OK but what is the policy bottom line? Principally that we need to use forward-looking modes of risk to build hazard-mitigating infrastructure and create incentives for building in areas that are less vulnerable to storm (or river flooding or wildfire) damage. Exactly how much ACC increases the potential for harm is neither hear nor there for harm reduction.
This is not an either/or issue, as you note (either climate change or societal change driving tropical cyclone *impacts*). But your argument appears to rely on the same tactic you disparage in others: "the selective emphasis of certain facts that bolster their stance."
You omit the abundant and vital array of studies of "paleotempestology" records showing that strong hurricanes can be frequent in periods when sea temperate were cooler: See Jeff Donnelly's work over the last two decades, a 2007 study I wrote up in The New York Times: "Over the last 5,000 years, the eastern Caribbean has experienced several periods, lasting centuries, in which strong hurricanes occurred frequently even though ocean temperatures were cooler than those measured today, according to a new study." https://www.nytimes.com/2007/05/24/science/earth/24storm.html
You're also way out of date. Relying on Kerry Emanuel's near-decade-old rebuttal to Roger's 538 post misses Roger's subsequent output (see links in his reply to this post) and misses Kerry's important recent work with PhD advisee Rapahel Rousseau-Rizzi nailing down that shifts in *aerosol* pollution have been the dominant shaper of recent North Atlantic hurricane patterns (not CO2-driven warming): Natural and anthropogenic contributions to the hurricane drought of the 1970s–1980s: https://texmex.mit.edu/pub/emanuel/PAPERS/Rousseau-Rizzi_Emanuel_2022_published.pdf
"It is likely that the global proportion of Category 3–5 tropical cyclone instances … have increased globally over the past 40 years." (Section 11.7.1.2)
Andrew, I know you do this as a hobby, and I appreciate that you cite the IPCC, but you are cherry picking. Why limit yourself to the past 40 years? We know that there is lot of decadal variability (and even annual auto-correlation) when it comes to hurricanes, and therefore the longer the observation period the better. Why not cite the first paragraph of the very same section?
"There is low confidence in most reported long-term (multi-decadal to centennial) trends in TC frequency- or intensity-based metrics"
Based on these long term trends I'd argue it is incorrect to say "with some certainty that TCs are on average more intense than those that form in a cooler climate."
1. Tropical cyclones are becoming more destructive: sea level. This seems to be a strong case. It argues for stronger protections against floods and storm surges.
2. Tropical cyclones are becoming more destructive: rainfall. This seems like a good intuitive case. You cite the IPCC's conclusion that climate change is responsible for extreme rainfall in Hurricane Harvey. I'm curious if there's been any systematic measurement of rainfall from tropical cyclones over time. I can't find any reference to such studies. I know there are models predicting that anthropogenic causes will increase rainfall, decrease translation speeds, etc. It would be nice if there were any historical data to identify things like: What's a normal range for rainfall from a hurricane? Has there been a trend in rainfall from hurricanes? Does any of this change over the multi-decadal cycles observed in hurricane activity? Aside from modeling, is there any evidence of anthropogenic causes to any of this?
3. Tropical cyclones are becoming more destructive: intensity. This claim seems much less established. The abstract of the article you link for "basic physics" doesn't claim that overall warming temperatures make hurricanes more intense - it actually states "the factors that control the intensity of hurricanes are still poorly understood, leading to almost no reliability in forecasts of hurricane intensity evolution." Your quotes from the IPCC are hardly compelling. "It is likely that the global proportion of Category 3–5 tropical cyclone instances … have increased globally over the past 40 years." But the same section of the IPCC report notes that "A subset of the best-track data corresponding to hurricanes that have directly impacted the USA since 1900 is considered to be reliable, and shows no trend in the frequency of USA landfall events". NOAA data also shows no trend in the number or proportion of Category 3-5 hurricanes in the same period. It is clear that Atlantic hurricane activity has increased over the last 40-50 years, but this is because the 1970s were the decade of lowest recorded activity ever. The increase since then is clearly, at least in part, a return to "normal" levels of activity. Your conclusion "You can say with some certainty that TCs are on average more intense than those that form in a cooler climate." is utterly unsupported by any of the sources you mention, or any other published data I've seen.
