NASA affiliated scientist and colleagues at Pennsylvania State University  have created a highly speculative scenario where Aliens become concerned over the levels of CO2 in our atmosphere.
In this scenario the Aliens would need to destroy mankind for the betterment of the universe.

Other possible outcomes and scenarios were proposed, such as they will come to eat us or kill us with diseases. At first I thought, these scientists were just having a little fun amongst themselves pretending Alien life forms  might  become involved in our political debates and concerns.

Then there report concluded with this:

"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.

 

I though it was bad enough that my toilet paper is now sold as a "Green" product and environmentally beneficial, now the aliens are going to be intergalactic enviro enforcers?  And if we don't abide by their rules they'll eradicate us due to our selfishness.

I can come up with these ideas for fun as in my last blog, "Tempus Eradicus", but these  "Scientist" take it seriously. Another reason I just can't take global warming seriously! This is another "absurdtation".

Here's the link from the UK Gaurdian: http://www.guardian.co.uk/science/2011/aug/18/aliens-destroy-humanity-protect-civilisations