The tough re­al­i­ties of cli­mate talks

Lesotho Times - - Opinion -

IN less than a month, del­e­gates from more than 190 coun­tries will con­vene in Paris to fi­nal­ize a sweep­ing agree­ment in­tended to con­strain hu­man in­flu­ence on the cli­mate. But any post-meet­ing cel­e­bra­tion will be tem­pered by two sober­ing sci­en­tific re­al­i­ties that will weaken the ef­fec­tive­ness of even the most am­bi­tious emis­sions re­duc­tion plans that are be­ing dis­cussed.

The first re­al­ity is that emis­sions of car­bon diox­ide, the green­house gas of great­est con­cern, ac­cu­mu­late in the at­mos­phere and re­main there for cen­turies as they are slowly ab­sorbed by plants and the oceans.

This means mod­est re­duc­tions in emis­sions will only de­lay the rise in at­mo­spheric con­cen­tra­tion but will not pre­vent it. Thus, even if global emis­sions could be re­duced by a heroic av­er­age 20 per­cent from their “busi­ness as usual” course over the next 50 years, we would be de­lay­ing the pro­jected dou­bling of the con­cen­tra­tion by only 10 years, from 2065 to 2075.

Un­con­di­tional na­tional com­mit­ments made by coun­tries for the Paris meet­ing are pro­jected to re­duce to­tal green­house gas emis­sions through 2030 by an av­er­age of only 3 per­cent be­low the busi­nes­sas-usual av­er­age rise of 8 per­cent.

This is why dras­tic re­duc­tions would be needed to sta­bi­lize hu­man in­flu­ences on the cli­mate at sup­posed “safe” lev­els. Ac­cord­ing to sce­nar­ios used by the United Na­tions In­ter­gov­ern­men­tal Panel on Cli­mate Change, global an­nual per capita emis­sions would need to fall from to­day’s five met­ric tons to less than one ton by 2075, a level well be­low what any ma­jor coun­try emits to­day and com­pa­ra­ble to the emis­sions from such coun­tries as Haiti, Ye­men and Malawi.

For com­par­i­son, cur­rent an­nual per capita emis­sions from the United States, Europe and China are, re­spec­tively, about 17, 7 and 6 tons.

The sec­ond sci­en­tific re­al­ity, aris­ing from pe­cu­liar­i­ties of the car­bon diox­ide mol­e­cule, is that the warm­ing in­flu­ence of the gas in the at­mos­phere changes less than pro­por­tion­ately as the con­cen­tra­tion changes.

As a re­sult, small re­duc­tions will have pro­gres­sively less in­flu­ence on the cli­mate as the at­mo­spheric con­cen­tra­tion in­creases.

The prac­ti­cal im­pli­ca­tion of this slow log­a­rith­mic de­pen­dence is that elim­i­nat­ing a ton of emis­sions in the mid­dle of the 21st cen­tury will ex­ert only half of the cool­ing in­flu­ence that it would have had in the mid­dle of the 20th cen­tury.

Th­ese two sci­en­tific re­al­i­ties make emis­sions re­duc­tions a slug­gish lever for con­strain­ing hu­man in­flu­ences on the cli­mate. At the same time, so­ci­etal re­al­i­ties con­spire to make emis­sions re­duc­tions them­selves dif­fi­cult.

En­ergy de­mand, which is strongly cor­re­lated with ris­ing in­comes and liv­ing stan­dards, is ex­pected to grow by some 50 per­cent by mid­cen­tury, driven by eco­nomic progress in de­vel­op­ing coun­tries and by pop­u­la­tion growth to about 9.7 bil­lion peo­ple from the cur­rent 7.3 bil­lion.

Fos­sil fu­els, which are not run­ning out any­time soon, sup­ply over 80 per­cent of the world’s en­ergy to­day and are usu­ally the least ex­pen­sive and most con­ve­nient means of meet­ing grow­ing en­ergy de­mand.

