My understanding is the climate change is increasing the frequency as well as the severity of phenomena like hurricanes, due to warming waters. etc. (and I am wondering about the severity of the Santa Ana winds last week.) Could we speak more boldly about causality and still be scientific?
Certainly climate change is making hurricanes more destructive (https://open.substack.com/pub/theclimatebrink/p/climate-change-is-making-hurricanes-09e), also heatwaves. For the Santa Ana winds, I don’t think it’s clear what impact climate change had. Thus, I think you need to consider the evidence for each phenomenon before you assert a connection to climate change. For many, the connection is there, but not all.
"The average and maximum rain rates associated with tropical cyclones (TCs), extratropical cyclones and atmospheric rivers across the globe, and severe convective storms in some regions, increase in a warming world (high confidence)...It is likely that the global proportion of Category 3–5 tropical cyclone instances has increased over the past four decades."
That chapter also says:
"The frequency and intensity of hot extremes (including heatwaves) have increased, and those of cold extremes have decreased on the global scale since 1950 (virtually certain)...Human-induced greenhouse gas forcing is the main driver of the observed changes in hot and cold extremes on the global scale (virtually certain ) and on most continents (very likely )."
Thank you for this overview. The 2023 population of greater LA was 18.42 million (2023). I am reminded of the water demands by 7 states on ONE water source, the Colorado River:"Colorado’s water among seven states: Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Today, water from the Colorado River watershed slakes the thirst – and sprinkles the lawns and fills the swimming pools — of 40 million people. It irrigates cropland that generates 15 percent of the country’s food.". Source: https://www.c-win.org/the-colorado-river-compact#:~:text=It%20is%20thus%20entitled%20to,Aqueduct%20and%20the%20All%2DAmerican
Terrific and informative, Andrew. As a long-time Southern California resident who has studied our wildfires, there is just one point that I disagree with. Last year’s heavy rains probably did not change the amount of brush around the LA fire vicinities very much. Also, the amount of brush matters little when Santa Ana winds sweep through mountains and canyons that have not had any rain for eight or nine months. When that happens, everything burns.
Well, at first i would like to thank you for the clear presentation of the facts once more!
I am both sad and angry at the same time.
The socio-economic and environmental exploitation of societies everywhere is due to the demand for abundant energy and not for abundant fossil fuels and fuels in general, if you specify it in its causes. Ergo: the climate crisis automatically turns into an energy crisis, not a fossil fuel crisis.
Is the primary issue something more innovative? Is it not the finding of alternative energy sources but the vision of a sapiens that should have been to reduce the need for primary energy rather than fuel? In this way, it would not be necessary, nor sufficient, to need, for example, to search for land for wind farms and photovoltaics that capture a large part of arable land. Do we create social equality with our lower energy needs, which is not the case with our high energy consumption and needs? As energy use grows, it makes sense that if you think about it, social inequality will also increase, let's not talk about environmental inequality, who pays for the externalization of the costs of energy production and consumption, whether it is from fossil fuels or renewable sources.
Thanks Andrew. At every level of this explainer, I stop to consider how my eco-somatic self is processing the information. This is climate mindfulness.
Empathy, anger, overwhelm. Anyone reading this: in order for us to be "sustainable" activists, we should gather in a community to process and consider our feelings. This is according to experts,among many- Renee Lertzman and Britt Wray.
Seek out a Climate Circle, a peer support group- non-clinical, to be heard and move on from grief and despair that could hinder and disrupt our effective climate activism.
Here's my promotional piece: Cascadia Stack offers Climate Mindfulness Circles online and occasionally in-person, in Portland Oregon. Link in my bio.
There seems to be some misunderstanding expressed in the comments about what the IPCC has to say about intensity and frequency of climate extremes. I guess it's time to quote Chapter and Verse:
AR6 WG1: Chapter 11: Weather and Climate Extreme Events in a Changing Climate. Executive Summary, PG. 1517.
"Regional changes in the intensity and frequency of climate extremes generally scale with global warming. New evidence strengthens the conclusion from the IPCC Special Report on Global Warming of 1.5°C (SR1.5) that even relatively small incremental increases in global warming (+0.5°C) cause statistically significant changes in extremes on the global scale and for large regions (high confidence). In particular, this is the case for temperature extremes (very likely), the intensification of heavy precipitation (high confidence) including that associated with tropical cyclones (medium confidence), and the worsening of droughts in some regions (high confidence)."
We have disrupted the hydrological cycle by lack of vegetation cover loss of 'soil carbon sponge' which holds water, helping to prevent fire, ensures longevity of growth and feeds aquifers (Walter Jehne) as well as creating eccessive evaporation and loss of soil structure. This is due to landuse change and loss of forests. The living conditions on this planet have always been provided to us by plants creating oxygen and driving the hydrological cycle. Forests have an essential function in creating what is known as 'the biotic pump' which lowers air pressure as water droplets from their evaporation condense, pulling in moisture from the sea. This creates rain clouds that shield heat from the sun as well as enough moisture to create rain. In general there is a lack of cloud cover on a global level. See the missing summer storms by Rob Lewis on substack which speaks of the scientist Millan Millan who studied this in depth.
