other unpredictable effects.

Many independent analysts have raised similar concerns.Attempts to increase the amount of carbon in the oceans, in order to remove GHGs, have so far shown disappointing results. One report doubted that geo-engineering could slow sea-level rise. Another said it could not arrest the melting of Arctic ice. A third study found that geo-engineering would make things little better and might even make global warming worse.

Transboundary impacts

The lead author of the CBD geo-engineering report is a British scientist, Dr Phillip Williamson, of the UK’s Natural Environment Research Council. He is an associate fellow in the School of Environmental Sciences at the University of East Anglia, UK.

The CBD originally became involved in climate geo-engineering in 2008, because member governments were concerned that experiments to fertilise the oceans could pose unknown risks to the environment (they were then unregulated when carried out in international waters).

The CBD’s concern expanded to include other geo-engineering techniques, especially atmospheric methods which could have uncertain transboundary impacts. Some scientists argue that “geo-engineering” is a hazily-defined term and prefer to speak instead simply of “greenhouse gas removal”.

Dr Williamson and his colleagues say assessment of the impacts of geo-engineering on biodiversity “is not straightforward and is subject to many uncertainties”.

On greenhouse gas removal they warn that removing a given quantity of a greenhouse gas would not fully compensate for an earlier ‘overshoot’ of emissions.

New risks

In some cases, they say, the cure may be worse than the disease: “The large-scale deployment of bioenergy with carbon capture and storage (BECCS) seems likely to have significant negative impacts on biodiversity through land use change.”

When it comes to attempts to reflect sunlight back out into space or to manage solar radiation, a familiar theme recurs: “There are high levels of uncertainty about the impacts of SRM [solar radiation management] techniques, which could present significant new risks to biodiversity.”

Time and again, it seems, a potential advance is liable to be cancelled by an equally likely reverse: if SRM benefits coral reefs by decreasing temperature-induced bleaching (as it may), in certain conditions “it may also increase, indirectly, the impacts of ocean acidification.” There could even be a risk in some circumstances of loss to the Earth’s protective ozone layer.

Dr Williamson and his colleagues believe that geo-engineering is essential – if it can be made to work – because of the diminishing chances that anything else will.

They write: “It may still be possible that deep and very rapid decarbonisation by all countries might allow climate change to be kept within a 2°C limit by emission reduction alone. However, any such window of opportunity is rapidly closing.”

Repeatedly, those two words recur: a suggested technique or development will be “highly uncertain”. Most of the report amounts to a very cautious call for more research, coupled with an implicit acceptance that in the end geo-engineering is unlikely to prove capable of contributing much to climate mitigation.

Dr Williamson told the Climate News Network: “I’m sceptical. That’s not to say bio-energy with carbon capture and storage is impossible, but it seems extremely unlikely to be feasible (for all sorts of reasons)” at the scale needed.

When the CBD member governments meet in December they are expected to call for more research: a safe option in most circumstances, but far from a ringing endorsement of a technology once seen as very promising. – Climate News Network

Read more!

Sucking CO2 from the Air Would Not Halt Effects of Global Warming

Sans reduced emissions, using extreme geoengineering to remove atmospheric carbon dioxide would not protect the oceans, models show
Maria Temming Scientific American 12 Aug 15;

As nations repeatedly fail to make major cuts in their greenhouse gas production, scientists and others have begun to wonder if climate change might be halted not by emissions cuts but by technology that removes those gases from the atmosphere. The approach is called geoengineering. Unfortunately, a recent simulation of its effects on the oceans found that even extreme methods would not be able to completely rehabilitate the ocean environment. The work was published in Nature Climate Change on August 3. (Scientific American is part of Nature Publishing Group.)

The experiments focused on carbon dioxide removal (CDR), the process of extracting excess CO2 directly from the atmosphere. In theory this could help oceans because they become dangerously acidic when they absorb too much atmospheric CO2. One CDR idea is to plant trees that consume large amounts of CO2 and then burn the trees in facilities where the emissions can be captured and stored underground. But no one has ever tested this or similar carbon removal schemes on a large scale.

The next-best thing to large-scale testing is a large-scale simulation. In the new study researchers led by Sabine Mathesius, an environmental scientist at the Potsdam Institute for Climate Impact Research, used a computer model to investigate CDR’s effectiveness in rehabilitating seawater damaged by CO2 emissions.

A tale of two experiments

Mathesius’s team used their computer simulation in two experiments. In the first they wanted to see if carbon removal could reduce the atmosphere’s CO2 concentration to the level that was typical before the industrial revolution, thus restoring the marine environment its preindustrial state.

The researchers based their simulation on real-world carbon dioxide emissions from 1800 to 2005, and then projected those emissions into the year 2250. Then they simulated what would happen if technology could remove 18 billion tons of carbon dioxide per year—about half of present-day emission rates—from 2250 until 2700. The researchers found this did decrease atmospheric CO2 levels but could not restore the ocean’s preindustrial dissolved oxygen content or temperature. Even after 450 years of geoengineering, the model ocean was still almost as acidic as it would have been without any intervention at all.

But what might happen if someone invented a better, marvelous new carbon removal technique? The scientists wanted to know, so they raised the maximum removal rate to 90 billion tons of CO2 per year. That high performance is “frankly ridiculous,” says geophysicist Donald Penman from Yale University, who was not involved in the research. Yet even at this level, in the year 2700 the ocean was still warmer, more acidic and held less oxygen than the preindustrial marine environment.

In their second simulation the team modeled a world where, against all odds, present-day humans substantially reduced their greenhouse gas production. They wanted to learn whether emission cuts or after-the-fact carbon removal was better. And they did: When it came to preserving the ocean environment, removal was no match for decreased emissions. Even in the simulation where CDR pulled 90 billion tons of CO2 from the atmosphere per year, the deep ocean was far more acidic than it was in the reduced emissions model. Penman says, “It is clear that rather than trying to clean up a mess, it would be wiser to simply not create the mess in the first place.”

According to Mathesius, CDR is ineffective for combating ocean acidification because of the way seawater circulates. There are regions of the ocean where surface water submerges into the deep ocean and stays there for centuries or even millennia, cut off from the atmosphere. So even if CDR does manage to significantly decrease the atmospheric CO2 concentration, the deep ocean remains highly acidic.

This is not the only work indicating that carbon removal will come up short. A study published on August 3 in Nature Communications shows that capping global warming at 2 degrees Celsius requires removing 1.8 billion tons of carbon from the atmosphere yearly from now until 2100—a tall order that exceeds the capabilities of current technology.

The studies do not mean that carbon removal is completely useless, Mathesius notes. “We’re only saying that CDR would not be strong enough to counter a business-as-usual scenario,” she says. “But there’s still the possibility that you take CDR as a supplemental measure.” Removal, although it cannot undo all the damage of excess emissions, might still prove valuable if combined with actual carbon cuts.

Read more!

As El Nino looms, cloud seeding gets tailwind

COLIN PACKHAM Reuters 7 Jul 15;

Circling thousands of feet above Tasmania's farmland in a light aircraft, Christina Nebel prepares to release tiny chemical particles as part of a cloud-seeding scheme estimated to have helped boost rainfall on the Australian island by over 10 percent.

The program is one of a handful globally riding a wave of renewed interest in the decades-old technology as drought hits places from the United States to the Philippines, with the specter of a strong El Nino weather pattern later this year threatening worse to come.

"We are looking for fronts crossing Tasmania," said Nebel, cloud seeding officer at renewable energy producer Hydro Tasmania.

