It’s 2030. Where Will U.S. Carbon Emissions Come From?
Researchers at the Rhodium Group have 11 answers.
The year is 2030.
For much of the past decade, the United States has taken aggressive action to fight climate change. After passing the Inflation Reduction Act in 2022, the Biden administration regulated carbon pollution from power plants and cars and trucks. (Let’s also stipulate, for the sake of argument, that it kept the rules in place by winning re-election in 2024.) Progressive states such as California, New York, and Illinois responded by passing even tougher climate laws of their own. And now, at the end of the decade, America has a good shot of hitting its Paris Agreement goal of cutting emissions in half as compared to their all-time high.
Here’s the question: In this rosy scenario, where will America’s remaining greenhouse gas emissions come from? What should climate policy focus on next?
That’s the subject of a fascinating new report from the Rhodium Group, a nonpartisan research firm. The study, published today, offers a glimpse at what climate hawks might be focusing on next decade (if they’re lucky). It’s meant to begin a yearslong conversation over what the next climate law — the Inflation Reduction Act of 2032, in other words — might look like.
Perhaps surprisingly, it finds that a handful of economic activities will dominate the country’s emissions. Just 11 industries or types of polluting sources will generate more than 80% of the country’s greenhouse gas emissions in 2030, the study finds. And just three of these will emit nearly half of the country’s total pollution. If we can decarbonize those activities, then a net-zero U.S. economy will be in sight.
But those 11 activities will be tough to crack. They fall into a few categories:
- About 19% of the remaining emissions will come from parts of the fossil-fuel economy directly involved in storing, moving, or transforming oil or natural gas into other products. Pipelines, refineries, and chemical plants all require the on-site combustion of fossil fuels, and while the Environmental Protection Act is cracking down on methane leaks from those facilities, carbon dioxide will keep flowing from them.
- Another 12% of the remaining emissions will come from some of the tougher problems in transportation: heavy-duty freight trucking and aviation. The latter problem will be particularly tough. Rhodium projects that domestic aviation, which is responsible for about 2% of the country’s carbon pollution today, will rise to 4% of national emissions by the end of the decade. Americans fly more today than they did in 2005, and fuel-efficiency improvements are not keeping up with that increasing demand.
- Farms will fill out another 10% of leftover emissions. About half of those emissions will come from fermentation of plant matter in the guts of plants and animals — the infamous cow burps. But the other half will arise from the interaction of soils, microbes, and fertilizer. When fertilizer is applied to soil, bacteria convert its nitrogen into nitrous oxide, a greenhouse gas nearly 300 times more potent than carbon dioxide on a 100-year time scale. This process will generate 6% of America’s greenhouse gas emissions by 2030, according to the study.
By far the most important category of emissions are what you might think of as the “Big Three,” which together will account for nearly half of 2030 emissions. They are cars, trucks, and SUVs; furnaces and water heaters in buildings; and power plants, and they will dominate the country’s emissions in 2030 as much as they dominate them today.
The “Big Three” are also the focus of powerful climate policies already, and Rhodium’s analysts expect those policies to be effective. “We’re pushing on them a lot, and they’re coming down. But they remain the top three,” Hannah Kolus, a senior analyst at Rhodium and an author of the report, told me. Carbon pollution from light-duty vehicles, for instance, will fall 32% from its 2005 level by 2030, the report projects.
But cars, building furnaces, and power plants take so long to turn over that even supremely effective policy will take decades to zero out emissions. The average car on the road in America right now is 12 years old. Even if electrics made up 100% of all new car sales by 2030 — which, under Rhodium’s projection, they won’t — it might take 20 years for them to totally replace the vehicle fleet. In other words, climate hawks will be thinking about cars and trucks, building furnaces, and power plants for a long time.