Cautiously Pessimistic

My position on climate change in a nutshell: 1⃣ 𝐇𝐚𝐬 𝐭𝐡𝐞 𝐩𝐥𝐚𝐧𝐞𝐭 𝐛𝐞𝐞𝐧 𝐠𝐫𝐚𝐝𝐮𝐚𝐥𝐥𝐲 𝐠𝐞𝐭𝐭𝐢𝐧𝐠 𝐰𝐚𝐫𝐦𝐞𝐫 𝐟𝐨𝐫 𝐭𝐡𝐞 𝐥𝐚𝐬𝐭 𝟏𝟕𝟓 𝐲𝐞𝐚𝐫𝐬? — Yes, but it has been warming since at least 1750. Only since ~1950 or so has there been any potentially significant anthropogenic influence. How can anyone on the alarmist side explain the previous 200 years? What caused the initial warming? What caused the warming between 1910 and 1945, which is ~40% of post-1850 warming, but only ~10% of emissions? So, if natural variability hasn't contributed to any warming since 1850 (which is assumed in the climate models), then you are ignoring that. 2⃣ 𝐈𝐬 𝐫𝐞𝐜𝐞𝐧𝐭 𝐠𝐥𝐨𝐛𝐚𝐥 𝐰𝐚𝐫𝐦𝐢𝐧𝐠 𝐦𝐚𝐧-𝐦𝐚𝐝𝐞? — I think at least 𝑠𝑜𝑚𝑒 of it has been. I don't know how much exactly because it cannot be measured. Perhaps 25% or 50%. Maybe 75%? Carbon dioxide (CO₂) is in fact a “greenhouse gas” (GHG). All else being equal, adding more of it to the atmosphere should cause at least some warming; that is, ~1°C (~1.8°F) per doubling of its concentration, plus any positive feedbacks that act to amplify it (the Planck feedback, which makes the sum of feedbacks net negative, is already accounted for in the RF2xCO2 calculation). In theory, this explanation makes sense. It's radiative transfer physics. Some of it is basic math, some of it is more complicated, but it is well-understood. But a challenge in actually attributing GHG emissions to all recent warming is that the natural energy flows in and out of the Earth's climate system cannot be measured with the accuracy and precision needed to ascribe all recent warming to GHGs. The uncertainty on the TOA flux is about 5-10 W/m², which is much larger than the estimated Earth energy imbalance (EEI) allegedly from CO₂ on the order of 0.8–1.2 W/m². What's more, the climate models are artificially tuned such that there can be no natural causes of warming, CO₂ is added, then it's declared that CO₂ is the only cause of global warming since 1850. 3⃣ 𝐖𝐡𝐚𝐭 𝐚𝐛𝐨𝐮𝐭 𝐮𝐫𝐛𝐚𝐧𝐢𝐳𝐚𝐭𝐢𝐨𝐧 𝐚𝐧𝐝 𝐥𝐚𝐧𝐝 𝐮𝐬𝐞 𝐜𝐡𝐚𝐧𝐠𝐞? — I think that urban sprawl and land use have been significant contributors to local + regional warming trends. Theoretically, this could explain part or even most of the warming globally outside the north polar region, which is mostly rural. We are investigating this in more detail because we are convinced that urban influences have not entirely been removed from the temperature record. 4⃣ 𝐈𝐬 𝐫𝐞𝐜𝐞𝐧𝐭 𝐰𝐚𝐫𝐦𝐢𝐧𝐠 𝐮𝐧𝐮𝐬𝐮𝐚𝐥𝐥𝐲 𝐫𝐚𝐩𝐢𝐝 𝐨𝐫 𝐮𝐧𝐩𝐫𝐞𝐜𝐞𝐝𝐞𝐧𝐭𝐞𝐝? — I don't think so. Alarmists always bring up the “rate of change” argument in threads, but the idea that the recent warming spike is unprecedented in the last few thousand years is based on Michael Mann's infamous tree ring-based “Hockey Stick” graph from MBH (1998, 1999) and the alleged independent look-a-like “verifications” that followed (e.g., PAGES2K). But the attempts to verify it with different proxies all used the same (or a similar) methods that will generate hockey stick-shaped graphs from red noise. The shape of the graphs are largely a statistical artifact, not an accurate representation of global climate variability over the last 2,000 years. I tested this myself using random data. Ex-post correlation screening always produces a hockey stick shape. 