Pollution needs to be brought under control within ten years to stop runaway climate change, according to the latest Met Office predictions.
Louise Gray, The Telegraph 15 Nov 09;
In the first study of its kind, climate scientists looked at how much pollution the world could afford to produce between now and the end of the century in order to keep temperature rises within a "safe limit".
A number of different scenarios were run and the most likely outcome was that carbon dioxide from factories and cars peaked somewhere between 2010 and 2020 and then fell rapidly to zero by 2100.
In the worse-case scenario, modelled by the Met Office Hadley Centre, emissions had to turn negative by 2050 to stand any chance of keeping the temperature rise below 2C (3.6F). This would mean using "geo-engineering" such as artificial trees that are designed to suck carbon dioxide out of the atmosphere.
The five-year Ensembles Project is funded by the European Commission and led by the Met Office. It brings together scientists from 66 institutions around the world.
The new research developed five climate models that predicted how much greenhouse gas could be produced by mankind, as well as naturally from plants, the oceans and soil, before concentrations of carbon dioxide in the atmosphere caused temperatures to rise more than 2C.
The models assumed that the maximum concentration of carbon dioxide equivalent (CO2e) in the atmosphere could not go beyond 450 parts per million (ppm), even though it is already close to 400 ppm now.
Paul van der Linden, director of the project, said it would be tough for the world to keep temperature rises within a safe limit.
"To limit global mean temperature [increases] to below 2C, implied emissions of CO2 to the atmosphere at the end of the century fall close to zero in most cases," he said.
Mr van der Linden said the study highlighted how important it was for the world to agree an international deal in Copenhagen this December that forced both rich and poor countries to cut emissions.
"It is a question that affects every human being but it is up to the politicians now to make the pragmatic decisions on the lifestyle changes and technology needed to solve this problem," he added.
The Ensembles Project has also predicted the effect of an average 2C temperature rise in Europe over the next century on agriculture, health, energy, water resources and insurance. Regional variations would imply under such an average rise that temperatures could be up by 4C in areas of north-west Europe including the UK. Winter wind storms, forest fires, heatwaves, water shortages and flooding were predicted. Wheat yields would go up in some areas but there would be drought elsewhere. Animal diseases and pests were expected to spread.
The models highlighted concerns that certain countries would lose their national dishes. For example a low durum wheat yield in Italy could make pasta more expensive while in Poland potato crops were under threat.
Dan Norris, the Environment Minister, said the work by the Met Office was helping scientists around the world to prepare for climate change.
"Not only do we need to tackle the causes of climate change but we must deal with the consequences," he said.
The finals results of the project will be presented at a symposium at the Met Office on Monday.