If the conditions are right, she releases a small amount of silver iodide, which attracts water particles, encouraging clouds to grow and, she hopes, rain on the land below.

But Tasmania is blessed with near-perfect conditions for the process with clouds containing a large amount of cold water vapor whipping in off the Southern Ocean, meaning the scale of success of its program, which has its roots in the 1960s, could be difficult to replicate elsewhere.

Nonetheless atmospheric experts say the technology is enjoying a renewed emphasis as governments fret over scorching weather and as populations grow, while falling costs could increase its use in future.

"What is driving the attention is that winter cloud seeding holds some promise and in many places, including the western U.S., water shortages are becoming severe," said Professor Terry Deshler from the University of Wyoming's atmospheric science department.

Research suggests cloud seeding in winter produces better results than in other periods.

RAIN AGAIN?

While many of the world's cloud-seeding programs are small and unlikely to have more than a limited impact, China has a large-scale scheme in place.

The nation launched its "human affected weather" program in 1958, and has done extensive research in cloud seeding. It aims to induce more than 60 billion cubic meters of additional rain each year by 2020 using the technique, as it looks to fight chronic water shortages.

That figure is equivalent to more than one-and-a-half times the volume of the Three Gorges reservoir, one of the largest in the country.

On a far smaller scale, the government in the Philippines, one of the world's biggest rice consumers, is spending a record 15 million pesos ($330,000) this year on cloud-seeding operations and could allocate another 15 million pesos in the face of El Nino, which can bring crop-damaging dry weather to many regions.

"We of course don't want to be caught unprepared, especially now that weather experts are predicting a prolonged El Nino," said Silvino Tejada, director of the Philippines Bureau of Soils and Water Management.

The cost of cloud seeding has traditionally been one of the main hurdles to usage. Fuel costs are often the biggest drag on budgets, researchers said, with some seeding operations often requiring multiple flights.

But the Nevada-based Desert Research Institute has recently started testing drones that could be used in cloud seeding that it says could cut costs substantially. Drones would also be able to fly closer to mountains, where clouds offer the best potential for seeding.

Back in Tasmania, Nebel is busy, with 10 seeding operations so far in the season that runs from May to October, more than double the number at the same point in 2014.

That water falls into irrigation channels and onto pasture and feed crops, helping boost the state's dairy sector, where milk production is up about a tenth so far this season.

($1 = 45.1350 Philippine pesos)

(Additional reporting by Enrico Dela Cruz in Manila; Editing by Joseph Radford)

Read more!

Warning over aerosol climate fix

Simon Redfern BBC 16 Apr 15;

Any attempts to engineer the climate are likely to result in "different" climate change, rather than its elimination, new results suggest.

Prof Ken Caldeira, of Stanford University, presented research at a major conference on the climate risks and impacts of geoengineering.

These techniques have been hailed by some as a quick fix for climate change.

But the impacts of geoengineering on oceans, the water cycle and land environments are hotly debated.

They have been discussed at a meeting this week of 12,000 scientists in Vienna.

Researchers are familiar with the global cooling effects of volcanic eruptions, seen both historically and even back into the deep past of the rock record.

With this in mind, some here at the European Geosciences Union General Assembly have been discussing the possible worldwide consequences of pumping sulphate aerosols into the stratosphere to attempt to reflect sunlight back into space and cool the planet.

Planetary sunshade

Two hundred years ago this month, the huge volcano Mount Tambora erupted in Indonesia, throwing tonnes of gas and ash into the stratosphere.

Maybe as much as 100 million tonnes of sulphur dioxide aerosols spread as a blanket around the globe, acting like a planetary sunshade.

Global temperatures plummeted, and across America and Europe 1816 became known as the year without a summer.

Such global cooling processes, but managed in a geoengineering solution, have been touted by some as a possible mechanism to extricate the planet from its path towards a warmer future.

Solar radiation management would use stratospheric sulphate aerosols to dim the Sun. Using a variety of climate models, Ken Caldeira, from the Carnegie Institution for Science in Stanford, California, has investigated the likely consequences of such geoengineering on agriculture across the globe.

His research shows that while dimming could rapidly decrease global temperatures, high CO2 levels would be expected to persist, and it is the balance between temperature, CO2, and sunlight that affects plant growth and agriculture.

Exploring the regional effects, he finds that a stratospherically dimmed world would show increased plant productivity in the tropics, but lessened plant growth across the northerly latitudes of America, Europe and Asia.

It is easy to see how there might be geopolitical shifts associated with changes in regional food production across the globe.

"It's probably the poor tropics that stand to benefit and the rich north that stands to lose," said Prof Caldeira.

But what if geoengineered sulphate aerosols were, nonetheless, deployed and then a large volcanic eruption like Pinatubo in the Philippines took place? Three such eruptions occurred in the last century so the scenario seems likely.

Bad timing

Hannele Korhonen, of the Finnish Meteorological Institute, suggests that the climate impacts could be quite unexpected.

Her results indicate increased temperatures in the Southern Ocean and in northerly latitudes, as well as the mid-Pacific, but cooling in African and Asian mid-latitudes.

Regional weather patterns would still change, as they did after Tambora in 1816, with similar widely felt disruption.

"Deploying solar radiation management methods would lead to a completely new climate state with enhanced greenhouse effect and reduced solar radiation," said Korhonen, adding: "There are great uncertainties, related especially to the regional climate impacts of solar radiation management."

Commenting on the results, Helene Muri, of the University of Oslo, said: "These modelling experiments have highlighted the new risks associated with solar radiation management. The safest option is, of course, to reduce greenhouse gas emissions and aim for a more sustainable way of living and managing the planet."

It is not at all obvious what the other consequences of global geoengineering approaches might be. For example, Patrick Applegate from Pennsylvania State University, reported that solar radiation management may yet fail to prevent sea-level rise from melting ice sheets, which respond on much longer time scales than the temperature effects of solar shielding.

Aside from being ineffective in stemming sea-level rise, solar radiation management - according to results from Jerry Tjiputra at Bergen University - would lead to increased ocean acidification in the North Atlantic.

These results also suggest that climate engineering could not offer a long-term solution, with the world eventually being in the same place, by 2200, as it would reach without any geoengineering interventions.

Asked whether he believed solar radiation management would be deployed, Prof Caldeira responded: "A lot has to do with how bad climate change will end up being. Humans are quite adaptable as a species.

"On the other hand, projections for summers in the tropics suggest almost every summer will be hotter than the hottest summer yet on record, associated with crop failures. There is the possibility that there would be widespread crop failures in the tropics in the summer.

"The only thing a politician can do to start the planet cooling is solar geoengineering. If a catastrophic outcome does occur, the pressure to deploy a scheme could be overwhelming.

"Research into this is an act of desperation on the part of scientists. People see the greenhouse gas concentrations increase and are looking for other ways to reduce environmental risk."

Read more!

'Climate intervention' strategies unlikely to work

AFP Yahoo News 11 Feb 15;

Miami (AFP) - Attempts to curb climate change by capturing carbon underground or geo-engineering to help the Earth better reflect incoming sunlight are nowhere near ready for use, a US panel of scientists said.

"There is no substitute for dramatic reductions in greenhouse gas emissions to mitigate the negative consequences of climate change," said the National Research Council in a two-part report on proposed climate-intervention techniques.

"If society ultimately decides to intervene in Earth's climate, any actions should be informed by a far more substantive body of scientific research, including ethical and social dimensions, than is presently available."

The panel urged against "albedo-modification technologies, which aim to increase the ability of Earth or clouds to reflect incoming sunlight," saying they "pose considerable risks and should not be deployed at this time."

