This is part three of a three-part series. Read parts one and two here.

Blogging economist J. Bradford DeLong has read the “global cooling” chapter of SuperFreakonomics and has asked six wonkish questions about climate science and policy. DeLong’s final two questions were about the lifecycle costs of deploying solar power. In SuperFreakonomics, Dubner and Levitt cite billionaire mosquito-laser inventor Nathan Myhrvold’s argument that solar power is not actually a “good thing” when it comes to tackling global warming.

Solar panels, Myhrvold argues, create both an “albedo debt” and a “warming debt.” If a “black” solar panel is placed on a light-colored surface, even as it generates electricity it will increase air temperatures. Furthermore, the construction of large-scale solar plants generates global warming pollution, which Myhrvold claims would counteract the benefit of replacing coal-burning plants. He makes the radical claim that the “warming debt” from solar plant construction would make “emissions and global warming worse every year until we’re done building out the solar plants, which could take 30 to 50 years.” DeLong, not surprisingly, finds these claims a bit dubious:

5: “The problem with solar cells is that they are black… designed to absorb light from the sun…. But only about 12 percent gets turned into electricity, and the rest… contributes to global warming.” Surely the heat energy reradiated from a solar panel is a small fraction of the heat trapped by all the carbon dioxide that would be produced by the coal-fired plants that would otherwise generate the electricity, isn’t it?

6: “The energy consumed by building the thousands of new solar plants necessary to replace coal-burning and other power plants would create a huge long-term ‘warming debt’.” I had thought that practically none of the power plants that we will use in 2050 are now in operation, and that building them–whether for open-carbon cycle, closed-carbon cycle, or non-carbon–will cost about the same amount of energy, and thus that there is no significant extra power-plant construction debt from going green in our new power-plant construction over the next forty years as long as it is done gradually. Am I wrong?

Myhrvold has defended his arguments, saying that when he said “black,” he didn’t mean black, just, well, rather dark. Although Dubner and Levitt radically misrepresented Ken Caldeira’s opinions in their chapter, they were spot on with Myhrvold, who blogged:

If we go hell-bent for leather in building solar plants for the next 50 years or so, it is entirely possible that we won’t see much small benefit for 30 to 50 years.

This is nonsense. Take a simplified model of the world that starts with 100 percent high-emission coal plants emitting 10,000 MMT of carbon dioxide a year and no zero-emission solar plants. Let’s assume that the construction of each solar plant has a three-year “warming debt” and that the use of each plant has a two-year “albedo debt,” in line with Myhrvold’s estimates. We’ll also assume slow growth in total energy demand (an assumption which does not affect the results of this thought experiment). If all the coal plants are replaced over a forty-year period (by 2050), the world starts seeing the benefit in only twenty years (by 2030): Read more

This is part two of a three-part series. Read part one here.

Blogging economist J. Bradford DeLong has read the “global cooling” chapter of SuperFreakonomics and has asked six wonkish questions about climate science and policy. Below are responses debunking Levitt & Dubner’s myth of decreasing temperature, and their claim that moving away from “cheap” coal would cause “economic suicide.”

3: “Then there’s this little-discussed fact about global warming: while the drumbeat of doom has grown louder over the past several years, the average global temperature during that time has in fact decreased…” As best as I can see from http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.txt, this year is: 1/5 of a degree F warmer than last year, the same temperature as 2007 and 2006, 1/7 of a degree F cooler than 2005, 1/10 of a degree F warmer than 2004, the same temperature as 2003 and 2002, 1/7 of a degree F warmer than 2001, 2/5 of a degree warmer than 1999 and 2000, the same temperature as 1998, and warmer than every single other year since the start of the Industrial Revolution–a full degree F warmer than 1960, for example.

How do you get from that temperature record to the statement that “over the past several years… average global temperature… has in fact decreased”?

The assertion that this “decrease” in temperature is a “little-discussed fact” is nonsensical. A search for “1998 cooling global” returns seven million hits. This “little-discussed fact” is one of the most popular canards among global warming skeptics.

Levitt and Dubner, like Marc Morano, Prison Planet and the Free Republic, are relying on the UK Met Office Hadley Centre temperature set — which has 1998 as the hottest year on record — as opposed to the NASA temperature set DeLong cites — which has 2005 as the hottest record. However, both sets agree that the temperature of every year since 2001 has been within the 95% confidence interval of 1998′s temperature. On a decadal scale, the average global surface temperature is increasing at a quickening pace.

Moreover, this “fact” of “global cooling since 1998″ is an error based on semantic confusion and misinterpretation of data. “Global warming” refers to the radiative forcing from greenhouse gas concentrations in the atmosphere. That effect has been consistently rising as emissions accumulate. It does not refer to year-over-year surface temperatures, which are influenced by solar output and atmospheric-oceanic circulation, both of which contributed to raise the average surface temperature of 1998.

The New Scientist, as Joe Romm has repeatedly pointed out, has a comprehensive analysis of the misunderstanding behind claims of recent cooling. The New Scientist also discusses the differences between the NASA and Hadley datasets:

The main reason is that there are no permanent weather stations in the Arctic Ocean, the place on Earth that has been warming fastest. The Hadley record simply excludes this area, whereas the NASA version assumes its surface temperature is the same as that of the nearest land-based stations.

Based on this exclusion, Romm writes, “it is almost certainly the case that the planet has warmed up more this decade than NASA says, and especially more than the UK’s Hadley Center says.” Read more