We could easily bring back rain and cooling if there were enough efforts to regenerate a certain percentage of degraded land. See also Alpha Lo's articles.
To be sure, loss of vegetation cover shouldn't be ignored! Changes in cloud cover and rainfall may or may not be attributable to land use changes everywhere, however. I'm skeptical that "We could easily bring back rain and cooling if there were enough efforts to regenerate a certain percentage of degraded land." Are you able to link to peer-reviewed sources? Whoever Alpha Lo is, I'm pretty sure his isn't a consensus view.
Well, here you are trying to deny the cost of anthropogenic climate change again, Jake the rake. Did you read the article? "It" is about both adaptation and mitigation! Quoting Prof. Dessler:
"Of course, other factors also play a role, such as the amount and arrangement of available fuel. Forest management practices over the past century have led to accumulations of understory vegetation and dead organic material in many forests. The expansion of cities into wildland areas introduces more potential ignition sources, adds structures and infrastructure that can fuel fires, and creates zones where preventive measures like prescribed burning are challenging to implement.
"Climate misinformers [that's you, Jake: MA] often exploit these multiple contributing factors to downplay climate change’s role. They present a false, illogical choice: 'If poor forest management is to blame, then climate change can’t be playing a role.' The best available science tells us otherwise — climate change’s influence on fire behavior has grown increasingly significant in recent decades, amplifying the effects of any management decisions or human development patterns."
Your comment unmistakably presents that false, illogical choice! Why?
Show me the long-term weather variability over 30 years and the trend you are concerned about....
The data I have shows significant variability but no trends, and this is even supported by the IPCC.
Yes… adaption may be needed and certainly management if we insist on inhabiting volatile locations…. but don’t expect me to destroy our prosperity on pointless CO2 mitigation action.
Show me the long-term weather variability over 30 years and the trend you are concerned about....
The data I have shows significant variability but no trends, and this is even supported by the IPCC.
Yes… adaption may be needed and certainly management if we insist on inhabiting volatile locations…. but don’t expect me to destroy our prosperity on pointless CO2 mitigation action.
Find this whole discussion odd. We can’t affect the climate in the short to medium term even if we did the impossible and went stone cold net zero tomorrow. And even if we could, our emissions reductions would be swamped by India and China’s coal-fueled growth. So why don’t we focus on mitigation and preparedness instead? My concern is that worrying climate change becomes an excuse to do nothing at all.
Well, 49.9% of US voters aren't focused on decarbonization *or* on mitigation, because the Denier-in-Chief says climate change is a hoax. What a genius! And choosing one over the other is a fool's game. "Mitigation" usually refers to efforts to slow or cap global warming, a more ultimate cause of these fires. I guess we'd call fuel reduction, buffer zones, etc. "mitigation" also, however. "Adaptation" means just that: individuals and communities must disproportionately bear the socialized cost of powering the global economy with fossil fuels. That's already happening, with the usual winners and losers. In the US, collective mitigation of global warming only began with the IRA of 2022, 34 years after we all learned about it. The delay hasn't needed any excuse, just the raw power of carbon capital!
BTW: "But China (India, whoever)" is the classic denialist *tu quoque* objection to unilateral action. India's emissions are growing, but still comparatively minor. China is rapidly decarbonizing its own exploding economy, and may have already reached its peak emissions. But why should the US ride free on China, and wait for India to act first? Our emissions are still the second largest, so we and the entire world benefit disproportionately from every fractional reduction we achieve.
If I used my real name, you'd show up at my house. I've been "Mal Adapted" on the Internet for almost 20 years. Anything appearing under that pseudonym is mine, so far. That's all you need to know about me!
Stop using denialist. It’s an ugly word. If you think that we can get to net zero anytime soon you’re even stupider than this screed suggests. There are concrete things we can do to reduce the increased risks from a warming planet, but we in California are not doing them. Instead we focus on pie in the sky bs like wind and solar (which is working out wonderfully for Germany!) and forcing everyone into EVs they don’t want, thus empowering Trump and the right as there’s no constituency for net zero beyond a few fanatics like you.
Stop denying denialism. Yes, it's pejorative, but claims it has an obligate association with the Nazi Holocaust are bullshit (realclimate.org/index.php/archives/2024/11/twenty-years-of-blogging-in-hindsight/#comment-828096). You're not the master of "deny", "denier", "denial" and "denialist": by long-standing convention, they're all appropriate terms for anyone who thinks America should wait for "China and India" to decarbonize first (climateball.wordpress.com/but-china/). Deniers just don't like to be told they're fooling themselves.