Such techniques "would only temporarily mask the warming effect caused by high CO2 concentrations, and present serious known and possible unknown environmental, social, and political risks, including the possibility of being deployed unilaterally," said the report.

Carbon dioxide removal is better understood "but current technologies would take decades to achieve moderate results and be cost-prohibitive at scales large enough to have a sizeable impact," it added.

"Direct air capture of carbon is an immature technology with only laboratory experiments carried out to date and demonstration projects in progress," the report said.

"Technologies for storing the captured carbon are at an intermediate stage, but only prototypes exist and are not at the scale required for significant sequestration."

Other techniques such as forest restoration and low-till agriculture are "mature, readily deployable technologies with well-known environmental consequences," the report said.

It also warned against ocean-based approaches to accelerate natural removal of carbon dioxide, saying they "carry significant environmental and socio-political risks."

The study was sponsored by the National Academy of Sciences, the US intelligence community, the US space agency NASA, the National Oceanic and Atmospheric Administration, and the Department of Energy.

Read more!

Scientists urge global 'wake-up call' to deal with climate change

Climate change has advanced so rapidly that work must start on unproven technologies now, admits US National Academy of Science
Suzanne Goldenberg The Guardian 10 Feb 15;

Climate change has advanced so rapidly that the time has come to look at options for a planetary-scale intervention, the National Academy of Science said on Tuesday.

The scientists were categorical that geoengineering should not be deployed now, and was too risky to ever be considered an alternative to cutting the greenhouse gas emissions that cause climate change.

But it was better to start research on such unproven technologies now – to learn more about their risks – than to be stampeded into climate-shifting experiments in an emergency, the scientists said.

With that, a once-fringe topic in climate science moved towards the mainstream – despite the repeated warnings from the committee that cutting carbon pollution remained the best hope for dealing with climate change.

“That scientists are even considering technological interventions should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change,” Marcia McNutt, the committee chair and former director of the US Geological Survey, said.

Asked whether she foresaw a time when scientists would eventually turn to some of the proposals studied by the committee, she said: “Gosh, I hope not.”

The two-volume report, produced over 18 months by a team of 16 scientists, was far more guarded than a similar British exercise five years ago which called for an immediate injection of funds to begin research on climate-altering interventions.

The scientists were so sceptical about geo-engineering that they dispensed with the term, opting for “climate intervention”. Engineering implied a measure of control the technologies do not have, the scientists said.

But the twin US reports – Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration and Climate Intervention: Reflecting Sunlight to Cool the Earth – could boost research efforts at a limited scale.

The White House and committee leaders in Congress were briefed on the report’s findings this week.

Bill Gates, among others, argues the technology, which is still confined to computer models, has enormous potential and he has funded research at Harvard. The report said scientific research agencies should begin carrying out co-ordinated research.

But geo-engineering remains extremely risky and relying on a planetary hack – instead of cutting carbon dioxide emissions – is “irresponsible and irrational”, the report said.

The scientists looked at two broad planetary-scale technological fixes for climate change: sucking carbon dioxide emissions out of the atmosphere, or carbon dioxide removal, and increasing the amount of sunlight reflected away from the earth and back into space, or albedo modification.

Albedo modification, injecting sulphur dioxide to increase the amount of reflective particles in the atmosphere and increase the amount of sunlight reflected back into space, is seen as a far riskier proposition.

Tinkering with reflectivity would merely mask the symptoms of climate change, the report said. It would do nothing to reduce the greenhouse gas emissions that cause climate change.

The world would have to commit to continuing a course of albedo modification for centuries on end – or watch climate change come roaring back.

“It’s hard to unthrow that switch once you embark on an albedo modification approach. If you walk back from it, you stop masking the effects of climate change and you unleash the accumulated effects rather abruptly,” Waleed Abdalati, a former Nasa chief scientist who was on the panel, said.

More ominously, albedo modification could alter the climate in new and additional ways from which there would be no return. “It doesn’t go back, it goes different,” he said.

The results of such technologies are still far too unpredictable on a global scale, McNutt said. She also feared they could trigger conflicts. The results of such climate interventions will vary enormously around the globe, she said.

“Kansas may be happy with the answer, but Congo may not be happy at all because of changes in rainfall. It may be quite a bit worse for the Arctic, and it’s not going to address at all ocean acidification,” she said. “There are all sorts of reasons why one might not view albedo modified world as an improvement.”

The report also warned that offering the promise of a quick fix to climate change through planet hacking could discourage efforts to cut the greenhouse gas emissions that cause climate change.

“The message is that reducing carbon dioxide emissions is by far the preferable way of addressing the problem,” said Raymond Pierrehumbert, a University of Chicago climate scientist, who served on the committee writing the report. “Dimming the sun by increasing the earth’s reflectivity shouldn’t be viewed as a cheap substitute for reducing carbon dioxide emissions. It is a very poor and distant third, fourth, or even fifth choice. |It is way down on the list of things you want to do.”

But geoengineering has now landed on the list.

Climate change was advancing so rapidly a climate emergency – such as widespread crop failure – might propel governments into trying such large-scale interventions.

“The likelihood of eventually considering last-ditch efforts to address damage from climate change grows with every year of inaction on emissions control,” the report said.

If that was the case, it was far better to be prepared for the eventualities by carrying out research now.

The report gave a cautious go-ahead to technologies to suck carbon dioxide out of the air, finding them generally low-risk – although they were prohibitively expensive.

The report discounted the idea of seeding the ocean with iron filings to create plankton blooms that absorb carbon dioxide.

But it suggested carbon-sucking technologies could be considered as part of a portfolio of responses to fight climate change.

It would involve capturing carbon dioxide from the atmosphere and pumping it underground at high pressure – similar to technology that is only now being tested at a small number of coal plants.

Sucking carbon dioxide out of the air is much more challenging than capturing it from a power plant – which is already prohibitively expensive, the report said. But it still had a place.

“I think there is a good case that eventually this might have to be part of the arsenal of weapons we use against climate change,” said Michael Oppenheimer, a climate scientist at Princeton University, who was not involved with the report.

Drawing a line between the two technologies – carbon dioxide removal and albedo modification – was seen as one of the important outcomes of Tuesday’s report.

The risks and potential benefits of the two are diametrically opposed, said Ken Caldeira, an atmospheric scientist at Carnegie Institution’s Department of Global Ecology and a geoengineering pioneer, who was on the committee.

“The primary concern about carbon dioxide removal is how much does it cost,” he said. “There are no sort of novel, global existential dilemmas that are raised. The main aim of the research is to make it more affordable, and to make sure it is environmentally acceptable.”

In the case of albedo reflection, however, the issue is risk. “A lot of those ideas are relatively cheap,” he said. “The question isn’t about direct cost. The question is, What bad stuff is going to happen?”

There are fears such interventions could lead to unintended consequences that are even worse than climate change – widespread crop failure and famine, clashes between countries over who controls the skies.

But Caldeira, who was on the committee, argued that it made sense to study those consequences now. “If there are real show stoppers and it is not going to work, it would be good to know that in advance and take it off the table, so people don’t do something rash in an emergency situation,” he said.

Spraying sulphur dioxide into the atmosphere could lower temperatures – at least according to computer models and real-life experiences following major volcanic eruptions.

But the cooling would be temporary and it would do nothing to right ocean chemistry, which was thrown off kilter by absorbing those emissions.

“My view of albedo modification is that it is like taking pain killers when you need surgery for cancer,” said Pierrehumbert. “It’s ignoring the problem. The problem is still growing though and it is going to come back and get you.”

