2021 emissions surge leaves less than 10 years to avoid 1.5 degree warming: study
Although carbon emissions dropped sharply in 2020 amid the COVID pandemic, a subsequent surge wiped out any time the decrease may have bought, according to a new study published in the journal Nature Reviews Earth & Environment.
The first year of the pandemic saw emissions decline 11 percent as a number of activities ground to a halt. However, in 2021, as restrictions lifted, they surged 4.8 percent compared to 2020. Greenhouse gas emissions, including carbon dioxide emissions, are the primary cause of climate change.
International governments have identified 1.5 degrees Celsius as the temperature increase that warming must be kept below to avert long-term catastrophe.
The so-called carbon budget measures the emissions scientists believe can be released before the 1.5-degree threshold is unavoidable. The 2021 spike in emissions “consumed 8.7% of the remaining carbon budget for limiting anthropogenic warming to 1.5 [degrees], which if current trajectories continue, might be used up in 9.5 years at 67% likelihood,” the study states.
Particularly worrisome is the fact that many of the most emissions-heavy sectors have seen their emissions rebound faster than emissions in general, according to the report. For example, the power sector saw its emissions increase by 5 percent, while the ground transport industry saw its emissions rebound 8.9 percent.
The biggest single-sector rebound was in the aviation industry, which saw a 25.8 percent domestic increase and an 18.1 percent international rebound.
China and the U.S., the world’s top two emitters, also saw a bigger rebound than the worldwide average. Chinese emissions rebounded by 5.7 percent, while American emissions rebounded by 6.5 percent, according to researchers.
The study backs up earlier research indicating 2021 emissions increased after the steep drop in 2021, A January estimate from research firm Rhodium Group indicated that in 2021, emissions increased by 6.2 percent from 2020 but were still 5 percent below 2019 levels.