Ex­treme events heighten ur­gency of US cli­mate re­port

The State (Sunday) - - News - BY BRAD PLUMER AND HENRY FOUN­TAIN

Global warm­ing is now af­fect­ing the United States more than ever, and the risks of fu­ture dis­as­ters – from flood­ing along the coasts to crop fail­ures in the Mid­west – could pose a pro­found threat to Amer­i­cans’ well-be­ing.

That’s the gist of Vol­ume Two of the lat­est Na­tional Cli­mate Assess­ment, a 1,656-page re­port is­sued Fri­day that ex­plores both the cur­rent and fu­ture im­pacts of cli­mate change. The sci­en­tific re­port, which comes out ev­ery four years as man­dated by Congress, was pro­duced by 13 fed­eral agen­cies and re­leased by the Trump ad­min­is­tra­tion.

This year’s re­port con­tains many of the same find­ings cited in the previous Na­tional Cli­mate Assess­ment, pub­lished in 2014. Tem­per­a­tures are still go­ing up, and the odds of dan­gers such as wild­fires in the West con­tinue to in­crease. But re­flect­ing some of the im­pacts that have been felt across the coun­try in the past four years, some of the re­port’s em­pha­sis has changed.

Pre­dicted ef­fects have hap­pened: More and more of the pre­dicted im­pacts of global warm­ing are now be­com­ing a re­al­ity.

For in­stance, the 2014 assess­ment forecast that coastal cities would see more flood­ing in the com­ing years as sea lev­els rose. That’s no longer the­o­ret­i­cal: Sci­en­tists have now doc­u­mented a record num­ber of “nui­sance flood­ing” events dur­ing high tides in cities like Mi­ami and Charleston, South Carolina.

“High tide flood­ing is now pos­ing daily risks to busi­nesses, neigh­bor­hoods, in­fra­struc­ture, trans­porta­tion, and ecosys­tems in the South­east,” the re­port says.

As the oceans have warmed, dis­rup­tions in U.S. fish­eries, long pre­dicted, are un­der­way. In 2012, record ocean tem­per­a­tures caused lob­ster catches in Maine to peak a month ear­lier than usual, and the distri­bu­tion chain was un­pre­pared.

Tied to­gether: The re­port sug­gests a dif­fer­ent ap­proach to as­sess­ing the ef­fects of cli­mate change, by con­sid­er­ing how var­i­ous im­pacts – on food sup­plies, wa­ter and elec­tric­ity gen­er­a­tion, for ex­am­ple – in­ter­act with each other.

“It is not pos­si­ble to fully un­der­stand the im­pli­ca­tions of cli­mate change on the United States with­out con­sid­er­ing the in­ter­ac­tions among sec­tors and their con­se­quences,” the re­port says.

It gives sev­eral ex­am­ples, in­clud­ing re­cent droughts in Cal­i­for­nia and else­where that, in com­bi­na­tion with pop­u­la­tion changes, af­fect de­mand for wa­ter and en­ergy. The re­port also cites Su­per­storm Sandy, six years ago, which caused cas­cad­ing im­pacts on in­ter­con­nected sys­tems in the New York area, some of which had not been an­tic­i­pated. Flood­ing of sub­way and high­way tun­nels, for ex­am­ple, made it more dif­fi­cult to re­pair the elec­tri­cal sys­tem, which suf­fered wide­spread dam­age. Be­yond bor­ders: The U.S. mil­i­tary has long taken cli­mate change se­ri­ously, both for its po­ten­tial im­pacts on troops and in­fra­struc­ture around the world and for its po­ten­tial to cause po­lit­i­cal in­sta­bil­ity in other coun­tries.

The re­port cites these in­ter­na­tional con­cerns, but goes far be­yond the mil­i­tary. Cli­mate change is af­fect­ing U.S. com­pa­nies’ over­seas op­er­a­tions and sup­ply chains, it says, and as these im­pacts worsen it will take a toll on trade and the econ­omy. Adap­ta­tion: Since 2014, more de­tailed eco­nomic re­search has es­ti­mated that cli­mate change could cause hun­dreds of bil­lions of dol­lars in an­nual dam­age, as deadly heat waves, coastal flood­ing, and an in­crease in ex­treme weather take their toll. To limit that harm, com­mu­ni­ties will need to take steps to pre­pare.

The previous assess­ment warned that few states and cities were tak­ing steps to adapt to the im­pacts of cli­mate change. That’s slowly chang­ing, the new re­port finds. Some com­mu­ni­ties are tak­ing mea­sures such as pre­serv­ing wet­lands along the coasts to act as buf­fers against storms.

But out­side of a few places in Louisiana and Alaska, few coastal com­mu­ni­ties are re­think­ing their de­vel­op­ment pat­terns in or­der to avoid the im­pacts from ris­ing seas and se­vere weather that the re­port says are surely com­ing.

The re­port warns that the coun­try is par­tic­u­larly un­pre­pared for the up­heavals that will come as ris­ing sea lev­els swamp coastal cities: “The po­ten­tial need for mil­lions of peo­ple and bil­lions of dol­lars of coastal in­fra­struc­ture to be re­lo­cated in the fu­ture cre­ates chal­leng­ing le­gal, fi­nan­cial, and eq­uity is­sues that have not yet been ad­dressed.”

Fo­cus on air qual­ity: The re­port puts a re­newed em­pha­sis on the im­pacts of other at­mo­spheric pol­lu­tants such as ozone and smoke, which can cause res­pi­ra­tory prob­lems and lead to pre­ma­ture death.

The re­port notes with “high con­fi­dence” that cli­mate change will in­crease ozone lev­els, as ris­ing tem­per­a­tures and changes in at­mo­spheric cir­cu­la­tion af­fect lo­cal weather con­di­tions. But the in­creases will not be uni­form. By near the end of the cen­tury, the worst ozone lev­els will be found across a wide ex­panse of the Mid­west and North­ern Great Plains.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.