December 10, 2017

Are California Coastal Wildfires Connected With Global Warming: The Evidence Says No

California's coastal mountains have been hit by two major wildfire events, resulting in dozens of deaths and billions of dollars of damage

The first occurred on October 8-9th in the "Wine Country" north of San Francisco.  The second started on December 4th in Ventura County and now has spread south to Los Angeles and San Diego.

A number of political leaders, media outlets, and activist groups have boldly stated that these fires were caused by, enhanced by, or consistent with climate change forced by anthropogenic global warming.

Governor Jerry Brown has made it clear that the fires are a "new normal" forced by global warming.

The NY Times has made the same point:

The climate advocacy group Climate Central talks about climate change "stoking the fires"

And quite honestly, I could easily give you dozens of additional examples of the such claims.  That global warming is a key element driving California coastal fires.

The trouble is that these claims are not correct.    A reading of the peer-reviewed literature on California fires and an examination of observations and prior climate information can easily show that these claims are baseless, if not outright wrong.

Let me demonstrate this to you, with facts, peer reviewed papers, and the best science can tell us. 

First, some facts everyone should agree on:

1.  That wildfires took advantage of an environment with sufficient dry fuels (e.g., grasses and shrubs) to support fires.
2.  The initiation of the wildfires were associated with the onset of strong offshore (northeasterly) winds that developed as high pressure built into the intermountain West.

The question, of course is whether these elements had anything to do with global warming.  As we will see, the answer is clearly no.  And we will also see that there is a slew of other elements (prior fire suppression, irresponsible expansion of homes, influx of invasive grasses) that have made the situation much worse.

Did Global Warming Produce Drying That Led to the Fires?

The simple answer is no.   Coastal California has dry summers because the jet stream goes far north during the warm season and they don't have many thunderstorms because of the relatively cool Pacific.   So grasses, shrubs, and other fuels will be dry by the end of summer and during fall, no matter what.    And even if the fuels weren't dry, they would dry within hours of the initiation of strong, offshore winds--which accompany virtually every major fire event.

So even if the summer/fall temperatures rose and the conditions dried further under global warming, IT WOULD NOT MATTER.  Without any additional warming, the fuels in late summer and fall are dry enough to burn over coastal California and always have been.  There is a large number of papers in the scientific literature that state this fact (Keeley and Fotheringham 2003; Keely et al., 2004, Abatzoglou and Kolden 2013, Keely and Syphard 2016). And one might note that the recent fires were actually associated with cool air and temperatures dropping into 30sF at night.
"climate does not appear to be a major determinant of fire activity in all landscapes. Lower elevations and lower latitudes shown little or no increase in fire activity with hotter and drier conditions" Keeley and Syphard, 2016

So if the summer/fall precipitation and temperatures are not important, what about the quantity of fuels? 

This year there was a bountiful crop of grass in southern/central coastal California because last winter was so wet.  And there a number of studies that document that heavy precipitation the winter before results in more grasses that contribute to wildfires the next summer and fall. 

There is NO reason to expect global warming has or will provide southern California with MORE winter rain.   Here is the winter precipitation trend from the latest U.S. national assessment (last 30 years minus the first half of the century).  Very small changes, with varying sign over coastal CA.

Changes are the average for present-day (1986–2015) minus the average for the first half of the last century (1901–1960 for the contiguous United States

The trend of December to March precipitation over coastal southern California shows no obvious trend since 1950.  So during a period in which greenhouse gases have been rapidly rising, there is no hint of increasing precipitation over coastal southern CA.

Looking to the future, Deser et al., 2012 completed a large ensemble of climate simulations for the period 2005-2060.  They found drying over the California in the ensemble mean for the winter season (DFJ) (below)

Other climate simulations have provided a variety of solutions, most with drying in southern California grading to moistening over the Pacific Northwest.

Bottom line:  no reason to suggest that the excessive winter rains this year and subsequent bountiful grasses have much to do with global warming.

Ok... so the summer conditions are not relevant because the fuels are dry enough to burn in any case, and there is no indication of increasing winter rains and more grass from global warming.  Some may argue that global warming is delaying the onset of precipitation in the fall, which might contribute to a longer fire season. In fact, Governor Brown said this.

But two facts contradict such a suggestion.  First, there is no trend in late fall (October to December) precipitation over the southern CA coastal zone (see below).  Here is the proof.  And there is no downward trend in December precipitation either (see second plot).

