Guardian: Aliens may destroy humanity to protect other civilisations, say scientists

Rising greenhouse emissions could tip off aliens that we are a rapidly expanding threat, warns a report
Thursday 18 August 2011

It may not rank as the most compelling reason to curb greenhouse gases, but reducing our emissions might just save humanity from a pre-emptive alien attack, scientists claim.

Watching from afar, extraterrestrial beings might view changes in Earth's atmosphere as symptomatic of a civilisation growing out of control – and take drastic action to keep us from becoming a more serious threat, the researchers explain.

This highly speculative scenario is one of several described by a Nasa-affiliated scientist and colleagues at Pennsylvania State University that, while considered unlikely, they say could play out were humans and alien life to make contact at some point in the future.
the rest-HAHAHAHAHA!!