This week we talk about greenhouse gases, renewable energy capacity, and China’s economy.

We also discuss coal power plants, natural gas, and gigatons.

Recommended Book: What If We Get It Right? by Ayana Elizabeth Johnson

Transcript

In 2024, global CO2 emissions hit a new all-time high of 37.8 gigatons, that figure including emissions from industrial processes, oil well flaring, and the combustion of fuel, like petroleum in a vehicle.

And for context, a gigaton is one billion metric tons, which is about 2.2 trillion pounds. A single gigaton is about the weight of 10,000 fully equipped aircraft carriers, it’s about twice the mass of all human beings on the planet, and it’s approximately the same mass of all non-human land-mammals on earth.

That’s one gigaton, and global CO2 emissions last year hit 37.8 gigatons; so quite a lot of carbon dioxide headed into the atmosphere, every year, these days.

That’s up about .8% from 2023 levels, and it resulted in an atmospheric CO2 concentration of about 422.5 parts per million, which is around 3 ppm higher than 2023, and 50% higher than pre-industrial levels. And again, for context, if we don’t want to experience global average temperature increases, more extreme weather, and disrupted water cycles, the general consensus is that we want to keep atmospheric CO2 levels at or below 350 ppm, and we’re currently at 422.5 ppm.

That said, while emissions grew last year, mostly because fuel combustion increased by around 1%, which overshadowed the decrease in industrial process emissions, which was down 2.3% for the year, emissions growth in 2024 was less than GDP growth; and that’s important because for a long time it was assumed that in order to grow global wealth, according to that metric for wealth, at least, more fossil fuels would need to be burned, because that was the pattern for a long time, industrial revolution, onward.

Beginning in the early 2000s, though, GDP growth and emissions growth diverged, and that decoupling has become more prominent as many wealthy nations, including the US, have upped the efficiency of many previously energy-hogging aspects of their economies—things like appliances and the aforementioned industrial processes—while also shifting a lot of energy generation away from massively polluting fuels like coal and oil, over to less-polluting fuels like gas, and non-polluting sources like solar and wind, and in some cases nuclear, as well.

This relationship varies significantly from country to country, and the benefits are mostly being seen in so-called advanced economies right now, as many poorer nations are still seeing increased emissions from more polluting power sources, generating electricity, and the growth in wealth leading to more people buying cars and scooters, many of which run on dirty fuels.

In the US, though, GDP has doubled since 1990, but CO2 emissions have dropped back down to around 1990 levels.

Which to be clear is still a whole lot, as Americans consume a lot of stuff and use a lot of energy, and there are a lot of people living in the US using all that energy and buying all that stuff. But it serves as a good example of this divergence, which we’re also seeing across the EU, where European economies, on average, are 66% larger than in 1990, and CO2 emissions are about a third lower than levels from that same year.

What I’d like to talk about today, though, is how this dynamic is playing out in China, a place with a staggeringly high population, a rapidly enlarging middle class, and a whole lot of energy needs.

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China is a renewable energy powerhouse.

It’s an energy of all kinds powerhouse, truthfully, but its development of renewable energy technologies, and its deployment of those technologies, has been truly remarkable, especially over the past decade or so.

China has more renewable energy capacity—mostly solar and wind—than the next 13 countries combined. The US comes in second place, but China has four-times as much renewable energy capacity than the US.

Despite that, though, because of China’s huge population and its remarkable wealth-spreading success story, having brought something like 800 million people out of poverty over the past 40 years, a lot of people in the country need a lot more energy, every year. Because as people make more money, they tend to use more electricity and heat, and they tend to buy more things, need bigger homes, and so on. All of which requires more energy.

So even though they’ve been building solar panels and wind turbines at a blistering rate, spreading these things all over the place, massively increasing their capacity for clean electricity, they’ve also been building more fossil fuel-burning power plants, especially coal power plants, and that’s made it the world’s biggest emitter of greenhouse gases; a little less than half of the country’s total installed generation capacity burns fossil fuels, which is a huge drop from even a handful of years ago, but because so much of the remaining fossil fuel stock is coal-burning, those energy assets account for an outsized portion of global emissions.

New, official data released by the Chinese government, so probably smart to take it with a grain of salt, though these sorts of numbers are usually more reliable than the economy-related numbers they put out, these days, but new data was crunched by Carbon Brief, and they found that March of 2024 was China’s most recent peak in terms of emissions, and since then, their emissions have dropped by 1%.

The drop might be accelerating, too, as they also found that new installations in the first quarter of 2025 dropped emissions by 1.6% compared to the same quarter in 2024, so they may be scaling up their renewables deployment efforts, which could lead to even more of a drop.

And remarkably, China’s power sector tallied an emissions drop of 5.8%, despite demand for power increasing by 2.5% that same period: which suggests that although China’s population is still wanting more electricity and stuff, the same energy, or rather, a bit more of it, now produces fewer emissions, which means the ratio of renewables to non-renewables in their grid is shifting further in renewables’ favor.

Now, as with many other countries, China is beginning to replace coal in some of their power plants with natural gas, instead of swapping them out for solar, wind, and nuclear. Which is absolutely better than coal, but gas still emits CO2 when burned, and there are entirely different problems associated with gas infrastructure, including leaky pipes than allow methane to seep into the atmosphere, which stays up there for a shorter duration than CO2, but is a lot more potent, in terms of heat-capture—so gas in better in some ways, especially short-term ways, than coal, and less polluting for people on the ground, too, but definitely not as good for long-term outcomes as renewables.

All that said, there’s some optimism here, as this is the first time this sort of peak and drop has been noted in China’s emission numbers in a context where that drop hasn’t been directly attributable to economic factors; the pandemic, for instance, where a lot less energy was needed, fewer people were driving, and thus there were far fewer emissions globally, for a while.

There’s a chance, though, that this trend could be disrupted by the burgeoning trade-war between the Trump administration and essentially everyone, but China in particular. The China-facing component of Trump’s tariffs has been mellowed for a few months, but is still significant at around 30% as of the day I’m recording this. And that could lead to a rewiring of global supply chains, but also a shift in what China manufacturers are producing, how they’re getting those goods to their destination.

Those shifting variables could lead to short-term or long-term changes in who’s producing what, how it’s being shipped, and thus, what sorts of energy expenditures we’ll see, and how that energy’s being produced, because of the peculiarities of those new, perhaps rapidly deployed, needs.

Show Notes

https://www.worldbank.org/en/news/press-release/2022/04/01/lifting-800-million-people-out-of-poverty-new-report-looks-at-lessons-from-china-s-experience

https://e360.yale.edu/features/china-renewable-energy

https://arstechnica.com/science/2025/05/analysis-shows-that-chinas-emissions-are-dropping-due-to-renewables/

https://www.carbonbrief.org/analysis-clean-energy-just-put-chinas-co2-emissions-into-reverse-for-first-time/

https://mn350.org/understanding350

https://www.iea.org/reports/global-energy-review-2025/co2-emissions

https://www.iea.org/commentaries/the-relationship-between-growth-in-gdp-and-co2-has-loosened-it-needs-to-be-cut-completely

https://wmo.int/media/news/record-carbon-emissions-highlight-urgency-of-global-greenhouse-gas-watch

https://www.carbonbrief.org/analysis-global-co2-emissions-will-reach-new-high-in-2024-despite-slower-growth/

https://ourworldindata.org/co2-emissions

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