5⃣ 𝐈𝐬 𝐞𝐱𝐭𝐫𝐞𝐦𝐞 𝐰𝐞𝐚𝐭𝐡𝐞𝐫 𝐛𝐞𝐜𝐨𝐦𝐢𝐧𝐠 𝐰𝐨𝐫𝐬𝐞? — Not really. There have been no increases in floods, droughts, thunderstorms + tornadoes + hailstorms, tropical cyclones, winter storms, or wildfires that can be attributed to GHG emissions at a global scale. There are definitely regional increases and decreases in some of these event types that are within the bounds of natural variability. In the case of certain drought types (e.g., hydrological and ecological) and wildfires that have increased regionally, that is usually attributable to land use change + poor water resource management and poor forest management, respectively. Evidence that GHG forcing has led to an increase in said events is, in my assessment, weak. You can maybe argue an increase in heatwaves and heavy rainfall since 1950 globally, but the increase in heavy rainfall occurred suddenly around 1990, which is largely an artifact of the change to automation and more efficient rain gauges. There is also a lot of data (usually legitimate extreme Tmax and precipitation values) that get falsely marked as “missing” in the digitized data, which means they get missed in every analysis published in journals and on databases. We are finding that when you look at the original paper forms, most “missing” data aren't actually missing and so we have to go in and correct the records. This is a major problem in the U.S. (in fact, filling all of the missing 20th century rainfall data in Texas in turns an increase in the top 1% of heavy rainfall events per station to a slight negative trend since 1900). I assume this problem exists outside the U.S., but at this point in time, I can't be too sure. I haven't looked into it yet. 6⃣ 𝐀𝐫𝐞 𝐭𝐡𝐞𝐫𝐞 “𝐟𝐢𝐧𝐠𝐞𝐫𝐩𝐫𝐢𝐧𝐭𝐬” 𝐨𝐟 𝐦𝐚𝐧-𝐦𝐚𝐝𝐞 𝐰𝐚𝐫𝐦𝐢𝐧𝐠? — No, not really. All global warming, natural or man-made, will result in higher latitudes warming faster than the mid-latitudes and land heating up faster than water (and by extension, the Northern Hemisphere warming faster than the Southern). So, while these changes would be consistent with GHG forcing, it's also consistent with changes in solar activity, cloud cover changes, etc. The cooling in the stratosphere since the late 1970s is probably due to CO₂. So, at least some of the warming in the troposphere since then is due to CO₂. But not all of it can be attributed to CO₂ necessarily because the physics of heat transfer in the troposphere are far more complex than that of the upper atmosphere where radiation is king and the physics are simpler. In the troposphere, you have convection and precipitation processes (latent heating) that are highly uncertain and these processes can change naturally. The fluxes on these are larger than the relatively small EEI estimated by CERES instrumentation and assumed to be due to CO₂. 7⃣ 𝐈𝐬 𝐠𝐥𝐨𝐛𝐚𝐥 𝐰𝐚𝐫𝐦𝐢𝐧𝐠 𝐝𝐚𝐧𝐠𝐞𝐫𝐨𝐮𝐬? — As far as I can tell, no. The quality of life on Earth has never been better than it is today, and it is only projected to improve through 2100 by almost every measurable metric. We can adapt to whatever climate changes there are just like we always have. But just like with any climate change that has ever occurred, natural or man-made, there will be pros and cons to it depending on where you live. I am what you call a “lukewarmer.” I do not deny that there is anthropogenic influence on the climate system, but I'm also not running around like a hysterical chicken either. There are far more important environmental problems that need to be addressed that are within our control.

