Yesterday we talked about taking some of the heat out of global warming by planting reflective crops. The more solar radiation we reflect, the less is emitted as terrestrial radiation to heat up the green house gases in our atmosphere. But I know what you’re thinking: Can’t we just launch massive space mirrors into orbit and preemptively keep the sunlight from entering our atmosphere? Well, it’s certainly one of the planet hacking options on the table.

University of Calgary environmental scientist Dr. David Keith is a big supporter of this geoengineering approach to fixing the planet. Keith presented the idea at a 2007 climate change conference in Cambridge, Mass. Need to prevent ice from melting on Greenland? Simply throw some space mirrors up there to provide some shade.

The potential cooling factor for this planet hacking scheme is immense, but the challenges and risks involved are obvious. First, building these mirrors and getting them into orbit isn’t a simple endeavour. New Scientist predicts that such an effort wouldn’t be ready to deploy for centuries. Plus, the Earth’s atmosphere is a complicated and chaotic system. We simply don’t know what kind of effect these space mirrors would have on global conditions.

Russian scientists looked into doing just the opposite with space mirrors in the 1990s. According to the New York Times, the Znamya project was designed to reflect sunlight to dark regions of the country, allowing longer planting and harvest seasons. While experiments with the prototype were said to be successful, the Russians abandoned the project in 1999 and allowed Znamya 2.5 to burn up on re-entry.

Still, the Znamya project showed that space mirrors aren’t nearly as fanciful as they sound. Might this be just the crutch a future Earth needs to limp through its environmental nightmare in the 22nd century?

Tomorrow we’ll continue to look at yet another planet hacking scheme that involves reflection. In the meantime, read the previous planet hacking schemes or head on back to the HowStuffWorks.com home page.

10 Planet Hacking Schemes:
No. 10: Foresting
No. 9: Fake Plastic Trees
No. 8: Reflective Crops