My colleague at the Center for Astrophysics, Jonathan McDowell, recently wrote an article in Physics Today[1] trying to answer the question: where does outer space start? At what height above the surface of the earth do we transition from the terrestrial realm to outer space? This may seem an entirely esoteric, or at least academic, question of little interest to anyone but space buffs and (maybe) astronomers. Not so! Countries have control over the airspace over their territories, but that space does not extend to the end of the universe, aside from the problems earth’s rotation would cause for such a concept. It stops at the boundary in the atmosphere that separates earth’s airspace from outer space. Above that altitude national airspace becomes international outer space, similar in nature to international waters and governed by the Outer Space Treaty.
The Outer Space Treaty went into force on 10 October 1967 and states:
The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind.
Laura Grego summarized the characteristics of the treaty in a white paper of the Union of Concerned Scientists (UCS) in 2017[2]:
“With this treaty, scores of states, including all the spacefaring nations at the time, laid out the fundamental principles by which outer space is to be governed.
Key among these principles: space is to be used for peaceful purposes; states parties must exercise due regard to the interests of others and avoid harmful contamination while using space; and no state can appropriate space or celestial bodies.”
It is clear today that the treaty badly needs a substantive update, as technology and the state of the world have changed drastically over the past 53 years. Weaponization and commercialization of outer space present reason for concern. The white paper lays it out in more detail. In addition, there is, of course, the question where outer space starts. Jonathan’s answer, in summary, is: at 80 km, because any spacecraft whose perigee is below 80 km will very soon fall out of the sky, while orbits with perigees above 80 km are relatively stable and can survive for a long time.
An article pair in the Boston Globe on Solar Geoengineering that drew my attention also deals with things that (may) happen high above our heads. The Globe has started a podcast Brave New Planet[3], “a conversation about science, society, and how the decisions we make today will impact generations to come” that “delves deep into the most exciting and challenging scientific frontiers, helping us understand them and grapple with their implications.” At the time of this writing there are, in addition to the introduction, five episodes: Deepfakes and the Future of Truth; a Radical Approach to Climate Change (Geoengineering); Robots and the Future of War (Killer Robots); What Algorithms Say about You (Predictive Algorithms); and Reshaping Nature through Gene Drives. Each of these are well worth our attention, as they focus on the convergence of science, technology, and ethics — which are the secular equivalents of the S, T, and CF in PASTCF.
Solar geoengineering is a good example of technological application of scientific knowledge that should receive a strong critical look at the ethical questions involved: its merits, drawbacks, side effects, potential for long term disaster, particularly its effect on disadvantaged nations in this world, etc. What is (solar) geoengineering? Starting with climate change and global warming, the problem can be simply stated as: the carbon dioxide (and let’s not forget the methane) content of the atmosphere is causing too much, and increasingly so, heat to be trapped in the troposphere. Generally, efforts to remedy the problem are based on a two-pronged approach: drastically reduce the release of CO2 into the atmosphere, and capture and sequester CO2 from the atmosphere. But there is, in principle, a third way to battle climate change, and that is reducing the amount of solar radiation that reaches the troposphere by increasing the reflectivity of the earth’s atmosphere. This can be done by releasing certain aerosols high into the atmosphere and allowing prevailing winds to disperse them across larger or smaller parts of the globe. It artificially simulates the effect of multiple volcanic eruptions. A more in-depth description is provided, for instance, by the UCS[4].
There is a host of problems with it, though. The aerosols won’t stay up there forever (which is actually a good thing), which means that this becomes a never-ending enterprise. And, if CO2 emissions are not curtailed, this will require a continuously increasing volume of these releases. This is not a sustainable way of countering global warming. Any country could undertake such an engineering project, but its effects would not be limited to that nation. I recommend the article by Raymond Pierrehumbert in the Boston Globe[5] or the position of the UCS[6]. There are many questions that are not being addressed, nor is there a broad public conversation, while actual work is in progress, pretty much under the radar. In January of this year, for instance, the government quietly allocated $4M for geoengineering research at NOAA.
I have commented on this general subject before. Scientific discovery has been accelerating over our lifetimes and with it, the development for new technologies. Serious consideration of whether or not application of such technologies is wise – or what, if any, restrictions need to be imposed — is largely absent. Such conversations need to precede the actual development of technologies, since efforts to put them back into the bottle have a very poor track record. The fact that there is little or no discussion in society about the ethics and ethical consequences of the application of new technologies is highly disturbing. More often than not the justification for application has come down to “we’ll do it because we can.” If nobody else speaks up, there is a case to be made for prophetic witness. Can ASTCF be the thorn in the side of the PC(USA) in this matter?
[1] https://doi.org/10.1063/PT.3.4599
[2] https://ucsusa.org/sites/default/files/attach/2017/12/50-Years-OST-article.pdf
[3] https://www.bravenewplanet.org/ (podcasts) and https://www.bostonglobe.com/opinion/brave-new-planet/ (articles)
[4] https://ucsusa.org/resources/what-climate-engineering
[5] https://www.bostonglobe.com/2020/10/19/opinion/when-it-comes-solar-geoengineering-were-still-very-much-dark/
[6] https://ucsusa.org/sites/default/files/attach/2019/gw-position-Solar-Geoengineering-022019.pdf