Read more!

Geo-engineering: Climate fixes 'could harm billions'

David Shukman BBC News 25 Nov 14;

Schemes to tackle climate change could prove disastrous for billions of people, but might be required for the good of the planet, scientists say.

That is the conclusion of a new set of studies into what's become known as geo-engineering.

This is the so far unproven science of intervening in the climate to bring down temperatures.

These projects work by, for example, shading the Earth from the Sun or soaking up carbon dioxide.

Ideas include aircraft spraying out sulphur particles at high altitude to mimic the cooling effect of volcanoes or using artificial "trees" to absorb CO2.

Long regarded as the most bizarre of all solutions for global warming, ideas for geo-engineering have come in for more scrutiny in recent years as international efforts to limit carbon emissions have failed.

Now three combined research projects, led by teams from the universities of Leeds, Bristol and Oxford, have explored the implications in more detail.

The central conclusion, according to Dr Matt Watson of Bristol University, is that the issues surrounding geo-engineering - how it might work, the effects it might have and the potential downsides - are "really really complicated".

Sun block

"We don't like the idea but we're more convinced than ever that we have to research it," he said.

"Personally I find this stuff terrifying but we have to compare it to doing nothing, to business-as-usual leading us to a world with a 4C rise."

The studies used computer models to simulate the possible implications of different technologies - with a major focus on ideas for making the deserts, seas and clouds more reflective so that incoming solar radiation does not reach the surface.

One simulation imagined sea-going vessels spraying dense plumes of particles into the air to try to alter the clouds. But the model found that this would be far less effective than once thought.

Another explored the option of injecting sulphate aerosols into the air above the Arctic in an effort to reverse the decline of sea-ice.

A key finding was that none of the simulations managed to keep the world's temperature at the level experienced between 1986-2005 - suggesting that any effort would have to be maintained for years.

More alarming for the researchers were the potential implications for rainfall patterns.

Although all the simulations showed that blocking the Sun's rays - or solar radiation management, as it is called - did reduce the global temperature, the models revealed profound changes to precipitation including disrupting the Indian Monsoon.

Prof Piers Forster of Leeds University said: "We have found that between 1.2 and 4.1 billion people could be adversely affected by changes in rainfall patterns.

"The most striking example of a downside would be the complete drying-out of the Sahel region of Africa - that would be very difficult to adapt to for those substantial populations - and that happens across all the scenarios."

Despite the risk of catastrophic side-effects from geo-engineering, the study authors believe that research should continue just in case runaway warming leaves no other options.

Prof Forster said: "If we were in a really desperate situation, trying to cool the temps for a 10-20 year time period, there could be some merit in those circumstances in introducing solar radiation management to give you a 10-20 year time period."

Lack of knowledge

According to Prof Steve Rayner of Oxford University, it is easier to devise the technology than to understand its effects or how its use should be governed.

"If you were just thinking of the capability of putting sulphate aerosols in the atmosphere, that you could do in less than two decades - whether you would know it was smart to do it in less than two decades is another question.

"We don't know enough - we have a few islands of knowledge in a sea of ignorance and it's absolutely worth knowing more. There is the potential that some of these technologies may be part of a broader tool kit of ways in which we can better manage climate change.

"People decry solar radiation management as a band-aid but band-aids can be useful for healing."

Geo-engineering has long been one of the most controversial aspects of the debate about solutions to climate change and few experiments have been conducted in the field.

One of the largest, known as Lohafex, was an Indian-German experiment in 2009 which involved dumping six tonnes of an iron solution into the South Atlantic to encourage plankton to bloom - trapping carbon which would then be sent to the seabed when the organisms died. Results showed limited success.

Another proposal for the trial flight of a balloon in Britain, as part of geo-engineering research for the SPICE project, attracted stiff opposition from environmental groups and was cancelled.

It would have been the precursor to a test of a technique for pumping sulphate aerosols into the atmosphere in an effort to bounce solar radiation back into space and cool the planet.

Read more!

Geoengineering Ineffective Against Climate Change, Could Make Worse

Charles Q. Choi, Live Science Yahoo News 25 Feb 14;

Current schemes to minimize the havoc caused by global warming by purposefully manipulating Earth's climate are likely to either be relatively useless or actually make things worse, researchers say in a new study.

The dramatic increase in carbon dioxide levels in the atmosphere since the Industrial Revolution is expected to cause rising global sea levels, more-extreme weather and other disruptions to regional and local climates. Carbon dioxide is a greenhouse gas that traps heat, so as levels of the gas rise, the planet overall warms.

In addition to efforts to reduce carbon dioxide emissions, some have suggested artificially manipulating the world's climate in a last-ditch effort to prevent catastrophic climate change. These strategies, considered radical in some circles, are known as geoengineering or climate engineering.

Many scientists have investigated and questioned how effective individual geoengineering methods could be. However, there have been few attempts to compare and contrast the various methods, which range from fertilizing the ocean so that marine organisms suck up excess carbon dioxide to shooting aerosols into the atmosphere to reflect some of the sun's incoming rays back into space. [8 Ways Global Warming is Already Changing the World]

Now, researchers using a 3D computer model of the Earth have tested the potential benefits and drawbacks of five different geoengineering technologies.

Will it work?

The scientists found that even when several technologies were combined, geoengineering would be unable to prevent average surface temperatures from rising more than 3.6 degrees Fahrenheit (2 degrees Celsius) above current temperatures by the year 2100. This is, the current limit that international negotiations are focused on. They were unable to do so even when each technology was deployed continuously and at scales as large as currently deemed possible.

"The potential of most climate engineering methods, even when optimistic deployment scenarios were assumed, were much lower than I had expected," said study author Andreas Oschlies, an earth system modeler at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany.

One strategy, known as afforestation, would irrigate deserts, such as those in Australia and North Africa, to promote the growth of vegetation that can absorb carbon dioxide. However, this vegetation would also absorb sunlight the deserts currently reflect back into space, thus actually contributing to global warming. That finding supports the results of previous studies.

Another tactic, known as artificial ocean upwelling, would use long pipes to pump deep, cold, nutrient-rich water upward in order to cool ocean-surface waters and promote the growth of photosynthetic organisms that can absorb carbon dioxide. However, the scientists noted that if this strategy were ever stopped, the oceans would rebalance their heat levels, potentially causing disastrously rapid climate change.

One approach, known as ocean alkalinization, would dump lime into the water to chemically increase oceanic absorption of carbon dioxide. Another technique, known as ocean iron fertilization, would dump iron into the oceans to boost the growth of photosynthetic organisms that can absorb carbon dioxide. However, like other geoengineering strategies, the models suggest that both are of little use in reducing global temperatures.

The last method, known as solar radiation management, would reduce the amount of sunlight Earth receives, most likely by pumping reflective sulfate-based aerosols into the atmosphere. The subsequent dimming of sunlight on Earth would cool the planet, but the researchers note that carbon dioxide would continue to accumulate in the atmosphere. This suggests that if this strategy were ever halted, the globe would rapidly warm after the aerosols dispersed.

Possible side effects

All in all, these strategies are relatively ineffective; individually, they reduce global warming by less than 8 percent each, assuming carbon dioxide emission levels continue to remain as high as they are now. In all simulations, atmospheric carbon dioxide levels will still reach more than twice current levels by the end of the century, the researchers found.

Moreover, each geoengineering technique can have potentially severe side effects. For example, solar radiation management would alter patterns of precipitation such as rainfall and reduce total precipitation across the globe.