They con­tinue to be widely adopted as the de­vel­op­ing world builds its en­ergy-sup­ply in­fras­truc­ture, be­cause what­ever the emis­sions ben­e­fits of tech­nolo­gies such as nu­clear fis­sion, car­bon se­ques­tra­tion, wind and so­lar, all cur­rently have draw­backs (in­clud­ing cost, land use and in­ter­mit­tence) that ham­per their de­ploy­ment at scale.

And in the de­vel­oped world, the en­er­gy­sup­ply in­fras­truc­ture of elec­tric gen­er­at­ing plants, trans­mis­sion lines, re­finer­ies and pipe­lines changes slowly be­cause of the large cap­i­tal costs and long fa­cil­ity life­times, and be­cause dif­fer­ent parts of the en­ergy sys­tem must work to­gether (for ex­am­ple, cars, their fuel and the fu­elling in­fras­truc­ture must all be com­pat­i­ble).

Im­prove­ments in en­ergy ef­fi­ciency can help, but even if to­day’s an­nual per capita emis­sions of three tons in the de­vel­op­ing world grew by mid-cen­tury to only five tons (about 70 per­cent of Europe’s per capita emis­sions to­day), an­nual global emis­sions would in­crease by 60 per­cent.and, over­ar­ch­ing all this, the ten­sion be­tween emis­sions re­duc­tions and de­vel­op­ment is com­pli­cated by un­cer­tain­ties in how the cli­mate will change un­der hu­man and nat­u­ral in­flu­ences and how those changes will im­pact nat­u­ral and hu­man sys­tems.

Th­ese sci­en­tific and so­ci­etal re­al­i­ties com­pound to make sta­bi­liza­tion of the at­mo­spheric con­cen­tra­tion of car­bon diox­ide, let alone its re­duc­tion, a dis­tant prospect. As a re­sult, even as the world strug­gles to re­duce emis­sions, hu­man in­flu­ences on the cli­mate will not be de­creas­ing for many decades. Thus, adap­ta­tion mea­sures such as rais­ing the height of sea walls or shift­ing to drought-re­sis­tant crops be­come very im­por­tant. For­tu­nately, adap­ta­tion is on the ta­ble in Paris to com­ple­ment emis­sions re­duc­tions.

Adap­ta­tion can be ef­fec­tive. Hu­mans to­day live in cli­mates rang­ing from the trop­ics to the Arc­tic and have adapted through many cli­mate changes, in­clud­ing the Lit­tle Ice Age about 400 years ago.

Adap­ta­tion is also in­dif­fer­ent to whether the cli­mate change is nat­u­ral or hu­man-in­duced; it can be pro­por­tional, de­pend­ing upon how much or how quickly the cli­mate changes; and it can be po­lit­i­cally eas­ier to ac­com­plish be­cause it does not re­quire a global con­sen­sus and has demon­stra­ble lo­cal and im­me­di­ate ef­fects.

Adap­ta­tion will no doubt be more dif­fi­cult if the cli­mate changes rapidly (as it has done nat­u­rally in the past), and, like emis­sions re­duc­tions, it will in­duce in­equal­i­ties, as the rich can adapt more eas­ily than the poor.

Adapt­ing ecosys­tems to a chang­ing cli­mate will re­quire a more care­ful mon­i­tor­ing and deeper un­der­stand­ing of the nat­u­ral world than we have to­day.

The crit­i­cal role of adap­ta­tion in re­spond­ing to the re­al­i­ties of cli­mate change de­mands a deeper anal­y­sis and more prom­i­nent dis­cus­sion of the na­ture, ef­fec­tive­ness, tim­ing and costs of var­i­ous adap­ta­tion strate­gies. But what­ever the out­come in Paris, or of fu­ture dis­cus­sions of emis­sions and the cli­mate, the re­al­ity is that hu­mans must con­tinue to adapt, as they al­ways have. — NY Times

lkoonin is the di­rec­tor of the Cen­tre for Ur­ban Sci­ence and Progress at New York Univer­sity.

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