The optimism of the coming Space Age 2 – with its tourism, mineral mining, colonization and endless derivative benefits – may be short-lived if we kill ourselves faster back on Earth from the carbon cost of accelerating such an era. The footprint of a routine space launch is around 100 times larger than a long airplane flight, already substantial. Furthermore, launches release large amounts of soot, hurting both the stratosphere and the ozone layer. As Rebecca Heilweil at Vox reports, “a study from 2010 found that the soot released by 1,000 space tourism flights could warm Antarctica by nearly 1 degree Celsius.” That’s why the scientists interviewed for Heilweil’s article make clear that they do not think space tourism and the like come close to justifying their wider environmental costs.

So: is climate-sensitive space travel possible? That’s a difficult argument to answer. At present, researchers are testing a variety of green fuel fixes that could change the risk assessment considerably. All of these solutions presuppose that enough shareholders and stakeholders will demand that the fuels be prioritized even if they cost more in the short term, and that governments will incentivize or mandate the transition. If that were to happen, we could likely mitigate the carbon impact of launches, although the technology may not be carbon neutral as carbon would be a necessary ingredient in the manufacturing of the technology itself.

Importantly, this green technology already exists. The challenge, however, lies in scaling and adapting. While it is possible that rockets could become smaller in some cases, ultimately we will have to eliminate carbon from the process, or at least use a much smaller amount that’s offset elsewhere.

“Green hydrogen” is “produced using water electrolysis (using electricity to extract the naturally occurring hydrogen from water) and renewable energy sources.” The BBC reports that it’s both completely carbon neutral and currently very expensive. The same BBC article discusses a second option, bio-fuels, which are “produced from organic material” or biomass like plants, animal waste, food waste, that kind of thing. At the center of any discussion, however, is the recognition of whether or not we have the political will to develop something or take a certain action. In many ways, the development of biofuels epitomizes this: it proves both that the harnessing of alternative and widely available energy sources is possible, and also that their role in transitions are not inevitable.

One source of optimism is that entrepreneurs themselves talk a good game and, in doing so, make themselves publicly accountable if they drag their feet later. For example, the Los Angeles Times reports that the chief of executive of British rocket developer Orbex openly says climate change is real and that making the emissions problems a thing of the past is imperative. Orbex “uses bio-propane that it says can cut CO2 emissions by 90% compared with traditional launch fuel,” which is huge if true. Similarly, a German satellite maker has developed a “mini-launcher,” a very small rocket with an environmentally-friendly propellant, which has the potential to become a model for light-load tourist launches. Stefan Brieschenk, the chief engineer at Rocket Factory Augsburg, the German satellite maker, shared an interesting observation with Reuters: He is only 34 years old, and his colleagues not only at RFA but throughout the industry are mostly young like him. As such, they understand there is a climatic responsibility that’s been placed on their shoulders and they accept their consideration of climate change in their work is a necessity.

Finally, it’s important to keep in mind that if we create permanent bases, colonies, and off-Earth construction and industrial operations, we likely will no longer need to burn anything near the amount of fuel required to leave Earth. That being said, we must simultaneously be committed to preserving the living systems on Earth, regardless of where we are in the universe; and the elimination of carbon from space flight, especially if/as it becomes more common, is both a moral and ecological imperative.