Climate Change

       Now I've got the blogging bug again, so I'll sound off on anthropogenic global warming. As part of our home school, we watched a DVD course from The Great Courses  called Earth's Changing Climate and taught by Professor Richard Wolfson. The statistic that most stuck in my mind was that we're putting about 90 Gt of carbon dioxide into the atmosphere every year, while only about two of those get absorbed back into the ground via the carbon cycle. Unlike water vapor, which cycles in and out of the atmosphere in a matter of days, carbon dioxide hangs around in the atmosphere for decades, so it's accumulating. The current scientific consensus on climate sensitivity appears to be that doubling CO2 causes an increase in global surface temperature of approximately 3ºC. (Water vapor has a significant effect on increasing temperature, but is a feedback and not a forcing in that increased temperatures from CO2 lead to more evaporation.) Current temperatures differ from Ice Age averages by only about 6ºC, so relatively small changes can have huge effects. Houston, we have a problem!
       I'm always a little puzzled by the vehemence with which AGW (anthropogenic global warming) is denied, usually with the same old, oft-debunked canards that blame solar activity or claim Earth's surface has been cooling since 1998, etc. These claims have been made so often that their refutations have for convenience been collected here.
       Forbes magazine and all the Rupert Murdoch news outlets love climate skepticism, so it was no surprise to learn recently from Forbes that New NASA Data Blow Gaping Hole in Climate Alarmism . Well, maybe not so much. The article was written by Heartland Institute journalist, James Taylor, and the NASA article he was referring to merely indicates that aerosols in the atmosphere have a slight negative forcing that is causing global surface temperature to rise a little slower than was predicted. Then Real Climate jumped in with a refutation of the original paper published in a journal called Remote Sensing and written by Roy Spenser and Danny Blackwell. The comments are of as much interest as the article.