Here is my first reaction after a quick look at the summary for policymakers of the latest report by the Intergovernmental Panel on Climate Change. This is what happens when science is done by majority vote in a committee of government bureaucrats.
For example, the IPCC reports on page 23 that sea level is very likely to rise .40 to .63 meters by 2100. That's 16 to 25 inches; 4.6 to 7.2 millimeters per year for the next 87 years. Actual sea level rise for the 20th century was about 7 1/2 inches or 2 mm per year. Actual rise for the past 20 years, when satellite measurement became available, has been at the rate of 3 mm per year, plotting as a straight line with no acceleration.
If we have seen no acceleration in 20 years, why does IPCC insist that sea level will rise at 1.5 to 2.5 times faster starting now and for the next 87 years? Keep in mind that for every year its rise doesn't get faster, the rate for the remaining (fewer) years must get bigger to reach the prediction.
Hilton Head Island