4. What we’re not sure about: number of tropical cyclones. Well, I'm not sure, either, aside from what I mentioned above. Enough said on that.
5. What we’re not sure about: monetary damage from tropical cyclones. You claim that Professor Kerry explains why it's wrong to claim no trend in "normalized" damage from tropical storms. I won't wade into this debate because it covers only 23 years' worth of data. But, as noted in 3. above, there's no trend over the last 120 years in the number of storms making US landfall, or in their intensity. There may be some increase from storm surge damage due to rising sea level, but it seems pretty clear that any other trend has to be due to simply having more property, and more valuable property, in storm-affected areas. You cite the wisdom of insurance companies in raising rates and withdrawing from Florida, but the insurance companies claim the rates are rising because of increasing fraud, aided by a 2017 Florida Supreme Court decision that made fraudulent claims harder and more expensive for insurance companies to fight. https://www.insurance.com/home-and-renters-insurance/home-insurers-leaving-florida
Point 1 seems to be strong. The others seem to range from speculative to unsupportable. If you have stronger evidence, I'd like to see it.
The numbers on the cost of climate change vs the cost of current climate hysteria driven political policies clearly demonstrates we are on the wrong political trajectory with respect to how we are phasing out fossil energy in the west.
It's true tropical cyclones are trending stronger, yet the trend isn't as great as activists portray, and the real global warming driving this increase has both natural and human causes. Here's more on the science of climate change. https://normanjansen.substack.com/p/climate-catastrophe
I find this article long on speculation and short on details. The New York example is very weak. Sorry, not convincing at all except to the naive climate change alarmist groupies. This is typical propaganda. The devil is in the details. I'm a retired mechanical engineer with experience in failure analysis and I find climate change analysis to be too vague, lacking data, political, biased etc etc.
Andy, If you'd unblock me on Twitter we could discuss this topic out in the open.
Meantime:
1. Your piece repeats a major error made in the IPCC (confusing fixes with storms):
https://rogerpielkejr.substack.com/p/a-tip-from-an-ipcc-insider
2. Here is a more comprehensive look at the scientific consensus on tropical cyclones:
https://rogerpielkejr.substack.com/p/2023-update-what-the-media-wont-tell
OK but what is the policy bottom line? Principally that we need to use forward-looking modes of risk to build hazard-mitigating infrastructure and create incentives for building in areas that are less vulnerable to storm (or river flooding or wildfire) damage. Exactly how much ACC increases the potential for harm is neither hear nor there for harm reduction.
This is not an either/or issue, as you note (either climate change or societal change driving tropical cyclone *impacts*). But your argument appears to rely on the same tactic you disparage in others: "the selective emphasis of certain facts that bolster their stance."
For instance, I don't know how anyone can omit the vital NOAA guidance on hurricanes and climate change: https://www.gfdl.noaa.gov/global-warming-and-hurricanes/
You omit the abundant and vital array of studies of "paleotempestology" records showing that strong hurricanes can be frequent in periods when sea temperate were cooler: See Jeff Donnelly's work over the last two decades, a 2007 study I wrote up in The New York Times: "Over the last 5,000 years, the eastern Caribbean has experienced several periods, lasting centuries, in which strong hurricanes occurred frequently even though ocean temperatures were cooler than those measured today, according to a new study." https://www.nytimes.com/2007/05/24/science/earth/24storm.html
You're also way out of date. Relying on Kerry Emanuel's near-decade-old rebuttal to Roger's 538 post misses Roger's subsequent output (see links in his reply to this post) and misses Kerry's important recent work with PhD advisee Rapahel Rousseau-Rizzi nailing down that shifts in *aerosol* pollution have been the dominant shaper of recent North Atlantic hurricane patterns (not CO2-driven warming): Natural and anthropogenic contributions to the hurricane drought of the 1970s–1980s: https://texmex.mit.edu/pub/emanuel/PAPERS/Rousseau-Rizzi_Emanuel_2022_published.pdf
"It is likely that the global proportion of Category 3–5 tropical cyclone instances … have increased globally over the past 40 years." (Section 11.7.1.2)
Andrew, I know you do this as a hobby, and I appreciate that you cite the IPCC, but you are cherry picking. Why limit yourself to the past 40 years? We know that there is lot of decadal variability (and even annual auto-correlation) when it comes to hurricanes, and therefore the longer the observation period the better. Why not cite the first paragraph of the very same section?
