So make sure you recycle! According to a report coming out of NASA for some reason, we might be more likely to face hostile space aliens because of climate change. The report, also presented by the University of Pennsylvania, speculates on different scenarios of alien visitation: beneficial, neutral, or harmful.
The International Business Times says:
The scientists have also pondered over the possibility of aliens trying to destroy us in order to maximize their number or diversity of civilizations. This could occur if the earth's resources could be used to more efficiently generate or retain other civilizations; though this possibility seems highly remote, given how efficiently tuned humanity is to its environment.
The authors also warn that the attack might be due to the fact that the aliens may be wary of the way that humans have altered the natural eco systems. The chemical composition of Earth's atmosphere over recent time may be a poor choice for a message because it would show a rapid accumulation of carbon dioxide from human activity.