To cool the earth?
Lower the incident power density:
1) Move our orbit out. (energy/mass conversion requirement is beyond what humanity is at)
Block or reflect the incident power density:
2) Come up with a scheme to 'pollute' the upper atmosphere with particulates (Volcanoes are great! Just hard to set up an explosive volcano... I mean, we can release the pressure in existing active volcanoes easily)
3) We could blow up the moon! But the amount of energy required to cut/explode/bore/grind up the moon would be astronomical (pun intended) and would wreak havoc with Earth (we like tides).
4) Paint your roof white and black... flip to white during the day, and black at night... It's not sufficient to merely reflect the heat from the sun, we must also re-radiate absorbed heat at night! (I speak figuratively, white body-> black body type behavior)
To reduce the effect of human impact on atmospheric greenhouse gases?
1) Nuclear power, can't beat it. The amount of deforestation or natural destruction required to convert to wind/solar/hydroelectric would make even China shudder. (yes, it is that bad)
http://www.terradaily.com/reports/Renew ... t_999.html
Don't get me wrong, I LIKE the concept of renewable energy! I just don't like the environmental impact, or people that claim it is more than just a temporary solution.
2) Pandemic... simplest, safest, cheapest culling. (not that I advocate it, and likely the developed countries using the most energy will weather it the best, not really helping as much as a basic per capita percentage based culling)
3) Find a new organic battery (algae is great!) to start sucking out some greenhouse gases, and converting as much incident energy to chemical stored energy... basically reverse the fossil-fuel burning process.
Realistically? People just need to suck it up, start building nuclear power plants, buying efficient vehicles (as opposed to luxury SUVs and sports cars...), and turning off the freaking light... maybe even walking!
And STOP advocating fluorescent light bulbs
... it's a marketing ploy. Just like wind and solar power, they'll help reduce our demand on fossil fuel based energy, but they're not 'green'. They are VERY efficient and contain a significant amount of mercury... If everyone switched to florescent light bulbs, we'd use less energy and likely pollute nearly all of our groundwater (though it may be considered a lost cause in some areas). I think companies that can be monitored and fined are great... they can dispose of them properly, but that lady who buys 15 florescent light bulbs for her house because she's guilty about the luxury SUV she drives around is just going to toss half of them in the trash because disposing of them properly isn't worth her time. If everyone has compact fluorescents right now... any area with save ground water would be a ticking time bomb.
Say it with me! L E D
(Sorry if I come off a little abrasive, I'm currently in LA... where the only reason anyone ever bought a hybrid was because it's 'trendy'. Most self-centered culture I've ever lived in... the ONLY reason people advocate what is conveniently environmental for them is out of some half-arsed attempt to lessen their own guilt over their own decadent lifestyle.
The only way you're going to get these people to change is to hit them where it hurts, in their image and in their pocketbook... and they're not afraid to be in debt up to their eyeballs!)
The difference between science and the fuzzy subjects is that science requires reasoning while those other subjects merely require scholarship.
Anyone who considers protocol unimportant has never dealt with a cat. -From books by R.A.Heinlein