Carbon dioxide emissions increased by almost 5% last year, meaning that the world now has a two-in-three chance of reaching 1.5 degrees Celsius of global warming over pre-industrial levels within the decade, according to a new study published in the online journal Nature Reviews Earth & Environment.
Due to the COVID-19 pandemic, carbon emissions dipped 11% in 2020, potentially buying the world time to transition to clean sources of energy. But in 2021, as economic activity rebounded, the emissions that cause climate change increased 4.8% from 2020.
“These 2021 emissions consumed 8.7% of the remaining carbon budget for limiting anthropogenic warming to 1.5 °C, which if current trajectories continue, might be used up in 9.5 years at 67% likelihood,” the report stated.
The carbon budget means the amount of carbon dioxide that can be emitted before reaching 1.5 degrees Celsius (2.7 degrees Fahrenheit) of warming over pre-industrial temperatures. The goal of limiting warming to 1.5 degrees Celsius has been set by the Intergovernmental Panel on Climate Change (IPCC), which has analyzed thousands of studies and found that warming beyond that threshold could set devastating events in motion, such as massive glacier melting that would flood cities and trigger even more warming since ice reflects solar radiation that would instead be absorbed by land and water.
To avoid that outcome, the IPCC has estimated that global greenhouse gas emissions must be cut by 45% by 2030 and reach net-zero by 2050. If current trends continue, the Nature study authors calculate that 1.5 degrees Celsius of warming will likely be reached in or before 2031.
Virtually every country in the world has signed on to global agreements, including the Paris climate agreement of 2015 and the Glasgow Climate Pact of 2021, pledging to make their best efforts to stay below 1.5 degrees Celsius of warming. Even the global scientific community’s fallback goal of 2 degrees Celsius (3.6 degrees Fahrenheit) of warming will probably be reached in 30 years, according to the Nature analysis.
The world’s biggest economies, which are the biggest contributors to climate change, drove the increase in emissions last year. Emissions increased by roughly 6% to 7% each in the United States, the European Union and the United Kingdom. Large middle-income countries, including China and Russia, also saw emissions jump, as did India, the largest developing country.
Among the worrisome trends for climate change, coal use surged in 2021, accounting for 40% of the increase in emissions, according to a recent report by the International Energy Agency (IEA). Transportation was the only economic sector for which emissions remained well below 2019 levels, but that was due to an overall decrease in driving due to the coronavirus pandemic rather than improved fuel efficiency. “The emissions reduction impact of record electric car sales in 2021 was canceled out by the parallel increase in sales of SUVs,” the IEA noted.
With its population of more than 1.4 billion and its rapid economic growth, China is particularly responsible for growing emissions. According to the IEA, “electricity demand in China jumped by 10% in 2021, adding the equivalent of the total demand of all of Africa.”
The news that catastrophic climate change is coming in less than 10 years unless governments enact a new set of policies may be greeted with skepticism by some American conservatives. In 2019, Rep. Alexandria Ocasio-Cortez, D-N.Y., said “The world is going to end in 12 years if we don’t address climate change.”
Republicans such as Sen. Rand Paul, R-Ky., responded with ridicule.
“No @AOC the world will not end in 12 years but we must, absolutely must do something, over the next 500 million years,” Paul chided in a tweet, referencing the estimated time when astronomers say the sun will burn about 10% brighter, causing temperatures to rise on Earth.