Three recent studies point to just how broad, bizarre, and potentially devastating climate change is to life on Earth. And we’ve only seen one degree Celsius of warming so far.
Jeremy Hance The Guardian 5 Apr 17;
Climate change is rapidly becoming a crisis that defies hyperbole.
For all the sound and fury of climate change denialists, self-deluding politicians and a very bewildered global public, the science behind climate change is rock solid while the impacts – observed on every ecosystem on the planet – are occurring faster in many parts of the world than even the most gloomy scientists predicted.
Given all this, it’s logical to assume life on Earth – the millions of species that cohabitate our little ball of rock in space – would be impacted. But it still feels unnerving to discover that this is no longer about just polar bears; it’s not only coral reefs and sea turtles or pikas and penguins; it about practically everything – including us.
Three recent studies have illustrated just how widespread climate change’s effect on life on our planet has already become.
“It is reasonable to suggest that most species on Earth have been impacted by climate change in some way or another,” said Bret Scheffers with the University of Florida. “Some species are negatively impacted and some species positively impacted.”
Scheffers is the lead author of a landmark Science study from last year that found that current warming (just one degree Celisus) has already left a discernible mark on 77 of 94 different ecological processes, including species’ genetics, seasonal responses, overall distribution, and even morphology – i.e. physical traits including body size and shape.
Woodland salamanders are shrinking in the Appalachian Mountains; the long-billed, Arctic-breeding red knot is producing smaller young with less impressive bills leading to survival difficulties. Marmots and martens in the Americas are getting bigger off of longer growing seasons produce more foodstuffs, while the alpine chipmunks of Yellowstone National Park have actually seen the shape of their skulls change due to climate pressure.
Life is proving just as strange under our new climate regime when it comes to genetics. Pink salmon genetics are evolving for earlier migrations – with fewer salmon encoding their genes for earlier migrations. In making its way north, the southern flying squirrel has begun hybridising with the northern flying squirrel. The water flea has seen its genetics change over just a few decades to respond to higher water temperatures.
But the fact that so many species are undergoing genetic changes doesn’t mean they are successfully adapting to our warmer world.
“In many instances genetic diversity is being lost due to climate change, not just in nature but also in resources that human’s depend on such as crops and timber,” Scheffers said. “It is important to not confuse species responses and adaptation as an indicator that everything will be okay.”
Scheffers and his colleagues’ findings are furthered by a study in Nature Climate Change this February that found that 47 percent of land mammals and 23 percent of birds have already suffered negative impacts form climate change. In all, nearly 700 species in just these two groups are flagging under climate change, according to this research.
We now have evidence that entire ecosystems, some the size of entire states within the USA, are changing.
Brett Scheffers
“There has been a massive under-reporting of these impacts,” co-author James Watson with the University of Queensland said in a press release, pointing out that the IUCN Red List only considers seven percent of mammals and four percent of birds as threatened by climate change and severe weather. The IUCN often drags behind the latest science – many species wait decades for an update while most species on Earth have never been evaluated.
In worst-case scenarios, species are simply vanishing.
A third study – this one in PLOS Biology – found that more than 450 plants and animals have undergone local extinctions due to climate change. Local extinction, as its name implies, doesn’t mean the species are gone for good, but that they vanish from a portion of their range. For example, the barren ground shrew has seen its range constrict aggressively as its tundra home warms.
“If global warming continues, species that cannot change or move quickly enough may go globally extinct,” the study’s author, John Wiens with the University of Arizona, said.
Such global extinctions have already happened. Last year, scientists discovered that the Bramble Cay melomys – an Australian rat-like rodent – went extinct recently (it was last seen in 2007) due to rising seas inundating its tiny coral island.
It’s the first mammal confirmed to be pushed to extinction entirely due to climate change – or one could say our fossil fuel addiction.
Wiens’ study also found that local extinctions were happening more in the tropics than in temperate areas. This is worrying since the tropics hold the vast bulk of the world’s biodiversity, with many tropic species still unstudied and even undiscovered by scientists.
But changes are rippling even beyond single extinctions.
“We now have evidence that entire ecosystems, some the size of entire states within the USA, are changing in response to climate change,” said Scheffers. He pointed to kelp forests that he said “are dying” and being replaced by rocky, less-productive ecosystems.
Made up of giant brown algae, kelp as tall as trees provide essential nurseries for fish, protect coastlines against worsening storm surges, store vast amounts of carbon, and provide homes for species like sea otters. But warming waters combined with ocean acidification is taking its toll.
And Scheffers expects more “ecosystem shifts,” as scientists describe them, in the future. Cloud forests are at risk of becoming high altitude grasslands, coral reefs of becoming algal-dominated ecosystems, and Arctic sea ice – open ocean.
“Given what we are seeing now, just imagine what will happen to all these species when temperatures increase by four of five times that amount,” said Wiens.
If global society doesn’t kick its fossil fuel addiction – and quick – scientists estimate that temperatures could rise 4-5 degrees Celsius by the end of the century. Such a rise would be not so much catastrophic, but apocalyptic.
“One thing that is certain is that this global response to climate change points to an increasingly unpredictable future for humans,” Scheffers said.
More than half of the world’s humans today live in cities – but that won’t make any of us immune to the changes going on in nature. According to Scheffer’s research, humans will see a drop in productivity of various crops or timber species, a drastic loss in marine fisheries, a potential rise in new diseases as well as disease spreading to places they’d never been before. Meanwhile, declines in coral reefs, kelp forests and mangroves could lead to more lives lost in climate-fueled storms. Loss of global biodiversity will also have knock-on effects in societies around the world, from less productive ecosystems to impacts we simply can’t predict today.
“I was not surprised,” Scheffers said of his research. “But I was alarmed. The extent of impacts is vast and has impacted every ecosystem on the Earth.”
Is all this alarmist? Sure. But it’s high time we set off the alarms – they should have started ringing in the 1980s and been deafening by the early 1990s.
Does all this imply nothing can be done? Of course not.
“Governments and large organisation can invest and commit to reducing carbon emissions and protecting natural ecosystems that increase resilience to climate change not only for nature but for people as well,” Scheffers said. “These include large areas of connected forests which cool local and regional climate, pristine coral and oyster reefs that not only provide food but reduce storm surges, and well managed watersheds that will maintain adequate fresh water.”
Wiens agreed, but added that “there also needs to be more, bolder, large-scale efforts to reduce the carbon that is already in the atmosphere.”
A number of companies have already produced technologies that do just that: they pull carbon out of the atmosphere. But to date, lack of money and support have delayed rolling out such devices en masse.
Meanwhile, the researchers agree that the Paris Agreement – the only global agreement to tackle climate change – must be protected.
“Wisdom comes from combining truth with beliefs. There is a global scientific consensus around climate change and its impacts on nature and humans. It is truth that climate change will have devastating impacts on human health and quality of life,” Scheffers said, noting that the Trump Administration’s current flirtation with pulling out of the Paris Agreement “is not only an unwise decision but a dangerous decision.”
