Scientists warn G7 humanitarian and economic costs of breaching 1.5C will far exceed costs of achieving it

As the leaders of seven of the world’s wealthiest nations meet in Cornwall for the G7 summit, the scientists have launched a 1.5 Degree Charter to highlight how breaching the 1.5C target outlined in the Paris Agreement will cost far more than paying poorer nations to help global efforts to reach it.

It is hoped governments, businesses and the public will get behind the Charter to influence the conversation on climate finance and steer key decisions made at the next UN climate summit, COP26 in Glasgow in November.

Those most vulnerable to the impacts of the climate crisis predominantly live in the global South, but they have contributed the least to greenhouse gas emissions.

The Charter argues that, to sufficiently reduce emissions, it will require richer countries to pay reparations to poorer countries.

The amounts must reflect fairly the former’s responsibility for the crisis and the latter’s vulnerability to it.

The aim of the Charter therefore is to act as a catalyst to encourage wealthy nations to support those less wealthy to not only decarbonise but also ensure they can afford to put in place measures to protect their homes, jobs and lands from climate-related impacts like extreme weather, poor health, job losses and food insecurity.

To support the Charter, the academics involved are developing a global research project to fully identify and compare the cost of exceeding a 1.5C temperature rise versus the costs already anticipated of the decarbonisation required to meet the 1.5C target.

The 1.5C Degree Charter calls on governments in particular to:

· Recognise the human and economic cost of exceeding 1.5C and that this cost will be borne disproportionately around the world and by future generations.

· Act on their commitment to limit global heating to 1.5C.

· Encourage the development of climate finance mechanisms that link the cost of delaying climate action with the cost of decarbonisation. Professor Tim Lenton, Director of the Global Systems Institute at the University of Exeter, said: “Global warming above 1.5C markedly increases the risk of crossing climate tipping points which will do greatest harm to the world’s poorest. Multiple abrupt climate changes occur between 1.5 and 2C global warming in IPCC climate model runs. Going to 2C warming risks a collapse of the West Antarctic ice sheet that would accelerate sea-level rise and threaten low-lying islands and coastlines such as Bangladesh. It would also degrade essentially all tropical coral reefs on which many depend for their livelihoods.