The US may not have made much progress on collective decarbonization, due primarily to the decades-long campaign of denialist propaganda and political extortion funded by carbon capital, but other countries are moving toward carbon-neutrality with alacrity. The purely political obstacles to US decarbonization include both denialism of the urgency, and the denial of the possibility of capping the costs. You're evincing the latter here, including blaming the Democrats, the party of collective action in America for better or worse. Realists have a more nuanced view, allowing for guarded optimism. Whether we can get to net zero "anytime soon" depends critically on the value of "soon", when unpredictable human collective behavior will decisively determine what happens over 5, 10, 25, or 100 years. You're free to dump your nihilism on us until Zeke or Andrew moderates you. I can't stop you: I don't even know where you live! But you'll have to deal with pushback from those who are neither denialists nor doomers. You don't own our language. Oh, never mind - deniers deny!
I think the problem depends on which kind of media each consumes, and where you live. As well as many (usually conservative) media sources try to ignore climate change as the increased risk that it is because of politics, we also have lots of media (normally progressive or from the green left) which tries to put all the blame on climate change because of politics.
I'd say that both sides are being dishonest and making people just ignore the problem and not trust media.
Plants have roots and they provide a lot of resilience. It takes a month or so before most plants wilt because the roots supply moisture. Trees and plants with deep roots take a lot longer to wilt.
So nothing is dried out unless there is no vegetation: a desert.
It's probably too early to be sure abut the contribution of the accumulation of CO2 in the atmosphere since whenever to the change in probability of the wet/dry/wind combination that made the fire more intense.
BTW for the sake of clarity, lets always say "accumulation of CO2 in the atmosphere" as the cause of anything. "Climate change" is a _result_ not a cause.
And although you did touch on it, the accumulation of fuel, building fire-vulnerable structures in fire-prone areas and unavailability of insurance are all the result of policy decisions. And they are policy decision that can be traced back at least in part to failing to take on board the effects of CO2 accumulation in the atmosphere.
The greater risks of wind-enhanced wildfires caused (we can be pretty sure) by the accumulation of CO2 raises the benefits of good forest-chaparral fuel management. Apparently these high-value investment have not been made.
People moving to fire-vulnerable structures in fire prone areas needed to see the degree of risk they were exposed to in insurance premia based on forward-looking assessment of risks for the specific area and characteristics of the structure. Apparently insurance companies did not offer that kind of policy and perhaps were not even allowed to do so. Only when losses from beachward-looking risk assessment caught up with companies that had to make large increases in premia or not insure at all when it was too late for property owners to adjust.
Global warming is causing climate change, and global warming refers to the manmade global warming caused by humans' GHG emissions and changes in land use etc.
Semantics is a problem because we are not habitually writing/talking with the clarity and care of a scientific journal.
You're largely right, but while "climate change resulting from accumulation of CO2 in the atmosphere" is more precise, it's more cumbersome than simply "climate change". Same with "global warming": it's a more ultimate cause of anthropogenic climate change leading to increased wildfire risks, but accumulation of CO2 is even more ultimate. I'm pretty sure we all acknowledge that here! I agree with Dennis: we are not writing/talking with the clarity and care of a scientific journal. This is a blog.
"Policy X that costs $Z addresses/fights/prevents 'climate change'" invites a smile or a frown. "Policy X that costs $Z addresses/fights/prevents 'accumulatio of CO2 in the atmosphere'" invites the response of "by how much?" "Would policy X' reduce it more at lower cost?"
Warmer air suck moisture out of everything (that is why we warm air with a hair dryer or in a dryer for clothes). The rate is about 7% more drying per degree Celsius. It dries things out and causes wilting of plants and all vegetation.
How can something that is already dry be dried out an additional 7% per K?
Actual evapotranspiration (ET) is constrained by moisture availability, making it a process limited by water, not temperature. As desertification progresses, ET decreases rather than increases.
If ecosystems were able to sustain moisture, actual ET and precipitation could potentially rise by 2–3% per K. However, ERA5 data indicates that land evapotranspiration plateaued 20 to 30 years ago, breaking the previously observed correlation between rising temperatures and increased drying. This suggests that the rate of evapotranspiration is primarily constrained by desertification, not by temperature.
Wildfire behavior is strongly influenced by fuel moisture content, which is almost never zero, as even kiln-dried wood retains 20% moisture, bound more or less tightly to internal surfaces (nwcg.gov/publications/pms425-1/11-weather-and-fuel-moisture). Fuel moisture, in turn, is influenced by soil moisture (drought.gov/topics/soil-moisture), which is almost never zero, because some water is tightly bound to soil particles, but available to plants with very fine rootlets or mycorrhizae that can get close enough to the binding surfaces.
Please link to a peer-reviewed source for your claim that ERA5 data showing ET has plateaued.
well obviously the limiting factor is moisture content, not T. the 7% saturation vapor pressure increase of air shouldn't be confused with 7% more drying. Even over ocean ET-P isn't expected to increased 7%/K. it's a different thing. you could argue hot air dries faster, not necessarily more.
here's some obs. satellites and CMIP are outliers compared to Ground obs (FluxCOM) and reanalysis. CMIP parameters tuned to satellite or an assumption about the amount of moisture. Reanalysis says no.
