It’s absolutely critical that we do something right now to save our planet from certain peril. An eye-opening new special on global warming will air tomorrow night on the National Geographic Channel. It’s called “Six Degrees Could Change The World.”

In it, some of the world’s top experts on global warming lay out what to expect as the earth warms over the next century:

At 1 degree Celsius, most coral reefs and many mountain glaciers will be lost. A 3-degree rise would spell the collapse of the Amazon rainforest, disappearance of Greenland’s ice sheet, and the creation of deserts across the Midwestern United States and southern Africa. A 6-degree increase would eliminate most life on Earth, including much of humanity.

How do we fight this impending doom? Several people have some very creative, yet expensive ideas. There is hope yet. Check out the following ideas:

Simulating Volcanic Eruptions
The 1991 eruption of Mount Pinatubo in the Philippines sent an estimated 20 million tons of sulfur dioxide high into the stratosphere. Winds proceeded to spread it all over the planet, forming a high-level haze that reflected back light from the sun and reduced global temperature by 0.5 degrees Celsius. Nobel prize-winning atmospheric chemist Paul Crutzen has proposed simulating the Pinatubo effect by using artillery guns or balloons to inject sulfur into the atmosphere. (Rockets filled with sulfur could also do the trick). Crutzen calculates that the cooling effect would begin within six months and last for up to two years. Artificially duplicating Mount Pinatubo’s effects each year might cost $250 billion, though Crutzen says a relatively affordable $25-$50 billion worth would be enough to make a difference. A major downside is the possibility of creating acid rain or wreaking havoc with global weather patterns, as the eruption of the Indonesian volcanic island of Krakatoa did in the 1880s.

Lenses In Space
University of Arizona astronomer Roger Angel has suggested using non-polluting, magnetically-powered vehicles—a concept that NASA is already exploring—to transport trillions of lenses made of silicon nitride film into space and deposit them near inner Lagrange point 1, an area where the combined effect of gravity of the Earth and the Sun would keep them in the same place relative to Earth’s rotation. The lenses would be about three feet across but incredibly thin, weighing about a gram. Rather than blocking sunlight, they would bend some of it slightly away from Earth, reducing the amount of energy transmitted by about 2 percent. Manufacturing the immense quantity of lenses and putting them into space—some 20 million launches would be required—make Angel’s idea a lengthy and pricey one, but he has estimated that the cost would average out to $100 billion annually over the lenses’ 50 year lifetime. The lenses would also be difficult to turn “off” if necessary, and could lead to uneven cooling effects.

Turning Pollution Into Baking Soda
Burning coal to generate electricity is one of the planet’s major sources of carbon emissions. To cope with their seemingly insatiable demand for electric power, the U.S., China, and India plan to build 850 new coal-fired plants by 2012, which will spew five times as much carbon dioxide into the atmosphere as the Kyoto Protocol nations aim to eliminate. Many believe that carbon sequestration, in which carbon dioxide emissions from smokestacks are trapped and stored, is the best answer. But most ideas for what to do with the carbon dioxide—such as pumping it into manmade caverns—would be costly, and there’s always the risk that the gases will escape. That’s where a Texas-based startup company, Skyonic, and its innovative new carbon sequestration technology, gets involved. Plastic mesh sheets capture 90 percent of the carbon dioxide emitted by a power plant, which is then mixed with sodium hydroxide to produce harmless baking soda. Solids are easier to store, and since the baking soda produced is high-grade, it can be recycled for industrial applications or even used for baking. Texas utility Luminant installed a pilot version of the technology at its Brown Steam Electric Station in 2006, and Skyonics is now designing a system that it hopes to install on a large 500-megawatt power plant in 2009.