Global carbon emissions are projected to bounce back to 36.4 billion metric tons this year after an unprecedented drop caused by the response to the coronavirus pandemic, according to an annual report by the Global Carbon Project.
Fossil carbon emissions dropped by 5.4% in 2020 amid Covid lockdowns, but the new report projects they will increase by 4.9% this year.
“The rapid rebound in emissions as economies recover from the pandemic reinforces the need for immediate global action on climate change,” said lead author Professor Pierre Friedlingstein, of Exeter’s Global Systems Institute.
The findings were released as world leaders meet at COP26 in Glasgow, Scotland, to address the climate crisis and try to agree on a plan of action going forward.
While total emissions of carbon dioxide, or CO2, from fossil fuel use and land-use change combined have remained relatively constant around 40 billion metric tons over the past decade, emissions from China and India continue to increase as emissions of CO2 generated by the United States and European Union continue to decline.
The Global Carbon Project annually estimates the amount of future carbon dioxide pollution that can be emitted if the world community stands a chance of limiting global temperature rise to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels as called for in the Paris agreement, which the United States Biden administration rejoined in February.
The report concludes that at current levels of pollution, the world has 11 years left before global warming surges past the Paris goals. Reaching net zero CO2 emissions by 2050 would require cutting total CO2 emissions by roughly the same amount observed during the coronavirus slowdown – every year.
Scientists from 70 institutions on five continents contribute to the Global Carbon Budget. NOAA contributes the data used to establish global atmospheric CO2 levels used in the report. In addition, NOAA scientists and colleagues with the University of Colorado have developed a breakthrough method for distinguishing between CO2 emissions generated by fossil fuels from CO2 generated by natural sources. This capability will be essential to evaluating the credibility of emissions reduction commitments in the future. NOAA also provides approximately half of all the surface ocean CO2 observations for the global database used to calculate the ocean carbon sink.
These baseline measurements are essential for understanding the global carbon cycle: the amount of carbon emitted to the atmosphere and the amount removed by carbon sinks such as terrestrial plants, soils, and the ocean. Carbon sinks are important to understand because they help to offset greenhouse gas pollution that would otherwise accumulate more rapidly in the atmosphere.
“The point we like to emphasize is that, in addition to emissions, we need to quantify and understand the natural sinks to make meaningful projections about future levels of atmospheric CO2,” said NOAA oceanographer Rik Wanninkhof.
For example, the land and ocean CO2 sinks combined to take up about half of the CO2 emitted to the atmosphere during the period from 2011-2020. A series of modeling studies suggests that during the same period climate change reduced the land sink by about 15% and the ocean sink by about 5%. However, ocean observations suggest that the ocean sink increased over that time period. “This points to the need for more work,” Wanninkhof said.