Pre­dicted en­vi­ron­men­tal changes could sig­nif­i­cantly re­duce global pro­duc­tion of veg­eta­bles

Iran Daily - - Cultural Heritage & Environment -

The study, led by the Lon­don School of Hy­giene and Trop­i­cal Medicine (LSHTM), is the ¿rst sys­tem­at­i­cally to ex­am­ine the ex­tent to which pro­jected changes such as in­creases in tem­per­a­ture and re­duced wa­ter avail­abil­ity could af­fect the pro­duc­tion and nu­tri­tional qual­ity of com­mon crops such as toma­toes, leafy veg­eta­bles and pulses.

If no ac­tion is taken to re­duce the neg­a­tive im­pacts on agri­cul­tural yields, the re­searchers es­ti­mate that the en­vi­ron­men­tal changes pre­dicted to oc­cur by mid- to end-cen­tury in wa­ter avail­abil­ity and ozone con­cen­tra­tions would re­duce av­er­age yields of veg­eta­bles and legumes by 35 per­cent and nine per­cent re­spec­tively, phys.org wrote.

In hot set­tings such as South­ern Europe and large parts of Africa and South Asia, in­creased air temperatures would re­duce av­er­age veg­etable yields by an es­ti­mated 31 per­cent.

En­vi­ron­men­tal changes, in­clud­ing cli­mate change, wa­ter scarcity and bio­di­ver­sity loss, are pre­dicted to be­come more pro­found in the 21st cen­tury — pos­ing signi¿cant chal­lenges to global agri­cul­ture, food se­cu­rity and nutri­tion.

While there is grow­ing ev­i­dence that pre­dicted fu­ture changes in tem­per­a­ture and rain­fall will lead to signi¿cant re­duc­tions in the yields of many sta­ple crops such as rice and wheat, the im­pacts on veg­eta­bles and legumes — im­por­tant con­stituents of healthy di­ets are largely un­known.

To ad­dress this ev­i­dence gap the re­searchers con­ducted a sys­tem­atic re­view of all the avail­able ev­i­dence from ex­per­i­men­tal stud­ies pub­lished since 1975 on the im­pacts of changes in en­vi­ron­men­tal ex­po­sures on the yield and nu­tri­tional qual­ity of veg­eta­bles and legumes. Ex­per­i­ments in­cluded in the re­view were con­ducted in 40 coun­tries.

The team then es­ti­mated the ef­fects on the yields and nu­tri­tional qual­ity of crops of changes in key en­vi­ron­men­tal ex­po­sures, in­clud­ing in­creases in green­house gases (tro­po­spheric car­bon diox­ide and ozone), re­duced wa­ter avail­abil­ity for ir­ri­ga­tion and rising am­bi­ent temperatures.

Pre­vi­ous re­search has shown that raised lev­els of car­bon diox­ide would in­crease crop yields, but this study identi¿ed for the ¿rst time that these po­ten­tial yield bene¿ts are likely to be can­celled out in the pres­ence of si­mul­ta­ne­ous changes in other en­vi­ron­men­tal ex­po­sures.

The re­searchers warn that in the ab­sence of sub­stan­tial ef­forts to re­spond to pre­dicted fu­ture en­vi­ron­men­tal changes, re­duc­tions in the yields of veg­eta­bles and legumes will sub­stan­tially al­ter their avail­abil­ity glob­ally.

Such changes may af­fect the af­ford­abil­ity and con­sump­tion of veg­eta­bles and legumes in the midto long-term and this could have signi¿cant im­pacts on pop­u­la­tion health all around the world.

Dr. Pauline Scheel­beek, lead au­thor at LSHTM, said, “Our study shows that en­vi­ron­men­tal changes such as in­creased tem­per­a­ture and wa­ter scarcity may pose a real threat to global agri­cul­tural pro­duc­tion, with likely fur­ther im­pacts on food se­cu­rity and pop­u­la­tion health.

“Veg­eta­bles and legumes are vi­tal com­po­nents of a healthy, bal­anced and sus­tain­able diet and nu­tri­tional guide­lines con­sis­tently ad­vise peo­ple to in­cor­po­rate more veg­eta­bles and legumes into their diet.

“Our new anal­y­sis sug­gested, how­ever, that this ad­vice conÀicts with the po­ten­tial im­pacts of en­vi­ron­men­tal changes that will de­crease the avail­abil­ity of these im­por­tant crops un­less ac­tion is taken.”

To mit­i­gate the risks that fu­ture en­vi­ron­men­tal changes pose to these crops, re­searchers said that in­no­va­tions to im­prove agri­cul­tural pro­duc­tion must be a pri­or­ity, in­clud­ing the de­vel­op­ment of new crop va­ri­eties as well as en­hanced agri­cul­tural man­age­ment and mech­a­niza­tion.

Pro­fes­sor Alan Dan­gour, se­nior au­thor at LSHTM, said, “We have brought to­gether all the avail­able ev­i­dence on the im­pact of en­vi­ron­men­tal change on yields and qual­ity of veg­eta­bles and legumes for the ¿rst time.

“Our anal­y­sis sug­gested that if we take a ‘busi­ness as usual’ ap­proach, en­vi­ron­men­tal changes will sub­stan­tially re­duce the global avail­abil­ity foods.

“Ur­gent ac­tion needs to be taken, in­clud­ing work­ing to sup­port the agri­cul­ture sec­tor to in­crease its re­silience to en­vi­ron­men­tal changes and this must be a pri­or­ity for gov­ern­ments across the world.

“But our study also identi¿es the broader pol­icy rel­e­vance of en­vi­ron­men­tal change.

“Veg­eta­bles and legumes are es­sen­tial con­stituents of healthy di­ets and so ef­forts to en­sure that their global avail­abil­ity is not threat­ened by pre­dicted en­vi­ron­men­tal changes must also be high on the global pub­lic health agenda.”

The au­thors ac­knowl­edge lim­i­ta­tions of the study, in­clud­ing the fact that col­lated ev­i­dence on the im­pact of en­vi­ron­men­tal changes on the nu­tri­tional qual­ity of veg­eta­bles and legumes was lim­ited and the re­search team identi¿ed this as an area re­quir­ing more ev­i­dence gen­er­a­tion.

The study was funded by the Wel­come Trust as part of its Our Planet, Our Health pro­gram.

Dr. Howie Frumkin, head of Our Planet, Our Health at Wel­come, said, “Im­prove­ments in agri­cul­tural tech­nol­ogy have dra­mat­i­cally boosted the world’s food pro­duc­tion over the last 80 or so years.

“But we mustn’t be com­pla­cent. En­vi­ron­men­tal changes, in­clud­ing more chaotic weather pat­terns and a warm­ing cli­mate, threaten our abil­ity to feed the world’s peo­ple.

“This ex­cel­lent re­view high­lights that some of the most im­por­tant foods, and some of the world’s most vul­ner­a­ble peo­ple, are at high­est risk.

“This re­search is a wake-up call, un­der­lin­ing the ur­gency of tack­ling cli­mate change and of im­prov­ing agri­cul­tural prac­tices.” of these im­por­tant

phys.org

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