Not if warmer air very moist air. Your clothes dryer only works because the moisture in the hot air is vented from the machine. The clothes wouldn't dry at all if the air inside the drier were to reach saturation point, even though that air was hot. Evaporation is much faster in dry desert air than very humid tropical forest air at the same temperature. Also, movement of air greatly affects the rate of evaporation. The fierce Santa Ana winds would have dried out vegetation very quickly and there is no suggestion that those winds have been made more fierce by the secular rise in surface temperature. Weather, both seasonal and on the scale of days and hours, is what caused the meteorological conditions favourable to these fires.
Finally, we wouldn't even be having this conversation were it not for the fact that these fires were started by humans, intentionally or accidentally and which, once started, were made very difficult to extinguish by humans because of criminal negligence and incompetence.
Andrew clearly didn't say that climate change, which affects the weather on an hourly and daily basis, caused the Santa Ana winds to be fiercer.
He said that the 'incredibly' wet winter led to an abundance of vegetation and biomass which, as you say, was quickly dried out by the fierce Santa Ana winds. Your argument about evaporation rate seems to be irrelevant to this point.
And yes, climate change has not yet got so bad that people and houses spontaneously burst into flame with the extreme heat, as a policeman's hair did at Bradford city. There has to be a spark, such as a cigarette in a very large pile of dry rubbish.
The difficulty of putting out the fires, which with the best will in the world would have been extremely difficult, doesn't mean that climate change isn't a very big cause for concern.
I'm not sure I should respond at all to somebody who accuses me of always being disingenuous, but for your information, I was responding specifically to Kevin's point about evaporation, and then I made the further observation that movement of air (wind) also increases the rate of evaporation of vegetation (meaning both living and dead vegetation). Thus the downslope Santa Ana winds would have further desiccated already dry fuel and, once that fuel was ignited would obviously contribute greatly to the spread of the fires. This is weather. There IS no evidence for any climate change influence on the frequency or severity of Santa Ana winds that I'm aware of, but it is these winds, along with the sources of ignition and the lack of provision for extinguishment, which are the direct proximate cause of the tragic fires. Andrew argues that climate change 'set the scene' for these fires by first accelerating the growth of vegetation during a very wet winter, then drying it out during a hot summer and very dry subsequent winter. There's very little evidence that a secular rise in global mean surface temperature is making such 'weather whiplash' events more frequent or severe either. So mostly, the LA fires look like plain old weather combining with criminal incompetence and negligence, plus arson and other human sources of ignition.
Of course. However, the warmer air from global climate change is pervasive and stresses plants, and dwellings, long before the Santa Ana comes along. This is especially the case in a Mediterranean climate like California's: long hot dry summers. Certainly exacerbated by the dry winter in southern Cal. The increase in ET is the strongest signal of climate change and increases the risk of wildfire.
The origin of the fires is another matter altogether.
One article doth not a scientific consensus make. In any case, the impacts on ET differ between latitudes. From the abstract at your link:
"For most locations investigated, we calculated reductions in daily transpiration rates over the twenty-first century that became stronger under higher atmospheric CO2 concentrations. It showed that the effect of CO2-induced reduction of stomatal conductance would have a stronger transpiration-depressing effect than the stimulatory effect of future warming. For currently cold regions, global warming would, however, lengthen the growing seasons so that annual sums of transpiration could increase in those regions despite reductions in daily transpiration rates over the summer months."
Annual fire seasons in temperate regions have been widely observed to be extended, as in the current conflagration in the LA basin.
"The authors identified different forest ecoregions, grouped them into 12 global forest pyromes, and described their differing sensitivities to climate, humans, and vegetation. Their analysis shows how forest fire carbon emissions have increased in extratropical pyromes, where climate is the major control, overtaking emissions from the tropical pyromes, where human influence is most important. "
It’s great to have this simple, clear, carefully-written article to reference.
Thanks!
-Bob Meyer
Powering a Planet
My understanding is the climate change is increasing the frequency as well as the severity of phenomena like hurricanes, due to warming waters. etc. (and I am wondering about the severity of the Santa Ana winds last week.) Could we speak more boldly about causality and still be scientific?
Certainly climate change is making hurricanes more destructive (https://open.substack.com/pub/theclimatebrink/p/climate-change-is-making-hurricanes-09e), also heatwaves. For the Santa Ana winds, I don’t think it’s clear what impact climate change had. Thus, I think you need to consider the evidence for each phenomenon before you assert a connection to climate change. For many, the connection is there, but not all.
Then you understand wrong. Take a look at the IPCC report.
Well, AR6 WG1 says (https://www.ipcc.ch/report/ar6/wg1/chapter/chapter-11/):
"The average and maximum rain rates associated with tropical cyclones (TCs), extratropical cyclones and atmospheric rivers across the globe, and severe convective storms in some regions, increase in a warming world (high confidence)...It is likely that the global proportion of Category 3–5 tropical cyclone instances has increased over the past four decades."
