Scientists: Copenhagen pledges will see global temps rise past 2°C

An opinion piece from climate scientists due out in today’s journal Nature says that unless major loopholes in the Copenhagen Accord are patched and a more binding agreement urgently made, the likelihood is high that warming will exceed 2 degrees Celsius by 2100.

Concerns include the fact that countries are likely to meet the higher ends of the emissions reduction target ranges, the banking of surplus emissions allowances, and the possibility that some countries may be given extra allowances.

The article analyses best- and worst-case scenarios for how well countries might hold to their pledges, and finds that, “in the worst case the Copenhagen Accord pledges could permit emission allowances to exceed business-as-usual projections.”

New Zealand scientists have sent the Science Media Centre the following comments on the issues raised:

Dr Andy Reisinger, NZ Climate Change Research Institute, Victoria University of Wellington says:

“The hard-hitting analysis by Rogelj, Meinshausen and colleagues highlights the increasing divergence between political rhetoric and the actions that would be needed to achieve the stated long-term goals. Rogelj and colleagues analysed two potential outcomes from the Copenhagen Accord, a pessimistic one where countries do only the minimum they pledged, and an optimistic one where all countries adhere to the most stringent end of their pledged emissions reductions without using any additional credits from forestry or banked credits from the Kyoto Protocol’s first commitment period.

“Even in the optimistic case, the weak emissions targets for 2020 and the even weaker or absent targets for 2050 by many countries imply a greater than 50% chance that global warming will exceed 3°C by 2100. In the pessimistic case, which is more likely to become reality if the Copenhagen Accord is not turned into a strong and legally binding agreement, long-term warming is likely to be even greater.

“More than 130 countries, including the New Zealand government, agreed under the Copenhagen Accord to limit warming to 2°C. Hopes to actually achieve this goal are fading rapidly and irreversibly, because the concrete commitments by countries do not match the level of ambition that is needed. Given the weak 2020 emissions reduction targets, global emissions would need to be reduced subsequently from 2021 to 2050 by 3 to 3.5% per year, every year, to leave at least an even chance of not exceeding 2°C. None of the climate policies and measures currently contemplated, let alone implemented, has an even remote chance of achieving and sustaining such rapid emissions reduction rates post-2020.

“This analysis shows that it is imperative to substantially strengthen the emissions targets for 2020 as part of a strong international agreement if the world is to have a realistic chance of limiting warming to 2°C. We are no longer gambling the future of the planet – if we stick with current emissions targets we are folding our cards entirely and leaving it to our (and other people’s) kids to pay our accumulated debts.”

Prof Martin Manning, NZ Climate Change Research Institute, Victoria University of Wellington says:

“The aim of limiting global warming to 2°C seems to become more difficult to achieve every day. The analysis by Joeri Rogelj and his colleagues shows that even the most optimistic interpretation of current plans by the leading countries is not on track. The key question is whether it is just not on track YET, or whether the current approach to dealing with climate change will ever get there.

“The UNFCCC meeting last December spent a lot of time talking about keeping global warming to 1.5°C. The credibility of doing that, when we do not yet seem to have any clear way of even keeping to 2°C, was challenged by scientists at a Royal Society meeting in London recently.

“These criticisms reflect a growing concern that the global policy process is becoming disconnected from reality. The basic issue is whether to rapidly accelerate technological development or continue to focus on using last century’s technology to make more profits. So the key question is whether the current UNFCCC process influences that to any extent.

“It is becoming increasingly obvious that dealing with climate change is something that needs to become driven by society more broadly. People need to consider how much of a problem we want to pass on to our grandchildren and tell politics and industry to act accordingly. “