And in any case, southern CA climatologically gets very little precipitation during the fall--and this the impacts are minor.  For example, at downtown LA (see below) Sept. and October get .5 inches or less and November only 1.25 inches.  Not enough to make much a difference when a strong Santa Anna wind is blowing.

The bottom line of all this is that observations and the best scientific reasoning do NOT suggest that global warming is enhancing CA coastal wildfires through effects on temperature and precipitation.

So what is left to consider?  

The winds. 

The two big events this year, and a deep collection of peer-reviewed research reports show that virtually every major coastal wildfire event has been been associated with strong offshore winds.  In southern California they are known as Santa Anas and in central California as Diablo Winds.  The meteorological set ups for these event are very similar:  surface high pressure builds in across the intermountain west, establishing offshore winds at crest level of the regional terrain, and an offshore pressure gradient at lower levels.  The pressure pattern at 4 PM Tuesday illustrates this pressure configuration at the surface (and the upper air map at 500 hPa--roughly 18,000 ft-- at the same time is also shown).  Note the position of the upper level ridge:  just off the Pacific  Northwest. And you can see the strong offshore flow at higher levels in the 500 hPa map.

So the question is whether this ridge pattern and the offshore flow it produces has become more frequent during the past few decades due to global warming, something that is being claimed by some folks that suggest that a Ridiculously Resilient Ridge is becoming more frequent (e.g., the work of Swain and Diffenbaugh).    I won't get into the details of these papers, but they have scientific and technical issues, and fail to provide any real evidence of a long-term trend in West Coast ridging.

Let's see if observations support their claims.  Are upper high pressure ridges becoming more frequent just west of the Pacific Northwest?  Using the reanalysis grids available from NOAA ESRL, I created a time series of the heights/pressure in this critical area for the cool season (November to March)....see below.

The major drought year (2015) had a big positive anomaly, but looking back several decades indicates little upward trend, particularly after 1975 when there was a switch in the sign of a major north Pacific mode of natural variability, the PDO.   Bottom line: there are no long-trends of ridging that would produce more offshore flow or increasing droughts.

A recent, highly publicized paper (Cvijanonic et al) has suggested that reductions of arctic sea ice results in greater ridging along the West Coast (see figure from their paper).  But there has been a large loss of sea ice the last few decades and no trend in the ridging in the exact position they talked about.  So their hypothesis does not seem well founded.

What about easterly (from the east) flow over southern California for the Santa Anna season (Sept to Nov)?  As shown below, there is no trend toward more offshore (easterly) flow (negative numbers) over the region.

There are several papers (e.g., Hughes et al. 2009Hughes et al. 2011) that have examined the issue of whether Santa Ana winds will change under global warming.  Their findings based on both historical data and climate simulations for the next century is that Santa Ana winds have not increased in magnitude/frequency and will be reduced under global warming.  Yes, reduced.  And this makes sense.  Part of the forcing of Santa Ana is the difference in temperature between the interior and the ocean.  A very robust finding of virtually all climate models is that the interior of the continent will warm more quickly than the eastern Pacific.  Thus, warming should WEAKEN a major forcing mechanism of Santa Anas. 

What about the observed trends of major wildfires over coastal California during the past decades?  Any evidence of a GW effect?   Dennision et al., 2014 published a comprehensive paper about western wildfires, finding a REDUCTION in major wildfires over the coastal region from San Diego to San Francisco.  Here is a plot from their paper.  Totally consistent with everything I have described above.  Totally inconsistent with the claims of Governor Brown, some climate activists, and a too many media outlets.

Finally, any consideration of the origin of any trends in wildfires must consider that humans are the cause of fire ignition for most California fires.   An article in the Proceedings of the National Academy of Sciences (found here)  noted that 84% of  U.S. wildfires were initiated by humans, with particularly high human ignition over southern/central California.   This is not surprising considering the population density and lack of lightning over the region.

Putting it all together

Considering the results of numerous studies of wildfires over coastal California and its relationship to prior and concurrent conditions, observed trends in key meteorological drivers, and even the number of major wildfires themselves strongly suggests there is no credible evidence that global warming is causing an increase currently or will increase in the future  of the number or intensity of wildfires over coastal California from San Diego to the SF Bay region.