That chapter also says:
"The frequency and intensity of hot extremes (including heatwaves) have increased, and those of cold extremes have decreased on the global scale since 1950 (virtually certain)...Human-induced greenhouse gas forcing is the main driver of the observed changes in hot and cold extremes on the global scale (virtually certain ) and on most continents (very likely )."
Give her a break.
Simple and clearly wrong.
In what way is Prof. Dessler's article "clearly wrong"? Surely you have more to say than that!
Thank you for this overview. The 2023 population of greater LA was 18.42 million (2023). I am reminded of the water demands by 7 states on ONE water source, the Colorado River:"Colorado’s water among seven states: Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Today, water from the Colorado River watershed slakes the thirst – and sprinkles the lawns and fills the swimming pools — of 40 million people. It irrigates cropland that generates 15 percent of the country’s food.". Source: https://www.c-win.org/the-colorado-river-compact#:~:text=It%20is%20thus%20entitled%20to,Aqueduct%20and%20the%20All%2DAmerican
Terrific and informative, Andrew. As a long-time Southern California resident who has studied our wildfires, there is just one point that I disagree with. Last year’s heavy rains probably did not change the amount of brush around the LA fire vicinities very much. Also, the amount of brush matters little when Santa Ana winds sweep through mountains and canyons that have not had any rain for eight or nine months. When that happens, everything burns.
Well, at first i would like to thank you for the clear presentation of the facts once more!
I am both sad and angry at the same time.
The socio-economic and environmental exploitation of societies everywhere is due to the demand for abundant energy and not for abundant fossil fuels and fuels in general, if you specify it in its causes. Ergo: the climate crisis automatically turns into an energy crisis, not a fossil fuel crisis.
Is the primary issue something more innovative? Is it not the finding of alternative energy sources but the vision of a sapiens that should have been to reduce the need for primary energy rather than fuel? In this way, it would not be necessary, nor sufficient, to need, for example, to search for land for wind farms and photovoltaics that capture a large part of arable land. Do we create social equality with our lower energy needs, which is not the case with our high energy consumption and needs? As energy use grows, it makes sense that if you think about it, social inequality will also increase, let's not talk about environmental inequality, who pays for the externalization of the costs of energy production and consumption, whether it is from fossil fuels or renewable sources.
Thanks Andrew. At every level of this explainer, I stop to consider how my eco-somatic self is processing the information. This is climate mindfulness.
Empathy, anger, overwhelm. Anyone reading this: in order for us to be "sustainable" activists, we should gather in a community to process and consider our feelings. This is according to experts,among many- Renee Lertzman and Britt Wray.
Seek out a Climate Circle, a peer support group- non-clinical, to be heard and move on from grief and despair that could hinder and disrupt our effective climate activism.
Here's my promotional piece: Cascadia Stack offers Climate Mindfulness Circles online and occasionally in-person, in Portland Oregon. Link in my bio.
There seems to be some misunderstanding expressed in the comments about what the IPCC has to say about intensity and frequency of climate extremes. I guess it's time to quote Chapter and Verse:
AR6 WG1: Chapter 11: Weather and Climate Extreme Events in a Changing Climate. Executive Summary, PG. 1517.
"Regional changes in the intensity and frequency of climate extremes generally scale with global warming. New evidence strengthens the conclusion from the IPCC Special Report on Global Warming of 1.5°C (SR1.5) that even relatively small incremental increases in global warming (+0.5°C) cause statistically significant changes in extremes on the global scale and for large regions (high confidence). In particular, this is the case for temperature extremes (very likely), the intensification of heavy precipitation (high confidence) including that associated with tropical cyclones (medium confidence), and the worsening of droughts in some regions (high confidence)."
https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter11.pdf
We have disrupted the hydrological cycle by lack of vegetation cover loss of 'soil carbon sponge' which holds water, helping to prevent fire, ensures longevity of growth and feeds aquifers (Walter Jehne) as well as creating eccessive evaporation and loss of soil structure. This is due to landuse change and loss of forests. The living conditions on this planet have always been provided to us by plants creating oxygen and driving the hydrological cycle. Forests have an essential function in creating what is known as 'the biotic pump' which lowers air pressure as water droplets from their evaporation condense, pulling in moisture from the sea. This creates rain clouds that shield heat from the sun as well as enough moisture to create rain. In general there is a lack of cloud cover on a global level. See the missing summer storms by Rob Lewis on substack which speaks of the scientist Millan Millan who studied this in depth.
We could easily bring back rain and cooling if there were enough efforts to regenerate a certain percentage of degraded land. See also Alpha Lo's articles.
To be sure, loss of vegetation cover shouldn't be ignored! Changes in cloud cover and rainfall may or may not be attributable to land use changes everywhere, however. I'm skeptical that "We could easily bring back rain and cooling if there were enough efforts to regenerate a certain percentage of degraded land." Are you able to link to peer-reviewed sources? Whoever Alpha Lo is, I'm pretty sure his isn't a consensus view.
Its clear that it’s all about adaption and not mitigation.
