Thank you for your testimony. “Low confidence” is the inconvenient truth for many, yet there is high confidence in the future of climate anomalies and extremes, especially in this era of information overload and exploitation.
Roger - I appreciate your official take, but cannot help but be struck by what is actually occurring all over this planet. How many areas across the globe are experiecing serious water stress? Perhaps some of the many water crises across the planet are the combination of changes in land use, resource mismanagement and climate change. The Amazon is an example where with deforestation, there has been a clear pattern of "drying out"; e.g., https://www.nature.com/articles/s41586-022-05690-1 and see Rob Lewis' series on Milan Millan: https://theclimateaccordingtolife.substack.com/p/millan-millan-and-the-mystery-of . Perhaps this cannot be teased out or attributed to climate change per se, but doesn't it feel like millions of people across the globe are facing extreme water scarcity either for drinking water, agriculture or both in an unprecedented manner? The increase in heat is certainly an issue with climate change, but it feels like a drier planet - at least in some areas - will ultimately drive a loss of vegetation, a loss in water storage and terrestial water recycling and ultimately desertification. Habitable land is going to become scarcer. Doesn't this deserve more attention, press and action?
I agree with you 100% that there are regions that have experienced drying.
According to the IPCC (not me) attribution to human-caused climate change remains challenging. (Rob Lewis is excellent.)
I do not however agree that the world is drying out. Indicators suggest global precipitation has increased worldwide over the past century:
"On average, total annual precipitation has increased over land areas in the United States and worldwide (see Figures 1 and 2). Since 1901, global precipitation has increased at an average rate of 0.04 inches per decade, while precipitation in the contiguous 48 states has increased at a rate of 0.20 inches per decade."
I appreciate the quick reply. I understand warmer air can hold more water and I am not disputing that. It is its re-distribution as precipiatation that I am worried about. If one buys that land use affects downwind rainfall, then it feels like one could theoretically develop a global map of the relative importance of land to the re-distribution of precip in order to prioritize land conservation or restoration. Perhaps this is the kind of nuance you are referring to?
I'm not too bullish on us ever being able to produce skillful long-term predictions of climate (i.e., from seasonal to decades) so that means that policies that focus on increasing resilience and reducing vulnerability will make the most sense. Dry-prone regions, like the American West, already know this, but taking knowledge into action is always a challenge.
Highly complex systems are impossible to model. Weather is indeed a highly complex system. I traded Bond options for 20 years and can attest that there is no model that can capture the tail events that are characteristic of highly complex systems. I humorously tell people that I have seen eight once in a lifetime events in my 43 year career! 🤣
I remember reading 35 years ago an engineer saying that all of the space shuttles would catastrophically fail. His argument was that they were essentially so complex that all the various outcomes could not be modeled. My son is an engineer and out of college worked on the next generation of aircraft carriers. I asked him if this same problem of these ships bordering on highly complex systems applied . He said yes. I asked how they were going to address the issue and he said that basically they would beta test the first one via aggressive and diverse use.
Saying that it just feels like drought in some places must be climate related is not scientific. It is more likely random chance if not a local land use problem. The human mind wants to see patterns where there are none. And it wants answers even if there are none. The beauty of disciplined scientific method is that it avoids these dynamics.
I am extremely skeptical of the IPCC models. But thanks to Roger I now believe that while they are misguided they are at least generally acting in good faith.
Thanks for the reply. Had to smile at “super-nuanced”! One of the understatements of the year.
The work I alluded to by Roy Spencer of UAH is reported in his website: Roy Spencer, PhD (drroyspencer.com)
The piece on CO2 modeling and the less extreme emissions reduction needs (from his perspective) is in the current website and was reported in two parts. Scroll down below the monthly temperature chart for the second part (dated April 23rd ) shown first, followed by the first part dated April 18th.
You are naturally aware of his work in general, as he and co-workers (including John Christy) have themselves been invited to various Senate hearings over the years with (sadly) the same “drive by shooting” attempts you yourself and others have suffered when not adhering to the "consensus script".
