Inventory of global emissions by launchers for 2024
This paper presents IGEL 2024, a comprehensive, gridded global dataset quantifying 131 kilotons of rocket launch emissions from 223 missions in 2024, detailing their chemical composition and vertical distribution across atmospheric layers to support climate and atmospheric chemistry modeling.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine the sky above us as a giant, invisible ocean. Just like the ocean has currents, temperature layers, and delicate ecosystems, our atmosphere is a complex, living system that keeps Earth habitable. For a long time, we've known that cars, factories, and power plants dump pollutants into this ocean, changing its chemistry and warming our planet. But there's a new, rapidly growing source of pollution that has been harder to track: rockets. Every time a rocket blasts off, it shoots a massive plume of exhaust straight up, piercing through the lower air, the middle layers, and even the thin air near space. Scientists are starting to worry that these high-altitude exhausts might be messing with the ozone layer (the sun's sunscreen) and the climate in ways we don't fully understand yet. To figure this out, we first need a really good map of exactly what is being released, where, and how much.
This is where a new study comes in, acting like a cosmic accountant for the year 2024. The researchers, a team from the German Aerospace Center (DLR) and a university in Braunschweig, created something called the "Inventory of Global Emissions by Launcher" (IGEL) for 2024. Think of it as a high-definition, 3D map of every rocket launch that happened that year. Instead of just guessing, they rebuilt the rockets, engines, and flight paths of 25 different launch vehicles on a computer to simulate exactly how much fuel they burned and what came out of their tails. They tracked 223 launches, covering more than 95% of all the fuel burned in space missions that year.
The team found that in 2024, rockets dumped a total of 110 kilotons of "primary exhaust" (the stuff coming straight out of the engine) into the sky. After that exhaust mixes with the air and changes a bit, it becomes 131 kilotons of "final emissions." The biggest chunk of this pollution is carbon dioxide (CO2) and water vapor (H2O), which make up nearly 90% of the total. However, the more dangerous stuff is also there: about 700 tons of black carbon (soot), 720 tons of nitrogen oxides, and 810 tons of aluminum oxide (a white powder from solid rockets).
What makes this map special is that it doesn't just say "rockets pollute." It shows exactly where the pollution lands. About 40% of the exhaust is released in the troposphere (the lowest layer where we live and where weather happens), 30% in the stratosphere (the middle layer that holds the ozone), and the remaining 30% goes even higher. The study also highlights that the type of rocket matters a lot; for instance, the new, massive Starship rockets, even though they only flew four test flights, were responsible for a huge chunk of the fuel burned that year.
The researchers admit that this is a simulation based on the best data they could find, not a direct measurement of every single puff of smoke. They had to use math and physics models to guess how the exhaust changes as it rises, because we don't have sensors floating in space to measure every rocket's tail. However, they checked their work against real flight data and found their maps match reality very well. By providing this detailed, open-source dataset, they are handing climate scientists a powerful new tool. Now, instead of guessing how rockets affect our atmosphere, scientists can plug this specific, accurate data into their climate models to see exactly how these high-speed exhausts might be changing our world's chemistry. It's a crucial first step in understanding the environmental cost of our journey to the stars.
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