The Guardian reports on a scenario analysis conducted by several scientists considering possible scenarios resulting from contact with alien life forms. The analysis covers many basic scenarios, such as basic communication or the possibility of disease transmission from physical contact, but also suggests global warming could give aliens an excuse to attack.
The authors warn that extraterrestrials may be wary of civilisations that expand very rapidly, as these may be prone to destroy other life as they grow, just as humans have pushed species to extinction on Earth. In the most extreme scenario, aliens might choose to destroy humanity to protect other civilisations.
“A preemptive strike would be particularly likely in the early phases of our expansion because a civilisation may become increasingly difficult to destroy as it continues to expand. Humanity may just now be entering the period in which its rapid civilisational expansion could be detected by an ETI because our expansion is changing the composition of the Earth’s atmosphere, via greenhouse gas emissions,” the report states.
“Green” aliens might object to the environmental damage humans have caused on Earth and wipe us out to save the planet. “These scenarios give us reason to limit our growth and reduce our impact on global ecosystems. It would be particularly important for us to limit our emissions of greenhouse gases, since atmospheric composition can be observed from other planets,” the authors write.
Somehow, I don’t think an alien race capable of interstellar space travel would consider humanity much of a threat — we have yet to put people on Mars — but the authors do characterize these scenarios as “highly speculative.” If we’re willing to accept the premise that aliens come to earth and care about what we’re doing, why should we assume the alien race embraces contemporary environmental ideology? It seems to me the scientists are engaged in a bit of projection.
We could just as easily speculate about an advanced alien race seeing things quite differently. Perhaps the aliens would come from a planet with a much warmer temperature and see global warming as our invitation for them to colonize the planet. Or maybe they’d see gradual warming as a sign that we are a productive civilization that has been able to conquer and subdue our natural environment and is therefore worth trading and cooperating with. Or maybe this race would follow something like the “Prime Directive” and see our expansion as a reason to just leave us alone. Or maybe they would watch cable television and conclude we are a primitive, debased species not worth their time.
[Note: Extra links added.]