Spencer, like yourself is in agreement that emissions are a major factor in recent warming. However, like much of your own work he does some excellent analysis of numbers going back in history. For example, some of his work in recent years was a painstaking analysis of a vast surface temperture (land and sea data) to determine the likely extent of the UHIE on recorded surface temperatures. The UHIE appears (from their analysis at this time) to account for about 0.3C of the 1.2C above “pre-industrial” times (1850-1900).
After 28 or so years in the emission-based climate change space, partly as an active consultant and daily reader of the still-evolving science, sad to say I'll not likely live long enough to see a more collaborative approach to the real but manageable challenges. But it is still a fun journey and experts like yourself will, in time, lead the world to more realistic scenarios to guide credible policy.
Bloomberg New Ernergy Outlook suggests Carbon Emissions have peaked. This is additional support for the argument that RCP8.5 is implausible and even RCP4.5 is on the high side.
Have now had a chance to listen to the whole hearing. Re my confusion below,maybe what we are seeing is IPCC saying:
Human driven climate change SHOULD (my added word) affect the various forms of drought (which would not surprise me in principle)
BUT to date (40+ years of emission-influenced climate change) has largely not been detected to date and has generally low confidence that that attribution will be detected, even as far forward as 2100.
Great blog as always, but a couple of things that confused me:
1) In your written testimony, page 4 you refer to “ET” but I cannot find a definition in your paper?
2) In your blog text, as I read it all, you show that the IPCC has little evidence and low confidence to attribute any drought patterns (in any direction) to human-caused climate change. But then you say:
"The IPCC finds with high confidence (i.e., an 8 in 10 chance) that human-caused climate change influences the global hydrological cycle and thus drought.
Did you mean “has not detected” ?
While I understand your position on the need to reduce emissions, you will be aware of recent work by Dr. Spencer et al (UAH) where his own theory and modelling, adding the element of increased natural CO2 sequestration by higher mass transfer/higher photosynthesis (expected of course from first principles) means draconian CO2 reduction targets currently set for “net zero” are unnecessary to achieve the kind of long-term atmospheric CO2 levels required to reasonably address climate change. Do you have any comments on that work?
1) In your written testimony, page 4 you refer to “ET” but I cannot find a definition in your paper?
RESPONSE
Evapotranspiration
IPCC Glossary: "The combined processes through which water is transferred to the atmosphere from open water and ice surfaces, bare soil and vegetation that make up the Earth’s surface."
2) In your blog text, as I read it all, you show that the IPCC has little evidence and low confidence to attribute any drought patterns (in any direction) to human-caused climate change. But then you say:
"The IPCC finds with high confidence (i.e., an 8 in 10 chance) that human-caused climate change influences the global hydrological cycle and thus drought."
Did you mean “has not detected” ?
RESPONSE
Yes, the IPCC is super nuanced here.
Yes - human-climate change affects the hydrological cycle.
No - the detection and attribution of trends in drought (all three definitions) has NOT been achieved with high confidence.
While I understand your position on the need to reduce emissions, you will be aware of recent work by Dr. Spencer et al (UAH) where his own theory and modelling, adding the element of increased natural CO2 sequestration by higher mass transfer/higher photosynthesis (expected of course from first principles) means draconian CO2 reduction targets currently set for “net zero” are unnecessary to achieve the kind of long-term atmospheric CO2 levels required to reasonably address climate change. Do you have any comments on that work?
Did it come up at all that increases in atmospheric CO2 are most certainly improving crop yields worldwide? I'd think that this is something the senators would want to know as there are real positives associated with getting back to a more normal level, in terms of geologic time, of atmospheric CO2.
Regarding these hearings happening in front of the budget committee, as “climate emergency” is being used to destroy national budgets with vast borrowing for nonsensical useless solutions, I’d suggest that is exactly the right place for it.
As to the rest, there is no emergency now, as per the data therefor all claims of future emergency remain based on models.
I will continue to not worry about climate change but I continue to worry about the real threat to us all, climate change policy.
