Last Year Saw The Biggest Increase In CO2 Emissions Ever Recorded


Dr. Katie Spalding

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory.

Freelance Writer


More than one third of the increase came from one country. Image: humphery/Shutterstock

Remember this time last year, when we finally had some good news about the environment?

The pandemic, it turned out, had resulted in a drop in global carbon dioxide emissions of 7 percent compared to the previous year – and even more than that in high-income countries. At the peak of their decline, daily CO2 emissions had been as much as a quarter lower than expected, and some predicted that the world was about to see the biggest drop in emissions since World War II.


But by July, things were back to normal – a term which here means “hurtling towards climate catastrophe". And this year, the International Energy Agency (IEA) reported Tuesday, humanity has created the largest ever rise in carbon dioxide emissions in recorded history.

“The increase in global CO2 emissions of over 2 billion tonnes [2.2 billion tons] was the largest in history in absolute terms, more than offsetting the previous year’s pandemic-induced decline,” the agency said of its analysis.

As the world rebounded from the COVID-19 pandemic, carbon emissions rose to 36.3 billion tonnes [40 billion tons], their highest level on record. Add that to estimates of methane emissions and nitrous oxide and flaring-related CO2 emissions and the IEA analysis puts overall greenhouse gas emissions from energy at their highest ever level in 2021 also.

“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,” the IEA noted.


Chief among the countries responsible for this increase in CO2 emissions is China, whose economic growth and technological advances throughout the pandemic meant the biggest increase in demand for electricity ever seen in the country – a jump of 10 percent, or about 700 TWh. For comparison, it would take about one in every five Americans – or the entirety of Africa – suddenly switching to a hermit lifestyle to counteract the increase in China’s electricity use between 2019 and 2021.

Despite China’s renewables market also seeing its largest ever increase last year, the demand for power massively outstripped supply, and more than half of the new energy production ended up coming from coal, the IEA explained. Overall, China’s CO2 emissions rose above 11.9 billion tonnes [13.1 billion tons] in 2021 – easily more than one-third of the global total.

“Coal is the single largest source of global carbon emissions, and this year’s historically high level of coal power generation is a worrying sign of how far off track the world is in its efforts to put emissions into decline towards net zero,” said Fatih Birol, IEA Executive Director, in a statement regarding the increase in coal use at the end of last year.

“Without strong and immediate actions by governments to tackle coal emissions – in a way that is fair, affordable and secure for those affected – we will have little chance, if any at all, of limiting global warming to 1.5 C.”


There is good news, however. Although emissions from coal reached an all-time high of 15.3 billion tonnes [16.9 billion tons] in 2021 – over two-fifths of the overall annual rise – renewable energy sources and nuclear power actually provided a higher share of global electricity generation than coal in 2021, with renewable energy being the only fuel to increase demand throughout 2020. A record-high 8,000 TWh of power came from renewable energy sources last year, and while there’s still a ways to go if we want to reach net zero (or more), the renewables market is accelerating faster than ever before.

“Clean energy provisions in the recovery packages of several major economies have contributed somewhat to mitigating the near-term rebound in emissions, largely where low-carbon programmes were already in place and could channel the additional support quickly,” the IEA analysis notes.

“The world must now ensure that the global rebound in emissions in 2021 was a one-off – and that sustainable investments combined with the accelerated deployment of clean energy technologies will reduce CO2 emissions in 2022, keeping alive the possibility of reducing global CO2 emissions to net zero by 2050.”


  • tag
  • climate change,

  • nature,

  • environment,

  • fossil fuels