Lately, it seems that everyone is either scrambling to reduce their carbon footprint or trying to figure out what the hell that means. While some ideas seem reasonable, others feel, well, a little misguided. Here are five of the dumbest (or most brilliant) ways to save the Earth.

Condoms as carbon offset
Preventing the birth of one child in Africa can offset the carbon footprint of a flight from London to Sydney, according to the U.K.'s Optimum Population Trust (OPT). OPT wants to provide contraception to those who want it in developing nations.

Still, developed nations produce the most carbon and these countries have access to contraception. Preventing the birth of an American child, for example, would have a much greater impact than preventing the birth of a child in sub-Saharan Africa, and we could take a lot more flights to Sydney.


From desert to forest
Speaking of the Sahara, some scientists suggest converting the desert -- and the Australian outback -- into forests. Leonard Ornstein believes if fast-growing trees such as eucalyptus were planted, the trees would absorb 8 billion tons of carbon annually.

The plan hinges on the creation of desalinization plants on the North African and Australian coastlines, providing fresh water via aqueducts. Sounds good so far. But the price tag for maintaining a plant for a year is about $2 trillion. And this new moist weather might cause plagues of locusts. Other than that, it sounds great.

Save a cow, save the planet
Cow farts play a devastating role in global warming -- methane is 23 times more damaging than carbon monoxide. To reduce the threat, important-sounding Lord Stern of Brentford suggests the world convert to vegetarianism. Meat production accounts for 18 percent of carbon emissions, according to UN estimates. Ironically, Lord Stern isn't a vegetarian. Next...

Just Do It -- Nike saves the Amazon
Even Nike is worried about cows. Starting in July, the company promises its sneakers won't come from Amazon-bred cows. After Greenpeace released a report tallying the effects of deforestation in places like the Amazon, Nike announced plans to discontinue use of Brazilian leather.

While we applaud Nike's gesture, the company refuses to say how much it spends on Amazon leather so there is no estimate of how much of an impact this will have.


Cover the world with shade
In what seems like a plot launched by a super-villain, researchers propose blasting sulfur into the atmosphere to shade the Earth. The hope is to mimic the effects of the 1991 Mount Pinatubo eruption, which spewed 20 million tons of sulfur into the atmosphere, cooling the Earth by 0.5 degree Celsius.

But Ken Caldeira of Stanford tells the BBC: "One of the problems of putting sulfate particles in the stratosphere is that it would destroy the ozone layer; so you might solve the global warming problem, but then we'll all die of that." Some people are just always negative.