The U.N.’s Intergovernmental Panel on Climate Change officially released the executive summary of its fifth climate change report today. The takeaway headline seems to be: Scientists are 95 percent certain that humans are responsible for at least half the earth’s warming over the past 50 years.
Putting that in perspective, since the earth has warmed about 1.3 degrees over the past 150 years, with just over half of that warming coming since 1979, that means that scientists are 95 percent certain that humans are responsible for 25 to 30 percent of the earth’s recent temperature increase. If they are correct, then humans are hardly driving the recent temperature rise but rather are responsible for a small share of a modest temperature increase. Put this way, the IPCC’s report hardly merits the headlines it’s getting.
The report acknowledges, finally, that the temperature has plateaued for 16 years now, which the scientists admit they can’t explain. However, as with past reports, due to political pressure, scientists removed all mention of the fact that all the computer models upon which the IPCC relies upon to make its predictions missed the continuing lull in the temperature rise and that on average the models have overestimated the amount of warming that the planet should have experienced by double what has actually occurred.
Thus even the small portion of the present measured warming that scientists with 95 percent confidence believe is due to human activities is based on models that demonstrably overstate global warming by more than double, models that get past and present temperatures wrong by more than a degree. How much faith should legislators or the average citizen place in such predictions.
And if, as skeptics have long argued, and the IPCC is now grudgingly admitting may be true, the earths’ temperature is less sensitive to CO2 levels than previously predicted shouldn’t the projections of future catastrophes from a further modest warming also be moderated considerably. Indeed, most of the harms predicted based on much higher temperatures are very unlikely to occur because they were the result of the higher temperature ranges.
I had a piece in Investor’s Business Daily today that runs through some of the things we do know – and what we do know is hardly alarming. For instance:
- · Despite IPCC prophecies of more — and more intense — hurricanes, the actual number and intensity of hurricanes has declined on average for seven years and has never strayed beyond the natural range of variability.
- · Sea levels are rising, yes — as they have consistently done since the end of the last ice age. But at just 2/16 of an inch per year, sea levels are rising at a far slower rate now than they have on average for the past 17,000 years.
- · Weather-related deaths are lower now than at any time in history, with fewer than 19,000 per year. Compared to 485,000 annual weather-related deaths in the 1920s or 74,000 weather-related deaths in the 1970s (when the next ice age was the weather scare du jour), this is a tremendous, felicitous decline.
Rather than inspiring fear, these facts should inform us to keep our collective head. We’ve got time to figure out what is going on and what our response should be.