My greener friends are rejoicing over the apparent “conversion” of Richard Muller, head of the Berkeley Earth Surface Temperature (BEST) research team, from “climate change skeptic” to believer in global warming. A closer read of his New York Times op-ed, published on July 30, during what is climatologically the hottest week of the year, would certainly cool their enthusiasm.
In it, Muller discusses the fact that the surface temperature of the planet indeed is warmer than it was at the end of the Little Ice Age in the 19th century. While not one climate scientist finds this at all newsworthy, his “admission” has been ballyhooed in environmental circles as a defection that will end the Hot War. Trouble is, Muller’s statements don’t come close to any sort of radical retraction — and there is evidence his conclusions are obviously flawed to begin with.
There are three philosophies in the world of global warming. Loudest are the “hotheads,” who maintain that drastic (and impossible) measures are needed to curtail the emission of greenhouse gases and prevent the seas from rising dozens of feet in a hundred years. The data relied upon by this segment is suspect, but their alarmist message garners more than its share of attention.
The recognized antithesis of hotheads are the “flatliners,” who contend that there is no measurable warming caused by increasing atmospheric carbon dioxide. Their bible is the lack of warming in the last 16-odd years, when CO2 levels have risen the most. They do have a problem explaining the rise in temperatures in the preceding decades.
In the third school, where I find myself, reside the “lukewarmers” — those who argue that carbon dioxide indeed is warming surface temperatures, but that its effect is modest and that we are inadvertently adapting. Our mantra: “It’s not the heat, it’s the sensitivity.” In other words, most climate projections assume that surface temperature is overly sensitive to “forcing” from carbon dioxide. Our bible consists of observed temperature trends as CO2 increased in the last several decades.
I would like to welcome Dr. Muller to the noble fellowship of lukewarmers.
In his op-ed, he forecast that land surface temperatures will rise 1.5°F over the next 50 years. That’s about the same amount that they rose since 1900 — and in the intervening period, life expectancy doubled and per-capita income in constant dollars rose tenfold in the United States.
Muller wrote an important caveat, which is that warming would be much greater if atmospheric carbon dioxide rocketed upwards. Rapidly declining emissions in the U.S., resulting in large part from the exponential substitution of natural gas (sourced from shale), instead of coal for electrical generation, suggest this is not likely. Shale is ubiquitous worldwide, and what began here is likely to spread around the planet.
Note that Dr. Muller is talking about land temperatures, which applies to about 30% of the earth’s surface. Given that the remaining 70% that is water tends to warm at about 60% of the land rate, his global warming forecast is 1.1°F by 2060, which is precisely lukewarm.
For comparative purposes, the median 2010-2060 warming predicted by the United Nations’ Intergovernmental Panel on Climate Change (IPCC) is around 2.7°F. NASA’s James Hansen, the head hothead, has it at around 2.4° for his “Scenario B,” which implies some reduction in emissions from “business-as-usual” (BAU). “Scenario A,” which Hansen explicitly labels BAU, yields a whopping 5.6°, which Hansen now says is on the high side.