Evidence of the slowing momentum of China's domestic economy since December 2024 continued mounting in September 2026. It did so in the form of the continuing decline in the pace of carbon dioxide accumulation in the Earth's atmosphere. That pace has dropped to levels consistent with where large recessions have bottomed during the 21st century.

Much of that decline is an outgrowth of a debt crisis, in which the Chinese government's previous efforts to stimulate the nation's economy to stave off recessions with its debt-fueled investments has left its domestic economy with the overhang of overproduction. China's internal property market directly reflects that outcome, which has become a deflationary drag on both the housing and banking sectors of its economy as production has stalled. That decline has shown up in the atmosphere in the form of reduced carbon dioxide emissions from the nation's cement production and also its production of steel.

Meanwhile, China's export-oriented industries have also taken a major hit from the global tariff war between the U.S. and China. Chinese exporters have sought to get around the loss of U.S. business by cranking up their exports to other regions like the European Union, but that effort has created an economic backlash which is leading to new curbs on its automotive exports. Falling industrial production to support its export economy from tariffs and other trade restrictions is also contributing to falling CO₂ emissions.

The following chart shows the still continuing downward trend in the rate at which carbon dioxide accumulates in the Earth's air:

The decline in the pace of carbon dioxide accumulation in the atmosphere has slowed in recent months, which might be attributed to increasing emissions from other parts of the global economy that are growing. Even so, China remains the world's largest producer of carbon dioxide emissions by a very wide margin. Because of that fact, changes in atmospheric CO₂ concentration tells us much more about the relative health of China's economy than that of any other nation.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 September 2026.

Image Credit: OCO-3 Carbon Source-Sink Infographic by NASA. U.S. Government work public domain image.

The pace at which carbon dioxide accumulates in the Earth's atmosphere has been falling since peaking in January 2025. New data on the changing concentration of CO₂ in the air however suggests that long trend may be ending.

The decline since the January 2025 peak has largely coincided with the negative impact of the U.S.-China tariff war, which has contributed to the slowing of China's economy in the period since. Because China is, by far and away, the world's largest source of carbon dioxide emissions, changes in those emissions can provide a window in the relative health of its economy.

In August 2026, data reported by the remote Mauna Loa Observatory indicates the downward trend in the accumulation rate of CO₂ in the Earth's air has begun to slow. This new data points to a positive change in momentum for China's economy that follows an increase in trade between the U.S. and China, which we've observed in the form of an increase in goods exported from China to the U.S. since April 2026. The combination of this increase in trade with the positive change in momentum for CO₂ emissions indicates China's economic output is picking up.

The following chart shows the downward trend in the pace of carbon dioxide accumulation in the atmosphere is decelerating.

The deceleration in the downward trend is taking place near the levels where reversals in downward economic momentum have been observed during the last twenty years.

On a final note, our featured secondary (inset) chart is taken from the United Nations Environmental Programme's 2025 Emissions Gap Report. We're featuring it because the upper chart shows China's very much larger than every other nation's emissions of greenhouse gases, which is predominantly made up of carbon dioxide emissions.

But there's a surprise in the lower chart of the figure: the U.S. no longer holds the top rank for per capita greenhouse gas (GHG) emissions! The UN's data suggests the Russian Federation's per capita GHG emissions have overtaken the U.S. for the top spot.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 September 2026.

United Nations Environment Programme (2025). Emissions Gap Report 2025: Off target – Continued collective inaction puts global temperature goal at risk [Olhoff, A., chief editor; Lamb, W.; Kuramochi, T.; Rogelj, J.; den Elzen, M.; Christensen, J.; Fransen, T.; Pathak, M.; Tong, D. (eds)]. Nairobi. [PDF Document]. DOI: 10.59117/20.500.11822/48854.

Measuring economic activity using astronomical and other scientific tools is a relatively recent development that has come into its own during the 21st century.

One of the neater tools are telescopes and cameras mounted on Earth-orbiting satellites that take pictures of the night-darkened surfaces of the world. NASA's Black Marble project uses those images to tracks how the nighttime lights spread across entire regions change in brightness over time, with fully processed imagery now covering the years from 2014 through 2022.

