For the first time this week at the UN conference on climate change, scientists today sounded their views on the specifics they believe the road from Bali should lead to if we are to avoid catastrophically changing the climate.
Signed by more than 200 of the world’s most eminent climatologists, the ‘Bali Climate Declaration by Scientists’ issues a stark warning to negotiators that unless they take immediate, bold action on reducing greenhouse gas (GHG) emissions, many millions will be at high risk of some of the most sinister effects of global warming including extreme sea level rise and increased drought and heatwaves.
“This declaration makes a clear and unambiguous statement about what our emissions targets have to be. To achieve these targets, we need action now, this week, here in Bali, said Matthew England, climate modeller at the University of New South Wales, Australia.
Specifically, the document states that atmospheric GHG concentrations need to be stabilised long-term at 450 ppm CO2e (carbon dioxide equivalent) or lower to keep global temperatures from rising by more than 2 degrees Celsius. Formally announced at a press briefing in Bali this morning, the declaration calls on governments to reduce emissions “by at least 50% below 1990 levels by the year 2050”.
Though the science is taken from the latest report from the Intergovernmental Panel on Climate Change (IPCC) and the signatories comprise the most prominent IPCC authors, the policy-prescriptive statement is distinct from the UN process which assesses the current understanding of climate change. “This is simply outside the charge of the IPCC process”, said Richard Somerville, meteorologist at Scripps Institution of Oceanography at the University of California, San Diego.
Not all of those invited signed. England, one of the coordinators of the declaration, reckons they had at least a 70% success rate with getting authors on board. According to Andrew Pitman, a climate scientist also at the University of New South Wales, Australia, some authors didn’t sign because they felt the emissions cuts called for were simply not tough enough.
The declaration advises stabilising at 450ppm CO2e, yet this would only give us a 50% chance of avoiding dangerous climate change, explained Pitman. To increase that chance to 75%, we would need to bring atmospheric GHG levels down to 400ppm CO2e. With emissions steadily increasing, the urgency of the situation is brought home by the fact that we are now at GHG levels close to those at which the scientists recommend we stabilise.
Developed nations party to the Kyoto Protocol agreed in Vienna in August that emissions should be cut by 25-40% by 2020, based on 1990 levels. England confirmed that the target announced today is in line with this figure.
But the scientists won’t go as far as to say when the targets should be implemented or how nations should go about reducing their emissions. “We don’t have recommendations for how the negotiations should proceed”, said Somerville. He added that there is no magic bullet and that all approaches to reducing emissions will need to be considered.
As for whether their recommendations are likely to be taken on board, it’s probably too early to say. Diana Liverman, climate policy expert at Oxford University, UK and signatory of the statement, said that she hasn’t seen any evidence of the talks derailing yet and that a consideration of stricter targets than those under Kyoto may come next week.
On being asked for his response to the consensus document, US Senior Climate Negotiator Harlan Watson said that he wasn’t aware of it. He added that the US administration wholly approved of the IPCC, but that they wouldn’t endorse any specific scenarios from the latest report.
The IPCC will present their synthesis report at the plenary tomorrow morning – watch this space….