Altogether, the climate engineering technologies analyzed here are ineffective in reducing carbon dioxide concentrations and in most cases temperature. And this lack of effect "is really striking," said climate scientist Kelly McCusker at the University of Victoria in Canada, who did not take part in this research. McCusker and her colleagues also recently found that a sudden stop in solar radiation management strategies would exacerbate global warming.

"This study nails home the continued importance of reducing our emissions of greenhouse gases," McCusker told Live Science.

The researchers noted they used a moderately complex earth system model, and that more complex models involving a more intricate look at how winds might respond to geoengineering "may give different answers, particularly for precipitation changes," Oschlies said.

Oschlies and his colleagues David Keller and Ellias Feng detailed their findings online Feb. 25 in the journal Nature Communications.

Read more!

Geoengineering could bring severe drought to the tropics, research shows

Study models impact on global rainfall when artificial volcanic eruptions are created in a bid to reverse climate change
Damian Carrington theguardian.com 8 Jan 14;

Reversing climate change via huge artificial volcanic eruptions could bring severe droughts to large regions of the tropics, according to new scientific research.

The controversial idea of geoengineering – deliberately changing the Earth's climate – is being seriously discussed as a last-ditch way of avoiding dangerous global warming if efforts to slash greenhouse gas emissions fail.

But the new work shows that a leading contender – pumping sulphate particles into the stratosphere to block sunlight – could have side-effects just as serious as the effects of warming itself. Furthermore, the impacts would be different around the world, raising the prospect of conflicts between nations that might benefit and those suffering more damage.

"There are a lot of issues regarding governance – who controls the thermostat – because the impacts of geoengineering will not be uniform everywhere," said Dr Andrew Charlton-Perez, at the University of Reading and a member of the research team.

The study, published in the journal Environmental Research Letters, is the first to convincingly model what happens to rainfall if sulphates were deployed on a huge scale.

While the computer models showed that big temperature rises could be completely avoided, it also showed cuts in rain of up to one-third in South America, Asia and Africa. The consequent droughts would affect billions of people and also fragile tropical rainforests that act as a major store of carbon. "We would see changes happening so quickly that there would be little time for people to adapt," said Charlton-Perez.

Another member of the research team, Professor Ellie Highwood, said: "On the evidence of this research, stratospheric aerosol geoengineering is not providing world leaders with any easy answers to the problem of climate change."

The study considered what would happen if carbon dioxide levels quadrupled in the atmosphere – the sort of extreme situation in which geoengineering might be seriously considered. Without intervention, temperatures rose by 4C, far above the 2C level considered dangerous by the world's governments.

But the temperature rise was reduced to zero if a massive geoengineering effort took place. The 60m tonnes of sulphur dioxide pumped into the stratosphere each year in the simulation is equivalent to five volcanic eruptions, each on the scale of Mount Pinatubo, the huge 1991 eruption in the Philippines that cut global temperatures by about 0.5C in the following year or two.

The sulphate particles in the model not only reflected incoming sunlight, cutting temperatures, but also absorbed heat rising up from the Earth's surface. This reduced the temperature difference between the lower and upper atmosphere, which is the engine that drives cloud formation and rainfall. The reduction in rainfall seen in the geoengineering model was as big as the increase in rainfall projected if global warming was unabated.

Dr Matthew Watson, a researcher at the University of Bristol and advocate of further research into geoengineering, said: "The researchers chose an extreme climate scenario so we should not be surprised if that, and any geoengineering attempt to counter it, had severe and uneven impacts."

He added: "It remains the case that our only guaranteed way forward is to reduce the record levels of greenhouse gases we continue to pump into the atmosphere. It's vital that scientists continue researching geoengineering; but no government serious about climate change should see it as a quick fix."

Read more!

Earth-cooling schemes need global sign-off, researchers say

World's most vulnerable people need protection from huge and unintended impacts of radical geoengineering projects
Ian Sample The Guardian 31 Mar 13;

Controversial geoengineering projects that may be used to cool the planet must be approved by world governments to reduce the danger of catastrophic accidents, British scientists said.

Met Office researchers have called for global oversight of the radical schemes after studies showed they could have huge and unintended impacts on some of the world's most vulnerable people.

The dangers arose in projects that cooled the planet unevenly. In some cases these caused devastating droughts across Africa; in others they increased rainfall in the region but left huge areas of Brazil parched.

"The massive complexities associated with geoengineering, and the potential for winners and losers, means that some form of global governance is essential," said Jim Haywood at the Met Office's Hadley Centre in Exeter.

The warning builds on work by scientists and engineers to agree a regulatory framework that would ban full-scale geoengineering projects, at least temporarily, but allow smaller research projects to go ahead.

Geoengineering comes in many flavours, but among the more plausible are "solar radiation management" (SRM) schemes that would spray huge amounts of sun-reflecting particles high into the atmosphere to simulate the cooling effects of volcanic eruptions.

Volcanoes can blast millions of tonnes of sulphate particles into the stratosphere, where they stay aloft for years and cool the planet by reflecting some of the sun's energy back out to space.

In 2009, a Royal Society report warned that geoengineering was not an alternative to cutting greenhouse gas emissions, but conceded the technology might be needed in the event of a climate emergency.

Writing in the journal Nature Climate Change, Haywood and others show that moves to cool the climate by spraying sulphate particles into the atmosphere could go spectacularly wrong. They began by looking at the unexpected impacts of volcanic eruptions.

In 1912 and 1982, eruptions first at Katmai in Alaska and then at El Chichón in Mexico blasted millions of tonnes of sulphate into northern skies. These eruptions preceded major droughts in the Sahel region of Africa. When the scientists recreated the eruptions in climate models, rainfall across the Sahel all but stopped as moisture-carrying air currents were pushed south.

Having established a link between volcanic eruptions in the northern hemisphere and droughts in Africa, the scientists returned to their climate models to simulate SRM projects.

The scientists took a typical project that would inject 5m tonnes of sulphate into the stratosphere every year from 2020 to 2070. That amount of sulphate injected into the northern hemisphere caused severe droughts in Niger, Mali, Burkina Faso, Senegal, Chad and Sudan, and an almost total loss of vegetation.

The same project had radically different consequences if run from the southern hemisphere. Rather than drying the Sahel, cooling the southern hemisphere brought rains to the Sahel and re-greened the region. But Africa's benefit came at the cost of slashing rainfall in north-eastern Brazil.

The unintended consequences of SRM projects would probably be felt much farther afield. "We have only scratched the surface in looking at the Sahel. If hurricane frequencies changed, that could have an impact on the US," said Haywood.

Matthew Watson, who leads the Spice project at Bristol University, said the study revealed the "dramatic consequences" of uninformed geoengineering.

"This paper tells us there are consequences for our actions whatever we do. There is no get-out-of-jail-free card," he told the Guardian.

"Whatever we do is a compromise, and that compromise means there will be winners and losers. That opens massive ethical questions: who gets to decide how we even determine what is a good outcome for different people?

"How do you get a consensus with seven billion-plus stakeholders? If there was a decision to do geoengineering tomorrow, it would be done by white western men, and that isn't good," Watson said.

Read more!

Is cloud seeding preventing further flooding in Indonesia?

Scientists claim rainfall has reduced since the project began, but experts call for more evidence
Dyna Rochmyaningsih guardian.co.uk 19 Feb 13;

Indonesia is banking on an unusual strategy to prevent further flooding in its inundated capital Jakarta, and officials claim that they are already seeing positive results.

They are using 'cloud seeding' — a weather modification technology often resorted to during drought. The method involves injecting clouds with substances that encourage the formation of ice crystals heavy enough to fall, thereby speeding up the production of rain.