What is my stance on climate change? Well, I'll lay it out for all of you newcomers. Grab some popcorn! 🍿 First, I do not deny the fact that the Earth has warmed up by ~1.2°C since 1850. However, nobody knows precisely how much because of data quality issues (e.g., uneven surface station distribution; fragmented records, especially outside of the United States; station siting changes; and urban heat island contamination) that have not been (and likely cannot be) removed from the record. But, I have no doubt that the Earth is [slightly] warmer than it was 175 years ago or that 𝑠𝑜𝑚𝑒 of that warming might be due to carbon dioxide (CO₂) emissions. Second, contrary to what the online army of alarmist foot soldiers have 𝑚𝑖𝑠𝑙𝑒𝑑 people to believe, there are not really any so-called “fingerprints” that distinguish human-caused global warming from warming caused by other forcings / variability. Numerous scientific papers claim to have found such a “fingerprint,” but the only evidence that they have presented is that the anomaly of interest is 𝑐𝑜𝑛𝑠𝑖𝑠𝑡𝑒𝑛𝑡 𝑤𝑖𝑡ℎ anthropogenic warming. But these authors fail to mention that said anomaly would also be consistent with natural warming. Case in point, a reduction in low- and mid-altitude stratiform cloud cover, for instance, would allow more sunlight into the climate system, which would warm the oceans. A warmer ocean—all else being equal—increases the rate of evaporation, which raises the vapor pressure (humidity) contributing to polar amplification and faster land warming than the ocean (e.g., Compo & Sardeshmukh, 2008). 🔗link.springer.com/article/10… / open-access: psl.noaa.gov/people/gilbert.… All warming, natural or man-made, results in: 1⃣ Higher latitudes warming faster than both the mid-latitudes and tropics. 2⃣ Land heating up faster than the oceans. This is just basic physics; look up heat capacity. Also, an increase in, say, solar forcing would have the same material effect, though we can admittedly likely rule that out as the cause of modern trends because sunspot activity has been declining in recent decades. But the sun does affect our climate in ways that have not really been thoroughly researched because little, if any funding, is ever allocated for such projects by the funding agencies such as the National Science Foundation (NSF). In any case, the 𝒃𝒆𝒔𝒕 empirical evidence that I have seen to suggest that there is probably [at least some] anthropogenic “fingerprint” on recent temperature increases is stratospheric cooling. First, you need to understand that in atmospheric physics, heat flux is measured as power—measured in Watts (that is, Joules per second)—standardized per square meter of surface area. This is written as W/m². Next, the average radiation flux into the atmosphere is on the order of 239 ± 3.3 W/m² of absorbed solar radiation (ASR) averaged over a year (Stephens et al., 2012). This means that in order for the Earth's surface to maintain a constant temperature, the surface must emit 239.7 ± 3.3 W/m² back to outer space. 🔗nature.com/articles/ngeo1580 / open-access: researchgate.net/publication… Global warming theory maintains the direct radiative forcing from doubling atmospheric CO₂ levels (often noted as RF 2×CO₂) is 3.7 ± 0.4 W/m² (e.g., IPCC TAR, 2007). That means that the net outgoing longwave radiation (OLR) to outer space is reduced by 3.7 W/m², which creates an Earth energy imbalance (EEI), which leads to a slight warming tendency in the troposphere (surface to ~13 km altitude). 🔗ipcc.ch/site/assets/uploads/… (p. 357) In the stratosphere (~13-50 km altitude), this causes a cooling tendency because less infrared radiation (IR) flux is moving upward from below. These relationships were first demonstrated in Manabe & Strickler (1964). 🔗journals.ametsoc.org/view/jo… NASA satellite measurements indicate that cooling in the stratosphere has been observed since the late 1970s, although there has been very little cooling over the last 25 years, all the while the troposphere has continued to warm. 