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Showing posts from July, 2023

Sniff Test for USFS Annual Report Fire Data (1926-1959)

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The NIFC website contains a good deal of historical information about wildfires in the US. Up through 2018, one page contained historical wildfire data from 1960 to the current year. However, between 2018 and 2021, the NIFC added data from 1926 to 1959 coming from USFS annual reports. These data were not wildfire data comparable to data following 1983, and the NIFC included a warning not to compare the two sets of data. However, contrarians did so anyway and the data from 1926 to 1982 was eventually removed from the site, prompting conspiracy theories that the NIFC was hiding data. I detailed this in another post , and I'd highly recommend reading that post first to get a better sense of what I want to show here. In that post I researched what the USFS says about this data from 1926-1959 - what is known and what is unknown - from several reports written by Karen Short. Short made several points by delineating how much of the reported fire data was on unprotected vs protected l...

Can Atmospheric Pressure or Density Explain the Earth's Temperature?

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In my last post , I responded to the claim that the greenhouse effect contradicts the second law of thermodynamics. When people make this claim, I often ask what it is that makes the Earth's temperature warmer than its effective temperature if there's no greenhouse effect. The response I get back usually has to do with what can only be described as an ill-informed, "crackpot" theory arguing that this is due to atmospheric pressure or density. Using the ideal gas law, critics of science calculate the temperatures on planets like Venus, Earth and Mars from other known quantities in the ideal gas law, and then assert that this means planetary temperature is due to density or pressure instead of the GHE. There are multiple versions of this, all of which claim either that there is no greenhouse effect or that the greenhouse effect has nothing to do with greenhouse gases and everything to do with atmospheric pressure and/or density. To my knowledge the original version of t...

Does the Greenhouse Effect Contradict the 2nd Law of Thermodynamics?

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Occasionally I hear people claim that the greenhouse effect isn't real because it would contradict the 2nd law of thermodynamics. The idea behind this is that the atmosphere is cooler than the Earth's surface, and the 2nd law of thermodynamics says that the net flow of heat always goes from hot to cold. Therefore, the Earth's atmosphere can't heat the Earth's surface. Therefore, the greenhouse effect can't exist in a universe in which the 2nd law of thermodynamics is operable. The silliness of this objection can become apparent with a simple analogy. If you walk outside with a thin t-shirt on a cold day (let's say 20°F), you'll quickly feel cold, and the surface of your skin will be significantly colder than normal. If you find a winter coat outside, its temperature will be 20°F. But if you put it on, you will begin to warm. It's not that the coat is generating heat and sending it to your body. It's simply slowing down the rate at which heat leav...

Is CO2 Saturated in the Atmosphere?

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There is a very common objection to climate science that 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. Of course, if this were true, there would be no reason to prevent CO2 from increasing above current levels, since doing so would not cause any more warming than has already been caused. But is this true? No. This objection to climate science takes a correct observation then uses faulty logic based on a misunderstanding of the greenhouse effect to make an erroneous conclusion. Let's begin with the correct observation. CO2 concentrations at the surface are sufficient already to absorb nearly all the IR radiation leaving the Earth's surface that it could possibly absorb. But this observation does not mean that increasing CO2 concentrations will not cause more warming, and here are two important reasons why. 1. Whenever CO2 molecules absorb IR ra...

This is Just Too Funny

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Two things happened recently at Watts Up With That , and the combination of the two, I think is rather hilarious. Observant readers will know that contributors to WUWT regularly claim that climate models are "alarmist" because they overestimate how much warming has occurred. My favorite of these is Christopher Monckton, who provides us with a steady dose of this kind of rhetoric. There are two necessary components to his tactic: He regularly exaggerates how much warming models predict. In a recent post , he claims CMIP6 models predict 0.386° C /decade warming. He regularly cherry picks short-term trends beginning somewhere around 2014 or 2015 to claim that there has been a pause in global warming in the UAH lower troposphere dataset. I blogged about this in my first post on debaters behaving badly . UAH has a long-term warming rate of about 0.13° C /decade. From this he claims that models predict 282% too much warming. Here's how Monckton portrays this: Monckton on Models...

Climate in 2023: A Mid-Year Update

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 We're now just past half way through 2023. At the beginning of the year, it was expected that there was a good likelihood that we would transition into El Niño conditions sometime in the Spring or Summer, and this might lead to a new record high GMST in 2024, with a small chance of this happening in 2023. However, with developments occurring over the last couple months, all that has changed. On Twitter, Zeke Hausfather provided data from Berkeley Earth that, barring some event like a large volcanic eruption, there is an  81% chance  that 2023 would beat out 2016/2020 as the warmest year on record. In fact, the year-to-date average already surpasses 2020, and there's a small potential that this year could be the first year to hit the +1.5 ° C above the 1850-1900 mean. Hitting 1.5 ° C would not mean that we have missed the IPCC target of 1.5 ° C, since that target is built on the 30-year average, not a single year. But what changed from the beginning of the year ...

Why are Global Temperatures Reported as Anomalies?

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For over 100 years, scientists investigating climate change have estimated that the Earth's surface temperature is ~288 K (or ~15°C), which is about 33 K warmer than the Earth's effective temperature of ~255 K (or -18°C). The first paper I know of to use ~15°C as the Earth's "current" temperature is Svante Arrhenius' paper .[1] I've read reports that Fourier did as well but I haven't been able to find where he actually uses this figure. The figure of ~15°C has become somewhat standardized in explanations of the greenhouse effect, with various authors continuing to use the same figure of ~15°C, even as global temperatures rise. Since the sources using this figure are not basing the value on global measurements, I suspect it's best to view it has having an uncertainty of at least ±1°C. Can we do better? Accuracy of Anomalies vs Absolute Temperatures More recently, organizations like NASA have estimated that GMST for their 1951-1980 baseline averaged ...

Is there a Global Average Temperature?

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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, or more specifically global mean surface temperatu...