Rain is the last thing that Indonesia needs now, as it has been experiencing heavy rainfall since mid-January.

But Indonesian scientists believe that inducing rains to fall over the ocean before the rainclouds reach the city will help prevent further flooding in Jakarta.

"We are mimicking nature. It is easy to make rain in most clouds above the sea. We found out that salt from sea water, which evaporates from the sea, accelerates the rain process because it encourages the cloud particles to adsorb water," Tri Handoko Seto, a top official of the Weather Modification Technical Unit of the Agency for the Assessment and Application of Technology, tells SciDev.Net.

Last month (26 January), military planes carrying tonnes of salt started the cloud seeding operation scattering salt onto rainclouds across the ocean. The operation is expected to last two months.

The operation has come into the national spotlight recently because of the Indonesian government's claims that it had succeeded in decreasing Jakarta's rainfall rate, particularly from 26­-29 January when local meteorologists had predicted heavier rains and flooding.

"We have conducted an evaluation using the data in our radar device, which records cloud development and movement. From our analysis, cloud seeding contributed to the decrease of rainfall in Jakarta during this period," says Seto.

But Zev Levin, chair in atmospheric physics at Tel Aviv University in Israel, says that it is difficult to prove how much rain would have fallen before reaching the city had the clouds not been seeded.

To prove the effectiveness of cloud seeding, Levin says, well designed experiments must be conducted based on robust statistical design with an unseeded control area and random allocation of seeding.

"In this case, Indonesia can't prove the success of their cloud seeding operation because they have no control area," says Levin.

He adds that cloud seeding in Indonesia will do nothing or very little to modify the weather because tropical clouds are not easy to modify.

"The dynamics of the clouds dominate the rain process and any attempt to modify it will only play secondary role at best," says Levin.

But Seto defends their programme and says that they will submit their work for publication in international journals to refute claims that their operations are not scientific.

Scientists produced the first evidence that cloud seeding can boost long-term rainfall in 2009. But they also urged caution over the technique due to unrealistic claims about its success and difficulties faced in comparing clouds to prove if the technique really works.

Read more!

Rogue geoengineering could 'hijack' world's climate

Techniques aimed at averting global warming could lead to an unpredictable international crisis, a report has warned
John Vidal guardian.co.uk 8 Jan 13;

The world's climate could be hijacked by a rogue country or wealthy individual firing small particles into the stratosphere, claims a warning that comes not from a new Hollywood movie trailer but a sober report from the World Economic Forum (WEF).

The deployment of independent, large-scale "geoengineering" techniques aimed at averting dangerous warming warrants more research because it could lead to an international crisis with unpredictable costs to agriculture, infrastructure and global stability, said the Geneva-based WEF in its annual Global Risks report before the Davos economic summit later this month. It also warned that ongoing economic weakness is sapping the ability of governments to tackle the growing threat of climate change.

"The global climate could, in effect, be hijacked. For example, an island state threatened with rising sea levels may decide they have nothing to lose, or a well-funded individual with good intentions may take matters into their own hands," the report notes. It said there are "signs that this is already starting to occur", highlighting the case of a story broken by the Guardian involving the dumping of 100 tonnes of iron sulphate off the Canadian coast in 2012, in a bid to spawn plankton and capture carbon.

The top two global risks identified for the WEF by more than 1,000 business leaders and experts were the growing wealth gap between rich and poor and a major financial economic crisis. But the next three on the list of 50 were environmental, including climate change, and water and food supply crises.

Lee Howell, the editor of the WEF report, said: "Following a year scarred by extreme weather, from hurricane Sandy to flooding in China, respondents rated rising greenhouse gas emissions as the third most likely global risk overall, while the failure of climate change adaptation is seen as the environmental risk with the most knock-on effects for the next decade. These global risks are essentially a health warning regarding our most critical systems. With the growing cost of events like superstorm Sandy, huge threats to island nations and coastal communities, and no resolution to greenhouse gas emissions, the writing is on the wall. It is time to act."

The economic costs associated with extreme weather and climate change should make governments act, suggests the WEF. "Recent climate and weather events have reminded us of the economic and human cost of the kind of natural disasters that we know are likely to become more frequent and severe as climate continues to change. The estimated economic cost of the 2011 Thailand floods, for example, was $15-20bn and hurricane Katrina $125bn; meanwhile, the 2003 European heatwave resulted in more than 35,000 fatalities and the Horn of Africa droughts in 2011 claimed tens of thousands of lives and threatened the livelihoods of 9.5 million people."

According to the report, the cumulative economic cost of changes to the physical environment as well as health and food security from climate change, range from US$2 trillion to $4tn by 2030.

The authors fear that climate change could become a centre of litigation. "Although the Alaskan village of Kivalina – which faces being "wiped out" by the changing climate – was unsuccessful in its attempts to file a $400m lawsuit against oil and coal companies, future plaintiffs may be more successful. Five decades ago, the US tobacco industry would not have suspected that in 1997 it would agree to pay $368bn in health-related damages. For some businesses, investing in climate change mitigation now could be as much about enterprise risk management as about mitigating a global risk."

Read more!

Geo-engineering wins scant enthusiasm at U.N. climate talks

Alister Doyle PlanetArk 3 Dec 12;

Cheap, short-cut ideas to cool the planet such as shading sunlight are failing to win support from U.N. delegates looking to improve on the slow progress made by existing technologies.

Many scientists say the proposed solutions, known as geo-engineering, are little understood and might have side effects more damaging than global warming, which is projected to cause more floods, heatwaves, droughts and rising sea levels.

"Let's first use what we know," said Christiana Figueres, head of the U.N. Climate Change Secretariat, dismissing suggestions that it was time to try geo-engineering to halt a rise in greenhouse gas emissions.

"There are so many proven technologies we know exist that are tried and true that have not been used to their maximum potential," she told Reuters. "To begin with, the simplest is energy efficiency."

Geo-engineering options include adding sun-reflecting chemicals to the upper atmosphere to mimic the effect of big volcanic eruptions that mask the sun, or fertilizing the oceans to promote the growth of algae that soak up carbon from the air.

Among other ideas, a giant mirror could be placed in space to block some sunlight or sea spray could be injected into the air to create clouds whose white tops would reflect sunlight.

"Let's face it, geo-engineering has a lot of unknowns," Rajendra Pachauri, chairman of the U.N.'s panel of climate scientists, told Reuters on the sidelines of U.N.-led climate change talks among 200 nations in Doha from November 26-Dec 7.

"How can you go into an area where you don't know anything?" he said. The Intergovernmental Panel on Climate Change (IPCC) is examining geo-engineering in depth for the first time as part of a major report due in 2013 and 2014.

Still, one study by U.S. scientists in August indicated that planes or airships could carry a million tonnes a year of sun-dimming sulfate materials high into the atmosphere for an affordable price tag of below $5 billion.

CHEAPER

That would be far cheaper than policies to cut world greenhouse gas emissions, estimated to cost between $200 billion and $2 trillion a year by 2030, they wrote in the journal Environmental Research Letters.

"If you are looking at solutions you could look at solar energy," said Mira Mehrishi, head of India's delegation in Doha. "It's a little premature to start looking at geo-engineering."

"There's a lot of skepticism" about geo-engineering, said Artur Runge-Metzger of the European Commission. "Research is necessary to see if it could be viable in one way or other."

U.N. negotiations on slowing global warming have been running since a U.N. Climate Convention was agreed in 1992.

