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Deliberately alter Earth's environment? Let's prepare BUYING TIME ON GREENHOUSE GAS

March 16, 2008 12:16 am

SPRINGFIELD--

According to Jim Hansen of the NASA Goddard Institute for Space Studies, to whom many political and environmental leaders turn on climate-change questions, we must reduce greenhouse gases by 80 percent within 12 years or it will be too late to prevent a climate catastrophe. Hansen thinks this won't happen because it simply costs too much, He knows the citizens of the world won't give up their dream of a better life--a life that stands on the shoulders of cheap electric power and affordable trucks and cars.

Indeed, Hansen is partly correct. Surveys show that citizens are not willing to pay the price of massive greenhouse-gas reduction. After all, who wants to limit their automobile use to one day every two weeks--or one day a week if we can double gas mileage to 44 miles per gallon? Who wants to throw away all but one electronic device among their cell phones, BlackBerrys, laptops, DVD players, and HDTVs?

Which neighbor will take only one bath a week; which will wash dishes in the sink; which will hang clothes to dry; and, which will use window fans instead of air conditioning? Who is prepared to condemn the struggling nations in Africa and Asia to continued poverty?

'tipping point' reached

Yet this is what we would have to do to reduce greenhouse-gas emission by 80 percent, according to the Intergovernmental Panel on Climate Change's target reduction.

We are also too late. The world has already exceeded the greenhouse-gas emissions "tipping point" beyond which catastrophic warming cannot be stopped. To prevent catastrophic warming we had to keep greenhouse gases below a level equivalent to 450 parts per million of carbon dioxide. We passed that point in 2005. The Virginia plan to reduce greenhouse gases by a mere 30 percent by 2020 is too little, too late, and so is the even more aggressive IPCC proposal to reduce them by 80 percent.

When I explain this to elected and appointed officials, business leaders, fellow scientists, and others who operate in the public eye, they have two reactions. Publicly they maintain the position that this is a critical problem that requires "serious and immediate greenhouse-gas emissions reductions." Privately they ask me, "What can we do without losing jobs and going back to an 1850s lifestyle? Is there a way to get us more time to shift away from carbon-based fuels?"

NO SILVER BULLET

Happily, there is. It is not a silver bullet, nor is it a permanent solution. But we can give ourselves four or five decades to solve this problem while maintaining our lifestyles and continuing to expand our economy. The response to a climate-change emergency will be geoengineering--the deliberate modification of Earth's environment on a large scale to suit human needs and promote habitability.

The most often discussed methods aim for one of three outcomes--directly reduce the global temperature, correct the acid balance in the oceans, and pull carbon dioxide out of the atmo-sphere.

The first would prevent the potential climate catastrophe of ocean rise and flooding. The second is now assumed necessary to protect the corals and fish habitat that provide us an essential source of food. The third would offer pollution control on a global basis. Each is possible, each mimics natural global phenomena, and each has its problems.

In 1992, the National Academy of Sciences concluded that by placing small particles of reflective material into the stratosphere, humanity could reproduce the global cooling observed after a major volcanic eruption. Studies done in the past 18 months indicate we could cool the Earth enough to grow as little or as much Arctic sea ice as we want, thus preventing the melting of the Greenland Ice Sheet and avoiding massive ocean-level rise.

One leader in this work is Ken Caldeira at the Department of Global Ecology of the Carnegie Institution at Stanford University--a cautious, mainstream scientist of enormous repute. He has some qualms about this approach, but has investigated the potential adverse consequences of controlling solar radiation with these particles. Using the same models others use to predict global warming and climate change, he has concluded that this form of geoengineering will cause fewer local climate problems than would arise from catastrophic warming.

It could be used exclusively in the Arctic; if that proved effective and safe, it could be expanded to the entire surface of the planet. It can be turned on and off like a thermostat, and the cooling would begin almost immediately.

ocean recovery time

Protecting the ocean is another matter altogether. There remains debate as to whether warming caused by carbon dioxide has a net negative or net positive effect on ocean crustaceans. Assuming the worst, scientists from Harvard and Penn State have proposed using the same chemistry as found in natural weathering of rock but speeding that up considerably. By building chemical plant-size facilities that would re-balance the calcium carbonate equation, we would reduce the ocean's recovery time to only one or two decades. Again, this could be turned on and shut off at will.

Finally, there are ways to take carbon out of the land-ocean-air system. A commercial team is investigating "fertilizing" parts of the ocean in a way that causes small organisms to grow like a massive algae bloom. This would take large amounts of carbon dioxide out of sea water, giving room for the carbon dioxide in the air to dissolve into the ocean. The biochemistry works and, again, it can be turned on and off quickly.

The question is whether this method will sequester carbon forever. If, when the organisms die, they fall like snowflakes to the bottom of the ocean, this method will work. Due to ocean currents, this may not happen and they could simply turn back into carbon dioxide. The science needed to answer this question has only just begun.

Alternatively, there are other means to sequester carbon by geoengineering our soil. We can turn plant material into charcoal and put it back into the earth--probably on cropland. This is inexpensive and has no discernable downside.

However, we can't use any of these tomorrow. Most of them are scientifically sound proposals that have yet to be fully engineered. Which is why it is time to put some serious money into a climate-change emergency-preparedness plan. We have emergency plans that guide our response to everything from building fires to nuclear war. We need one for global warming.

When we are staring global starvation in the eye, only then would politicians be willing to use these approaches. But a prudent person would make sure we had a sensible, affordable, and effective plan ready for when we need it--maybe as soon as 12 years from now.