As the UN’s 20th climate change conference struggled to break a deadlock, ministers and delegates from more than 190 countries were reminded of the high stakes for the planet if they fail to move forward towards a new agreement.
Dr Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), warned that any increase in average global temperature above two degrees would have "terribly serious and profound impacts for all forms of life".
In the IPCC’s worst-case scenario of a 4.8-degree increase by 2100, the Indian-born scientist said this would spell disaster and doctors would be better qualified to say if life could continue: “It’s a scenario that human society cannot contemplate.”
Negotiators in Lima are attempting to lay the foundation for a global agreement on climate change in Paris next year.
Dr Pachauri called on all of the negotiators in Lima “not to lose sight of the science”, as spelled out in the IPCC’s comprehensive Fifth Assessment Report, which was finalised in October with the publication of a summary of its conclusions.
“It is absolutely essential that we mitigate greenhouse gas emissions, and the sooner we start doing that the better. Cuts of 40 to 70 per cent by mid-century would require substantial improvements in energy efficiency and quadrupling energy from renewables.”
He said there was “enough scientific information and assessment” available now to show that the prospects were “stark” if the world failed to take action. These could include a rise of nearly one metre in sea levels, threatening numerous coastal cities.
“The impacts of climate change will continue as result of past emissions, so we will have to deal with some level of impacts. But that in itself will not be enough, because we could cross thresholds or tipping points if emissions continue rising.”
Dr Pachauri also noted a key IPCC finding that 90 per cent of the warming since 1970 had been absorbed by the oceans to a depth of 700 metres, and said their increasing acidification would have “very major implications for marine ecosystems”.
But Lidy Nacpil, of Jubilee South, said one of the "fundamental flaws" in the current round of negotiations was "the lack of a clear global goal for limiting global warming based on science", with the result that any agreement was likely to be inadequate.
“In the last few years, we have seen the talks rapidly deteriorating to voluntary contributions, without any agreed reference points as to how ensure that the sum of the contributions will be enough to save people and the planet from climate catastrophe,” she said.
Rahman Mehta, of Action Aid India, said a new negotiating text – produced after a previous version had "ballooned out of control" – clearly set out options reflecting "irreconcilable differences" between parties that would have to be resolved by ministers.
The G77 group of 130-plus developing countries wanted time to consider the latest version, postponing a resumption of negotiations with the EU, the US and other developed country parties, and it's now expected that the conference will overrun into Saturday.
Much interest is now focused on a Brazilian proposal to break the impasse between rich and poor countries, under which they would form a multi-layered circle – with the rich at the centre making absolute reductions in their emissions, starting right away.
Under Brazil’s “concentric differentiation approach”, poorer countries would be in the outer layers but could move to the inner circle once they had reached a certain level of development – and this would be determined by a formal review every five years.
Manuel Arias Cañete, the new EU commissioner for climate action and energy, has described it as a “valuable proposal” that would be “worth looking at” as a way of breaking the logjam in Lima.