One problem is that adding sulfates - a form of pollution - to the air would not slow an acidification of the oceans since concentrations of greenhouse gases led by carbon dioxide in the atmosphere would keep building up.

Some carbon dioxide, absorbed into the oceans, reacts to form carbonic acid. That erodes the ability of creatures from clams or mussels to lobsters and crabs to build their protective shells. In turn, that could disrupt marine food chains.

"You might temporarily delay the warming but you are certainly not going to help the oceans at all," said Jean-Pascal van Ypersele, a vice-chair of the IPCC, of using sulfates. "Ocean acidification is a real emerging issue."

A mask of pollution might help some crops by reducing heat stress but it might have other side-effects, for instance, by disrupting Monsoon patterns. That could bring disputes between countries that benefited and others that suffered.

And Van Ypersele said that, if geo-engineering went wrong and needed to be shut down after a few years, there would be a big, damaging jump in temperatures.

(Editing by Helen Massy-Beresford)

Read more!

'Ocean fertilisation' experiment stores CO2

Richard Ingham (AFP) Google News 19 Jul 12;

PARIS — German researchers on Wednesday said they had evidence that sowing the ocean with iron particles sucks up and stores carbon dioxide (CO2), preventing the gas from stoking dangerous climate change.

But their work, touching on a fiercely controversial issue called geo-engineering, came under attack from other scientists and environmentalists.

These said a far bigger question -- whether such schemes could damage the marine biosphere -- remained unanswered.

Published in the science journal Nature, the paper is one of the biggest and most detailed probes into ocean fertilisation, a practice that is banned under international law although scientific research into it is permitted.

Its goal is to take CO2 from the atmosphere and store it in the deep sea so that it no longer adds to the greenhouse effect.

This would be done by scattering the ocean surface with iron dust, a nutrient for microscope marine vegetation called phytoplankton. As the plants gorge on the iron, they also suck up atmospheric CO2 thanks to natural photosynthesis.

In the next step, the phytoplankton die and sink to the deep ocean floor -- taking with them the CO2, which would lie in the sediment, possibly for centuries.

Critics, though, say geo-engineering schemes are riddled with unknowns, both in cost effectiveness and risks for the environment.

Scientists led by Victor Smetacek of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven took a research ship to the Southern Ocean off Antarctica in 2004.

There, they located a giant eddy -- a slowly-moving clockwise-rotating swirl 60 kilometres (37 miles across) that had relatively little interchange with the rest of the ocean -- and used it as a testbed for a five-week experiment.

They scattered seven tonnes of commercial iron sulphate particles, which within four weeks developed into a giant bloom of diatom plankton.

The diatoms then died, sinking in clumps of entangled cells, "far below" a depth of 1,000 metres (3,250 feet), according to samples measured with a gadget called a fluorometer.

They were probably deposited on the sea floor in a "fluff layer" that should remain for "many centuries and longer," Smetacek's team say.

Further work is needed to see what happens when sideways currents hit the diatom blooms, they add.

Other voices sounded a loud note of caution, saying the experiment took place in exceptional conditions and did not consider other environmental consequences.

Among them was Professor John Shepherd, who chaired a landmark report in 2009 by Britain's Royal Society into geo-engineering.

It concluded that ocean fertilisation would not suck up that much CO2 and could be harmful to the marine biosphere.

"Whilst the new research is an interesting and valuable contribution in this evolving field, it does not address the potential ecological side effects of such a technology in what is a poorly understood field," Shepherd said in an email to AFP.

The Canada-based ETC Group, an environmental NGO campaigning against geo-engineering, said the study "only focuses on a few narrow aspects and disregards or ignores others."

"The intended purpose of ocean fertilisation is to significantly disrupt marine ecosystems through drastic changes on phytoplankton, which is the base of the marine food web, so the effects would propagate throughout the ocean in unpredictable ways," it said.

Read more!

Geoengineering Could Backfire, Make Climate Change Worse

Joel Winston Wired UK 16 Jul 12;

Deploying giant space mirrors and spraying particles from stadium-sized balloons may sound like an engineer’s wild fantasy, but climate models suggest that the potential of geoengineering to offset rising atmospheric carbon dioxide may be significantly overstated.

Through a variety of computer simulations used for reporting to the Intergovernmental Panel on Climate Change (IPCC), the team investigated a scenario where an increase in the world’s atmospheric carbon dioxide levels was balanced by a “dimming” of the sun.

Across all four models tested, the team showed that geoengineering could lead to adverse effects on the Earth’s climate, including a reduction in global rainfall. They therefore concluded that geoengineering could not be a substitute for the reduction of greenhouse gas emissions.

However, in a field with divided opinion on geoengineering’s potential role in addressing climate change, some doubt the significance of this conclusion. “From a policy standpoint, this doesn’t provide very helpful guidance to decision-makers,” said Steve Rayner of the Oxford Geoengineering Program. “No serious player in this field suggests that [geoengineering] could ever be a substitute for mitigation and adaptation.”

The leader of the research, Hauke Schmidt of the Max Planck Institute, Germany, believes their experiment still contributes important details on how the Earth’s systems might respond to geoengineering. “The first thing we realized was that we had to ‘dim’ the sun 25 percent more than expected, in order for the Earth’s systems to show a response, which translates to needing more geoengineering than previously thought,” says Schmidt.

A reduction in global rainfall is not necessarily an equal one. “It becomes interesting when you look into the regional responses,” continues Schmidt. “If you have just a carbon dioxide increase, most models predict a global rainfall increase, but a strong decrease in the Mediterranean and subtropics. But if you try to balance this with geoengineering, these zones shift to Northern Europe, Northern Asia and North America.”

There’s also the question of how effective these simulations are in recreating real-world deployment of geoengineering. One particular concern is the study’s assumption of a quadrupling of carbon dioxide levels. “If it ever gets to that stage, then we have probably passed the point where geoengineering can be useful anyway,” says Rayner.

The researchers recognize this level is at the upper end. “But one of the simulations we’re running for the next IPCC has more than a quadrupling of CO2,” explains Schmidt. “That’s called the ‘business as usual’ scenario, and it’s not completely outside what’s conceivable.”

The team have also run simulations with smaller (and perhaps more realistic) CO2 increases and will publish results in the upcoming months. But they say the extreme CO2 increase in this first scenario helps to identify signals and understand how the system responds. “From the point of view of a climate researcher it is the most interesting scenario,” continues Schmidt. “While those who are interested in geoengineering applications may find it unrealistic.”

One scientist particularly interested in geoengineering applications is Matthew Watson, leader of the volcano-inspired Stratospheric Particle Injection for Climate Engineering (Spice) project. The government-funded project was investigating the potential effects of spraying solar-reflective sulphates into the stratosphere from a 20 kilometer-high, stadium-sized balloon. However, a scaled-down field test of a smaller balloon spraying water droplets was cancelled due to governance and patent issues.

Now Watson is concerned by the report’s conclusions, which he says could be used to suggest that geoengineering research is a waste of time. “Only through combined modelling and field research can we generate the evidence-base for a salient answer on whether climate engineering is a good or bad idea,” says Watson. “It’s vitally important that scientists are given the space within which to ask and try to answer difficult questions.”

To understand different components of the Earth’s systems, Schmidt agrees that a few experiments are necessary. “I’m not generally against small-scale field experiments if they help us understand processes in nature,” says Schmidt. “But they should obviously be benign, and we should be very careful.” However, small-scale field tests are also limited, Schmidt believes, with climate simulations possibly being the only way to fully grasp the long-term and large-scale climate effects of geoengineering.

