Questão 31 - UNISA PROVA II 2021/2

Leia o texto para responder à questão.

 

    Human activity emits far less methane than carbon dioxide, but methane packs a heavier punch. Over the course of 20 years, a tonne of the gas will warm the atmosphere about 86 times more than a tonne of CO2 . As a result methane, sometimes called carbon dioxide on steroids, is responsible for 23% of the rise in temperatures since pre-industrial times. Carbon dioxide gets most of the attention, but unless methane emissions are limited there is little hope of stabilising the climate.

    Unfortunately methane emissions have been anything but stable. After briefly declining in the early 2000s, atmospheric concentrations of the gas started rising again in 2007. A global inventory found that humans were largely to blame. Chief among the reasons for the rise are the gassy output of livestock farming (cows belch it), rice cultivation (wet environments accommodate micro-organisms that make it) and the fossil-fuel industry (pipelines and rigs leak it). Agriculture and energy each account for roughly one-third of annual methane emissions.

     By how much do methane emissions need to fall? The Intergovernmental Panel on Climate Change estimates that, to keep temperatures between 1.5º C and 2º C above pre-industrial levels, human methane emissions must drop to 35% below where they stood in 2010 by mid-century.

(www.economist.com, 03.04.2021. Adaptado.)

De acordo com o primeiro parágrafo, comparado ao dióxido de carbono, o metano