The weather variability appears to be far more important than any background climate change.
Its clearly a high-risk area and I am sure much more preventive management could be done.
Well, here you are trying to deny the cost of anthropogenic climate change again, Jake the rake. Did you read the article? "It" is about both adaptation and mitigation! Quoting Prof. Dessler:
"Of course, other factors also play a role, such as the amount and arrangement of available fuel. Forest management practices over the past century have led to accumulations of understory vegetation and dead organic material in many forests. The expansion of cities into wildland areas introduces more potential ignition sources, adds structures and infrastructure that can fuel fires, and creates zones where preventive measures like prescribed burning are challenging to implement.
"Climate misinformers [that's you, Jake: MA] often exploit these multiple contributing factors to downplay climate change’s role. They present a false, illogical choice: 'If poor forest management is to blame, then climate change can’t be playing a role.' The best available science tells us otherwise — climate change’s influence on fire behavior has grown increasingly significant in recent decades, amplifying the effects of any management decisions or human development patterns."
Your comment unmistakably presents that false, illogical choice! Why?
Show me the long-term weather variability over 30 years and the trend you are concerned about....
The data I have shows significant variability but no trends, and this is even supported by the IPCC.
Yes… adaption may be needed and certainly management if we insist on inhabiting volatile locations…. but don’t expect me to destroy our prosperity on pointless CO2 mitigation action.
"Don't expect me to destroy our prosperity on pointless CO2 mitigation action."
OK. You're a lost cause anyway. We'll just have to outvote you.
Ha Ha ..good luck with that...... based on the direction of politics..
You're making a self-fulfilling prophecy, you know. I, for one, don't believe you're an actual prophet.
@Jake the rake. You seem to miss understand the impact of climate change. It is responsible for the dramatically increased weather variability.
Show me the long-term weather variability over 30 years and the trend you are concerned about....
The data I have shows significant variability but no trends, and this is even supported by the IPCC.
Yes… adaption may be needed and certainly management if we insist on inhabiting volatile locations…. but don’t expect me to destroy our prosperity on pointless CO2 mitigation action.
Find this whole discussion odd. We can’t affect the climate in the short to medium term even if we did the impossible and went stone cold net zero tomorrow. And even if we could, our emissions reductions would be swamped by India and China’s coal-fueled growth. So why don’t we focus on mitigation and preparedness instead? My concern is that worrying climate change becomes an excuse to do nothing at all.
Well, 49.9% of US voters aren't focused on decarbonization *or* on mitigation, because the Denier-in-Chief says climate change is a hoax. What a genius! And choosing one over the other is a fool's game. "Mitigation" usually refers to efforts to slow or cap global warming, a more ultimate cause of these fires. I guess we'd call fuel reduction, buffer zones, etc. "mitigation" also, however. "Adaptation" means just that: individuals and communities must disproportionately bear the socialized cost of powering the global economy with fossil fuels. That's already happening, with the usual winners and losers. In the US, collective mitigation of global warming only began with the IRA of 2022, 34 years after we all learned about it. The delay hasn't needed any excuse, just the raw power of carbon capital!
BTW: "But China (India, whoever)" is the classic denialist *tu quoque* objection to unilateral action. India's emissions are growing, but still comparatively minor. China is rapidly decarbonizing its own exploding economy, and may have already reached its peak emissions. But why should the US ride free on China, and wait for India to act first? Our emissions are still the second largest, so we and the entire world benefit disproportionately from every fractional reduction we achieve.
What are you actually here for?
Also, why don’t you use your own name?
If I used my real name, you'd show up at my house. I've been "Mal Adapted" on the Internet for almost 20 years. Anything appearing under that pseudonym is mine, so far. That's all you need to know about me!
Stop using denialist. It’s an ugly word. If you think that we can get to net zero anytime soon you’re even stupider than this screed suggests. There are concrete things we can do to reduce the increased risks from a warming planet, but we in California are not doing them. Instead we focus on pie in the sky bs like wind and solar (which is working out wonderfully for Germany!) and forcing everyone into EVs they don’t want, thus empowering Trump and the right as there’s no constituency for net zero beyond a few fanatics like you.
Stop denying denialism. Yes, it's pejorative, but claims it has an obligate association with the Nazi Holocaust are bullshit (realclimate.org/index.php/archives/2024/11/twenty-years-of-blogging-in-hindsight/#comment-828096). You're not the master of "deny", "denier", "denial" and "denialist": by long-standing convention, they're all appropriate terms for anyone who thinks America should wait for "China and India" to decarbonize first (climateball.wordpress.com/but-china/). Deniers just don't like to be told they're fooling themselves.
