Research has shown that carbon dioxide emissions have decreased dramatically since lockdowns were imposed around the world due to the coronavirus crisis.

The study, published on Tuesday in the journal Nature Climate Change, reveals that global carbon emissions per day in April were 17% lower than the average daily emissions in 2019.

These findings show that the world has experienced the sharpest drop in carbon output since records began, after large sections of the global economy were brought to a standstill.

When the lockdown was at its most stringent, in some countries emissions fell by just over 26% on average. In the UK, the decline was about 31%, while in Australia emissions fell 28.3% for a period during April.

Likely to be temporary

According to Corinne Le Quéré, the lead author of the new study, the unprecedented fall is likely to be only temporary. As countries slowly get back to normal activity, over the course of the year, the annual decline is likely to be only about 7%.

This is only if some of the restrictions to curb the spread of the virus remain in place. However, if they are lifted in mid-June, the fall for the year is likely to only be 4%.

Even though it’s not encouraging, it would still represent the biggest annual drop in emissions since the second world war.

Le Quéré and her colleagues wrote that world leaders need to incorporate climate-change goals into their economic rebuilding efforts.

In order to meet the goals of the Paris agreement and keep global heating from reaching catastrophic levels, emissions must fall to net zero.

The study

The study was conducted by scientists from the University of East Anglia, Stanford University in the US, the Cicero Centre in Norway, as well as scientists in the Netherlands, Australia, France and Germany.

The study authors examined emissions data from more than 69 countries, including the US, and 30 Chinese provinces. The sampling represents 85% of the world population and 97% of global CO2 emissions.

Researchers used measurements of economic activity, energy generation, industrial production, transport and other proxies to estimate carbon dioxide output. They concentrated on six areas: power generation, surface transport, industry, public buildings and commerce, residential sources, and aviation.

Emissions from aviation showed a dramatic decline, of about 60%, as international flights between many countries were grounded. Emissions from surface transport fell less sharply, by about 36%. Power generation and industry accounted for about 86% of the total decline in emissions.