We haven't gotten too far into the data behind the images yet, but what we see in how nighttime lights have changed the years between 2014 and 2022 appears to correspond with how carbon dioxide emissions have changed in those regions. Nighttime lights in Asia, and especially in China and India have become significantly brighter during a period in which those nation's emissions of carbon dioxide have risen. By contrast, regions that have seen falling levels of CO₂ emissions such as the eastern portion of the U.S. and western Europe have seen the brightness of their nighttime lights grow dimmer.

That introduction brings us to the latest measurements of the concentration of carbon dioxide in the Earth's atmosphere, which is measured at the remote Mauna Loa Observatory. The latest data indicates the pace at which carbon dioxide is being emitted into the Earth's atmosphere is continuing to decline, which indicates the world's economic activity is falling.

The following chart reveals how the trailing twelve month average of the year-over-year change in the rate at which the concentration of carbon dioxide in the Earth's air is changing has changed from January 2000 through July 2026.

The rate at which CO₂ is increasing in the atmosphere is nearing levels where it has bottomed during periods of global recessions, or rather, significant regional recessions, in the 21st century.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 August 2026.

Image credit: Eastern Hemisphere Map: Total Radiance Change from 2014 through 2022, NASA Earth Observatory images by Michala Garrison, using data from Li, T., et al. (2026). Public Domain.

The Global Carbon Budget offers a wealth of data on carbon dioxide emissions. That includes estimates of how CO₂ each nation has emitted into the Earth's atmosphere in each year since 1850. The latest edition of the report covers emissions from that year through 2024.

But that's not the whole story for atmospheric carbon dioxide emissions. When carbon dioxide is emitted into the air, it enters into the planet's carbon cycle, which extracts a portion of the emitted carbon dioxide from the air. These natural processes then play out slowly over decades, centuries, and millennia.

It's possible to estimate how much of a given year's emissions still remain in the Earth's air.

The following chart reveals both the total historic emissions of carbon dioxide and the portion of those emissions that is still present in the air from the modern day territories of the United Kingdom, India, the European Union, China, the United States, and the combined rest of the world for emissions produced in the years from 1850 through 2024.

Here are the percentages to indicate the portion of each territory's total historic emissions from 1850 through 2024 that remain in the Earth's atmosphere:

• United Kingdom: 49.3%
• India: 78.6%
• European Union: 55.7%
• China: 78.5%
• United States: 57.8%
• Rest of the World: 66.4%

The following treemap chart visualizes each territory's share of the amount of excess carbon dioxide (defined as that coming from fossil fuel combustion in the years from 1850 through 2024) that is still in the air today:

In the three years from 2021 to 2024, China's share has risen from 17.3% to 18.5%, while the United States' share has declined from 22.3% to 21.4%. With those opposing trends, we project China's emissions that remain in the air will surpass those of the United States in 2031, the timing of which is unchanged from what we projected three years ago.

References

Friedlingstein et al. Global Carbon Budget 2025, Earth System Science Data, 13 May 2026. DOI: 10.5194/essd-18-3211-2026.

Political Calculations. How Long Does Carbon Dioxide Stay in the Atmosphere? [Online Article, Tool]. 19 July 2023.

Political Calculations. How Much Fossil Fuel CO2 Is in the Air? [Online Article]. 15 August 2023.

Political Calculations. Who Made the Excess Carbon Dioxide in Today's Air?. [Online Article]. 29 September 2023.

Image credit: Carbon Cycle by NASA on Wikimedia Commons Public Domain CC0 1.0 Universal Deed.

The rate at which carbon dioxide emissions accumulate in the Earth's air fell in June 2026. This measure of human economic activity is now at levels last seen near the bottom of the coronavirus pandemic.

Because China is the world's leading producer of carbon dioxide emissions by a wide margin, the changing concentration of CO₂ in the atmosphere is really telling us quite a bit about the relative health of China's economy. The falling pace of CO₂ accumulation communicates that China's productive economy is operating well below its potential.

That conclusion is supported by media reports that indicate China is experiencing its lowest economic growth since 2022. The slowing of China's economy has been visible in the trailing year average of the year-over-year change in atmospheric CO₂ concentration levels since they last peaked in January 2025.

The following chart shows how this measure has changed from January 2000 through June 2026, which allows us to compare the current decline with those recorded during the COVID era and other global economic downturns:

Getting back to the scale of China's carbon dioxide emissions, in 2024, China produced 31.8% of the world's total CO₂ emissions. By comparison, the United States produced 12.7% to rank second among nations.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 July 2026.

Image Credit: Smokestack emissions from a factory in Harbin, China photo by Ziang Guo on Unsplash.