The US may not have made much progress on collective decarbonization, due primarily to the decades-long campaign of denialist propaganda and political extortion funded by carbon capital, but other countries are moving toward carbon-neutrality with alacrity. The purely political obstacles to US decarbonization include both denialism of the urgency, and the denial of the possibility of capping the costs. You're evincing the latter here, including blaming the Democrats, the party of collective action in America for better or worse. Realists have a more nuanced view, allowing for guarded optimism. Whether we can get to net zero "anytime soon" depends critically on the value of "soon", when unpredictable human collective behavior will decisively determine what happens over 5, 10, 25, or 100 years. You're free to dump your nihilism on us until Zeke or Andrew moderates you. I can't stop you: I don't even know where you live! But you'll have to deal with pushback from those who are neither denialists nor doomers. You don't own our language. Oh, never mind - deniers deny!
Fact 1. More energy in the climate system means worse weather.
Fact 2. Absence of evidence is not evidence of absence.
Thanks for the post. I wouldn't agree more.
I think the problem depends on which kind of media each consumes, and where you live. As well as many (usually conservative) media sources try to ignore climate change as the increased risk that it is because of politics, we also have lots of media (normally progressive or from the green left) which tries to put all the blame on climate change because of politics.
I'd say that both sides are being dishonest and making people just ignore the problem and not trust media.
If increasing environmental hazards have "multiple contributing factors", why is the insurance issue therefore a "climate-fueled catastrophe".
does climate science provide evidence of increasing hydroclimate "whiplash" in California or not?
Well, this review article, "Hydroclimate volatility on a warming Earth" (nature.com/articles/s43017-024-00624-z) says it does.
Fig 2 has California less whippy https://www.nature.com/articles/s43017-024-00624-z/figures/2
See this from 2018
https://theconversation.com/climate-change-and-wildfires-how-do-we-know-if-there-is-a-link-101304
Plants have roots and they provide a lot of resilience. It takes a month or so before most plants wilt because the roots supply moisture. Trees and plants with deep roots take a lot longer to wilt.
So nothing is dried out unless there is no vegetation: a desert.
It's probably too early to be sure abut the contribution of the accumulation of CO2 in the atmosphere since whenever to the change in probability of the wet/dry/wind combination that made the fire more intense.
BTW for the sake of clarity, lets always say "accumulation of CO2 in the atmosphere" as the cause of anything. "Climate change" is a _result_ not a cause.
And although you did touch on it, the accumulation of fuel, building fire-vulnerable structures in fire-prone areas and unavailability of insurance are all the result of policy decisions. And they are policy decision that can be traced back at least in part to failing to take on board the effects of CO2 accumulation in the atmosphere.
The greater risks of wind-enhanced wildfires caused (we can be pretty sure) by the accumulation of CO2 raises the benefits of good forest-chaparral fuel management. Apparently these high-value investment have not been made.
People moving to fire-vulnerable structures in fire prone areas needed to see the degree of risk they were exposed to in insurance premia based on forward-looking assessment of risks for the specific area and characteristics of the structure. Apparently insurance companies did not offer that kind of policy and perhaps were not even allowed to do so. Only when losses from beachward-looking risk assessment caught up with companies that had to make large increases in premia or not insure at all when it was too late for property owners to adjust.
Global warming is causing climate change, and global warming refers to the manmade global warming caused by humans' GHG emissions and changes in land use etc.
Semantics is a problem because we are not habitually writing/talking with the clarity and care of a scientific journal.
You're largely right, but while "climate change resulting from accumulation of CO2 in the atmosphere" is more precise, it's more cumbersome than simply "climate change". Same with "global warming": it's a more ultimate cause of anthropogenic climate change leading to increased wildfire risks, but accumulation of CO2 is even more ultimate. I'm pretty sure we all acknowledge that here! I agree with Dennis: we are not writing/talking with the clarity and care of a scientific journal. This is a blog.
I think it can be more than semantic.
"Policy X that costs $Z addresses/fights/prevents 'climate change'" invites a smile or a frown. "Policy X that costs $Z addresses/fights/prevents 'accumulatio of CO2 in the atmosphere'" invites the response of "by how much?" "Would policy X' reduce it more at lower cost?"
Good article. It could use some links to attribution sites.
Warmer air suck moisture out of everything (that is why we warm air with a hair dryer or in a dryer for clothes). The rate is about 7% more drying per degree Celsius. It dries things out and causes wilting of plants and all vegetation.
How can something that is already dry be dried out an additional 7% per K?
Actual evapotranspiration (ET) is constrained by moisture availability, making it a process limited by water, not temperature. As desertification progresses, ET decreases rather than increases.
If ecosystems were able to sustain moisture, actual ET and precipitation could potentially rise by 2–3% per K. However, ERA5 data indicates that land evapotranspiration plateaued 20 to 30 years ago, breaking the previously observed correlation between rising temperatures and increased drying. This suggests that the rate of evapotranspiration is primarily constrained by desertification, not by temperature.
Wildfire behavior is strongly influenced by fuel moisture content, which is almost never zero, as even kiln-dried wood retains 20% moisture, bound more or less tightly to internal surfaces (nwcg.gov/publications/pms425-1/11-weather-and-fuel-moisture). Fuel moisture, in turn, is influenced by soil moisture (drought.gov/topics/soil-moisture), which is almost never zero, because some water is tightly bound to soil particles, but available to plants with very fine rootlets or mycorrhizae that can get close enough to the binding surfaces.
