Is geoengineering a good idea? In most cases, I say no.
Popular Mechanics, green websites and other sources have been offering geoengineering solutions such as massive carbon dioxide sinks to help offset pollution elsewhere. The latest example is using lime to cut carbon dioxide levels.
Geoengineering worries me because doing so on a planetary scale is inevitably fraught with unintended consequences. It is an attempt to control one of the most complex systems in existence: all of Earth. Testing is out of the question, as any test would inevitably fail to account for the trillions of variables involved in everyday life: ocean currents, surface and underwater temperature changes, sunlight (potentially filtered through lime/algae/etc.), amount of fish poop in the water, and on and on. Without testing, geoengineering is by definition a one-shot gamble, with the entire planet at stake.
And, at the end of the day, most geoengineering solutions involve combatting pollution with more pollution.
My favorite analogy is Pepsi Clear: during the manufacturing process of clear Pepsi, the drink begins its life as opaque syrup, and ingredients (read: chemicals) are added to the drink to make it clear. That is just plain unsettling. When one adds two positive numbers together, you don't get zero.