The pace at which human carbon dioxide emissions are accumulating in the Earth's air fell in May 2026, continuing a long downward trend that began in January 2025. The trailing 12-month average of the year-over-year change in atmospheric CO₂ concentration was 2.22 parts per million.

That's a reduction of 1.36 parts per million, or about 38%, from the modern-era record of 3.57 parts per million recorded in December 2024. The change coincided with a sharp slowdown in China's economic output following boosted production aimed at beating expanded tariffs and trade restrictions on the nation's exports. In recent months, newer geopolitical events like the Iran war and its disruption of oil shipping through the Hormuz Strait has also contributed to the decline.

The main impact of Iran war's disruption of oil shipping has increased pressures on nations whose supply of oil originates from Iran and other nations in the affected region. For China, much of that impact has been mitigated by tapping the nation's strategic oil reserves and shifting to alternative energy production methods to offset it. China's lowered economic output from the global tariff war has also reduced its demand for energy.

Similar factors have affected other nations whose oil supplies have been disrupted by the geopolitical event, though their CO₂ emissions are considerably smaller than those of China.

The slowdown is evident in atmospheric carbon dioxide concentration data because China is, by a very wide margin, the world's leading producer of carbon dioxide emissions. The following chart shows how this measure has changed from January 2000 through May 2026:

The following tool gives an estimate of how much economic activity in worldwide (and predominantly in China) has declined since December 2024. If you're accessing this article on a site that republishes our RSS news feed, please click through to our site to access a working version.

The tool's estimates are based on Jenny Cederborg's and Sara Snöbohm's 2016 paper. In their research, they investigated whether there is a relationship between economic growth and carbon dioxide emissions and identified a positive correlation between CO₂ emissions and GDP per capita. They found "CO₂ emissions increase by approximately 0.0002 [metric] tons (0.2 kg) per capita when GDP per capita increase by 1 dollar, holding all other variables constant".

That relationship doesn't take the effects of inflation into account, so the tool's results based upon it are likely understating the real reduction in global GDP associated with the reduced economic activity indicated by the reduction in CO₂ emissions.

That said, global GDP for 2024 is estimated to be around $110 trillion, which means the indicated global GDP reduction of $45.2 trillion since December 2024 is substantial.

Update 12 June 2026

Late breaking headline on global GDP growth: "World Bank cuts global growth outlook to 2.5%, warns of drop to 1.3% if war fallout spreads to markets".

If only there was some indicator to see how the Earth's economy is doing in near-real time!

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 June 2026.

Cederborg, Jenny and Snöbohm, Sara. Is there a relationship between economic growth and carbon dioxide emissions? Semantic Scholar. [PDF Document]. 2016.

Image credit: Stable Diffusion DreamStudio Beta. Prompt: "Digital art concept of carbon dioxide emissions being used to measure economic growth."

How has the Iran war geopolitical conflict affected how much carbon dioxide is being added to the Earth's air?

Thanks to its unique timing, atmospheric carbon dioxide concentration data collected by the remote Mauna Loa Observatory may provide a unique, almost real-time window into how a large-scale military and economic conflict can affect the environment.

What makes the timing unique is the conflict's major military actions began on 28 February 2026. That gives us the potential of a clear break in the monthly atmospheric CO₂ data, with a well defined before and after.

What makes that possible is the disruption of oil and gas shipments from the energy resource-rich nations of the region, which before the conflict, accounted for about 20% of the world's oil supply. The bulk of these oil shipments are bound for the nations of south and east Asia. Or would be, if the oil tankers carrying the supply were not at high risk of being attacked by Iranian drones, while Iran's own oil shipments are blocked by a naval blockade.

That much oil and gas powers a large share of the advanced economies that rely on the supply from this region. If those shipments stop, that's a lot of economic activity that can be shut down unless the supplies can be offset through strategic reserves or alternate sources. That reduced activity would reduce the net amount of CO₂ these economies emit into the Earth's atmosphere.

This assumes any fires resulting from military actions or from the increased flaring of excess gas production that cannot be captured and shipped to other countries because of the geopolitical event's disruption of shipping produce substantially less CO₂ emissions than these more productive activities.

With these assumptions, what we would look for in the data for the months after February 2026 is a reduction in the rate at which carbon dioxide accumulates in the Earth's atmosphere. Given the time it takes for carbon dioxide emissions to diffuse into the air from the affected economies and reach the remote Mauna Loa Observatory where it is measured, that reduction should start very slowly before falling off more sharply as the disruption continues.

