Humanity taking 'colossal risks', warn Nobel laureates

PARIS • The failure to halt climate change, the destruction of nature and other intertwined global crises pose an existential risk to humanity, 10 Nobel laureates said on Thursday following the first-ever Nobel Prize Summit.

Only profound changes in the way society produces, distributes and consumes almost everything - starting with energy - can forestall potentially catastrophic changes, they said in a joint statement, also signed by 20 other top thinkers.

"We need to reinvent our relationship with planet Earth," the statement said. "Without transformational action this decade, humanity is taking colossal risks with our common future."

The risks of pandemics, they noted, are now greater due to destruction of natural habitats, highly networked societies and the spread of fake news on social networks.

The Nobel winners said societies must repair and restore the "global commons" that have allowed our species to flourish - the climate, ice, land, ocean, freshwater, forests, soils, and the rich diversity of life that regulates the state of the planet.

"There is now an existential need to build economies and societies that support Earth system harmony rather than disrupt it," they warned.

"The next decade is crucial: Global greenhouse gas emissions need to be cut by half and destruction of nature halted and reversed."

The amount of carbon dioxide that humanity can emit and still cap global warming at 1.5 deg C - our "carbon budget" - will be exhausted before 2030, scientists have calculated. Earth's average global temperature has already gone up 1.2 deg C compared with pre-industrial levels.

At the same time, energy needs are rising: Every week until 2050, the Earth's urban population will increase by about 1.3 million.

The Nobel signatories included economists Joseph Stiglitz of Columbia University and Oliver Hart from Harvard, biophysicists William Moerner from Stanford and Jacques Dubochet of Lausanne University, and astrophysicist Brian Schmidt of the Australian National University.

There is no Nobel Prize for environmental or earth science.

"What we are doing amounts to an uncontrolled experiment on Earth's life-support system," said Earth system scientist Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research and a signatory of the statement.

"We are the last generation with a reasonable chance of retaining long-term stability of critical parts of the Earth system."

AGENCE FRANCE-PRESSE