Climate and the Covid-19 pandemic: global CO2 emissions fell 17% at the height of social isolation.

In early April, at the peak of social isolation in the countries assessed, the global reduction in daily CO2 emissions was 17% compared to the 2019 average, matching the daily emission rate observed in 2006.

That's what the study published today says. Nature Climate Change, coordinated by the University of East Anglia, England, with the participation of research centers from France, Germany, the Netherlands, Norway, Australia and the United States.

During the month of April, combined data on energy, economic and political activities from 69 countries were analyzed, representing 85% of the world's population and 97% of total carbon emissions.

Globally, the sector responsible for the largest amount of CO2 emissions is the energy sector (electricity and heat production), with 44,3% of the total, followed by industry (22,4%), land transport (20,6%), residential sector (5,6%), public sector and commerce (4,2%) and aviation (2,8%).

Most of the data analyzed refers to the first 15 days of April, reflecting the changes imposed by the health crisis, compared to a typical day of activity before the lockdown, taking into account seasonality and the day of the week.

In this way, scientists were able to estimate the variations in daily emissions during the social isolation adopted in the fight against the Covid-19 pandemic and their implications for the evolution of the total CO2 concentration in 2020.

At the peak of social isolation (on April 7th), the land transport sector accounted for 43% of the reduction in emissions; the same percentage for the industrial and energy sectors combined, and 10% for aviation.

The study's authors estimate that the global reduction in carbon emissions in 2020, compared to 2019, could range from 4% to 7%, depending on the duration of isolation measures; the extremes being between a period of 4 to 10 months, starting in March.

In quantitative terms, the planet's atmosphere received 1.048 million tons less carbon dioxide (MtCO2) in the first four months of 2020. China – the largest emitter of polluting gases – reduced its emissions by 242 MtCO2, followed by the United States (-207 MtCO2), Europe (-123 MtCO2), India (-98 MtCO2) and the United Kingdom (-18 MtCO2).

Considering that, in order to limit the increase in planetary temperature to 1,5 ^oBy 2100 – as advocated by the IPCC – CO2 emissions must be reduced by at least 7,6% per year until 2030. The study shows that casual social responses are insufficient to guarantee a sustainable reduction in emissions capable of minimizing climate change.

“Social isolation has led to drastic changes in energy consumption and CO2 emissions. However, these extreme reductions are likely to be temporary, as they do not reflect structural changes in the economic, transport, or energy systems,” says Corinne Le Quéré, climatologist and professor at [University Name]. School of Environmental Sciences, from the University of East Anglia, and leader of the research team that authored the study.

According to Robert Jackson, a professor at Stanford University (USA) and co-author of the study, "the drop in emissions was significant, but what we need is a systematic transition to green energy and electric vehicles, not temporary reductions caused by forced behaviors."

“There are real, sustainable and more resilient possibilities for future crises, through economic recovery plans that also target climate goals, especially those related to mobility, which was responsible for [almost] half of the reduction in emissions during social isolation,” concludes Le Quéré.

Sources: https://www.nature.com/articles/s41558-020-0797-x

https://www.eurekalert.org/pub_releases/2020-05/uoea-ccc051820.php

https://futureearth.org/2020/05/19/global-carbon-emissions-fall-sharply-during-covid-19-lockdown/