UN needs to plan for 4°C of warming say Tyndall Centre scientists

Scientists warn governments to be ‘politically pragmatic’ and prepare for worst case climate change scenarios

Source: Flickr / Nathan Gibbs

By Sophie Yeo

Focusing on keeping world temperatures beneath 2°C is no longer an effective policy strategy, warn scientists from the Tyndall Centre for Climate Change.

They say the UN needs to consider adapting climate policy to an amended goal of ‘Mitigate for 2 but adapt for 4’ as the 2°C limit – the point beyond which the effects of climate climate are likely to become catastrophic – starts to slip out of sight.

An overarching focus on 2°C could leave the world unprepared to face the impacts of the much higher degree of warming that is likely to occur, they add.

In a paper published in the journal Climate Policy, the scientists say that the 2°C limit has in any case failed to stimulate adequate policy action from politicians.

“This need not be a pretext for abandoning the existing target,” says Professor Jordan of the Tyndall Centre for Climate Change Research at the University of East Anglia.

“On the contrary, openly exploring the alternatives could encourage some of the policy makers who are less certain to commit more fully to the existing two degrees target, whatever it requires, as the least unattractive course of action.”

The paper is co-authored by Corinne Le Quéré and Alice Bows-Larkin, who both contributed to IPCC’s Fifth Assessment report, the first part of which was published last week.


The IPCC report warned that the world’s ‘carbon budget’ – the amount of Co2 it can emit if temperatures are to stay below 2C – could be exceeded as early as 2040.

The scientists argue the current high level of emissions means that policy needs to shift gear, moving on from the previous international target of keeping emissions below 2C, to explore alternative options that reflect the likely reality of the situation.

“When confronted with a deep policy dilemma, decision makers should be as aware as possible of all the implications of pursuing alternative courses of action”, says Le Quéré, Director of the Tyndall Centre for Climate Change Research.

This could include a renewed focus on short-term, achievable targets. Since an explicit overarching 2C target has so far failed to stimulate either the social change or policy action necessary to achieve it, they suggest that concentrating on more immediately achievable goals could be a more politically pragmatic solution.

“Choosing either a high or a low chance of avoiding 2°C makes a significant difference to decision making around the feasibility of mitigation options, as well as the design of long lasting infrastructure intended to be resilient to future climate change impacts”, said the Tyndall Centre’s Dr Alice Bows-Larkin.

Next month, the UN will meet in Warsaw to discuss a framework that will set the stage for the attempts to set a legally binding climate deal in Paris in 2015. The last global deal to reduce emissions was agreed in Kyoto 16 years ago.

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