🔗nsstc.uah.edu/data/msu/v6.1/… That means that most of the warming observed since 2000 is likely natural OR perhaps partly caused by a reduction in stratospheric sulfate aerosol concentrations, an artifact of particulate aerosol pollution regulations in recent years. But, yes, I would agree with most scientists that the cooling observed in the stratosphere, at least that from the 1970s to 2000, is most likely a result of CO₂ forcing. So what? What happens down here in the lower atmosphere in response to CO₂ forcing is a lot more nuanced. Why? Because here in the troposphere, there are feedbacks (largely cloud-related) and precipitation processes that affect the atmospheric radiation budget far more than CO₂. And how exactly clouds respond to warming in the troposphere, if at all, is not very well understood, and by extension, not well-modeled. What we do know, theoretically speaking, is that the direct warming effect of RF 2×CO₂ is actually very small. Specifically, it is on the order of ~1°C (e.g., Wijngaarden & Happer, 2020). 🔗arxiv.org/abs/2006.03098 However, amplifying (or dampening) feedbacks that kick in as a response to radiative forcing mean that the real-world value—that is, the equilibrium climate sensitivity (ECS)—will be higher (lower) than the ~1°C figure derived from radiative transfer calculations. So, three critical pieces information are unknown: 1⃣ Exactly how much warming has been man-made (since, let's say, 1950). We still don't know the answer to this because the coefficients that are used to ascribe anthropogenic versus natural forcings are all estimated from computer modeling, not real physical in-situ measurements. 2⃣ The exact value of ECS. 3⃣ Even if global warming is entirely man-made, is it really a net drawback to civilization? Is it a crisis? Is it a problem in the slightest? To break it down: • If ECS is <3°C, the climate is insensitive to GHGs, and impacts are exaggerated. • If ECS is ≥3°C, the climate is sensitive to GHGs, and warming could be a concern. The IPCC’s “best estimate” of ECS is 3°C with a range of 2-5°C. 🔗ipcc.ch/report/ar6/wg1/downl… (pp. 44-45) In 1994, using NASA's real-world bulk atmospheric temperature data, one of my mentors, Dr. John Christy and his co-worker, Dr. Richard McNider from the University of Alabama in Huntsville (UAH), calculated climate sensitivity by removing the effects of El Niño / La Niña and volcanic stratospheric aerosol injection (e.g., El Chichón, 1982; Mt. Pinatubo, 1991). Christy and McNider found that the human-induced warming rate is about 0.09°C / decade (lower than observations of actual temperature increase). This, by the way, came with the stipulation that unknown mechanisms of internal variability or external forcing are assumed to be zero. I attended a lecture where he talked about this paper in detail. 🔗nature.com/articles/367325a0 They then validated their 1994 findings in McNider & Christy (2017). Specifically, they found a near-identical anthropogenic warming rate of only 0.096°C / decade and a transient climate response (TCR) of 1.10 ± 0.26°K. 🔗link.springer.com/article/10… / open-access: sealevel.info/christymcnider… Many other recent studies (e.g., Lewis & Curry, 2018; Scafetta, 2021; Spencer & Christy, 2023; Lewis, 2025) have all estimated ECS to be far lower than the IPCC AR6's “best estimate.” 🔗journals.ametsoc.org/view/jo… 🔗mdpi.com/2225-1154/9/11/161 🔗link.springer.com/article/10… 🔗acp.copernicus.org/articles/… The jury on ECS is still out. 🤷‍♂️ What's more, in order to reliably detect anthropogenic influence on the climate system, EEI must be known to the nearest 0.1 W/m² (Von Schuckmann et al., 2016; Gebbie, 2021). 