Wood Romances

A new paper[1] by Spencer and Christy was published on urban heat islands (UHI), and I'd like to clarify what it says and what can actually be claimed as a result of it. The reason why has to do with a recent blog post from WUWT that claims the paper shows that 65% of global warming is due to UHI warming effects, rather than increasing greenhouse gas concentrations. Chris Rotter at WUWT says, A new study from the University of Alabama in Huntsville addresses the question of how much the Urban Heat Island (UHI) effect is responsible for the higher temperatures at weather stations across the world. Dr. Roy Spencer and Dr. John Christy have spent several years developing a novel method that quantifies, for the first time, the average UHI warming effects related to population density. Their finding: no less than 65% of “runaway global warming” is not caused by our emissions of carbon dioxide, but by the urbanization of the world. There's very little in this that resembles what the...

A few days ago, Dr. Roy Spencer wrote a piece for the Heritage Foundation called, " Global Warming: Observations vs. Climate Models " ( PDF ) essentially arguing that models show too much warming compared to observations, and if we stick to observations, "global warming offers no justification for carbon-based regulation." He claims to frame his argument in terms of answering three questions: Is recent warming of the climate system materially attributable to anthropogenic greenhouse gas emissions, as is usually claimed? Is the rate of observed warming close to what computer climate models—used to guide public policy—show? Has the observed rate of warming been sufficient to justify alarm and extensive regulation of CO2 emissions? We should keep in mind that this is a political document intended to support the political aims of the Heritage Foundation, and Spencer has carefully selected what he says and doesn't say to fit the political agenda of the Heritage Found...

A very common objection to climate science goes something like this - CO2 already absorbs all the IR radiation it can possibly absorb, so the greenhouse effect is saturated and adding more CO2 will not cause any more warming. Sometimes this objection is accompanied by an analogy. If you apply translucent tape to a clear window, you obstruct some but not all light passing through the window, but the more tape you add, the more lite is obstructed, and eventually you reach a thickness of tape beyond which no light can pass through. The tape has made the window opaque, and so adding more tape can't do anything more. Of course, if this were true, and if we are either at or near that saturation point, there would be no need to stop emitting carbon, since any additional carbon we add to the atmosphere won't change the Earth's temperature (it would continue to cause ocean acidification, though, but let's leave that for another day). The reasoning behind this objection is flawed...

Update 1/16/2025: I wrote a Part 2 for this post. As I write this, at least two reanalyses are showing what are still preliminary reports of record high temperatures, exceeding the warmest temperatures observed in the instrumental record. If these results hold up to scrutiny over the next couple weeks or so, this will be the hottest week on record. I want to say more about this in a future post, perhaps after the temperatures for these days are confirmed. But events like this sometimes bring out the worst in public debate, with some of extremists on the contrarian side going to the lengths of denying that there is even such a thing as a global average temperature. Now I've become used to reading contrarians claiming that the instrumental record is in some sense unreliable, either because of claims that the data isn't sound or that it's being deliberately corrupted in support of an alarmist narrative. But the outright denial of the concept of a global average temperature...