That the coronavirus emergency, and the consequent lockdowns adopted by dozens of countries around the world, had done the environment good was intuitive, but now there are even official data. According to the authoritative journal Nature Climate Change, the halt to various production activities and above all the reduction of car and air traffic have led to a reduction of CO2 emissions in the world equal to 8,6% compared to 2019. A significant figure, considering that: the period in question (January 1st to April 30th) was only partially affected by the quarantine (initially only in China, which in any case is the first country in the world for polluting emissions) ; we are talking about an almost entirely winter period and therefore with the radiators on in many western countries; not all countries have applied restrictive measures.
The figure, in quantitative terms, is equivalent to 1.048 million tonnes less released into the atmosphere, equal to about 3 times what Italy alone emits in an entire year (EIA 2018 data), which brings the planet back to the emission levels of the 2005. In fact, in all these years, despite the efforts, the carbon dioxide released into the air has continued inexorably to increase, so much so that Nature has estimated, provocatively, that a lockdown would be needed every year, or more likely an equivalent reduction of emissions on an annual basis, to achieve the climate objectives for 2030, i.e. limiting global warming to no more than 1,5°C. Even spread over the entire year, in fact, if the restrictions were to continue for months, the drop in CO2 emissions in 2020 should be 7%. This percentage would be the one to be aimed for for decarbonisation. In the worst case scenario, i.e. full recovery of activities everywhere between now and December, it would still remain a -2/-5%, in sharp contrast to the usual trend.
Lo Nature study, very detailed, reserves other interesting data. Meanwhile, the greenest day on a planetary level, due to the probable concurrence of the various lockdowns, was April 7: on that day alone the emission of 17 million tons of CO2 was avoided (-17% on 2019), equal to about 5% of Italy's total annual emissions. However, each area had its negative peak, e for Europe the figure is even more significant: -27%. Some countries, such as France and the USA, have achieved a reduction in a single day of 34 and 31% respectively. In absolute data, it is obviously China that has given the greatest contribution, also because part of the country has been closed since February: 242 million tons of CO2 less between January and April, compared to the same period last year, when the he world economy was running at full capacity, the virus was not yet circulating and many countries (precisely the most polluting ones) hesitated to share international environmental protocols.
Finally, there is also the analysis by sectors. The sector that has most reduced its activity is that of air traffic, with peaks of -76% and an average of -60%. Followed by surface transport, which collapsed up to -46%, industry up to -29%, energy production up to -14%, up to residential emissions, logically in contrast with an increase up to 6,7% . However, as is known, the pollution deriving from the increase in consumption in private homes has little effect, so much so that the emissions curve remained flat or in any case below +0,5%. The largest reduction in emissions the blockade of road traffic guaranteed it (demonstrating that restricted traffic areas and electric and shared mobility have a great future), reaching -10%, with energy production at -6% and industry at -7%. Even the drastic reduction in air traffic does not reach 3% of emissions avoided, compared to the normal trend.
