Global energy-related carbon dioxide emissions fell by 5.8% in 2020, primarily due to the impact of the COVID-19 pandemic on travel and economic activities, according to the International Energy Agency (IEA). However, after hitting a low in April, global emissions rebounded strongly and rose above 2019 levels in December.
"In absolute terms, the decline in emissions of almost 2 billion tonnes of CO2 is without precedent in human history - broadly speaking, this is the equivalent of removing all of the European Union's emissions from the global total," the IEA said.
Demand for fossil fuels was hardest hit in 2020 - especially oil, which fell by 8.6%, and coal, which dropped by 4%. Oil's annual decline was its largest ever, accounting for more than half of the drop in global emissions. Global emissions from oil use plummeted by more than 1.1 billion tonnes CO2, down from around 11.4 billion tonnes in 2019. The drop in road transport activity accounted for 50% of the decline in global oil demand, and the slump in the aviation sector for around 35%.
In the power sector, CO2 emissions declined by 3.3% (or 450 million tonnes) in 2020, the largest relative and absolute fall on record. While the pandemic reduced electricity demand last year, the accelerating expansion of power generation from renewables was the biggest contributor to lower emissions from the sector. The share of renewables in global electricity generation rose from 27% in 2019 to 29% in 2020.
The impact of the pandemic started to be felt in late February. By April, global emissions registered their largest monthly drop when a majority of advanced economies experienced various forms of restrictions on movement and travel. As the first wave of the pandemic was brought under control and economic activity increased towards the middle of the year, emissions increased. They continued to rebound through the rest of the year. In December 2020, global emissions were 2%, or 60 million tonnes, higher than they were in the same month a year earlier.
Major economies led the resurgence as a pick-up in economic activity pushed energy demand higher and significant policiy measures to boost clean energy were lacking, the IEA said. Many economies are now seeing emissions climbing above pre-crisis levels.
Call for policy changes
"For the world to achieve the climate goals of the Paris Agreement, notably of limiting global warming to well below 2°C, a decline in electricity sector emissions of around 500 million tonnes would need to occur every single year," according to the IEA. "Even greater annual drops in emissions from electricity generation would be required to put the world on a path in line with warming of 1.5°C."
"The rebound in global carbon emissions toward the end of last year is a stark warning that not enough is being done to accelerate clean energy transitions worldwide," said IEA Executive Director Fatih Birol. "If governments don't move quickly with the right energy policies, this could put at risk the world's historic opportunity to make 2019 the definitive peak in global emissions."
He added, "If current expectations for a global economic rebound this year are confirmed - and in the absence of major policy changes in the world's largest economies - global emissions are likely to increase in 2021.
"In March 2020, the IEA urged governments to put clean energy at the heart of their economic stimulus plans to ensure a sustainable recovery. But our numbers show we are returning to carbon-intensive business-as-usual. This year is pivotal for international climate action - and it began with high hopes - but these latest numbers are a sharp reminder of the immense challenge we face in rapidly transforming the global energy system."
In order to show a sustainable path forward, the IEA said it will publish on 18 May the world's first comprehensive roadmap for the energy sector to reach net-zero emissions by 2050.