Scientists warn G7 leaders over the existential costs of climate change

Explained: what is the G7 and why the 2021 summit is in Cornwall

A group of world-leading climate scientists are calling on G7 leaders to factor in the dire costs of failing to keep global warming below 1.5°C this century,

Scientists from UCL, the University of Exeter and the International Centre for Climate Change and Development on Friday launched a 1.5 Degree Charter to highlight how breaching the 1.5°C 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 reduce emissions sufficiently 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 is to act as a catalyst in encouraging wealthy nations to support those less wealthy not only to 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 identify and compare the cost of exceeding a 1.5 temperature rise versus the costs already anticipated of the decarbonisation required to meet the 1.5C target.

“This is about finding solutions to the climate crisis that embody fairness and build trust," said Simon Lewis, Professor of Global Change Science at UCL..

"Solving the climate crisis means acknowledging the damage already caused and making new alternative plans and choices to reverse that tide."

“The global south has been a small part of the problem so far but it’s a huge part of the solution. We need to demonstrate that the safety and security of its people are a priority.

"As with the coronavirus pandemic, none of us are safe until we are all safe. Similarly, no country can fully protect against the impacts of climate change unless we are all protected against them.

“Stabilising our climate requires emissions to drop to net zero. But building a prosperous and resilient world will require more than that.

"It will require increasing the power of the income poor and making investments to protect those who are already suffering the most through no fault of their own.”

Professor of Earth System Science at UCL, Mark Maslin, said, "The science is clear - going beyond 1.5°C will increase human misery around the world and put a huge financial burden on all of us.

"Our charter calls on governments of the world to invest in dealing with climate change now, which will not only increase people’s health and well-being now but will save trillions of dollars."

“We call on everyone that cares about our planet to sign our charter to show that citizens of the world want governments, corporations and the wealthy to invest in dealing with climate change.

"The burden of saving our planet must fall on the wealthiest in our global society as they have contributed most to the problem through excessive consumption.”

Professor Tim Lenton, Director of the Global Systems Institute at the University of Exeter, said, "Global warming above 1.5 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 2°C global warming in IPCC climate model runs.

Going to 2°C 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.

“Going from 1.5C to 2C warming would put hundreds of millions of people – mostly in sub-Saharan Africa and the Indian subcontinent – outside of the climate ‘niche’ that supports high human population densities today and has done in the past. It would also greatly increase their exposure to life-threatening hot and humid climate extremes."