How to best curb greenhouse gas emissions is a hotly debated topic. But new research suggests that putting the brakes on greenhouse gas levels is not enough to slow down climate change because the ocean responds so slowly to perturbations. The study results, published today in the journal Science, indicate that even if greenhouse gas levels had stabilized five years ago, global temperatures would still increase by about half a degree by the end of the century and sea level would rise some 11 centimeters.

"Many people don't realize we are committed right now to a significant amount of global warming and sea level rise because of the greenhouse gases we have already put into the atmosphere," says study author Gerald Meehl of the National Center for Atmospheric Research (NCAR) in Boulder, Colo. "The longer we wait, the more climate change we are committed to in the future." Meehl and his NCAR colleagues ran two coupled climate models that link major components of our planet's climate and incorporate their interactions. The researchers then analyzed scenarios in which greenhouse gases continue to accumulate in the atmosphere at low, moderate and high rates. The highest rates of accumulation led to model results that included a 3.5 degrees Celsius increase in global temperatures and a 30 centimeter rise in global sea level.

But even without additional greenhouse gas contributions, they found, global temperature would continue to rise because of a characteristic known as thermal inertia. Water in the oceans heats and cools more slowly than air does because of its greater density, leading to a delayed response. In addition, carbon dioxide and other greenhouse gases have long atmospheric lifetimes and can affect temperatures for years after first being introduced into the atmosphere. The authors conclude that "at any given point in time, even if concentrations are stabilized, there is a commitment to future climate changes that will be greater than those we have already observed."

3 Comments

1. 1. BillCar 04:42 PM 1/1/08

   I hope the calculations of the models of climate change are not done on computers using Windows operating systems. Namely, Windows produces computing errors - that is, miscalculations.

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2. 2. Bruce Tebo 10:13 PM 11/1/08

   I live in Fort Lauderdale, Florida.
   My house is 9 feet above sea level.
   When should I start packing to stay ahead of rising ocean levels?
   BruceTebo

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3. 3. blouis79 04:45 PM 12/29/09

   Kevin Trenberth, author of the "Global Energy Budget", a key paper for IPCC and global warming:
   
   Kevin Trenberth wrote:
   > Hi Tom
   > How come you do not agree with a statement that says we are no where
   > close to knowing where energy is going or whether clouds are changing to
   > make the planet brighter. We are not close to balancing the energy
   > budget. The fact that we can not account for what is happening in the
   > climate system makes any consideration of geoengineering quite hopeless
   > as we will never be able to tell if it is successful or not! It is a
   > travesty!
   > Kevin
   
   Source: http://chriscolose.wordpress.com/2008/12/10/an-update-to-kiehl-and-trenberth-1997/#comment-1449

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