Those that are claiming the global warming is having an impact are doing so either out of ignorance or their wish to use coastal wildfires for their own purposes.  For politicians, claiming that the big wildfires are the result of global warming provides a convenient excuse not to address the real problems:
  • Irresponsible development of homes and buildings in natural areas that had a long history of wildfires.
  • Many decades of fire suppression that have left some areas vulnerable to catastrophic fires.
  • Lack of planning or maintenance of electrical infrastructure, making ignition of fires more probable when strong winds blow.
  • Lack of attention to emergency management, or to providing sufficient fire fighting resources
  • Poor building codes, improper building materials (wood shake roofs), and lack of protective space around homes/buildings.
And to be extremely cynical, some politicians on the left see the fires as a convenient partisan tool.

Wildfires are not a global warming issue, but a sustainable and resilience issue that our society, on both sides of the political spectrum, must deal with.

Summing up, perhaps Mark Twain said it best:


  1. Good post Cliff. Good to see someone is keeping it real. There are so many reasons that increased fires are not caused by climate change

    In a 2017 paper researchers reported that across the USA from 1992 to 2012, “human-caused fire season was three times longer than the lightning-caused fire season and added an average of 40,000 wildfires per year across the United States. Human-started wildfires disproportionally occurred where fuel moisture was higher.” Furthermore “Human-started wildfires were dominant (>80% of ignitions) in over 5.1 million km2, the vast majority of the United States, whereas lightning-started fires were dominant in only 0.7 million km2.”

  2. Something worth pointing out: That last paper referenced—Dennison et al, 2014—and a great many other peer-reviewed studies, actually support the claim that global warming is having an impact on fire in western North America. Dennison et al "found significant, increasing trends in the number of large fires and/or total large fire area per year. Trends were most significant for southern and mountain ecoregions, coinciding with trends toward increased drought severity." Cliff correctly reported that Dennison et al did NOT find this trend in coastal California. They looked at ten regions of the west and found increasing trends in eight of them, no basis to conclude a trend in one of them, and the one exception, coastal California.
    It may be that people "using coastal wildfires for their own purposes" are simply taking something that they understand correctly and applying it too broadly.

  3. "Bottom line: there are no long-trends of ridging that would produce more offshore flow or increasing droughts. Busted."

    Can you post the time series you graphed and I'll run a LOESS? To my eye it looks like a trend, but we shouldn't be dueling eyeballs on this.

    Eyeballing noisy data for a lack of a trend just doesn't get you very far. Maybe if you see "serious scientific and technical issues" with the ridging papers it worth be worth laying them on the table.

    1. Could we get a data source that separates night and day values?

  4. Cliff, just wondering if you could elaborate on why you are skeptical of the findings of Swain and Diffenbaugh (e.g. this blog post: Furthermore, given that there is a difference in opinion in the scientific community when it comes to the long term trends in the RRR, can one truly conclusively say that climate change won't have a meaningful effect on California wildfires?

  5. This is the most likely reason for these fires down south. Thankfully, this guy was caught red handed. How many of the other fires were started by carelessness, antifa types, or illegal aliens? ...

    Also of note take a look at the record high temps for the LA area. The record for Dec 11th was set back in 1895. Amazing! ...

  6. I see that my Intellicast link in my first comment does not show what I claimed it showed. I must have been looking at another city in the area, but I have no idea which town/city had the records from the early 1900s and late 1800s. I'll see if I can run that down.

  7. Papers that suggest there is an uptick in fires and suggest that is consistent with global warming have several flaws.

    Mainly none separate out the 3 fold increase in human ignitions as shown in the 2017 paper

    And trends in most those papers are based on a very short term analyses that fail to account for the change in fire suppression policies. Suppression reduced that frequency of natural fires while increasing fuel loads. There has been a change in policy to allow more fires to burn if buildings are not threatened and thus causing an "uptick"

    Fires were far more prevalent during the 1800s as seen in the graph from Swetnam (1999) Historical Fire Regime Patterns in the Southwestern United States

  8. How close to conclusive data can you get when you're measuring an environment that is constantly being modified? (I don't have the answer, only the question.) It seems just as likely to me that human activity could cause whatever changes we see. Climate change is an easy excuse. Not to say it's wrong, but we should be skeptical.

  9. Mark - yes it's the overriding truth in this matter. All these very smart people are working very hard, but are actually busying themselves with trying herd cats.

  10. Many fires in this region during the 1800s were started by sparks from passing trains. See historic images of the railway corridors.

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  12. Cliff- a couple things:

    1. I see an upward trend in the geopotential height.

    2. Sure, hotter summers won't make much difference to soil and fuel moisture in southern CA, but warmer temperatures during the other seasons will lengthen the fire season by causing measurable drying, won't they?

