UN cli­mate re­port: Change land use to avoid a hungry fu­ture

The Saline Courier - - OPINION -

GENEVA — Hu­man­caused 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 which 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 help save the planet from 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. While heat-trap­ping gases are caus­ing prob­lems in the at­mos­phere, the land has been less talked about as part of cli­mate change. A 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 pos­si­ble fixes and made more 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 press 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 sci­ence panel of­fi­cial

Jim Skea, a pro­fes­sor at Im­pe­rial Col­lege Lon­don. “We want to get across the mes­sage that ev­ery ac­tion makes a dif­fer­ence.”

Still the stark mes­sage hit home hard for some of the au­thors.

“I’ve lost a lot of sleep about what the sci­ence is say­ing. As a per­son, it’s pretty scary,” Koko Warner, a man­ager in the U.N. Cli­mate Change sec­re­tariat who helped write a re­port chap­ter on risk man­age­ment and de­ci­sion-mak­ing, told The As­so­ci­ated Press af­ter the re­port was pre­sented at the World Me­te­o­ro­log­i­cal Or­ga­ni­za­tion head­quar­ters in Geneva. “We need to act ur­gently.”

The re­port said cli­mate change al­ready has wors­ened land degra­da­tion, caused deserts to grow, per­mafrost to thaw and made forests more vul­ner­a­ble to drought, fire, pests and dis­ease. That’s hap­pened even as much of the globe has got­ten greener be­cause of ex­tra car­bon diox­ide in the air. Cli­mate change has also added to the forces that have re­duced the num­ber of species on Earth.

“Cli­mate change is re­ally slam­ming the land,” said World Re­sources In­sti­tute re­searcher Kelly Levin, who wasn’t part of the study.

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.

In the worst-case sce­nario, food se­cu­rity prob­lems change from mod­er­ate to high risk with just a few more tenths of a de­gree of warm­ing from now. They go from high to “very high” risk with just an­other 1.8 de­grees Fahren­heit (1 de­gree Cel­sius) of warm­ing from now.

“The po­ten­tial risk of multi-bread­bas­ket fail­ure is in­creas­ing,” NASA’S Rosen­zweig said. “Just to give ex­am­ples, the crop yields were ef­fected in Europe just in the last two weeks.”

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.

For ex­am­ple, high lev­els of car­bon in the air in ex­per­i­ments show wheat has 6% to 13% less pro­tein, 4% to 7% less zinc and 5% to 8% less iron, she said.

But bet­ter farm­ing prac­tices — such as notill agri­cul­tural and bet­ter tar­geted fer­til­izer ap­pli­ca­tions — have the po­ten­tial to fight global warm­ing too, re­duc­ing car­bon pol­lu­tion up to 18% of cur­rent emis­sions lev­els by 2050, the re­port said.

If peo­ple change their di­ets, re­duc­ing red meat and in­creas­ing plant-based 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.

The sci­ence panel said they aren’t telling peo­ple what to eat be­cause that’s a per­sonal choice.

Still, Hans-otto Pört­ner, a panel leader from Ger­many who said he lost weight and felt bet­ter af­ter re­duc­ing his meat con­sump­tion, told a re­porter that if she ate less ribs and more veg­eta­bles “that’s a good de­ci­sion and you will help the planet re­duce green­house gas emis­sions.”

Re­duc­ing food waste can fight cli­mate change even more. The re­port said that be­tween 2010 and 2016, global food waste ac­counted for 8% to 10% of heat­trap­ping emis­sions.

“Cur­rently 25%-30% of to­tal food pro­duced is lost or wasted,” the re­port said. Fix­ing that would free up mil­lions of square miles of land.

With just an­other 0.9 de­grees F of warm­ing (0.5 de­grees C), which could hap­pen in the next 10 to 30 years, the risk of un­sta­ble food sup­plies, wild­fire dam­age, thaw­ing per­mafrost and wa­ter short­ages in dry ar­eas “are pro­jected to be high,” the re­port said.

At an­other 1.8 de­grees F of warm­ing (1 de­gree C) from now, which could hap­pen in about 50 years, it said those risks “are pro­jected to be very high.”

Most sce­nar­ios pre­dict the world’s trop­i­cal re­gions will have “un­prece­dented cli­matic con­di­tions by the mid-to-late 21st cen­tury,” the re­port noted.

Agri­cul­ture and forestry to­gether ac­count for about 23% of the heat-trap­ping gases that are warm­ing the Earth, slightly less than from cars, trucks, boats and planes. Add in trans­port­ing food, en­ergy costs, pack­ag­ing and that grows to 37%, the re­port said.

But the land is also a great car­bon “sink,” which sucks heat-trap­ping gases out of the air.

From about 2007 to 2016, agri­cul­ture and forestry ev­ery year put 5.7 bil­lion tons (5.2 bil­lion met­ric tons) of car­bon diox­ide into the air, but pulled 12.3 bil­lion tons (11.2 bil­lion met­ric tons) of it out.

“This ad­di­tional gift from na­ture is lim­ited. It’s not go­ing to con­tinue for­ever,” said study co-au­thor Luis Ver­chot, a sci­en­tist at the In­ter­na­tional Cen­ter for Trop­i­cal Agri­cul­ture in Colom­bia. “If we con­tinue to de­grade ecosys­tems, if we con­tinue to con­vert nat­u­ral ecosys­tems, we con­tinue to de­for­est and we con­tinue to de­stroy our soils, we’re go­ing to lose this nat­u­ral sub­sidy.”

Over­all land emis­sions are in­creas­ing, es­pe­cially be­cause of cut­ting down forests in the Ama­zon in places such as Brazil, Colom­bia and Peru, Ver­chot said.

Re­cent for­est man­age­ment changes in Brazil “con­tra­dicts all the mes­sages that are com­ing out of the re­port,” Pört­ner said.

Say­ing “our cur­rent way of liv­ing and our eco­nomic sys­tem risks our fu­ture and the fu­ture of our chil­dren,” Ger­many’s en­vi­ron­ment min­is­ter, Svenja Schulze, ques­tioned whether it makes sense for a coun­try like Ger­many to im­port large amounts of soy from Latin Amer­ica, where forests are be­ing de­stroyed to plant the crop, to feed un­sus­tain­able numbers of live­stock in Ger­many.

“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.

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