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NEWEST ITEMS
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CONSISTENT CLIMATE FINGERPRINTING
I have a paper forthcoming at Climate Dynamics which discusses the contribution of Chen et al. (2023) and also sets forth a consistent method for signal detection in climate science.
When I say this method is consistent I am using the statistical concept of consistency. It is my assertion, based on several previous publications, that the IPCC method (based on Allen and Tett 1999 and Allen and Stott 2003) yields biased and inconsistent signal detection coefficients and is uninformative for the purpose of GHG attribution. The method I propose relies on Instrumental Variables estimation with Conley SAC-robust errors. There's nothing new about it, only the application. I show in an empirical example that the IPCC method (which I call P-TLS) implies a much larger role for anthropogenic forcing than the consistent approach. I present standard model specification tests (for the first time ever in an optimal fingerprinting application as far as I know) to show why the consistent model is the preferred specification. |
May 19, 2025 A CONSISTENT METHOD FOR CLIMATE FINGERPRINTING |
RECENT ITEMS
Newspaper Columns, Commentary and OtherCANADA AT A CROSSROADS
Today (February 11, 2025) marks the start of a new series I am writing for the MacDonald-Laurier Institute called Canada at a Crossroads. Each volume will examine a pressing issue in public policy that a new government needs to address. VOLUME 1: THE HOUSING CRUNCH
VOLUME 2: THE FERTILITY CRISIS
VOLUME 3: REFORMING INCOME TAXES
VOLUME 4: BOOSTING INVESTMENT
VOLUME 5: REBUILDING CANADA'S HERITAGE
SOME RECENT NEWSPAPER OP-EDS
COMPLETE LISTING HERE January 30, 2025 Face reality. Net zero is neither affordable nor attainable financialpost.com/opinion/opinion-net-zero-neither-affordable-nor-attainable January 20, 2025 The usual tactics won't work with Donald Trump nationalpost.com/opinion/ross-mckitrick-the-usual-tactics-wont-work-with-trump April 2, 2024 Economists’ letter misses the point about the carbon tax revolt financialpost.com/opinion/carbon-tax-economists-letter-misses-point February 15, 2024 Canada's Eagle Pass symbolizes unity, America's exemplifies crisis financialpost.com/opinion/canada-eagle-pass-symbolizes-unity-america-exemplifies-crisis April 12, 2023 The important climate study you won't hear about financialpost.com/opinion/ross-mckitrick-the-important-climate-study-you-wont-hear-about TEMPERATURE TRENDS IN CANADA SINCE 1888
We hear a lot about climate change. Would someone who lived in, say, 1918 notice much change in the average weather conditions compared to today? Once you delve into temperature data you will see that it's very hard to offer a simple answer to such a question. Patterns vary over time, by season and by place. For those Canadians who are curious about how the climate might have changed near where they live, I have written a rather lengthy report on the subject.
Or rather, I wrote an R program that generated a lengthy report. I analyze long term records on monthly average daytime highs in Canada, in various segments based on collections of stations available back 40, 60, 80, 100 and 130 years. There are also some nice graphs. If you think you know what "climate change" looks like in Canada, now you can test your perceptions against the data. The R program is here. 
