The air remediation policies from pollution in Eastern Asia have removed the provisional cooling effect of aerosols.
The question has been known for some time: the necessary air pollution reduction policies have Also A counterproductive effect, because aerosols remove the growth of temperatures due to greenhouse gases. In practice, reclaiming the air from pollutants harmful to health We free ourselves of substances that partly attenuate global warming caused by man.
This could be one of the reasons for the acceleration of global warming in recent years, and now a study has measured the world effect of anti-pollution policies followed in China over the past 15 years.
A necessary evil
Based on research, published on Communications Earth and Environmentthe remediation of air in Eastern Asia, and in particular in China, which took place from 2010 onwards, would be among the causes of the decisive acceleration of global warming recorded globally in recent times, and also at the origin of heating in the region of the northern Pacific (the part of the Pacific Ocean to the north of the equator).
The study quantifies for the first time the effect of aerosol masking (Aerosol masking) in greenhouse gas heating of the region where China is locatedA country that starting from the beginning of the decade of 2010 has implemented drastic measures for the reduction of atmospheric pollutants. Air pollution is responsible every year of the premature death of 8.1 million people in the world, 2 million of whom in China, a country where almost a fifth of the world population resides.
Down the mask (but the damage was done)
The measures decided to counter the bad quality of the air breathed in China in the 2000s led to a 75% decrease in sulphate emissions (SO2)aerosols that reflect sun radiation and increase Albedothat is, the reflective power, of the clouds, thus exercising a cooling effect on the earth’s surface. We also know that, since 2010, global warming seems to grow acceleratedly (of about 0.24 ° C per decade, against 0.18 ° C every 10 years of the previous decades).
Several times it has been hypothesized that the cleaning of the air of pollutants had removed the substances that partly masked, attenuating it, the global warming due to greenhouse gasesbut so far understanding the contribution of the individual regions had been problematic.
The scientists of the Cicero Center for International Climate Research, a research foundation based in Oslo (Norway), and of the University of Reading (United Kingdom) used a large set of simulations deriving from eight different climatic models To demonstrate that the reduction of pollution to Eastern Asia, a global warming that we had already caused but which was expressed only in part:
«We have found an average per year heating in rapidly evolution of 0.07 ± 0.05 ° C, sufficient to be the main decisive factor of the increase in the global warming rate since 2010», The authors of the study write.
The problem is not clean air
Of these complex interactions between the factors that determine the climate, it is a duty to take into account, But without losing sight of the real problem: that is, that the greater the amount of CO2 in the atmosphere, the greater the probability that the earth system is out of balance and that things do not go as we had foreseen.
Assorting is necessary because it has beneficial effects on our health and the planet And it must be done decisively, also “serving” some effects only apparently paradoxical Like the provisional acceleration of global warming.
We remind you that it was us, pouring impressive quantities of CO2 into the atmosphere, that caused global warming, that the deposit He only helped to make us appreciate in his real guise; And that, while CO2 remains for centuries in the atmosphere, the aerosols only for a few months.
And since the climatic effects of aerosol pollution are short -lived, “also the acceleration of global warming due to pollution reductions is probably destined to last little“Clarifies Laura Wilcox, co -author of the study and atmospheric scientist of the University of Reading.
“We will attend an acceleration of heating while the mask fallsand then to a return of the heating rhythm linked to greenhouse gases as soon as the air pollution has stabilized ».