At least that's our working hypothesis. Since the NOAA just got around to publishing the monthly CO₂ data measured at the Mauna Loa Observatory for both March and April 2026 last week, we can look to see how much of an effect there may be already in the two months since the conflict began. The following chart shows the data for the trailing year average of the year-over-year change in atmospheric CO₂ concentration from January 2000 through April 2026:

What we see is that since December 2024, the rate at which carbon dioxide is being added to the Earth's air has been falling, with the rate affected by developments in global trade.

At least, up through February 2026, which has been generally falling at a steady rate. After February 2026, there are indications the pace at which CO₂ is emitted into the atmosphere has started declining at a faster pace. But that's based on a sample size of two months. We'll need more months of data to sort out the Iran war's impact, but at these early days, it appears to be following our hypothesis.

When we get that data and compare it against where the established trend for the data, we'll be able to put a dollar value on its impact to the world's GDP and compare it with other geopolitical events.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. 5 May 2026. Accessed 8 May 2026.

Image credit: Tankers at the Iraqi Al Basra Oil Terminal in the Northern Arabian Gulf photo by Samuel W. Shavers on Wikimedia Commons. Public domain image.

Quite a lot has happened since the last time we looked at now the pace at which carbon dioxide is accumulating in the Earth's air is changing.

The reporting of atmospheric CO₂ concentration data collected at the remote Mauna Loa Observatory has been delayed, not just because of the Senate Democrats' government shutdown fiasco, but also because of staff changes at the National Oceanic and Atmospheric Administration. The latest data that the NOAA used to routinely publish on or shortly after the fifth of each month hasn't been available on that schedule. At this writing, the CO₂ data is only available through February 2026.

That's okay this time around because it lets us present a timely snapshot of what the trend for that data was before the geopolitical event of the Iran War took place. The Iran War didn't begin until 28 February 2026, which means whatever disruptive impact it has had on oil and gas production, shipping, and consumption isn't yet included in the dataset.

The following chart shows how the rate at which carbon dioxide has been changing in the Earth's atmosphere from January 2000 through February 2026:

Atmospheric carbon dioxide concentration data lags behind changes in CO₂ output from human activities, taking several weeks to diffuse into the Earth's air after being emitted. For example, the peak in January 2025 coincides with Chinese emissions peaking in December 2024, which itself coincides with efforts by China's exporters to crank up production to beat the clock on new U.S. trade tariffs going into effect in 2025. January 2025 saw the Biden administration final tariff increases go into effect, while President Trump's new tariffs were put into effect in April 2025. Not uncoincidentally, there's a short spike upward in May 2025 that would correspond with a surge by producers in China to beat the clock on April 2025's tariffs.

Since the atmosphere's pace of CO₂ accumulation peaked at 3.57 ppm in January 2025, it has fallen by a full 1.00 ppm to 2.57 ppm through February 2026. With an estimated world population of 8.005 billion people, that drop represents roughly a reduction of 7.8 billion metric tonnes of carbon dioxide emissions. It also represents an estimated $33.23 trillion decline in the world's GDP in the last 13 months.

China's reduced output of carbon dioxide emissions, primarily stemming from its involuntarily reduced industrial output, represents a large share of that overall decline. If not for the impact of the global tariff war, it is highly unlikely a decline of this magnitude would have occurred in the absence of a major global recession.

Or perhaps a highly disruptive geopolitical event, like the Iran War, which has an outsized scope. Our next few snapshots will give a measure of just how disruptive the Iran War has been for the Earth's economy.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Data as of 5 March 2026.

Image Credit: CO2 Skywriting photo by Matthias Heyde on Unsplash.

China's economy is being slammed by the global tariff war.

Here is a sampling of recent headlines from the last month indicating China's economy is facing strong headwinds:

• China factory activity stumbles as export orders dry up
• China's exports suffer worst downturn since February
• Weak Data Raises Concerns for China's Economy
• China steel output slumps as iron ore imports head for record
• China manufacturing is slumping despite boost from US trade truce
• China's services growth slips to five-month low in November
• China's Trade Surplus Hits Record $1tn Despite Trump's Tariff
• Beijing Data Blackout Raising Alarm Bells About China's Economy

If you just went by these headlines, you might think that China's economy is merely slowing. Worse, you might think China's government is able to fully hide how its economy is performaing. But it's not just these reports that reveal the state of China's economy.