  13. About proximate causes for fires in this country's :
    But proximate causes and longer term climate-related causes (if/when that is in the picture) are not mutually exclusive.

  14. Cliff said:

    "Part of the forcing of Santa Ana is the difference in temperature between the interior and the ocean. A very robust finding of virtually all climate models is that the interior of the continent will warm more quickly than the eastern Pacific. Thus, warming should WEAKEN a major forcing mechanism of Santa Anas".

    If the interior is warming faster than the ocean doesn't this increase the temperature difference thus making the winds stronger, not weaker?

  15. OK already. Enough of the "this isn't conclusive evidence" trope. Anyone following this blog is cognizant of the message. We get it.

    Why not steer the subject ( current wildfire patterns direct relationship to climate change) in a direction that is helpful? That is, is it possible to filter the various other influences out to reveal how climate change might be a factor?

    One of the problems is the stated focus of this blog, which is the USA northwest or expanded to the entire USA west coast when is convenient. When you constrain your focus on a limited sample size, there is little wonder that general trends are distorted by very specific regional effects, primarily centred around "other" human interference in natural process, such as population growth and forestry practices.

    How about expand your focus occasionally to regions that filter out these "other" influences? How about Siberia or if you really have a bias to "built in America" to Alaska?

    "The observed fire history allows estimation of fire frequency back to the Little Ice Age (LIA) period. LIA within Siberia began in the 14th century and ended in 1850, approximately (Fig. 4). Comparison of the number of fires during LIA (1700–1849) and a similar post-LIA period (1850–2000) showed an approximate doubling of fire frequency in the post-LIA period (7 vs 13 fires). A similar result (doubling of fire frequency in the post-LIA warming) was obtained earlier for sites III and IV (Fig. 1) (Kharuk et al. 2008, 2013). These data support the hypothesis that modern climatic warming will increase fire frequency (e.g., Girardin et al. 2009)"


  16. Another interesting study, about lengthening fire seasons:

  17. Cliff,

    These large persistent ridges of high pressure and large persistent wave trains in the 500 mb occurred last summer and now this winter and again and again the past few years.

    Do you now see evidence that the reduction of Arctic Sea Ice may be changing the 500 mb wave train?

  18. “Research indicates a direct casual link between human-induced climate change and increased wildfire risk in California,” Climate Signals says. “Climate Change has contributed to California’s longer fire seasons, the growing number and destructiveness of fires, and the increasing area of land consumed.”

  19. I have some problems with your choice of datasets and assumptions that it is always this dry in Southern Ca. regardless of summer-fall precip
    Looking at the NOAA precipitation anomalies for CA south coast drainage from Nov back 3 6 and 9 months it has been abnormally dry in 2017 particularly in the March-Nov time frame, 2nd lowest on record (5.74" below the 7.66" average for 1901-2000). And, plotting a trend line from 1950-2017 shows a clear decrease of .33"/decade which appears to have accelerated lately. Seems to me that by only including the Dec-March data to prove that there has been little change in precip you are giving a distorted view of the historical trend. For this year the abnormally high rains that generated higher than normal vegetation growth coupled with a shift to abnormally dry conditions for an extended period of time during the hotter months would create a dryer than normal environment and the intensity of these fires would appear to validate that.


  20. Bruce, T o paraphrase your comment, "Anyone following this blog is cognizant" that you dislike any analyses that suggest recent weather catastrophes are natural and not due to CO2.

    The post was about the California fires and the disturbing climate alarmist demagoguery that has redirected our attention away from the real issues that must be dealt with such as fire suppression, human ignitions and unwise human expansion into fire prone areas.

    Your attempt to move the discussion to Siberia fires is a bit of similar misdirection in keeping with your attempt to show all things are due to Co2 climate change. But let me indulge you. Before you extrapolate your single Siberian reference to global warming consider the fact that less fires are due to low fuel loads. That's why fire suppression has resulted in current disasters, as it has anomalously increased fuel loads. In areas like Siberia, the cold of the LIA prevented any tree growth, and thus prevented fuel load build ups

    Read Devi 2008 "Expanding forests and changing growth forms of Siberian larch at the Polar Urals treeline during the 20th century"

    In the Ural Mountains (which divides Asia from Europe), Devi researchers found thousands of more than 500-year-old dead trees that grew before the Little Ice Age (LIA) struck. In contrast, remnants of any new trees that could have sprouted during the LIA were almost entirely absent"

    The LIA cold prevented fuel build ups because it prevented growth. Makes one wonder why current warming since the LIA is characterized as bad for the biosphere.

