Wood Romances

In a previous post I gave my rebuttal to a common objection to climate science that there is no global average temperature (or that it's incalculable or meaningless). At the time I was unaware of a paper published by Essex and McKitrick[1] on the subject, published in 2007 (hereafter EMA07). I've since read it, and while I don't think my previous post needs to change in response to it, I do think it may be worthwhile to update that post with responses specifically tailored to this paper. Others have already responded this paper (it's 18 years old), most notably at RealClimate and Rabett Run , and they do a thorough job of responding to the more technical aspects of this paper. I don't think I can add anything here that you wouldn't be better served reading there, but I do have a couple thoughts about this that I think would be helpful. Averaging Intensive Variables The main argument of this paper appears to be centered on the distinction between two types of v...

A few years ago, I began seeing contrarians promoting data from a website called temperature.global (TG), a website that claimed to publish global temperatures. According to their description, TG "calculates the current global temperature of the Earth. It uses unadjusted surface temperatures. The current temperature is the 12M average mean surface temperature over the last 12 months compared against the 30 year mean. New observations are entered each minute and the site is updated accordingly. This site was created by professional meteorologists and climatologists with over 25 years experience in surface weather observations." The website was run anonymously; to my knowledge, nobody knows exactly who is behind it. I corresponded with at least one of the people who ran the website, and he/she used the initials TG for the person's name. In another post I documented some of the failures of the website after seeking clarification from TG. The more I corresponded with TG, th...

Note: 1/15/2024. Graphs are updated to include 2024 when available. You sometimes hear that, at least on certain time scales, CO2 and global temperature (GMST) don't correlate very well or even that the two go in opposite directions. The implication drawn from this is that CO2 can't be the primary driver of climate changes. What I want to show here is that this claim is categorically false. On virtually all time scales in the Phanerozoic, CO2 and GMST correlate very well, especially when taking into consideration that GMST correlates with the log of CO2.  The best way for me to demonstrate this point is to simply show the correlation. Where I can, I convert CO2 to forcings (using RF = 5.35*ln(CO2/280)) and and plot CO2 forcings on the x-axis and GMST on the y-axis. This gives us two advantages: first, it allows us to calculate the r^2 for that correlation, and second, the slope of the correlation gives us an indication of sensitivity - that is, the temperature response to chang...

A new (currently not paywalled) Nature paper[1] was published this week with some really interesting findings. The authors examined potential biases in sea surface temperatures (SSTs) and found evidence of a cooling bias affecting SSTs between roughly 1900 and 1930 that, if corrected, would warm SSTS during that time frame and also coincidentally make the instrumental record conform more closely with model simulations for the early 20th century. Since this study did not discover a significant bias between 1850-1900, these corrections would not have a significant impact on the amount of global warming above the 1850-1900 mean, but it would have a significant impact on our understanding of multi-decadal variability in temperatures in the instrumental record. However, some on X have taken this to mean that scientists have overestimated the amount of global warming the earth has experienced. Ryan Maue called this a "bombshell climate paper" and found it disconcerting that it wa...

Along with the publication of Emily Judd's reconstruction[1] of global temperatures, she and her team compiled an up-to-date reconstruction of CO2 concentrations from proxy data. I shared in a previous post how this new reconstructions shows a CO2 and GMST as well-correlated on geologic time scales, with GMST increasing by ~8 C for 2xCO2. Her CO2 reconstruction is another step forward for paleoclimate because it makes use of a growing database of proxy evidence, much of which is being compiled at the Paleo CO2 project . For the Paleozoic and Mesozoic, Judd's reconstruction followed Foster et al 2017 [2] pretty closely, especially during the Paleozoic, but she also included additional data from Witkowski et al 2018[4][3]. Differences between Judd's and Foster's reconstruction had to do with different ways of site and time averaging and updates from Witkowski's study. During the Cenozoic, she followed more recent work by Rae et al 2021 [5] which agrees closely with t...

There's a conspiracy theory floating around the blogosphere and social media that argues (oddly) that climate scientists manufactured global warming by artificially lowering global temperatures. The "thinking" goes like this. Back in 1896, Svante Arrhenius calculated global mean surface temperature (GMST) to be 15°C. Following this, other scientists confirmed this value for later years. For instance, Hansen is reported to have claimed that value in 1981. The first IPCC report is claimed to confirm it again in 1990. In some incarnations of this conspiracy theory use other sources using 15°C, but the concept is the same. Then, after the so-called "pause" began in 1998, scientists needed another way to manufacture global warming, so they lowered GMST to 14°C so that they could increase it again. If that sounds confusing to you, it should. It doesn't make any sense. But let's unpack what's actually going on. Arrhenius' Calculation in 1896 Svante Arr...

CO2 Coalition seems to think it needs to say almost the same thing three times in slightly different ways. In " Fact #19 ," " Fact #20 " and " Fact #28 " they said in various ways that global temperatures have changed a lot across geologic history, and current temperatures are colder than most of geologic history. While these things are generally true, they are also completely irrelevant to whether humans are changing global temperatures through our carbon emissions and whether that is causing harm for human civilization and biodiversity. There are still several misleading things being said in these three "facts," beginning with the choice of graph. CO2 Coalition shows some version of the above graph in all three of these "facts," claiming it comes from "Scotese (2002)." This gives the impression they got this from a scientific paper, but it's not. It's a schematic that Christopher Scotese put on a website over 20 ye...