Global society may have finally slammed on the brakes for climate-warming pollution released by human fossil fuel combustion.
According to the Carbon Monitor Project, the total global climate pollution released between February and May 2024 declined slightly from the amount released during the same period in 2023. Many experts believe that the clean energy transition has reached the point where emissions will stabilize and then begin to decline. The critical milestone of peak climate pollution might be happening right now.
And it’s happening none too soon. The National Oceanic and Atmospheric Administration reported in early June that “carbon is accumulating in the atmosphere faster than ever — accelerating on a steep rise to levels far above any experienced in human existence.”
“Over the past year we’ve experienced the hottest year on record, the hottest ocean temperatures on record, and a seemingly endless string of heat waves, droughts, floods, wildfires, and storms,” said NOAA Administrator Rick Spinrad. “Now we are finding that atmospheric CO2 levels are increasing faster than ever. We must recognize that these are clear signals of the damage carbon dioxide pollution is doing to the climate system, and take rapid action to cut fossil fuel use as quickly as we can.”
How can CO2 levels in the atmosphere be increasing so rapidly if society is reaching peak emissions? It’s because the peak comes after two centuries in which more and more fossil fuels were burned every year to power economic growth. The relatively rare exceptions tended to come in years of economic decline, such as global recessions or pandemics. The global economy has grown in most years, and the consumption of fossil fuels for energy and their associated climate pollution has also increased as a result.
“Fossil fuel pollution just keeps building up, much like trash in a landfill,” Ralph Keeling, director of the Scripps CO2 program, said in the NOAA June 6 report.
Emissions have peaked at an unsustainably high level and now must fall steeply and quickly to reach net zero by the second half of the century. The clean energy transition has been a huge help; in most of the years over the past decade that weren’t affected by the COVID pandemic, including 2022 and 2023, global emissions only rose by about 1% even as the economy continued to grow. Yet global climate pollution stubbornly kept rising to record levels.
China and the U.S. must lead the way
As one of the world’s largest countries with a rapidly growing economy and continued expansion of coal power, China will play a key role in reducing carbon emissions. The U.S. presidential election in November will also play an outsized role. President Joe Biden is the only one of the two major party candidates who has a plan to reduce emissions. An analysis by Carbon Brief estimated that a victory by Donald Trump could add 4 billion tons of U.S. climate pollution — equal to the combined annual emissions of Europe and Japan.
Read: How Trump and Biden compare on climate change
According to the International Energy Agency, global energy-related carbon pollution in the rest of the world outside of China declined slightly in 2023. If the rest of the world can continue on that same trajectory, and if China can stabilize its climate pollution, then global emissions will peak.
As a November 2023 report from the climate science and policy institute Climate Analytics put it: “there is a 70% chance that emissions start falling in 2024 if current clean technology growth trends continue and some progress is made to cut non-CO2 emissions. This would make 2023 the year of peak emissions.”
Progress on clean technologies
To continue reducing pollution, the world would need to accelerate the rapid deployment of key clean technologies like solar panels, wind turbines, and electric vehicles, and slash levels of methane and other climate pollutants.
Clean technologies have thrived so far in 2024. According to an analysis by Lauri Myllyvirta, senior fellow at Asia Society Policy Institute and lead analyst at the Centre for Research on Energy and Clean Air, or CREA, rapidly expanding solar and wind generation covered 90% of the growth in electricity demand in China in March of this year. The numbers look even better for May. And EVs now account for about one out of every 10 vehicles on China’s roads.
“The clean energy sector in China has seen unparalleled growth,” wrote CREA China Policy Analyst Belinda Schäpe via email. “For the first time, the expansion rate of low-carbon energy sources is sufficient to exceed the average annual increase in China’s electricity demand. If this growth continues and energy demand stabilizes, following the unprecedented energy-intensive economic recovery, fossil fuel consumption could go down.”
According to Myllyvirta’s analysis, two other key factors are playing a role in the trajectory of Chinese climate pollution. The country lifted its severe ‘zero-COVID’ restrictions in December 2022, and the associated pollution rebound that occurred in 2023 appears to now have stabilized. And real estate construction activity in China has been contracting due to a glut of unsold homes and unfinished projects.
“Real estate investment has contracted for the third consecutive year, leading to an 11% drop in cement output and only a small increase of 2.9% in steel production between January and May 2024,” Schäpe noted. “The reduction in these industries has been partially offset by increased manufacturing activity, particularly in industrial machinery, some of which are producing renewable technology. However, the overall contraction in real estate has led to a significant decrease in emissions from industrial sectors, the second-largest contributor to China’s carbon emissions after the power sector.”
Whether Chinese climate pollution remains stable or rises again depends on whether the country’s rapid clean energy growth continues. According to Myllyvirta, the central government has set relatively unambitious solar and wind power targets compared to what Chinese clean energy industries expect to deploy in the coming years. But to meet its Paris climate commitments, China must continue rapid clean energy deployment. A Bloomberg New Energy Finance analysis concluded that China “could immediately peak emissions under an economics-led transition” in which the most cost-effective technologies are deployed because clean energy sources are so cheap.
The rest of the world
Other countries would also need to play their part. In Europe, as in the U.S., emissions have been declining largely due to the rapid deployment of clean electricity like solar and wind power, and heat pump installations have also begun to make a dent in the residential buildings sector. Europe also has been trying to eliminate reliance on Russian supplies of fossil gas, commonly called natural gas, since the war in Ukraine began.
Recent European Parliament elections did not send an encouraging signal for the climate. The European Green Party lost seats, while far-right parties made gains. Still, centrist parties will maintain majority control, so Europe’s relatively ambitious climate agenda should largely remain in place. Clean energy deployment around the world is already making a big difference in curbing climate pollution. The International Energy Agency estimated that without the accelerating deployment of five key clean energy technologies since 2019 — solar, wind, nuclear, heat pumps, and EVs — global emissions would have increased by 7.5% rather than the actual 2.5% rise over the past four years.
Achieving the peak emissions milestone would be the critical first step toward bending the curve downward to ultimately reach net zero emissions and stabilize Earth’s climate.
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