"There is low confidence in most reported long-term (multi-decadal to centennial) trends in TC frequency- or intensity-based metrics"
Based on these long term trends I'd argue it is incorrect to say "with some certainty that TCs are on average more intense than those that form in a cooler climate."
1. Tropical cyclones are becoming more destructive: sea level. This seems to be a strong case. It argues for stronger protections against floods and storm surges.
2. Tropical cyclones are becoming more destructive: rainfall. This seems like a good intuitive case. You cite the IPCC's conclusion that climate change is responsible for extreme rainfall in Hurricane Harvey. I'm curious if there's been any systematic measurement of rainfall from tropical cyclones over time. I can't find any reference to such studies. I know there are models predicting that anthropogenic causes will increase rainfall, decrease translation speeds, etc. It would be nice if there were any historical data to identify things like: What's a normal range for rainfall from a hurricane? Has there been a trend in rainfall from hurricanes? Does any of this change over the multi-decadal cycles observed in hurricane activity? Aside from modeling, is there any evidence of anthropogenic causes to any of this?
3. Tropical cyclones are becoming more destructive: intensity. This claim seems much less established. The abstract of the article you link for "basic physics" doesn't claim that overall warming temperatures make hurricanes more intense - it actually states "the factors that control the intensity of hurricanes are still poorly understood, leading to almost no reliability in forecasts of hurricane intensity evolution." Your quotes from the IPCC are hardly compelling. "It is likely that the global proportion of Category 3–5 tropical cyclone instances … have increased globally over the past 40 years." But the same section of the IPCC report notes that "A subset of the best-track data corresponding to hurricanes that have directly impacted the USA since 1900 is considered to be reliable, and shows no trend in the frequency of USA landfall events". NOAA data also shows no trend in the number or proportion of Category 3-5 hurricanes in the same period. It is clear that Atlantic hurricane activity has increased over the last 40-50 years, but this is because the 1970s were the decade of lowest recorded activity ever. The increase since then is clearly, at least in part, a return to "normal" levels of activity. Your conclusion "You can say with some certainty that TCs are on average more intense than those that form in a cooler climate." is utterly unsupported by any of the sources you mention, or any other published data I've seen.
4. What we’re not sure about: number of tropical cyclones. Well, I'm not sure, either, aside from what I mentioned above. Enough said on that.
5. What we’re not sure about: monetary damage from tropical cyclones. You claim that Professor Kerry explains why it's wrong to claim no trend in "normalized" damage from tropical storms. I won't wade into this debate because it covers only 23 years' worth of data. But, as noted in 3. above, there's no trend over the last 120 years in the number of storms making US landfall, or in their intensity. There may be some increase from storm surge damage due to rising sea level, but it seems pretty clear that any other trend has to be due to simply having more property, and more valuable property, in storm-affected areas. You cite the wisdom of insurance companies in raising rates and withdrawing from Florida, but the insurance companies claim the rates are rising because of increasing fraud, aided by a 2017 Florida Supreme Court decision that made fraudulent claims harder and more expensive for insurance companies to fight. https://www.insurance.com/home-and-renters-insurance/home-insurers-leaving-florida
Point 1 seems to be strong. The others seem to range from speculative to unsupportable. If you have stronger evidence, I'd like to see it.
The numbers on the cost of climate change vs the cost of current climate hysteria driven political policies clearly demonstrates we are on the wrong political trajectory with respect to how we are phasing out fossil energy in the west.
It's true tropical cyclones are trending stronger, yet the trend isn't as great as activists portray, and the real global warming driving this increase has both natural and human causes. Here's more on the science of climate change. https://normanjansen.substack.com/p/climate-catastrophe
I find this article long on speculation and short on details. The New York example is very weak. Sorry, not convincing at all except to the naive climate change alarmist groupies. This is typical propaganda. The devil is in the details. I'm a retired mechanical engineer with experience in failure analysis and I find climate change analysis to be too vague, lacking data, political, biased etc etc.