    Anyways the paper you linked to supports the correlation between greater fuel loads and shorter Fire Return Intervals ( FRI). Lower latitudes are warmer and more favorable to more tree growth and thus exhibit a faster increase in fuel loads to support more frequent fires. In contrast tree growth decreases, fuel loads decrease resulting in longer time periods between fires as one moves poleward.

    From your linked paper, " FRI increased with an increase in latitude and was observed to be about 80 years at 64°N, about 200 years near the Arctic Circle, and about 300 years nearby the northern limit of closed larch stands (~71°N+). Northward FRI increase was correlated with incoming solar radiation (r=0.95)"

    Accordingly the cold of the LIA and reduced tree growth ( coincides with LIA solar minimums).

    Renowned climate scientist Gov Brown is engaging in CO2 climate change demagoguery that is shamefully misleading the public. Hopefully Bruce you are getting your wildfire science from better sources.

  21. Fossil fuel burning = high pressure systems continually parked off NW coast = block rain bearing systems from California = dry conditions = firesuperstorms

    As for blaming it on eucs, learn:

  22. I find it interesting that whenever this blog's proprietor debunks so many of these claims, there are always a legion of adherents that leap to their defense, in an almost Tourette's Syndrome - style. He's never stated that AGW warming is not occurring and is not caused by man - made activities, merely elucidating that the alarmists due unnecessary harm to their cause via these pronouncements. Akin to the Salem Witch trials, anyone not agreeing 100% 24/7 is deemed a heretic and must be denounced and shunned. This is not a persuasive technique, try another avenue, folks.

  23. Also of note is that in the Dennison et. al. paper, they found (as Cliff pointed out) a weak negative trend (p>0.10) in number of large fires but a strong positive trend (p<0.05) in 90th percentile large fire size for Mediterranean California.

    Here's how that paper is summed up:

    "Due to complex interacting influences on fire regimes across the western U.S. and the relatively short period analyzed by this study, care must be exercised in directly attributing increases in fire activity to anthropogenic climate change. Even so, these changes in fire activity are a reflection of long-term, global fire trends that will likely occur with increased temperature and drought severity in coming decades."

  24. No Jim, once again you miss characterize what I had said in plain english. I doubt (and the authors suggest) that even in Siberia, northern Canada or Alaska where there is much less human influence on forests and fires that only a reasonable probabilistic inference of climate change exists as a contribution and then, as usual, only by looking at a large time frame. No one is making any statements of "Demagoguery" when they consistently state there is uncertainty in their conclusion! It is your own language that is demagogic.

    My point is this: Anyone following this blog is familiar with how both the media and politicians "get it wrong". Even the most drought related fires cannot be said to be a conclusive result of climate change because droughts are natural perturbations of climate. In other words, there is practically no fire (or wind storm, precip event, persistent ridge..... you name it) that can be characterized as a smoking gun of climate change.

    Yet if you look at global trends over time, there are consistent trends in increased size, number, season etc that correspond to predictions of a warming climate. I suggest that by looking at the fires in the boreal forests up north there is a better chance to see climate influences in the fire trends with much less 'other factors". Perhaps this is what we should all focus on.

    You mischaracterize my words with your biases. You fully engage in the same cognitive errors as the politicians and journalists that finger climate as a cause of the fires. You see what you want to see in my words, not what they plainly say.

    The whole idea of striving to pin an actual hurricane, flood, drought or fire on climate defeats the usefulness of the events. All anyone needs to say to illustrate the risk facing us is that what you see now, natural caused or otherwise, is what we will see more of later and if it doesn't materialize as fire, rest assured it will manifest as what the real problem is - ecological instability on a global scale.

    Whatever climate influence is happening now, it is not catastrophic no matter how destructive it is. The trend, such as it is, is what we get with one degree of warming. The problems start when we warm to 2 degrees, then 3, then 4...... at which point our kids are going to be cursing our names for our risk incompetence.

  25. We keep having these ridges of high pressure causing record warmth and drought on the West coast. I'm surprised that Prof. Mass finds it so easy to rule out the possibility that climate change, and specifically the massive changes in the Arctic, have made this scenario more likely. I'm no expert on the subject, but it doesn't seem far fetched that Arctic warming could cause circulation changes elsewhere on the planet, especially given that multiple peer-reviewed studies have suggested this. I think an alternate explanation offered in another blog post here was "Could be typical chaotic behavior of the atmosphere". The more hot summers and wildfires we have, the less convincing that is going to be. Another post here referred to the summer of 2015 as the "summer of 2070" because the heat was similar to what climate models predicted for the 2070s... well, at this rate it's starting to look more like the "summer of the 2010s".