Thanks for your fine summary. All of us need to be careful not to allow "confirmation bias" to creep into any conclusions that may be still substantially unclear. I site Matt Ridley from 31 October 2011 Robert W. Street
I would like to see a Senate Committee take testimony on the essay by Mark Mills in City Journal https://www.city-journal.org/article/the-energy-transition-wont-happen. I would title the session: "The Energy Transition isn't going to happen..............so what are we going to do instead to combat climate change."
The climate/insane only refer to the synthesis/summary reports which are written by activists for the climate insane in pursuit of decision based evidence making
"To be clear, I emphasize explicitly and unequivocally that human-caused climate change poses significant risks to society and the environment, and that various policy responses in the form of mitigation and adaptation are necessary and make good sense." Roger, if you recall my many past comments, you know that I respect you enormously and find your work invaluable (well, if I had billions, I would value it in the many millions based on what I would pay to support it).
That said, I have to object a little here. You affirm "significant risks to society and the environment." Fine. Warming will mean some costs. But you do not even mention the benefits of warming and increased carbon dioxide. It is not at all clear to me that costs will exceed benefits globally. Obviously the cost/benefit balance will vary considerably depending on what effect you consider and where you live. (For the record, I live in one of the hottest place on the planet, Arizona, but one with air conditioning and other technology-supplied balms and benefits.)
We are seeing enormous benefits such as increased agricultural productivity and fewer deaths from cold. (Deaths from cold outweigh deaths from heat by anything from 3 to 17 times.) Some land becomes less usable but much other land becomes more usable. Why do you not mention these? Why give the impression that warming (whether natural or anthropogenic) is only a bad thing?
Personally, I view mitigation as an enormous waste of resources, especially since no one country or even continent will make a real difference on its own. Adaptation clearly works and makes sense. The Netherlands shows how this can be done even in relatively extreme conditions. However, this is just my view. My main concern is that you are feeding the fear mongers by acknowledging the potential costs (perfectly reasonable) without even mentioning the benefits.
Am I reading table 1.A.2 wrong? For several items, including Heavy Precipitation, the probability is higher for the pre-industrial baseline than it is for 1995-2014. But 2 degC from pre-industrial times is less than from the 1995-2014 baseline, since we have already had some warming from pre-industrial times to that period. The latter baseline should show lower probabilities, right?
As you note, Roger: "a 1.5C change from that recent baseline is about the same as a 2.5C change from preindustrial." I'm really tired right now, so I'm probably missing something obvious.
"Despite a large increase in population, Southern California has cut its water consumption by about half since the 1970s." This will strike many as implausible but not to me. I live in Arizona where we use about the same amount of water as in the 1950s despite population increasing around 400%.
The most hard to believe point is this: "Almost all of the world’s carrot seeds are produced in the high desert of Oregon." That really does surprise me!
Yes, it is agriculture that uses most of it. It is also the specific type of agriculture. Arizona could do even better if subsidies were eliminated for growing plants better grown elsewhere.
It is actually an increase in efficiency. Not in the sense of getting more out of the same land using the same crops. It is in the sense that (a) shifting to different crops can reduce water usage; (b) moving production of water-intensive crops out of relatively dry states to better suited states is an efficiency improvement for the economy.
Thank you for your testimony. “Low confidence” is the inconvenient truth for many, yet there is high confidence in the future of climate anomalies and extremes, especially in this era of information overload and exploitation.
Roger - I appreciate your official take, but cannot help but be struck by what is actually occurring all over this planet. How many areas across the globe are experiecing serious water stress? Perhaps some of the many water crises across the planet are the combination of changes in land use, resource mismanagement and climate change. The Amazon is an example where with deforestation, there has been a clear pattern of "drying out"; e.g., https://www.nature.com/articles/s41586-022-05690-1 and see Rob Lewis' series on Milan Millan: https://theclimateaccordingtolife.substack.com/p/millan-millan-and-the-mystery-of . Perhaps this cannot be teased out or attributed to climate change per se, but doesn't it feel like millions of people across the globe are facing extreme water scarcity either for drinking water, agriculture or both in an unprecedented manner? The increase in heat is certainly an issue with climate change, but it feels like a drier planet - at least in some areas - will ultimately drive a loss of vegetation, a loss in water storage and terrestial water recycling and ultimately desertification. Habitable land is going to become scarcer. Doesn't this deserve more attention, press and action?
