Aliens may destroy Earth over environment

NASA-affiliated scientists have suggested that aliens may seek to wipe out the human race because of how we have treated planet Earth.

In a new report by the NASA Planetary Science Division at Pennsylvania State University, researchers suggest that alien races could see us as a long-term threat to the environment.

"A preemptive strike would be particular likely in the early phases of our expansion because a civilisation may become increasingly difficult to destroy as it continues to expand," the researchers suggest, according to The Guardian.

"Humanity may just now be entering the period in which its rapid civilisational expansion could be detected by an [alien race] because our expansion is changing the composition of Earth's atmosphere, via greenhouse gas emissions.

"'Green' aliens might object to the environmental damage humans have caused on Earth and wipe us out to save the planet," the report continues. "These scenarios give us reason to limit our growth and reduce out impact on global ecosystems."

The special report was put together to suggest plausible outcomes for the event in which Earth has a close encounter with an actual alien race.