🔗nature.com/articles/nclimate… / open-access: nora.nerc.ac.uk/id/eprint/51… 🔗annualreviews.org/content/jo… However, the aforementioned Stephens et al. (2012) estimates the EEI to be 0.6 ± 0.4 W/m², which is eight times larger than the anthropogenic detection limits. And the natural top-of-atmosphere (TOA) flux has a 6.6 W/m² margin of error, which is 66 times larger than the detection limits. This range of uncertainty remains in newer estimates, such as Loeb et al. (2021), which estimates EEI to be 1.12 ± 0.48 W/m². 🔗agupubs.onlinelibrary.wiley.… This means that 𝑚𝑜𝑠𝑡 (but not all!) of the observed global warming since 1950 could be natural and scientists would never know for certain (nor would most be humble enough to admit it because the vast majority of academics have high egos). Alternatively, warming could be mostly man-made like alarmists claim, but, even if that is the case, I'll ask again. . . SO WHAT? That doesn't mean it is an existential crisis or urgent problem. The big unknown are CLOUDS. ☁️ Why? Because (a) cloud albedo has a far greater impact on the atmospheric radiation budget than does CO₂, and (b) how clouds change in response, if at all, to CO₂ is unknown. What's more, cloud cover can (and does) change naturally without mankind's assistance for any number of reasons (e.g., El Niño / La Niña activity; ocean circulation changes; cosmic ray flux; etc.). Even a small decrease in global cloud area fraction (CAF) can more than offset any temperature rise caused by CO₂. Song et al. (2016), for instance, found that, 🗨️ “[𝐴]𝑙𝑡ℎ𝑜𝑢𝑔ℎ 𝑡ℎ𝑒 𝑔𝑟𝑒𝑒𝑛ℎ𝑜𝑢𝑠𝑒 𝑒𝑓𝑓𝑒𝑐𝑡 𝑐𝑎𝑛 𝑏𝑒 𝑒𝑛ℎ𝑎𝑛𝑐𝑒𝑑 𝑏𝑦 𝑖𝑛𝑐𝑟𝑒𝑎𝑠𝑖𝑛𝑔 𝐺𝐻𝐺𝑠 𝑎𝑛𝑑 𝑤𝑎𝑡𝑒𝑟 𝑣𝑎𝑝𝑜𝑟 𝑖𝑛 𝑡ℎ𝑒 𝑎𝑡𝑚𝑜𝑠𝑝ℎ𝑒𝑟𝑒, 𝑖𝑡 𝑐𝑎𝑛 𝑏𝑒 𝑤𝑒𝑎𝑘𝑒𝑛𝑒𝑑 𝑏𝑦 𝑑𝑒𝑐𝑟𝑒𝑎𝑠𝑖𝑛𝑔 𝑐𝑙𝑜𝑢𝑑𝑠. 𝐼𝑓 𝑡ℎ𝑒𝑠𝑒 𝑡𝑤𝑜 𝑎𝑐𝑡𝑖𝑜𝑛𝑠 𝑜𝑓𝑓𝑠𝑒𝑡 𝑒𝑎𝑐ℎ 𝑜𝑡ℎ𝑒𝑟, 𝑎 ℎ𝑖𝑎𝑡𝑢𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑔𝑙𝑜𝑏𝑎𝑙 𝑔𝑟𝑒𝑒𝑛ℎ𝑜𝑢𝑠𝑒 𝑒𝑓𝑓𝑒𝑐𝑡 𝑤𝑖𝑙𝑙 𝑟𝑒𝑠𝑢𝑙𝑡.” 🔗nature.com/articles/srep3331… I don't deny that global warming is occurring. I never have. I don't even deny an anthropogenic influence on it either. I never have. What I do reject, however, is unchecked alarmism and climate activism, particularly from fellow scientists. Activism is not science and has no place in science. If you are an activist, you cannot call yourself a scientist because you are not dispassionate and objective. This goes for the vast majority of self-described “climate scientists” who actively use social media and are well-known in the debate. Two notable exceptions on the other side of the spectrum from me, in my opinion, are Drs. Robert Rohde and Paul Williams, both of whom I have always had pleasant interactions with. I also reject the idea that every weather event needs to be blamed on climate change with a rushed, half-baked attribution study (namely the ones done by the clowns at World Weather Attribution that are often not scientifically rigorous, but get plenty of news media attention by the Associated Press, CNN, The New York Times, and The Washington Post). Attribution “science” is fraudulent anyway because one of the architects behind it admitted to Politico in 2021 that it was designed with the intention of using it in litigation against oil and gas companies. 🔗eenews.net/articles/science-… Conflict of interest much? It should also be abundantly clear that climate is just a statistical description of the mean and variability of the climate system, including long-term weather. So, a change in climate is just a change in statistics. That is an outcome, not a force or accelerant that causes an extreme weather event to occur. For what it's worth, I used to be a climate alarmist well before I got my degree in meteorology. Now that I know a great deal (but not everything and never will) about atmospheric science, my position has evolved to a cooler heads point of view. Perhaps it is not my judgement that's clouded, but rather that of the alarmist arm-wavers who have high trust in both academic institutions and their government officials who spoon-feed them pre-canned talking points on the daily.