Which of These Is Not Causing Global Warming Today?

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This is not to say that every sign of climate change reflects the heat-trapping effects of the gases we spew out of our utility plants, cars and planes. Increases in the sun's output were probably responsible for the warming that occurred in the early 20th century. And natural variability explains some sea-level rise and loss of arctic sea ice. Undoubtedly, other natural explanations for climate change will pop up; one currently getting some buzz (as well as lots of criticism) is that changes in the sun's output alter the barrage of cosmic rays that strike Earth, producing fewer clouds and therefore a warmer world.

But that raises a question for those who emphasize nature's contributions to global warming and other aspects of climate change. Let's suppose that those are nudging the climate toward worse storms and more droughts and more heat waves, just as greenhouse gases are. In that case, you'd think the world would want to control the causes of global warming that it can. At last check, no one had figured out how to turn down the sun.

Water vapor, while being a much more powerful greenhouse gas, cannot drive climate change, due to its limited duration in the atmosphere (a few days) and its massive regional variability. However, it can act as a strong feedback mechanism to reinforce warming driven by CO2 which is atmospherically well mixed and remains in the atmosphere for upwards of a hundred years.

Also, if you plot surface temperature data from any of the respected sources (UAH, RSS, NASA GISS, HadCRUT) from 1999-2008, you will see that the temperatures have indeed continued to rise. The common misconception that it stopped in 1998 is propagated by those who include the anomaly year of 1998 where temperatures were driven to record levels on top of anthropogenic influences by the "El Nino of the Century". Even noting the leveled temperature graph including 1998, it's worth considering that we are reaching temperatures on par with 1998, except now they are being reached during a solar minimum and a La Nina set of conditions, both of which tend to drive temperatures down. Global temperatures are still warming.

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Posted By: artesian @ 07/04/2008 9:48:56 PM

My information says that CO2 has 5-10 years residence time in the atmosphere. Many studies. Lawrence Solomon , "The Deniers".
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Posted By: artesian @ 07/04/2008 9:47:12 PM

CO2 stays in the atmosphere 5-10 years. Dozens of studies.
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Posted By: Descent @ 07/03/2008 1:29:24 PM

Water vapor, while being a much more powerful greenhouse gas, cannot drive climate change, due to its limited duration in the atmosphere (a few days) and its massive regional variability. However, it can act as a strong feedback mechanism to reinforce warming driven by CO2 which is atmospherically well mixed and remains in the atmosphere for upwards of a hundred years.

Also, if you plot surface temperature data from any of the respected sources (UAH, RSS, NASA GISS, HadCRUT) from 1999-2008, you will see that the temperatures have indeed continued to rise. The common misconception that it stopped in 1998 is propagated by those who include the anomaly year of 1998 where temperatures were driven to record levels on top of anthropogenic influences by the "El Nino of the Century". Even noting the leveled temperature graph including 1998, it's worth considering that we are reaching temperatures on par with 1998, except now they are being reached during a solar minimum and a La Nina set of conditions, both of which tend to drive temperatures down. Global temperatures are still warming.