In­creased weather ex­tremes ex­pected in the decades ahead as Earth con­tin­ues to heat up

The East African - - NEWS - By MATT MCGRATH BBC

sci­en­tists ar­gue that much of the “ex­tra­or­di­nary” weather seen this year bears the hall­marks of cli­mate change.

The World Me­te­o­ro­log­i­cal Or­gan­i­sa­tion’s pro­vi­sional fig­ures show that 2017 is “very likely” to be in the top three warm­est years on record. In fact, it could turn out to be the hottest year in the ab­sence of the El Niño phe­nom­e­non.

The WMO sci­en­tists ar­gue that the long-term trend of global warm­ing driven by hu­man ac­tiv­i­ties con­tin­ues un­abated and that much of the “ex­tra­or­di­nary” weather seen this year bears the hall­marks of cli­mate change.

On the open­ing day of this year’s key UN cli­mate talks, re­searchers from the WMO pre­sented their an­nual State of the Global Cli­mate re­port.

It fol­lows on their green­house gases study from last week that found that con­cen­tra­tions of CO2 in the at­mos­phere were the high­est on record.

While the new study only cov­ers Jan­uary to Septem­ber, the WMO says the av­er­age global tem­per­a­ture was 1.1°C above the pre-in­dus­trial fig­ure.

This is get­ting dan­ger­ously close to the 1.5 de­grees thresh­old that many is­land states feel tem­per­a­tures must be kept un­der to en­sure their sur­vival.

The anal­y­sis sug­gests that 2017 is likely to come in 0.47 °C warmer than the 1981-2010 av­er­age. This is slightly down on 2016 when the El Niño phe­nom­e­non saw tem­per­a­tures that were 0.56 °C above the av­er­age.

Ac­cord­ing to the WMO, this year vies with 2015 to be the sec­ond or third warm­est yet recorded.

“The past three years have all been in the top three years in terms of tem­per­a­ture records. This is part of a long-term warm­ing trend,” said WMO sec­re­tary gen­eral Pet­teri Taalas.

Se­vere food in­se­cu­rity

“We have wit­nessed ex­tra­or­di­nary weather, in­clud­ing tem­per­a­tures top­ping 50°C in Asia, record-break­ing hur­ri­canes in rapid suc­ces­sion in the Caribbean and At­lantic, (and) reach­ing as far as Ire­land, dev­as­tat­ing mon­soon flood­ing af­fect­ing mil­lions of peo­ple and a re­lent­less drought in East Africa. Many of these events bear the tell­tale sign of cli­mate change caused by in­creased green­house gas con­cen­tra­tions from hu­man ac­tiv­i­ties,” Mr Taalas said.

Sci­en­tists still need to clearly link spe­cific events from 2017 to ris­ing tem­per­a­tures. But they be­lieve the fin­ger­prints of cli­mate change are to be seen in trop­i­cal cy­clones, where the warmer seas trans­fer more heat to the gath­er­ing storms and in­creased sea lev­els make floods more dam­ag­ing.

The Ac­cu­mu­lated Cy­clone En­ergy In­dex, which mea­sures the in­ten­sity and du­ra­tion of these events, showed its high­est ever monthly val­ues in Septem­ber. It was also the first time that two Cat­e­gory 4 hur­ri­canes made land­fall in the same year in the US.

Hur­ri­cane Irma was a Cat­e­gory 5 storm. Rain gauges in Texas, recorded 1,539mm, the largest ever recorded for a sin­gle event in the main­land US.

Sci­en­tists say that ex­treme heat and drought contributed to many de­struc­tive wild­fires such as the re­cent one in Cal­i­for­nia

There were also sig­nif­i­cant flood­ing events with loss of life in Sierra Leone, Nepal, In­dia, Bangladesh and Peru.

In con­trast, droughts and heat waves af­fected many parts of Africa and South Amer­ica. In So­ma­lia, more than half of the coun­try’s crop­land was af­fected with live­stock herds re­duced by be­tween 40 and 60 per cent.

Also, more than 11 mil­lion peo­ple are ex­pe­ri­enc­ing se­vere food in­se­cu­rity in Ethiopia, Kenya and So­ma­lia.

“This year saw weather ex­tremes, which is not un­com­mon, but many of these events were made more se­vere by the sus­tained warm­ing caused by in­creas­ing at­mo­spheric green­house gas lev­els due to hu­man ac­tiv­i­ties,” said Richard Al­lan, pro­fes­sor of cli­mate sci­ence at the Univer­sity of Read­ing, in the UK.

“In­creased weather ex­tremes are ex­pected as the Earth heats up. It is only with the sub­stan­tive cuts in green­house gas emis­sions re­quired by the Paris Ac­cord that we can avert more wide­spread dam­age to our so­ci­eties and the ecosys­tems upon which they de­pend,” Prof Al­lan added.

These ex­tra­or­di­nary weather events bear the tell­tale sign of cli­mate change due to green­house gas con­cen­tra­tions from hu­man ac­tiv­i­ties.” Pet­teri Taalas, WMO sec­re­tary gen­eral

Pic­ture: File

Ema­ci­ated cat­tle ar­rive at Kenya Meat Com­mis­sion, Kibarani, for the off-take pro­gramme in Fe­bru­ary from the six coastal coun­ties af­fected by drought.

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