Because China is, by a very wide margin, the world's biggest producer of carbon dioxide emissions, the rate at which CO₂ accumulates in the Earth's atmosphere provides direct evidence of the relative health of the nation's economy. Data collected at the remote Mauna Loa Observatory indicates the trailing twelve month average rate at which carbon dioxide accumulates in the Earth's atmosphere is rapidly falling, from which we can infer economic growth is having trouble getting traction within the country.

The following chart shows how this measure has evolved from January 2000 through November 2025:

Atmospheric carbon dioxide concentration data lags behind changes in CO₂ output, taking several weeks to diffuse into the Earth's air after being emitted. The peak in January 2025 coincides with Chinese emissions peaking in December 2024, which itself coincides with efforts by China's exporters to crank up production to beat the clock on new U.S. trade tariffs going into effect in 2025. January 2025 saw the Biden administration final tariff increases go into effect, while President Trump's new tariffs were put into effect in April 2025. Not uncoincidentally, there's a short spike upward in May 2025 that would correspond with a surge by producers in China to beat the clock on April 2025's tariffs.

Since the atmosphere's pace of CO₂ accumulation peaked at 3.57 ppm in January 2025, it has fallen by 0.71 ppm to 2.87 ppm through November 2025. With an estimated world population of 8.005 billion people, that drop represents roughly a reduction of 5.5 billion metric tonnes of carbon dioxide emissions. It also represents an estimated $23.6 trillion decline in the world's GDP during the last ten months.

China's reduced output of carbon dioxide emissions, primarily stemming from its involuntarily reduced industrial output, represents a large share of that overall decline. If not for the impact of the global tariff war, which still threatens to hit China's industrial economy with even more tariffs, it is highly unlikely a decline of this magnitude would have occurred in the absence of a major global recession.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 December 2025.

Image credit: Plant with two smokestacks with one emitting flue gases on PxHere.com. Creative Commons Creative Commons - CC0 Public Domain.

Whenever you hear about historic carbon emissions by nations in the media, there's usually a huge omission in the information being transmitted. You'll often hear about the total CO₂ emissions that nations have emitted throughout history, but not necessarily how much of those emissions are still in the air.

That matters because carbon dioxide in the atmosphere is part of a global carbon cycle. One that begins reducing the emissions generated in any particular year from the very outset from when they were emitted. The following diagram illustrates major parts of the modern Earth's carbon cycle.

Not shown in the image are other natural sources of carbon dioxide emissions, like volcanoes, and natural sinks that absorb carbon dioxide out of the atmosphere, like oceans.

We've updated our estimate of how much CO₂ emissions produced within the modern world's largest national producers of carbon dioxide emissions since 1850 are still in the air. The following chart updates that data through the end of 2023.

This chart illustrates both total historic emissions and the amount estimated to still be in the atmosphere today, which is the more meaningful value with respect to the modern political debates over climate change.

The chart shows the largest share for any single nation is that for the United States, to which a little over one-fifth of the CO₂ is attributed, where our estimate using this data through 2023 is 21.8%, about a half percent lower than our estimate from two years ago.

China still ranks second by that measure at over 18.1% of the global total, and the combined nations of the European Union come in third at 14.5%. We also find India's 4.1% share outranks the United Kingdom's 3.3%, which is remarkable because the U.K. was once the world's largest producer of carbon dioxide emissions. The "Rest of the World" combines for nearly two-fifth's of the excess fossil-fuel based carbon dioxide emissions present in the atmosphere as of 2023, which exceeds the United States' total historic CO₂ emissions.

These relative shares have changed over time, with China and India's relative contributions to global CO₂ emissions increasing as the relative share of emissions of the United Kingdom, United States, and European Union have declined.

Looking forward, assuming no change in national carbon dioxide emissions from their 2023 levels, we estimate China will become the largest national historical contributor of human-generated carbon dioxide emissions still in the Earth's air in 2030.

References

Friedlingstein et al. National Fossil CO2 Emissions by Country (Territorial). 2024 v1.0. [Excel Spreadsheet]. 13 November 2024.

Political Calculations. How Long Does Carbon Dioxide Stay in the Atmosphere? [Online Article, Tool]. 19 July 2023.

