The Dalai Lama and 100 other Nobel laureates have recently urged world leaders to halt the use of fossil fuels.

The request, which came in a letter that was published on Earth Day, called on world leaders and governments to adopt a transformational plan that would allow economies to move away from dependence on oil, gas and coal, and offer global access to renewable energy.

“Climate change is threatening hundreds of millions of lives, livelihoods across every continent, and is putting thousands of species at risk. The burning of fossil fuels — coal, oil and gas — is by far the major contributor to climate change,” the letter says. “We write today, on the eve of Earth Day 2021 and the Leaders’ Climate Summit, hosted by President Biden, to urge you to act now to avoid a climate catastrophe by stopping the expansion of oil, gas and coal.”

The letter, which was coordinated by the Fossil Fuel Non-Proliferation Treaty Initiative, also references the importance of both the United Nations Framework Convention on Climate Change and the Paris Agreement. The agreement proposes to limit global warming to “well below” 2 degrees Celsius and restrict any rise to 1.5 degrees Celsius, compared to pre-industrial levels.

The letter also says failure to meet the 1.5 degrees target would risk “pushing the world towards catastrophic global warming.” It also adds that the Paris Agreement makes no mention of oil, gas or coal.

Along with the Dalai Lama, the signatories also included scientists, religious leaders, novelists and former presidents.