Yourenvironment.ca
The idea of this site is very simple: to build the complete environmental record of every community across Canada. The site currently shows air emissions by source (back to 1990), air contaminant levels (back to 1974), monthly average high temperatures (back to 1900) for hundreds of places across the country, and water pollution records for several provinces. The layout is self-explanatory and it's very easy to use. The data are all from government agencies, but most of it has not hitherto been disseminated in a usable form to the public. All my sources are linked and the data I use are easily-downloadable. So the next time you find yourself in a conversation about some aspect of the environment and you wonder what is actually going on, look at yourenvironment.ca to find out. |
Recent Journal Articles and Discussion PapersEXTENDED CROP MODEL DATA SET SHOWS NO YIELD LOSSES FOR CO2-INDUCED WARMING
A few years ago the Biden administration hiked its estimate of the Social Cost of Carbon, thus triggering a large number of new regulations on CO2 emission sources. A big part (about $50 worth) of the upward revision was due to a 2017 study arguing that warming would have much worse effects on crop yields than hitherto expected. I noticed that the 2017 study reached very different conclusions than a 2014 study that had used the same data. So I set out to try and understand why. The result is the following paper:
Both studies used a data set created by surveying several decades' worth of crop yield modeling studies. I obtained the data set and saw that despite it having about 1700 rows, half were missing the CO2 data and were therefore unusable. I looked into the underlying data sources and found several hundred of the missing CO2 entries. I found I could replicate the 2017 results showing negative crop yield effects from climate warming based on the incomplete data set, but when I added in the missing data the results all changed and the negative effects vanished, thus matching the 2014 findings. Basically the extra CO2 fully compensates for any negative effects of warming even out to 5C warming, across all crop types and in all regions. I conclude the upward revision to the SCC due to the supposed crop yield losses was unwarranted. ECONOMIC ANALYSES OF THE FEDERAL GHG EMISSION REDUCTION PLAN
There is an astonishing lack of economic analysis from the Canadian government regarding the likely impacts of its GHG Emission Reduction Plan (ERP). This is the largest and most consequential economic policy initiative in my lifetime, dwarfing the 1988 Free Trade Agreement and any other policy change I can think of, yet there has been zero economic analysis by the government. I have undertaken to fill the gap through the following Fraser Institute reports:
The first is a brief decomposition of the drivers of GHG emissions and a projection showing why we are unlikely to come close to the 2030 target. The second is a comprehensive critique of the federal policy package. I divide the ERP into three components: the carbon tax, the Clean Fuels Regulation and the regulatory systems. Using a detailed province-level dynamic CGE model I analyze the effects cumulatively. I show that the carbon tax will be costly but manageable, the CFS adds quite a bit to the cost without reducing emissions much, and the regulatory measures are extremely expensive for the small emission reductions they achieve. I conclude that the overall package is so damaging to the economy it is unlikely to survive implementation. The third extends the analysis to 2050 and also looks at whether a carbon tax alone could get emissions to zero. I find there is a hard cap on abatement at about 80%, but getting there would be intolerably costly. ECONOMIC IMPLICATIONS OF A PHASED-IN EV MANDATE IN CANADA
I have published a paper in the Canadian Journal of Economics looking at the Canadian plan to mandate 100% EV sales by 2035:
The key message is that an EV mandate is only affordable if it is also unnecessary. If you have to force people to switch to EVs the policy will push the auto sector into permanent losses. The key question is the pace at which EVs achieve cost parity. "Cost parity" doesn't just mean being able to buy an EV sedan for $30k. It means that across all vehicle classes, taking account of all purchase, maintenance and fuel costs, people are completely indifferent between EVs and internal combustion engines (ICEVs); analogous to the switch from LPs to CDs. If we reach cost parity by 2035 the mandate will be very costly but the economy will return to trend and the auto sector will probably survive albeit shrunken. But in that case the mandate is unnecessary. If cost parity takes longer and the mandate forces involuntary switching, the economic costs get very large very quickly and the auto sector goes into permanent losses. I simulate the outcome assuming 2050 cost parity and find the auto sector gets wiped out and the macroeconomic impacts are very painful. For the reasons stated in the paper I don't think it is realistic to expect EV cost parity by 2035, so my expectation is for the latter scenario. TLS OVERSTATES CLIMATE FINGERPRINTING COEFFICIENTS WHEN FORCING SIGNALS ARE NEGATIVELY CORRELATED
I have published a paper in Environmetrics which goes deeper into problems with Total Least Squares (TLS), a popular regression estimation method in the "optimal fingerprinting" field in climatology.
I have written up an explanatory essay at Judith Curry's Climate Etc. blog. Briefly, there's a problem in regression analysis when your explanatory variables are measured with error. This causes ordinary least squares to underestimate the slope coefficients. The usual remedy in econometrics is called Instrumental Variables (IV), but climatologists instead adopted another technique called Total Least Squares (TLS). The trouble is, while we can prove IV yields asymptotically unbiased results, you can't prove that TLS works without making some strong assumptions that can't be tested. I show that in typical applications in climatology TLS imparts positive upward biases to the results and overstates the slope coefficient estimates. |