Image credit: An Interactive Introduction to Organismal and Molecular Biology, 2nd ed. Copyright © 2021 by Andrea M.-K. Bierema is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

China is, by a very wide margin, the world's biggest producer of carbon dioxide emissions.

China's emissions of CO₂ are so large that we can use measurements of the concentration of carbon dioxide in the atmosphere collected by the remote Mauna Loa Observatory to get a relatively good sense of how its economy is performing. The reason we can do that is because China's production of materials like steel and cement, which are major contributors to its CO₂ emissions, are directly linked to its growth. Not uncoincidentally, China is the world's largest producer of both materials, with much of its production supporting the construction and industrial sectors of its economy. The following video we found to illustrate this article shows both coming together in a Chinese factory that produces prefabricated reinforced concrete panels for buildings.

In July 2025, the rate at which carbon dioxide is accumulating in the Earth's atmosphere slowed for the fifth time in the last six months. Measured as the trailing year average of the year-over-year rate of change in the atmospheric concentration of CO₂, this measure peaked in January 2025. Since then, it has fallen by nearly 11%, reversing what had been an period of increase dating back to the end of China's zero-Covid lockdowns at the end of December 2022.

The following chart shows how this measure has evolved from January 2000 through July 2025:

Atmospheric carbon dioxide concentration data lags behind changes in CO₂ output, taking several weeks to diffuse into the Earth's air after being emitted. The peak in January 2025 coincides with Chinese emissions peaking in December 2024, which itself coincides with efforts by China's exporters to crank up production to beat the clock on new U.S. trade tariffs going into effect in 2025. January 2025 saw the Biden administration final tariff increases go into effect, while President Trump's new tariffs were put into effect in April 2025.

Since the atmosphere's pace of CO₂ accumulation peaked at 3.57 ppm in January 2025, it has fallen by 0.38 ppm to 3.19 ppm in July 2025. With an estimate world population of 8.005 billion people, that drop represents roughly a reduction of 3 billion metric tonnes of carbon dioxide emissions. It also represents an estimated $12.6 trillion decline in the world's GDP during the last six months.

The decline in China's CO₂ emissions have been large enough that scientists are speculating it may represent a permanent peak in the country's emissions, with China's expansion of renewable energy sources like solar and hydroelectric power. While that remains to be seen, for now, this observation tells us that the portions of China's economy that are the heaviest users of the reliable power production supported by burning fossil fuels are struggling. Those sectors are, not uncoincidentally, the ones that produce steel and cement, whose production has been falling because China's economy is struggling. As described by the Centre for Research on Energy and Clean Air: "The steel and cement industries are the largest CO2 emitters in China, when emissions from their electricity use are included. They are also bellwethers of real estate, infrastructure and other fixed asset investments that play an outsized role in China's emissions and economy."

Research at the Mauna Loa Observatory has been targeted for potential funding cuts. We suggest that funding should continue because of the value of the CO₂ data it collects which is correlated with economic output, especially China's. Given that China's economic data is becoming more opaque over time and how large its CO₂ emissions are, U.S. intelligence services may find it useful to continue funding the observatory's measurements of carbon dioxide because of the practical application of what that data can tell us about the state of China's economy.

Or for that matter, assessing the magnitude of other geopolitical events.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 August 2025.

The rate at which carbon dioxide is accumulating in the Earth's atmosphere slowed in June 2025, reversing a brief uptick in the previous month's data. The change resumes a downward trend that has been in place since the end of 2024.

This period coincides with slowed output within China's economy. Much of this negative change occurred in response to new and expanded tariffs and trade sanctions imposed by the United States. 2024 had seen elevated carbon dioxide emissions arise out of China as the nation's factories rushed to meet orders for goods to beat the clock on the outgoing Biden administration's final trade restrictions and expanding tariffs expected to take effect in January 2025.

In April 2025, the Trump administration rolled out its global tariff program, which continued the downward pressure on China's industrial sector. Reuters describes several of the factors contributing to the nation's reduction in CO₂ emissions:

The latest tariffs imposed by U.S. president Donald Trump on Chinese products have impacted the demand for China-made goods and caused production lines to slow down across a variety of manufactured items.

The overall energy needs of these industries have been reduced by the slower pace on construction sites and production lines in factories. This has allowed power generation companies to reduce their production.

