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Showing posts from January, 2025

2024 CONUS Temperatures

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NOAA has released their December 2024 results for both nClimDiv and USCRN US temperatures, and 2024 turned out to be the warmest year for CONUS on record (records beginning in 1895). NOAA's website reports CONUS for 2024 as 55.51°F. Below I show several graphs for nClimDiv, with monthly temperatures, a 12-month running mean, and a 10-year running mean. ERA5 for CONUS is also out, and to make apples to apples comparisons, I changed nClimDiv to Celsius and set it to a 1951-2000 baseline. USCRN began recording CONUS temperatures in 2005, so the end of 2024 marks the 20th year for that dataset. Below I show graphs comparing USCRN to both nClimDiv and UAH-TLT for CONUS. Here's how USCRN compares to ERA5, with the scale switched to Celsius to match ERA5. Since USCRN only goes back to 2005, I can't give you 30-year trends, but CONUS is warming so rapidly, that the last 20 years is already statistically significant. From Jan 2005 to Dec 2024, CONUS trends were: USCRN: 0.451 ± 0.241...

What Exxon Knew in 1982

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If you've participated in discussion about climate change, you've probably come across the slogan "Exxon Knew." This came out as private, internal communications from within Exxon (and other fossil fuel companies) revealed that their scientists had been investigating potential catastrophic consequences of fossil fuel emissions, and they made predictions that turned out to be pretty accurate. To what extent Exxon is culpable for this is difficult to determine. However, what is clear (to me) is that Exxon and other fossil fuel companies ought to be held liable for knowingly promoting misinformation when their own scientists were telling them that there were valid concerns that continued fossil fuel emissions would have harmful consequences for humanity. Papers were published in 2021[1] and 2023[2] that evaluated the accuracy of the scientific work that Exxon knew by evaluating the internal studies that have now been made public. The above graph has been popularly shared...

Debunking the Most Ridiculous Climate Paper I've Seen Yet

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Even though there is no theoretical basis for the Beer-Lambert formula, ∆RF = αln(C/Co), it has been accepted by the scientific community as a reasonable approximation. In this paper we propose an improved mathematical approximation that... has no theoretical basis. ~ H. Douglas Lightfoot A paper was published in Energy & Environment by Lightfoot & Mamer back in 2014 (LM14)[1] arguing that we should toss out decades of research establishing a theoretical basis for and quantifying the logarithmic relationship between changes in CO2 ( ∆CO2) and radiative forcing ( ∆RF ) for no good reason. In it's place, they sought to replace it with the results of a curve fitting exercise for no good reason except to generate an equation that would conform with a climate myth that was conclusively refuted in the 1950s. A theoretical basis for the near-logarithmic relationship between  ∆CO2 and  ∆RF was established beginning in 1896 with Arrhenius' landmark paper. Arrhenius quantified ...

Data Tampering by Shewchuk and Heller

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If you follow climate discussions on X, you're bound to see John Shewchuk and/or Tony Heller show graphs that reportedly show that NOAA is tampering with temperature data to fabricate global warming with spurious warming trends. I've gone over many of the reasons why this is nonsense before in posts about bias correction and so-called  ghost stations . I think it's good to show what's actually going on with the graphs they present as "proof" of data manipulation, though. I think it can be easily demonstrated here that it's actually Shewchuk and Heller that are tampering with data. Shewchuk (Top) and Correct (Below) Above are two graphs. The top graph shows what John Shewchuk claims shows that NOAA is manipulating data. It shows USHCN "raw" and "altered" Tmax data for 1900 to 2023. The bottom graph above is the correct plot of NOAA's published data from the current and correct dataset ( nClimDiv ) with a 5-year running mean to m...

Is There a Global Average Temperature? Part 2

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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...

2024 Global Carbon Budget

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The 2024 Global Carbon Budget has been out for a while now, but I thought it would be helpful to show the results of this update now along with the 2024 "year in review" type posts. The data included in the report goes from 1750 to 2023, since the report was published before the end of 2024. Below FFI stands for fossil fuels and industry and LUC stands for land use change. I'm not including uncertainties in my graphs below for the sake of keeping the graphs readable, but the uncertainties are discussed in the report linked at the bottom of this post. Carbon emissions continue to increase, though rates have flattened over the last decade or so. The bad news is that 2023 experienced record high emissions, so we haven't reversed the trend towards decreasing emissions yet. Here are graphs showing this from 1850 and 1958 (when the Keeling Curve begins). Human carbon emissions are mirrored by the land and ocean sinks plus atmospheric growth, such that on average, human emis...

2024 Satellite Temperature

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The December 2024 data from RSS was just made available, so I thought I'd put together some summary graphs for RSSv4 and UAHv6.1. The 2023-2024 warming spike was more pronounced in satellite data, which is intriguing. But RSS continues to show more warming than UAH.   Here are trends for the full dataset and the last 30 years: 1979 - 2024 Trends UAH: 0.153 ± 0.012°C/decade (2σ) RSS: 0.230 ± 0.012°C/decade (2σ) 1995-2024 Trends UAH: 0.162 ± 0.025°C/decade (2σ) RSS: 0.249 ± 0.024°C/decade (2σ) These trends seem pretty disparate from each other (RSS shows ~50% more rapid warming), and my uncertainty calculation doesn't account for all the sources of error in these datasets. Most importantly (as I share here ), difficulties with satellites beginning around 1998 were resolved in different ways between RSS and UAH. The decisions made by each explain a good portion of the disagreement between them (they can be seen between 1998 and 2004 below), and that is not factored in to the abov...

2024 Global Mean Surface Temperature

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Most of the GMST temperature data is in for 2024, and as most predicted, it was the warmest year on record, though perhaps by a larger margin than expected. El Niño conditions developed in 2023, and typically the following year becomes the warmest year on record. When large El Niños developed in 1997 and 2015, it was the following year that became record years, and this pattern continued again.  Above, here's how 2024 looks in several major datasets. I put the 2-sigma uncertainties for HadCRUT5 in dotted lines. This graph is set to the 1951-1980 mean (left scale), and this allows you to see that most of the variability between the datasets occurs in the late 19th century. The right scale is offset to show the warming above the 1850-1900 baseline for HadCRUT5 with the 1.5°C target as a dotted horizontal line. Below I set the same data to the 1850-1900 baseline and plotted centered 30-year means from HadCRUT5; this has the effect of better showing warming for each dataset above ...