Please link to a peer-reviewed source for your claim that ERA5 data showing ET has plateaued.
well obviously the limiting factor is moisture content, not T. the 7% saturation vapor pressure increase of air shouldn't be confused with 7% more drying. Even over ocean ET-P isn't expected to increased 7%/K. it's a different thing. you could argue hot air dries faster, not necessarily more.
here's some obs. satellites and CMIP are outliers compared to Ground obs (FluxCOM) and reanalysis. CMIP parameters tuned to satellite or an assumption about the amount of moisture. Reanalysis says no.
https://www.nature.com/articles/s41597-024-03271-7/figures/6
"Warmer air suck moisture out of everything"
Not if warmer air very moist air. Your clothes dryer only works because the moisture in the hot air is vented from the machine. The clothes wouldn't dry at all if the air inside the drier were to reach saturation point, even though that air was hot. Evaporation is much faster in dry desert air than very humid tropical forest air at the same temperature. Also, movement of air greatly affects the rate of evaporation. The fierce Santa Ana winds would have dried out vegetation very quickly and there is no suggestion that those winds have been made more fierce by the secular rise in surface temperature. Weather, both seasonal and on the scale of days and hours, is what caused the meteorological conditions favourable to these fires.
Finally, we wouldn't even be having this conversation were it not for the fact that these fires were started by humans, intentionally or accidentally and which, once started, were made very difficult to extinguish by humans because of criminal negligence and incompetence.
Hi Jamie, as disingenuous as always.
Andrew clearly didn't say that climate change, which affects the weather on an hourly and daily basis, caused the Santa Ana winds to be fiercer.
He said that the 'incredibly' wet winter led to an abundance of vegetation and biomass which, as you say, was quickly dried out by the fierce Santa Ana winds. Your argument about evaporation rate seems to be irrelevant to this point.
And yes, climate change has not yet got so bad that people and houses spontaneously burst into flame with the extreme heat, as a policeman's hair did at Bradford city. There has to be a spark, such as a cigarette in a very large pile of dry rubbish.
The difficulty of putting out the fires, which with the best will in the world would have been extremely difficult, doesn't mean that climate change isn't a very big cause for concern.
I'm not sure I should respond at all to somebody who accuses me of always being disingenuous, but for your information, I was responding specifically to Kevin's point about evaporation, and then I made the further observation that movement of air (wind) also increases the rate of evaporation of vegetation (meaning both living and dead vegetation). Thus the downslope Santa Ana winds would have further desiccated already dry fuel and, once that fuel was ignited would obviously contribute greatly to the spread of the fires. This is weather. There IS no evidence for any climate change influence on the frequency or severity of Santa Ana winds that I'm aware of, but it is these winds, along with the sources of ignition and the lack of provision for extinguishment, which are the direct proximate cause of the tragic fires. Andrew argues that climate change 'set the scene' for these fires by first accelerating the growth of vegetation during a very wet winter, then drying it out during a hot summer and very dry subsequent winter. There's very little evidence that a secular rise in global mean surface temperature is making such 'weather whiplash' events more frequent or severe either. So mostly, the LA fires look like plain old weather combining with criminal incompetence and negligence, plus arson and other human sources of ignition.
Of course. However, the warmer air from global climate change is pervasive and stresses plants, and dwellings, long before the Santa Ana comes along. This is especially the case in a Mediterranean climate like California's: long hot dry summers. Certainly exacerbated by the dry winter in southern Cal. The increase in ET is the strongest signal of climate change and increases the risk of wildfire.
The origin of the fires is another matter altogether.
Except when the increase in ET from warming is more than compensated for by the decrease in ET caused by higher CO2 concentrations.
no such thing
Oh, OK.
https://link.springer.com/article/10.1007/s40725-018-0073-8
One article doth not a scientific consensus make. In any case, the impacts on ET differ between latitudes. From the abstract at your link:
"For most locations investigated, we calculated reductions in daily transpiration rates over the twenty-first century that became stronger under higher atmospheric CO2 concentrations. It showed that the effect of CO2-induced reduction of stomatal conductance would have a stronger transpiration-depressing effect than the stimulatory effect of future warming. For currently cold regions, global warming would, however, lengthen the growing seasons so that annual sums of transpiration could increase in those regions despite reductions in daily transpiration rates over the summer months."
Annual fire seasons in temperate regions have been widely observed to be extended, as in the current conflagration in the LA basin.
Also, take a look at "Global rise in forest fire emissions linked to climate change in the extratropics"(science.org/doi/full/10.1126/science.adl5889):
"The authors identified different forest ecoregions, grouped them into 12 global forest pyromes, and described their differing sensitivities to climate, humans, and vegetation. Their analysis shows how forest fire carbon emissions have increased in extratropical pyromes, where climate is the major control, overtaking emissions from the tropical pyromes, where human influence is most important. "