Hi Scott,
I agree with you 100% that there are regions that have experienced drying.
According to the IPCC (not me) attribution to human-caused climate change remains challenging. (Rob Lewis is excellent.)
I do not however agree that the world is drying out. Indicators suggest global precipitation has increased worldwide over the past century:
"On average, total annual precipitation has increased over land areas in the United States and worldwide (see Figures 1 and 2). Since 1901, global precipitation has increased at an average rate of 0.04 inches per decade, while precipitation in the contiguous 48 states has increased at a rate of 0.20 inches per decade."
https://www.epa.gov/climate-indicators/climate-change-indicators-us-and-global-precipitation
There is of course enormous temporal and spatial variability, and not everywhere sees the same trends.
"Desertification" was a big deal in the 1980s and 1990s, mainly due to land use change.
I agree that this difficult issue is of crucial importance and sits at the intersection of land use change, (mis)management, and climate.
That the IPCC does not have firm conclusions on attribution is useful because it points us in this more nuanced direction.
I appreciate the quick reply. I understand warmer air can hold more water and I am not disputing that. It is its re-distribution as precipiatation that I am worried about. If one buys that land use affects downwind rainfall, then it feels like one could theoretically develop a global map of the relative importance of land to the re-distribution of precip in order to prioritize land conservation or restoration. Perhaps this is the kind of nuance you are referring to?
That makes sense
I'm not too bullish on us ever being able to produce skillful long-term predictions of climate (i.e., from seasonal to decades) so that means that policies that focus on increasing resilience and reducing vulnerability will make the most sense. Dry-prone regions, like the American West, already know this, but taking knowledge into action is always a challenge.
Highly complex systems are impossible to model. Weather is indeed a highly complex system. I traded Bond options for 20 years and can attest that there is no model that can capture the tail events that are characteristic of highly complex systems. I humorously tell people that I have seen eight once in a lifetime events in my 43 year career! 🤣
I remember reading 35 years ago an engineer saying that all of the space shuttles would catastrophically fail. His argument was that they were essentially so complex that all the various outcomes could not be modeled. My son is an engineer and out of college worked on the next generation of aircraft carriers. I asked him if this same problem of these ships bordering on highly complex systems applied . He said yes. I asked how they were going to address the issue and he said that basically they would beta test the first one via aggressive and diverse use.
Saying that it just feels like drought in some places must be climate related is not scientific. It is more likely random chance if not a local land use problem. The human mind wants to see patterns where there are none. And it wants answers even if there are none. The beauty of disciplined scientific method is that it avoids these dynamics.
I am extremely skeptical of the IPCC models. But thanks to Roger I now believe that while they are misguided they are at least generally acting in good faith.
And who doesn’t like a good challenge?!
Roger:
Thanks for the reply. Had to smile at “super-nuanced”! One of the understatements of the year.
The work I alluded to by Roy Spencer of UAH is reported in his website: Roy Spencer, PhD (drroyspencer.com)
The piece on CO2 modeling and the less extreme emissions reduction needs (from his perspective) is in the current website and was reported in two parts. Scroll down below the monthly temperature chart for the second part (dated April 23rd ) shown first, followed by the first part dated April 18th.
You are naturally aware of his work in general, as he and co-workers (including John Christy) have themselves been invited to various Senate hearings over the years with (sadly) the same “drive by shooting” attempts you yourself and others have suffered when not adhering to the "consensus script".
Spencer, like yourself is in agreement that emissions are a major factor in recent warming. However, like much of your own work he does some excellent analysis of numbers going back in history. For example, some of his work in recent years was a painstaking analysis of a vast surface temperture (land and sea data) to determine the likely extent of the UHIE on recorded surface temperatures. The UHIE appears (from their analysis at this time) to account for about 0.3C of the 1.2C above “pre-industrial” times (1850-1900).