These dynamics have shown up in the pace at which carbon dioxide accumulates in the Earth's atmosphere because China is, by far and away, the world's largest producer of CO₂ emissions. The following chart shows how the trailing twelve month average of the year-over-year change in the concentration of atmospheric carbon dioxide measured at the remote Mauna Loa Observatory has evolved from January 2000 through June 2025:

Because the industrial sector of China's economy has slowed so much since the end of 2024, the reduction of demand for electrical power is expected to reduce China's CO₂ emissions to a "record low". Here's Reuters again:

China's utilities have been able to achieve record-low emissions in the first half of 2025 by focusing on clean energy supplies.

According to the energy portal, electricitymaps.com, carbon dioxide emissions per Kilowatt Hour (kWh) of Electricity averaged 492 Grams during the first half of 2025.

This was the first time a reading under 500 grams per kWh had been recorded. It is also down from 514g/kWh in the same period of 2024, and 539g/kWh between January and June 2023.

With a large portion of its industries running at reduced capacity, China has been able to use a larger share of its renewable energy sources to provide power, reducing its CO₂ emissions by significant amount. Reuters indicates however that an improvement in fortune for China's industrial sector will reverse that achievement:

China's power requirements will rise if the manufacturing and construction sectors recover. This will lead to a return of fossil fuels that emit pollution.

If China's economy is still slowed by the construction debt and the tariff concerns, then the use of fossil fuels could be further reduced, which would lead to further emissions reductions from the power sector.

Carbon dioxide is not the only kind of emission that is being reduced. The reduction of China's economic output during 2020's Coronavirus Pandemic also reduced emissions of aerosols, which a new study indicates contributed to an acceleration of global warming. Here's the abstract from the recently published paper:

Global surface warming has accelerated since around 2010, relative to the preceding half century¹–³. This has coincided with East Asian efforts to reduce air pollution through restricted atmospheric aerosol and precursor emissions₄–₅. A direct link between the two has, however, not yet been established. Here we show, using a large set of simulations from eight Earth System Models, how a time-evolving 75% reduction in East Asian sulfate emissions partially unmasks greenhouse gas-driven warming and influences the spatial pattern of surface temperature change. We find a rapidly evolving global, annual mean warming of 0.07 ± 0.05 °C, sufficient to be a main driver of the uptick in global warming rate since 2010. We also find North-Pacific warming and a top-of-atmosphere radiative imbalance that are qualitatively consistent with recent observations. East Asian aerosol cleanup is thus likely a key contributor to recent global warming acceleration and to Pacific warming trends.

It's not yet clear how economists and environmentalists feel about the role of tariffs operating as a de facto carbon tax that reduces carbon dioxide emissions along with economic activity or to the reduction of the emissions of aerosol pollutants and the resulting cleaner air contributing to global warming.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 14 July 2025.

Samset, B.H., Wilcox, L.J., Allen, R.J. et al. East Asian aerosol cleanup has likely contributed to the recent acceleration in global warming. Commun Earth Environ 6, 543 (2025). DOI: 10.1038/s43247-025-02527-3.

Image credit: Friedlingstein, Pierre et al. Global Carbon Budget 2024. GtCO2 slidedeck PDF. 14 March 2025.

The pace at which the concentration of carbon dioxide in the Earth's atmosphere is increasing picked up in May 2025, fully reversing the downward trend that began after December 2024.

The latter half of 2024 had seen record high levels of CO₂ accumulation in the Earth's air thanks largely to efforts by Chinese firms to produce and export as many goods as they could ahead of new tariffs and trade restrictions that were expected to be imposed on China-produced goods. Industrial production slumped in China following its efforts to front-run (or front-load) their exports before these anti-free trade measures were implemented. Since China is by far and away the world's biggest producer of carbon dioxide emissions, changes in its economic output directly affect the rate at which the concentration of CO₂ changes.

From January 2025 through March 2025, the rate of CO₂ accumulation fell, before stalling in April. The data for May 2025 however shows it rose, which suggests a new effort to stimulate China's economy began in early April. This timing coincides with President Trump's "Liberation Day" tariff announcement, which saw the U.S.' highest tariff rates applied to goods produced in China, which then escalated even higher as China imposed retaliatory tariffs on U.S.-produced goods and the U.S. responded in kind.

