I have been following with interest the columns and blogs related to climate change, most recently from Patrick Lockerby, who agrees with the evidence for human-caused global warming, and Karen Barnes, who comments on Jesse Ventura’s conspiracy theory.  Perhaps thoughttul readers of Scientific Blogging will be interested in seeing the actual data that supports global warming. Here is a NOAA website that succinctly summarizes the main lines of evidence.


    The evidence makes sense to me, and is consistent with Patrick’s conclusions. If someone wants to make a convincing case that global warming is not occurring, or is not caused by human activity, they need to provide equally convincing evidence to the contrary. 

     I think the reason that the general public is not overly concerned, or disbelieve the conclusions arising from the evidence, is that the changes so far are small: Only 0.8 degrees C rise in global temperature since 1900, and sea level changes measured as a few millimeters per year. People also experience their local climate, which might be cooler than average in a given year, and conclude that there can’t possibly be a warming trend. 

     As you will see from the NOAA website, climate scientists are instead observing global trends measured in decades, which are unmistakable. They are justifiably alarmed, and are warning that if the trends continue this century, the human race will face unprecedented coastal flooding, weather related crop failures and disease. They would be remiss in their duties if they tried to conceal their results.