After 28 or so years in the emission-based climate change space, partly as an active consultant and daily reader of the still-evolving science, sad to say I'll not likely live long enough to see a more collaborative approach to the real but manageable challenges. But it is still a fun journey and experts like yourself will, in time, lead the world to more realistic scenarios to guide credible policy.
Sorry for the rant!
Regards,
Len Flint - Ph.D, P.Eng. (ret).
Bloomberg New Ernergy Outlook suggests Carbon Emissions have peaked. This is additional support for the argument that RCP8.5 is implausible and even RCP4.5 is on the high side.
https://about.bnef.com/new-energy-outlook/?utm_medium=Adwords_SEM&utm_source=pdsrch&utm_content=amer_bnef_neo_2024&utm_campaign=833878&tactic=833878&gad_source=1&gclid=Cj0KCQjwpNuyBhCuARIsANJqL9NGLcSQIdvt44uu7wgHPi7CKasOQ_eqPre0HkI5IggzwGpwGJ_hpb8aAsquEALw_wcB
Have now had a chance to listen to the whole hearing. Re my confusion below,maybe what we are seeing is IPCC saying:
Human driven climate change SHOULD (my added word) affect the various forms of drought (which would not surprise me in principle)
BUT to date (40+ years of emission-influenced climate change) has largely not been detected to date and has generally low confidence that that attribution will be detected, even as far forward as 2100.
All a little confusing to the average person.
Great blog as always, but a couple of things that confused me:
1) In your written testimony, page 4 you refer to “ET” but I cannot find a definition in your paper?
2) In your blog text, as I read it all, you show that the IPCC has little evidence and low confidence to attribute any drought patterns (in any direction) to human-caused climate change. But then you say:
"The IPCC finds with high confidence (i.e., an 8 in 10 chance) that human-caused climate change influences the global hydrological cycle and thus drought.
Did you mean “has not detected” ?
While I understand your position on the need to reduce emissions, you will be aware of recent work by Dr. Spencer et al (UAH) where his own theory and modelling, adding the element of increased natural CO2 sequestration by higher mass transfer/higher photosynthesis (expected of course from first principles) means draconian CO2 reduction targets currently set for “net zero” are unnecessary to achieve the kind of long-term atmospheric CO2 levels required to reasonably address climate change. Do you have any comments on that work?
PS: look forward to the June 12th event with CDN.
Len Flint
Len, great Qs! Some replies below ...
1) In your written testimony, page 4 you refer to “ET” but I cannot find a definition in your paper?
RESPONSE
Evapotranspiration
IPCC Glossary: "The combined processes through which water is transferred to the atmosphere from open water and ice surfaces, bare soil and vegetation that make up the Earth’s surface."
2) In your blog text, as I read it all, you show that the IPCC has little evidence and low confidence to attribute any drought patterns (in any direction) to human-caused climate change. But then you say:
"The IPCC finds with high confidence (i.e., an 8 in 10 chance) that human-caused climate change influences the global hydrological cycle and thus drought."
Did you mean “has not detected” ?
RESPONSE
Yes, the IPCC is super nuanced here.
Yes - human-climate change affects the hydrological cycle.
No - the detection and attribution of trends in drought (all three definitions) has NOT been achieved with high confidence.
While I understand your position on the need to reduce emissions, you will be aware of recent work by Dr. Spencer et al (UAH) where his own theory and modelling, adding the element of increased natural CO2 sequestration by higher mass transfer/higher photosynthesis (expected of course from first principles) means draconian CO2 reduction targets currently set for “net zero” are unnecessary to achieve the kind of long-term atmospheric CO2 levels required to reasonably address climate change. Do you have any comments on that work?
RESPONSE
I am happy to have a look
Please send a link
Thanks!
Roger,
Did it come up at all that increases in atmospheric CO2 are most certainly improving crop yields worldwide? I'd think that this is something the senators would want to know as there are real positives associated with getting back to a more normal level, in terms of geologic time, of atmospheric CO2.
Regarding these hearings happening in front of the budget committee, as “climate emergency” is being used to destroy national budgets with vast borrowing for nonsensical useless solutions, I’d suggest that is exactly the right place for it.