Both options may have their individual limitations, according to Watson. “That small-scale experiments are, by their nature, incomplete is often used as an argument against climate engineering, but that can also be said of models, which are, by definition, imperfect.” In addition to large-scale simulations, Watson accepts the need for small, benign and well-governed field experiments in the interim.

Despite the controversy on the best course of action to take, there is agreement between all parties on the need to determine the effects of geoengineering with confidence. But this confidence may perhaps only be found by both peering through simulations to see long-term global effects, and engaging in detailed examination of field tests to assess the practical potential of specific interventions.

Watson says time is short: “Unfortunately, we don’t have hundreds of years before climate change really takes hold. So researching climate engineering now is much better than undertaking that effort only when it becomes clear it is necessary.”

Read more!

Scientists Warn Geoengineering May Disrupt Rainfall

Chris Wickham PlanetArk 7 Jun 12;

Large-scale engineering projects aimed at fighting global warming could radically reduce rainfall in Europe and North America, a team of scientists from four European countries have warned.

Geoengineering projects are controversial, even though they are largely theoretical at this point. They range from mimicking the effects of large volcanic eruptions by releasing sulphur dioxide into the atmosphere, to deploying giant mirrors in space to deflect the sun's rays.

Proponents say they could be a rapid response to rising global temperatures but environmentalists argue they are a distraction from the need to reduce man-made carbon emissions.

Critics also point to a lack of solid research into unintended consequences and the absence of any international governance structure for such projects, whose effects could transcend national borders.

A small geoengineering experiment in the UK was recently abandoned due to a dispute over attempts by some of the team involved to patent the technology.

In this new study scientists from Germany, Norway, France and the UK used four different computer models that mimic the earth's climate to see how they responded to increased levels of carbon dioxide coupled with reduced radiation from the sun.

Their scenario assumed a world with four times the carbon dioxide concentration of the preindustrial world, which lead author Hauke Schmidt says is at the upper end, but in the range of what is considered possible at the end of this century.

They found that global rainfall was reduced by about 5 percent on average using all four models.

"Climate engineering cannot be seen as a substitute for a policy pathway of mitigating climate change through the reduction of greenhouse gas emissions," they said in the study, published in Earth System Dynamics, an open access journal of the European Geosciences Union.

Under the scenario studied, rainfall diminished by about 15 percent, or about 100 millimeters per year, compared to pre-industrial levels, in large areas of North America and northern Eurasia.

Over central South America, all the models showed a decrease in rainfall that reached more than 20 percent in parts of the Amazon region.

(Editing by Mark Heinrich)

Read more!

Climate-Cooling Trial Balloon Gets Canceled

LiveScience.com Yahoo News 19 May 12;

One of the first trials of geoengineering Earth's climate would have launched a balloon with a hose that could pump two bath loads of water into the atmosphere to reflect sunlight. But disagreements about that small, symbolic step combined with a patent issue to force a cancellation of the British experiment.

The original idea took inspiration from Earth's huge volcanic eruptions that toss small particles into the atmosphere. Such small particles can reflect sunlight back into space and have a cooling effect on the Earth, and so some scientists have suggested mimicking the effect to counter the climate change effects of greenhouse gas warming. But experts still fight over whether humans should try geoengineering projects that could change the Earth's climate and environment on a grand scale.

Those disagreements slowed down even the small-scale balloon effort — an "environmentally benign experiment" with no impact on the Earth's climate or biodiversity, according to Matthew Watson, principal investigator of the Stratospheric Particle Injection for Climate Engineering (SPICE) project. He gave two main reasons for test's cancellation on his blog "The Reluctant Geoengineer."

First, no international agreement exists concerning where, when or how humans should try geoengineering. That lack of agreement on rules left even Watson feeling uncertain — he saw the balloon experiment as a "somewhat premature" technology demonstration, but added that "many in SPICE would disagree." [Changing Earth: 7 Ideas to Geoengineer Our Planet]

The technology itself is not the main challenge — aircraft or other existing technologies can already do the job of scattering small, reflective particles into the atmosphere. The planned balloon test would have been just 1/20th the size of a full-scale climate-cooling balloon, and would have taken place about one- third of a mile (1 kilometer) above a deserted field. But it had already been delayed once because of objections by environmental groups, according to Nature News.

Second, there was uneasiness over a related patent application. The SPICE project team only became aware of the patent a year into the project, which caused "significant discomfort" for Watson and many other members. They had all agreed they wanted to explore the effects of climate engineering "for the greater good" without exploiting such ideas for profit, and so they wanted time to make it clear that the patent is only to protect intellectual property.

Still, the field test's cancellation does not mean the end of the SPICE project. Watson and other SPICE members want discussions that can create an agreement to guide any future geoengineering efforts.

Read more!

Rio+20 talks 'too focused on techno fixes', UN hears

Aisling Irwin SciDev 27 Apr 12;

The conviction that new technologies will solve the world's environmental and social problems has overly dominated early negotiations leading up to the Rio+20 summit in Brazil in June, a UN General Assembly meeting has heard.

Mentions of technology were "almost endless" in the first draft of the outcome document, known as the 'zero draft', according to Pat Mooney, executive director of the Action Group on Erosion, Technology and Concentration (ETC Group), a non-governmental organisation based in Canada.

The message conveyed was that "... as policymakers, there's no longer any need to make policies, all you need to do is let technology sort your problems for you", Mooney told the General Assembly's Interactive Dialogue on Harmony with Nature earlier this month (18 April).

Although the first zero draft has been revised several times since, he said, "there is an assumption of a 'techno fix' for every problem".

Many leading areas of science and technology (S&T) are converging at the nano-scale, he said, giving rise to a belief that, together, biotechnology, genomics, nanotechnology and synthetic biology could solve various planetary crises, such as food crises, pandemics, limits to growth and peak oil.

Mooney acknowledged that S&T are "critical" to solving problems, but he said the debate leading up to Rio+20 remained too narrowly focused on solving the problem of technology transfer.

"Technology transfer is extraordinarily important, and it's a failing since 1992 [the first Earth Summit, in Rio] that we have not had adequate technology transfer."

But, in addition to this question of 'know-how', it was important to consider the 'know-what' and the 'know-why', he argued.

Calling for an international technology assessment system that could answer these questions, he said: "If you don't have in the UN system the capacity to address those three questions together, collectively, then something's going to go wrong ... and perhaps we are going to get it wrong in extraordinarily expensive ways".

Mooney argued that billions of dollars have been wasted, often by governments, on promising new technologies that have done little for the poor, citing examples such as nanotechnology and agro-biotechnology.

Adequate assessment might have led to better investment decisions, he said.

The International Council for Science (ICSU) — which co-led one of the official contributions to the zero draft — agreed that, while technology has a "huge" role to play, there had been a "fixation" on it in the first version of the zero draft.

"We were quite concerned that there seems to be lots of discussion of technology transfer rather than looking at interdisciplinary research: an overall picture of human society, behavioural change, consumption patterns, economics, is equally important," said Peter Bates, science officer for ICSU.

But he was cautious on the idea of a technology assessment body, saying that safety concerns needed to be balanced against stifling innovation.

Melissa Leach, director of the STEPS (Social, Technological and Environmental Pathways to Sustainability) Centre in the United Kingdom, agreed that there was a need for more technology assessment but said that, rather than this being done in a top-down way, it should involve participation across society.

Assessment should also recognise that most problems require a diversity of solutions, and will not respond well to a single fix, she said.

The second round of the 'Informal-informal' negotiations on the outcome document for Rio+20 continue this week (23 April–4 May).

Read more!