Global Carbon Emissions in 2021 Were the Highest in History

And so much for hitting the reductions that needed to stay below 1.5 degrees Celsius.

Coal plant in Baotou, China
A coal plant in Baotou, China.

Ryan Pyle/Corbis / Getty Images

Almost exactly a year ago we noted the pandemic had reduced carbon dioxide (CO2) emissions significantly and asked: Can we keep them down? According to the latest information from the International Energy Agency (IEA), the answer is a resounding no.

In fact, the news could hardly be worse. After a 5.2% reduction in emissions during the first year of the pandemic, emissions increased by 6% to 36.3 billion metric tons in 2021. According to the IEA:

"The increase in global CO2 emissions of over 2 billion tonnes was the largest in history in absolute terms, more than offsetting the previous year’s pandemic-induced decline, the IEA analysis shows. The recovery of energy demand in 2021 was compounded by adverse weather and energy market conditions – notably the spikes in natural gas prices – which led to more coal being burned despite renewable power generation registering its largest ever growth."  

Much of that coal was burned in China in its economic rebound, where electricity demand grew by 10%. But a lot of it also came from a switch from gas to coal, as gas prices went through the roof.

The 2021 red bar going up is bigger than the 2020 bar going down
The 2021 red bar going up is bigger than the 2020 bar going down.


The increase of 6% is also just about exactly the same as the increase in global economic output of 5.9%, proving once again that Vaclav Smil is right—that "every economic activity is fundamentally nothing but a conversion of one kind of energy to another, and monies are just a convenient (and often rather unrepresentative) proxy for valuing the energy flows." Or, as economist Robert Ayres noted, the economy is by definition energy consumption: “The economic system is essentially a system for extracting, processing and transforming energy as resources into energy embodied in products and services.”

So much for all of our talk of delinking and decoupling our economic growth from fossil fuels, or for building back better. Instead, we find the economy and carbon emissions marching in lockstep. It would have been even worse if air transport wasn't still at 60% of pre-pandemic levels and truck transport wasn't reduced by lockdowns. And of course, the IEA points out: "The emissions reduction impact of record electric car sales in 2021 was canceled out by the parallel increase in sales of SUVs."

The only good news in this report is renewables grew to an all-time high of over 8,000 terawatt-hours. Wind and solar were way up, and even nuclear grew by 100 terawatt-hours. Hydropower was down, due to drought in the U.S. and Brazil. The IEA also sees a bit of sunshine in the fact that while the global economy rebounded to pre-pandemic levels in 2021:

"CO2 emissions rebounded less sharply, signalling a more permanent trajectory of structural decline. CO2 emissions in the United States in 2021 were 4% below their 2019 level. In the European Union, they were 2.4% lower. In Japan, emissions dropped by 3.7% in 2020 and rebounded by less than 1% in 2021. Across advanced economies overall, structural changes such as increased uptake of renewables, electrification and energy efficiency improvements avoided an additional 100 Mt of CO2 emissions in 2021 compared with 2020."
Energy related greenhouse gas emissions, 2000-2021


But that wasn't enough to make a difference. Carbon intensity might be a bit better, but overall, emissions just popped right back.

Back in March of 2020, IEA Executive Director Fatih Birol suggested there might be an opportunity in the Covid crisis. "Rather than compounding the tragedy by allowing it to hinder clean energy transitions, we need to seize the opportunity to help accelerate them," said Birol.

In March of 2021, we all saw what happens when people stop consuming so much and stay home: We got an unprecedented reduction in CO2 emissions, just about what we needed to do every year from now on to have a prayer of keeping average global heating below 1.5 degrees Celsius (2.7 degrees Fahrenheit).

Now, in March of 2022, we see that we are right back to where we were before. I suspect that when we see the numbers a year from now, with gas supplies disrupted by Russia's war and everyone shoveling coal as fast as they can, we will have likely blown 1.5 degrees C, we may have blown 2, and we will be praying for 3. Wars run on fossil fuels.

The IEA says: "The world must now ensure that the global rebound in emissions in 2021 was a one-off – and that an accelerated energy transition contributes to global energy security and lower energy prices for consumers." Good luck with that this year.

View Article Sources
  1. "Global Energy Review: CO2 Emissions in 2021." International Energy Agency, Flagship Report. March 2022.

  2. "Global CO2 emissions rebounded to their highest level in history in 2021." International Energy Agency, 8 March 2022.

  3. Birol, Dr. Fatih, "Put clean energy at the heart of stimulus plans to counter the coronavirus crisis." International Energy Agency. 14 March 2020.