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Global carbon emissions need to shrink 10 times faster

Among the dozens of countries that reduced their emissions 2016-2019, carbon dioxide emissions fell at roughly one tenth the rate needed worldwide to hold global warming well below 2°C relative to preindustrial levels, a new study finds.

Aerial view of pollution rising from a coal fired power plant in Gansu Province
Investments postCOVID continue to be overwhelmingly dominated by fossil fuels in most countries. Image credit iStock

New research shows 64 countries cut their fossil CO2 emissions during 2016-2019, but the rate of reduction needs to increase tenfold to meet the Paris Agreement aims to tackle climate change.

Authored by researchers at the University of East Anglia, Stanford University and the Global Carbon Project, the study assesses progress in cutting fossil CO2 emissions since the Paris Agreement was adopted in 2015 and compares it what COVID-19 did to emissions in 2020. The results, published March 3 in Nature Climate Change, show a clear need for far greater ambition ahead of the UN climate summit in Glasgow in November 2021, known as COP26.

Carbon emission changes over time
Credit: Le Quéré et al. 2021, Nature Climate Change

In the 64 nations where emissions fell between 2016 and 2019, the average combined decrease was just 160 million metric tons of CO2 per year. At a global level, emissions reductions need to be roughly 10 times that amount, 1 to 2 billion tons each year, to hold global warming well below 2°C relative to preindustrial levels, the ambition of the Paris Agreement. Already, the world has warmed by more than 1°C since the Industrial Revolution because of emissions of greenhouse gases from human activities.

While emissions decreased in 64 countries, they increased in 150 countries. Globally, emissions grew by 240 million tons of CO2 per year during 2016-2019 compared to 2011-2015.

In 2020, confinement measures to tackle the COVID-19 pandemic cut global emissions by 2.6 billion tons of CO2, about 7 per cent below 2019 levels. The researchers say 2020 is a “pause button” that cannot realistically continue while the world overwhelmingly relies on fossil fuels. Confinement policies are neither a sustainable nor desirable solution to the climate crisis, they state.

“Countries’ efforts to cut CO2 emissions since the Paris Agreement are starting to pay off, but actions are not large-scale enough yet and emissions are still increasing in way too many countries,” said lead author Corinne Le Quéré, Royal Society Professor at UEA’s School of Environmental Sciences, led the analysis.

“The drop in CO2 emissions from responses to COVID-19 highlights the scale of actions and of international adherence needed to tackle climate change,” she said. “Now we need large-scale actions that are good for human health and good for the planet. It is in everyone’s best interests to build back better to speed the urgent transition to clean energy.”

Of the 36 high-income countries, 25 saw their emissions decrease during 2016-2019 compared to 2011-2015, including the United States (mean annual decrease of -0.7 per cent), the European Union (-0.9 per cent), and the United Kingdom (-3.6 per cent). Emissions decreased even when accounting for the carbon footprint of imported goods produced in other countries.

Thirty of 99 upper-middle income countries also saw their emissions decrease during 2016–2019 compared to 2011–2015, suggesting that actions to reduce emissions are now in motion in many countries worldwide. Mexico (-1.3 per cent) is a notable example in that group, while China’s emissions increased 0.4 per cent, much less than the 6.2 percent annual growth of 2011-2015.

Carbon emissions from 2019 levels for lower, upper-middle and high income countries
Credit: Le Quéré et al. 2021, Nature Climate Change

The growing number of climate change laws and policies appear to have played a key role in curbing the growth in emissions during 2016-2019. There are now more than 2000 climate laws and policies worldwide.

A full bounce-back in 2021 to previous CO2 emission levels appears unlikely.

However, the authors say unless the COVID-19 recovery directs investments in clean energy and the green economy, emissions will likely start increasing again within a few years. The nature of the disruption in 2020, particularly affecting road transport, means incentives to expedite the large-scale deployment of electric vehicles and encourage walking and cycling in cities are timely and would also improve public health. The resilience of renewable energy throughout the crisis, falling costs, and air quality benefits, are additional incentives to support their large-scale deployment.

Investments post-COVID continue to be overwhelmingly dominated by fossil fuels in most countries, in contradiction with climate commitments, including in the U.S. and China. The European Union, Denmark, France, the United Kingdom, Germany and Switzerland are among the few countries that have so far implemented substantial green stimulus packages with limited investments in fossil-based activities.

“The growing commitments by countries to reach net zero emissions within decades strengthens the climate ambition needed at COP26 in Glasgow. Greater ambition is now backed by leaders of the three biggest emitters: China, the United States, and the European Commission,” said co-author Rob Jackson, a professor of Earth system science at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth).

“Commitments alone aren’t enough. Countries need to align post-COVID incentives with climate targets this decade, based on sound science and credible implementation plans,” Jackson said.

Le Quéré added, “This pressing timeline is constantly underscored by the rapid unfolding of extreme climate impacts worldwide.”

Jackson is Stanford’s Michelle and Kevin Douglas Provostial Professor and a senior fellow at Stanford’s Woods Institute for the Environment and Precourt Institute for Energy. Additional coauthors are affiliated with CICERO Center for International Climate Research, Sorbonne Université, CSIRO Oceans and Atmosphere and University of California, Irvine.

This research was supported by the Royal Society, European Commission Horizon 2020 and the Australian National Environmental Science Programme-Earth Systems and Climate Change Hub.

This story was adapted from a press release issued by the University of East Anglia.

Media Contacts

UEA Communications Office
University of East Anglia; +44(0)1603 593496

Rob Jackson
Department of Earth System Science

Josie Garthwaite
School of Earth, Energy & Environmental Sciences

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