The following chart, which tracks the trailing twelve month average of the year-over-year change in the rate at which the concentration of carbon dioxide measured at the remote Mauna Loa Observatory has changed from January 2000 through May 2025, shows the reversal:

The January-March 2025 downturn also coincides with a quarter of negative real economic growth in the U.S., which was highly influenced by the frontrunning (or front-loading) of exports to the United States following their production in China in 2024.

On the stimulus side of the story, there are several developments that indicate unusual interventions by China's government is behind the increase in CO₂. First, China's government has approved new coal-fired power plants:

China approved 11.29 gigawatts (GW) of new coal power capacity in the first quarter of 2025, Greenpeace’s review of official documents showed. This pace of coal-fired electricity approvals already exceeds the 10 GW China approved in the first half of 2024.

Second, China's coal-fired power plant managers have been directed to buy more coal, even though China's economy has slowed and its demand wouldn't support it unless part of a larger stimulus effort:

China is pressing its coal-fired power plants to stockpile more of the fuel and import less in an effort to shore up domestic prices, sources with knowledge of the matter said, but traders are sceptical the measures will help to stop the slide.

The coal industry in China faces rising stockpiles of the fuel after a massive expansion of output following shortages and blackouts in 2021 is churning out more coal than even the world's largest thermal power fleet can consume.

To support miners whose profits are under pressure, the state planner has asked power plants to prioritise domestic coal and increase thermal coal stockpiles by 10%, setting an overall target of 215 million metric tons by June 10, the sources said.

Third, China announced earlier it will build additional coal-fired power generation capacity to compensate for gaps in the reliability of power produced by renewable energy sources. The announcement will see China continue producing coal-fired power plants through 2027 and represents a significant stimulus initiative.

On that final count, the world had a wake-up call from the collapse of Spain and Portugual's electricity grid on 28 April 2025, which was caused by unstable solar energy production and ensured by the absence of more reliable conventional fossil-fuel or nuclear-based power generation. China's government is backing increased coal-fired electricity production as a solution to this problem in the near term.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 June 2025.

Image credit: Shuozhou coal power plant in Shuozhou, Shanxi, China by Kleinolive on Wikimedia Commons. Creative Commons CC by-SA 3.0 Attribution 3.0 Unported Deed.

The pace at which human carbon dioxide emissions are accumulating in the Earth's air held steady in April 2025. The trailing 12-month average of the year-over-year change in atmospheric CO₂ concentration was 3.29 parts per million.

That's a reduction of 0.28 parts per million, or about 7.9%, from the modern-era record of 3.57 parts per million recorded in December 2024. The change coincides with a sharp slowdown in China's economic output following boosted production aimed at beating expanded tariffs and trade restrictions on the nation's exports.

The slowdown is evident in atmospheric carbon dioxide concentration data because China is, by a very wide margin, the world's leading producer of carbon dioxide emissions. The following chart shows how this measure has changed from January 2000 through April 2025:

The slowdown is evident in atmospheric carbon dioxide concentration data because China is the world's leading producer of carbon dioxide emissions by a very wide margin.

The following tool gives an estimate of how much economic activity in worldwide (and predominantly in China) has declined since December 2024. If you're accessing this article on a site that republishes our RSS news feed, you may need to click through to our site to access a working version.

The tool's estimates are based on Jenny Cederborg's and Sara Snöbohm's 2016 paper. In their research, they investigated whether there is a relationship between economic growth and carbon dioxide emissions and identified a positive correlation between CO₂ emissions and GDP per capita. They found "CO₂ emissions increase by approximately 0.0002 [metric] tons (0.2 kg) per capita when GDP per capita increase by 1 dollar, holding all other variables constant".

That relationship doesn't take the effects of inflation into account, so the tool's results based upon it are likely understating the reduction in global GDP associated with the reduction in CO₂ emissions.

That said, global GDP for 2024 is estimated to be around $110 trillion, which means the indicated global GDP reduction of $9.3 trillion since December 2024, or about 8.5%, is substantial.

And to underscore the point, this figure represents a low estimate for GDP loss through March-April 2025 because of the effects of inflation recorded since 2016, which includes the period of high inflation unleashed by the Biden-Harris administration in early 2021.

References

National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. Updated 5 May 2025.

Cederborg, Jenny and Snöbohm, Sara. Is there a relationship between economic growth and carbon dioxide emissions? Semantic Scholar. [PDF Document]. 2016.

Image credit: Stable Diffusion DreamStudio Beta. Prompt: "Digital art concept of carbon dioxide emissions being used to measure economic growth."