If one major economy take the lead and have other nation's follow, global warming can be kept below two degree Celsius, revealed scientists. They found the amount of emissions reductions it takes for a major economy to lead out of the climate gridlock.
Lead author Malte Meinshausen of the University of Melbourne said, "If either the European Union or the US would pioneer and set a benchmark for climate action by others, the negotiation logjam about fair burden sharing could be broken. Their analysis showed that economies would have to roughly double their current domestic 2030 emissions reductions targets, which would certainly require substantial efforts."
‘If either the European Union or the US would pioneer and set a benchmark for climate action by others, the negotiation logjam about fair burden sharing could be broken.’
A key factor to address is the two conflicting fairness criteria- one favoring 'distributive justice' leading to per-person emissions to be about the same for every nation by 2050, the other leaning toward 'corrective justice' and factoring in past emissions to obtain equal per-person cumulative emissions.
On board the first criterion are the Europe and US, with China and India for the second one. In this scenario, the US national emissions reduction target would have to be roughly 50% instead of currently 22-24% below 2010 levels by 2030. Alternatively, the equivalent target for the Europe would have to be about minus 60% instead of currently 27% below 2010. If China wanted to assume leadership, China would have to reduce emissions by 32% below 2010 levels by 2030. In a scenario of equalized cumulative per-capita emissions, it would only need to reduce them by 4%. This seems little, but would in fact be a most crucial contribution.
Researchers said, "Our study thus anticipated the upcoming Paris climate summit, which would see countries make their mitigation contributions in an independent bottom-up manner."
Joeri Rogelj of the International Institute for Applied Systems Analysis said, "Our study introduced an important new concept which helps them understand how major countries could still assume a leadership role on this highly fragmented playing field."
The study appeared in the Journal Nature Climate Change.