Study finds world's daily carbon emissions fell 17% in April

The world's daily carbon dioxide (CO2) emissions fell by 17% in April — the peak of global lockdowns aimed at slowing the spread of the coronavirus — when compared to 2019 levels, according to a study published in the journal Nature Climate Change on Tuesday.

The big picture: Though researchers say CO2 emission levels are again increasing as lockdowns are gradually lifted, they estimate that total emissions this year will be between 4% and 7% lower than 2019's total, which would be the largest annual decrease since the end of World War II.

• The decrease in total emissions depends on how quickly lockdowns are lifted and whether economic activity fully resumes.

Of note: Researchers say that the 4% to 7% decrease in total emissions "is comparable to the rates of decrease needed year-on-year over the next decades to limit climate change to a 1.5 °C warming," which aligns with the goals set by the Paris climate agreement.

Our thought bubble, via Axios' Ben Geman: The analysis lends weight to the idea that major policy shifts — not lockdowns occurring for tragic reasons — are needed to drive sustained future cuts. It also echoes other experts who see massive government economic recovery packages as a way to create or accelerate those changes.

• “[O]pportunities exist to set structural changes in motion by implementing economic stimuli aligned with low carbon pathways,” the study states.

By the numbers: China's carbon emissions for April fell by 242 megatons, while the United States' and India's fell by 207 and 98 megatons, respectively.

• Almost half of the world's emissions reductions last month came from a drop in transportation pollution, as people confined to their homes drove less. Reduced air travel only accounted for 10% of the emissions drop.

Go deeper: U.S. renewable energy on track to surpass coal in 2020