After Pandemic-driven Decline, Global Greenhouse Gas Emissions Surge Upward Again, UMD Research Finds

Global carbon emissions have rebounded to near pre-pandemic levels, according to a report by University of Maryland researchers released during the United Nations’ climate summit in Glasgow.

Department of Geographical Sciences professors George Hurtt and Louise Chini and adjunct Benjamin Poulter, a research scientist at NASA Goddard Space Flight Center, found in the Global Carbon Budget 2021 that widespread lockdowns contributed to a 5.4% decrease in global carbon emissions in 2020, but carbon emissions are projected to make up most of that difference and jump 4.9% this year.

“If there was one post-COVID ‘return to normalcy’ we could have avoided, it would have been great to see our global carbon footprint be one of them,” said Hurtt, the department's associate chair. “The data contained in this report make clear the impact of human activity on our environment and highlight a need for significant improvement at a particularly influential time.”

The 16^th annual report reinforces the challenges facing world leaders and climate and environmental experts—including UMD participants—gathered at the UN’s climate change Conference of the Parties (COP 26). More than 20 countries recently agreed to phase out coal by the 2030s and 2040s, but the United States, where the Global Carbon Budget 2021 report projects a 7.6% rise in emissions over 2020 and as a result contribute to 14% of global emissions, was not among them.

Land-use change and resulting emissions also play a key role in the global carbon budget, Chini said. In the last 10 years, global CO2 net emissions from land-use change measured 4.1 billion tons, according to the Land-Use Harmonization dataset the Department of Geographical Sciences annually produces.

“Although land-use emissions have been relatively stable in recent years, the high uncertainty in these estimates highlights the continued need for further research in this area,” she said.