As to the rest, there is no emergency now, as per the data therefor all claims of future emergency remain based on models.
I will continue to not worry about climate change but I continue to worry about the real threat to us all, climate change policy.
Thanks for your fine summary. All of us need to be careful not to allow "confirmation bias" to creep into any conclusions that may be still substantially unclear. I site Matt Ridley from 31 October 2011 Robert W. Street
I would like to see a Senate Committee take testimony on the essay by Mark Mills in City Journal https://www.city-journal.org/article/the-energy-transition-wont-happen. I would title the session: "The Energy Transition isn't going to happen..............so what are we going to do instead to combat climate change."
Thank you very much. Apparently, many alarmists do not even read and/or understand what the IPCC reports actually are saying.
The climate/insane only refer to the synthesis/summary reports which are written by activists for the climate insane in pursuit of decision based evidence making
Thank God for you!
"To be clear, I emphasize explicitly and unequivocally that human-caused climate change poses significant risks to society and the environment, and that various policy responses in the form of mitigation and adaptation are necessary and make good sense." Roger, if you recall my many past comments, you know that I respect you enormously and find your work invaluable (well, if I had billions, I would value it in the many millions based on what I would pay to support it).
That said, I have to object a little here. You affirm "significant risks to society and the environment." Fine. Warming will mean some costs. But you do not even mention the benefits of warming and increased carbon dioxide. It is not at all clear to me that costs will exceed benefits globally. Obviously the cost/benefit balance will vary considerably depending on what effect you consider and where you live. (For the record, I live in one of the hottest place on the planet, Arizona, but one with air conditioning and other technology-supplied balms and benefits.)
We are seeing enormous benefits such as increased agricultural productivity and fewer deaths from cold. (Deaths from cold outweigh deaths from heat by anything from 3 to 17 times.) Some land becomes less usable but much other land becomes more usable. Why do you not mention these? Why give the impression that warming (whether natural or anthropogenic) is only a bad thing?
Personally, I view mitigation as an enormous waste of resources, especially since no one country or even continent will make a real difference on its own. Adaptation clearly works and makes sense. The Netherlands shows how this can be done even in relatively extreme conditions. However, this is just my view. My main concern is that you are feeding the fear mongers by acknowledging the potential costs (perfectly reasonable) without even mentioning the benefits.
My thoughts, with great respect.
Great comment Max. I should have ready yours before I posted mine. Cheers.
Am I reading table 1.A.2 wrong? For several items, including Heavy Precipitation, the probability is higher for the pre-industrial baseline than it is for 1995-2014. But 2 degC from pre-industrial times is less than from the 1995-2014 baseline, since we have already had some warming from pre-industrial times to that period. The latter baseline should show lower probabilities, right?
As you note, Roger: "a 1.5C change from that recent baseline is about the same as a 2.5C change from preindustrial." I'm really tired right now, so I'm probably missing something obvious.
"Despite a large increase in population, Southern California has cut its water consumption by about half since the 1970s." This will strike many as implausible but not to me. I live in Arizona where we use about the same amount of water as in the 1950s despite population increasing around 400%.
The most hard to believe point is this: "Almost all of the world’s carrot seeds are produced in the high desert of Oregon." That really does surprise me!
Irrigation/agriculture uses far more water than human residences.
How much of that reduction is by reducing farm land and orchards to expand human habitation?
That's not an increase in efficiency, it's just a change in how the land is used which affects how much water is used per unit land.
Yes, it is agriculture that uses most of it. It is also the specific type of agriculture. Arizona could do even better if subsidies were eliminated for growing plants better grown elsewhere.
It is actually an increase in efficiency. Not in the sense of getting more out of the same land using the same crops. It is in the sense that (a) shifting to different crops can reduce water usage; (b) moving production of water-intensive crops out of relatively dry states to better suited states is an efficiency improvement for the economy.
Sorry Roger. Didn't read your response to Mr. Butterfield before writing this. I was reviewing it as you replied... Have a great Memorial Day!
No worries! Have a great rest-of-the weekend