Can We Use Science To Solve Global Warming?

Geoengineering Deserves Serious Consideration, Says NCPA Report


DALLAS (January 30, 2008) - Combating a warming world requires a portfolio of strategies, including exploring innovative new approaches to apply science and engineering, according to a new report from the National Center for Policy Analysis (NCPA).  The report warns that focusing solely on reducing carbon dioxide (CO2) emissions is too inflexible and politically unrealistic.

"If combating potentially harmful global warming requires substantially reducing CO2 emissions, then we will likely lose the fight," said Pete Geddes, executive vice president of the Foundation for Research on Economics and the Environment and an NCPA adjunct scholar who authored the report.  "We need to begin treating the illness, and stop focusing all our energies on the underlying cause or debating its origin."

CO2, a potent greenhouse gas, helps warm the planet.  Recently, the burning of fossil fuels has pushed atmospheric levels of CO2 from approximately 280 parts per million (ppm) at the start of the Industrial Revolution to approximately 380 ppm today.  Over the next few decades CO2 levels will continue to increase.  This worries scientists who argue that increasing CO2emissions are raising global temperatures substantially and later in the century could result in a variety of problems, including rising sea levels and the spread of tropical diseases. 

Worse still, there is a small possibility of abrupt and catastrophic change over one or two decades, including the sudden disintegration of the Greenland or West Antarctic ice sheets, causing a rapid, many-meter rise in sea levels.  Yet according to the NCPA report, this would happen over too short a time to reduce the damage through CO2 emissions reductions, particularly with the prospect of increasing energy use in the developing world over the next 50 years. 

In 1992 the National Academy of Sciences recommended three geoengineering options worth exploring: reforestation, directly screening out some sunlight and increasing ocean absorption of CO2.  

  • Reforestation.  Through photosynthesis, trees remove CO2from the atmosphere, thus reforestation (and reduced deforestation) can play an important role in offsetting carbon emissions.  The United Nations' Intergovernmental Panel on Climate Change estimates reforestation could remove the carbon equivalent to about 10 percent to 20 percent of projected fossil fuel emissions by 2050. 
  • Atmospheric Sun Screens.  Volcanic eruptions that release massive amounts of sulfur dioxide (SO2) into the atmosphere provide a natural cooling effect, because SO2eventually turns into highly reflective solid particles that bounce solar radiation back into space.  One proposal to mimic this effect would be to increase the planet's reflectivity by putting tiny particles of silicon dioxide (basically, kitty litter) into the stratosphere.  

    Other proposals to reduce the solar radiation reaching the Earth include putting a large mirror or shade into orbit between the Sun and the Earth, or placing trillions of small transparent sheets in orbit to reduce the sunlight reaching the Earth's surface by 2 percent (sufficient to offset warming even with a doubling of CO2), or laying a reflective film over much of the planet's deserts. 
  • Ocean Absorption.  A third idea is to add iron to the upper layers of the ocean.  Iron acts as a fertilizer, increasing the growth of phytoplankton which, like all plants, creates carbon compounds by removing COfrom the atmosphere.  The resulting "algal blooms," when they sink, would take carbon to the sea floor, essentially storing it away.

"If we are to truly fix our climate, we cannot dismiss these options out-of-hand," said Geddes.  "It's time to think outside our soapbox."