Global emissions of CO2 stabilize, but climate continues to hype
The Global Carbon Project's annual report shows the positive effect of the slowdown in coal consumption in China. But Indian issues are growing strongly.
THE WORLD | 14.11.2016 to 03h07 • Updated 14.11.2016 to 10h57 | By Pierre Le Hir
Good news on the climate front: global emissions of CO2, the main greenhouse gas released by human activities, have stagnated in 2015, and are expected to remain almost stable in 2016. This is apparent from the annual report published Monday November 14, on the eve of the meeting of heads of state at the climate conference in Marrakech (COP22), the Global Carbon Project (GCP), a consortium under the scientific Aegis of the British University of East Anglia.
This settlement is still insufficient to stop the runaway climate machine. Without a rapid and radical change in the energy model, the planet is preparing to burst the ceiling of warming 2 ° C that the international community has set itself.
In 2015, carbon dioxide emissions from the combustion of fossil fuels (coal, oil and gas) as well as cement plants amounted to 36,3 billion tonnes (gigatonnes or Gt), the same level as in 2014. This figure, the study notes, "marks a clear and unexpected break from the sharp rise in emissions (+ 2,3% per year) over the 2004-2013 decade". In 2014, the increase had already been contained at 0,7%. For 2016, experts predict a moderate increase of 0,2%, to 36,4 Gt.
A plateau in CO2's global emissions
However, this assessment does not take into account emissions from land-use changes, particularly deforestation. This is 4,8 Gt of CO2 (1 Gt more than the annual average of the previous decade) that must be added to the total, which is then established at 41,1 Gt.
China counterbalanced by India
The plateau observed for carbon emissions from fossil fuels and cement plants, over the three years 2014, 2015 and 2016, is no less remarkable, especially when compared to the growth of the world's gross domestic product (GDP), higher this year at 3%. "After three years of moderate growth, it is possible that the trajectory of global emissions will decorrelate permanently and in the long term the pace of growth," the researchers write.
How to explain it? To a large extent by the lesser consumption of coal by China. The world's leading polluter, alone responsible for 29% of global emissions, reduced its releases by 0,7% as they had grown by more than 5% per year in the previous decade. At the same time, the emissions of the United States, which weigh for 15% of the total, decreased by 2,6%, also because of a decline in the share of coal, replaced by oil and gas, less harmful for the climate. Conversely, in the Europe of the Twenty-eight, which weighs for 10%, the emissions are distributed on the rise (+ 1,4%) after a long decline.
Very uneven efforts in different countries
The benefit of China's relative coal efficiency is, however, offset by strong growth in India's emissions, which jumped by 5,2%, in line with the steady rise of recent decades. It is the two Asian giants that will depend, for many, the future curve of greenhouse gases of human origin.
"Huge uncertainty hangs over Chinese emissions forecasts for 2016, due to unreliable data," experts say. For India, there is "no forecast". Added to this is an additional and significant unknown: that of the energy policy of US President-elect Donald Trump, who promised a new golden age of fossil fuels.
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That's not all. The researchers point out that "reported emissions can not yet be controlled with independent data, as we are not yet able to accurately calculate carbon fluxes in the natural environment".
Exhaustion of the carbon budget
In any case, the leveling of carbon emissions from mankind does not prevent greenhouse gases from accumulating in the atmosphere. "In 2015, the atmospheric CO2 level has exceeded 400 parts per million (ppm), 44% above pre-industrial levels, the highest level since 800 000 years," the scientists recall.
"Of the total greenhouse gases emitted, between 45% and 50% go into the atmosphere, the rest being shared equally between the ocean and the terrestrial biosphere," explains climatologist Jean Jouzel. Each year, it is therefore close to 20 billion additional tons of CO2 that we inject into the atmosphere. In addition, he says, this report takes into account carbon dioxide alone, and not all greenhouse gases, "including methane, whose emissions continue to increase".
The concentration of CO2 in the atmosphere could beat a new record in 2016, say the researchers, because of the lower efficiency of the carbon sink that is the vegetation, damaged by the drought caused by the El Niño phenomenon in the regions tropical.
Read also: It's always hotter on the planet Earth
In the end, the stabilization of global emissions is far from sufficient to meet the climate goals set by the COP21 Paris Agreement, namely to contain the rise in average temperature "significantly below 2 ° C compared to pre-industrial levels "and strive not to exceed 1,5 ° C. In order for the mercury column not to climb more than two levels, it would require "a reduction of 0,9% emissions per year to 2030," the researchers say.
Otherwise calculated, the "carbon budget", that is to say the amount of carbon that humanity can still release without exposing itself to overheating, decreases as the worst of times. "We have already used more than two-thirds of the emissions quota to keep warming below 2 ° C," warn the authors. At this rate, the remaining emissions quota will be exhausted in less than 30 years or less if the goal is not to exceed 1,5 ° C. "
A rapid decline in emissions is needed to contain the warming
"The stabilization of emissions is of course a positive signal, says Jean Jouzel. But if we want to stabilize the atmospheric concentration of greenhouse gases and stay on the trajectory of 2 ° C, we must reduce them drastically. Starting with "leaving more than 80% of known fossil resources underground". Otherwise the Paris agreement, like the COP of Marrakech, will remain in vain.
Half a good news.
The good side is to watch a CO2 emissions plateau, perhaps marking the first effect of global efforts: stopping the growth of emissions.
The worst part is that they stabilize at a historical high (+ 45% compared to 2000), while climate change was already significant before 2000, and that as long as the emissions have not dropped far below those of the year 2000, the concentration of atmospheric CO2 will continue to increase by a few ppm per year.
you have no idea of the damage since that date 1992> 2016 = 25 years of technology for the daily life of rich countries
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