The Arizona Republic

UN warning on warming

New scientific report says changing how we use land could help save planet and fight hunger

- Seth Borenstein and Jamey Keaten

Human-caused climate change is dramatical­ly degrading the Earth’s land, and the way people use the land is making global warming worse, a new United Nations scientific report says.

“The stability of food supply is projected to decrease as the magnitude and frequency of extreme weather events that disrupt food chains increases,” the report said.

But if people change the way they eat, grow food and manage forests, it could help save the planet from a far warmer future, scientists said.

Scientists at a news conference Thursday in Geneva marking the report’s release emphasized both the seriousnes­s of the problem and the need to make societal changes soon.

GENEVA – Human-caused climate change is dramatical­ly degrading the Earth’s land, and the way people use the land is making global warming worse, a new United Nations scientific report says. That creates a vicious cycle that is already making food more expensive, scarcer and less nutritious.

“The cycle is accelerati­ng,” said NASA climate scientist Cynthia Rosenzweig, a co-author of the report. “The threat of climate change affecting people’s food on their dinner table is increasing.”

But if people change the way they eat, grow food and manage forests, it could reduce the chances of a far warmer future, scientists said.

Earth’s land masses, which are only 30% of the globe, are warming twice as fast as the planet as a whole. The special report, written by more than 100 scientists and unanimousl­y approved by diplomats from nations around the world Thursday at a meeting in Geneva, proposed fixes and made dire warnings.

“The way we use land is both part of the problem and also part of the solution,” said Valerie Masson-Delmotte, a French climate scientist who co-chairs one of the panel’s working groups. “Sustainabl­e land management can help secure a future that is comfortabl­e.”

Scientists at Thursday’s news conference emphasized both the seriousnes­s of the problem and the need to make societal changes soon.

“We don’t want a message of despair,” said panel official Jim Skea, a professor at Imperial College London. “We want to get across the message that every action makes a difference.”

The report said climate change already has worsened land degradatio­n. And the future could be worse. “The stability of food supply is projected to decrease as the magnitude and frequency of extreme weather events that disrupt food chains increases,” the report said.

Scientists had long thought one of the few benefits of higher levels of carbon dioxide, the major heat-trapping gas, was that it made plants grow more and the world greener, Rosenzweig said. But numerous studies show that the high levels of carbon dioxide reduce protein and nutrients in many crops.

If people change their diets, reducing red meat and increasing plantbased foods, such as fruits, vegetables and seeds, the world can save as much as another 15% of current emissions by mid-century. It would also make people more healthy, Rosenzweig said.

“We ought to recognize that we have profound limits on the amount of land available and we have to be careful about how we utilize it,” said Stanford University environmen­tal sciences chief Chris Field, who wasn’t part of the report.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsibl­e for all content.

 ?? SAMIR TOUNSI/AFP/GETTY IMAGES ?? Workers restore crop fields at a farming cooperativ­e in the Republic of Congo. A U.N. report supports sustainabl­e land management.
SAMIR TOUNSI/AFP/GETTY IMAGES Workers restore crop fields at a farming cooperativ­e in the Republic of Congo. A U.N. report supports sustainabl­e land management.
 ?? PATRICK PLEUL/AFP/GETTY IMAGES ?? If people change the way they eat, grow food and manage forests, they could help slow the planet’s warming, scientists said.
PATRICK PLEUL/AFP/GETTY IMAGES If people change the way they eat, grow food and manage forests, they could help slow the planet’s warming, scientists said.

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