“We’re looking at a level which is much more extreme and profoundly dangerous,” said Ruth Davis, chief policy adviser for Greenpeace. “It’s arguable the UN process has become dangerously cut adrift from the science of climate change.”
The Department of Energy and Climate Change said that, based on national offers of emissions reductions made in Copenhagen, the United Nations Environment Programme (Unep) and other bodies had calculated that it was possible to meet the 2C target, although this would depend on the targets set beyond 2020.
“There’s more work to do if we’re going to avoid a 2C temperature rise which is why we’re pushing the EU to cut its emissions by 30%,” said a DECC spokesman. “Keeping below 2C is still possible from the high end Copenhagen accord offers, but will require steeper action after 2020.”
However, many experts said the much higher temperature-rise estimates were a cause for serious concern that emissions cuts proposed for Cancún were too low and not enough was being done to prepare for further cuts beyond 2020, even though there are still nearly six months of negotiations before the talks.
“We’ve made progress but we’re clearly not headed where we need to be,” said Andrew Jones, co-director of Climate Interactive, which is backed by several universities including MIT. “No one is talking about changing any of the 2020 proposals, so we should be worried.” Climate Interactive’s model is also backed by a panel of experts including Prof Bob Watson, chief scientific advisor to the UK’s Department for Environment, Food and Rural Affairs (Defra), and a former head of the IPCC.
The Climate Interactive Scoreboard, for which researchers check daily for updates in emissions or other targets which would reduce pollution such as reductions in energy intensity or increases in renewable energy, makes a medium-range prediction of a 3.9C increase in temperatures, with a range of 2.3-6.2C (4.2-11.1F), based on committed targets, and a more encouraging 2.9C (5.2F) average, with a range of 1.7-4.6C (3.1-8.5F) based on “potential” commitments suggested but not enacted by many nations.
One of the major barriers to setting higher emissions cuts was a great many countries, including Canada and the EU, have said they do not want to increase their targets until the US sets significant reductions, which is proving hard for President Obama to achieve, said Davis.
Climate Analytics and Ecofys, under the banner of Climate Action Tracker, estimate a range of 2.8-4.3C.
The principal differences between the two calculations are that they use different models, and made different assumptions about what countries will do after their current targets expire, said Jones.
In both cases, there has been no improvement to the forecast outcome since the experts assessed the prospects immediately after the Copenhagen conference.
The predictions will be particularly worrying for many watchers because the 2C target was based on research which suggested that at that level there was only a low to medium risk of key changes to the conditions in which humans survive; however an update of the “burning embers diagram” by the authors, published last year by the Proceedings of the National Academy of Sciences in the US, suggested that at 2C there greater risk in all categories, including a significant to high risk to unique and threatened ecosystems, of extreme weather events and a global distribution of the worst threats.16 Dec 2009