  26. First, for those who have not read Jim Steele's book, Landscapes and Cycles, you should do so to get a bigger picture of the climate and what influences it. Also, in his book, he points out the need to really look at the data and how various ideas are taken out of context by the media/politicians to promote a certain world view. His book has helped me so much in pulling together ideas about the environment and climate.
    Cliff's blogs are a breath of fresh air in a world where sound bites are so prevalent.
    I have taken up the study of climate and weather on my own and the one thing I can say(as a neophyte on the subject) is that it is extremely complex, with various wind/ocean/sun/seasonal interactions thrown into the mix. To label every event by the mantra, "it is CO2", or "climate change" without really understanding these terms on a deep level is creating a collective ignorance that does not serve us. thank you Jim and Cliff!

  27. Please consider the effect of higher carbon dioxide levels (~400 ppm now, ~330 ppm mid 20th century) on plant growth.

  28. Where can we get the raw data used in the trend plots?

  29. Good Lord, Cliff. How many more of these "global warming has nothing to do with it" posts do we need to hear from you? Of course the connections are not well understood. Of course there is debate. But your continued brush-offs are beginning to feel deeply out of step with our times. I sure wish you would explore in depth what impacts we are seeing, and as importantly, what we can do now as science-informed folks observing these changes every day, every season. That would be a lot more helpful, and a lot more interesting.

  30. Belinda,

    I am always fascinated by the psychology of people who are accepting of unsupported demagoguery of climate alarmists/politicians like Gove Brown, while being simultaneously uncomfortable when scientific facts are presented such as presented by Cliff, that expose that demagoguery!

    Why is that?

    1. It would be helpful to read, if you haven't, the scientific research that Cliff disputes as inaccurate. You might see why this isn't a problem of "psychology", but rather a process of scientific debate. You can agree with Cliff's analysis of that research, and/or you can question it based on the findings of other scientists. You can imagine you understand it better than anybody else. But Cliff cites the research he questions. You can read it yourself. You can even read the New York Times story which Cliff has referenced here, since it is attached to an article which is mainly about a particular scientist's views. What isn't helpful is the ad hominem attacks. Nobody here has offered uncritical support for whatever Gov Brown said about the fires! Neither would any real scientist (Cliff included) expect uncritical support for his/her research, or offer uncritical support for the research work of others. Informed criticism is part of the scientific process.

  31. I think it's time to recognize the good journalism on climate change, instead of just bashing the less-informed sources. This article is pretty good:

  32. Belinda - You said "Of course the connections are not well understood", and in the same breath then proceed to bash Cliff for being "deeply out of step with our times".

    What "times" are those? The times when a scientist who intelligently and factually disagrees is subsequently attacked? The times when any weather event anywhere that deviates from the norm is labeled a result of climate change?

    Science loses credibility when those practicing it intimidate those who question them. It loses credibility when it is used for political purposes. Both have been going on for way too long now with AGW. It needs to stop.


  34. Please read the Dennison paper again, particularly the second paragraph of section 3. The authors note: "Unlike other ecoregions in the western U.S., the Mediterranean California ecoregion experienced a significant increase in the 90th percentile of large fire size, without demonstrating significant trends in the number of fires or total fire area." Didn't Twain also say something about statistics?

  35. Just finished reading a piece on melting permafrost in the Artic which included the following quote...

    "This (the rapid and unprecedented warming of the Artic region) is probably partly responsible for the current unusual weather in the United States that brought destructive wildfires to California and a sharp cold snap to the South and East, according to NOAA scientist James Overland and private meteorologist expert Judah Cohen."

    Cliff, I'd be interested on your take of this. Article posted by BY SETH BORENSTEIN ASSOCIATED PRESS 12/12/17

  36. like I said, that is not a Mark Twain quote, it's a much older quote, back to Josh Billings at least, and probably much farther. Do your research Cliff.

  37. Osu wxman - Yes he did although as is so often the case, his quote has been popularly cherry picked clear out of context to how it was intended.

    ""Figures often beguile me," he wrote, "particularly when I have the arranging of them myself; in which case the remark attributed to Disraeli would often apply with justice and force: 'There are three kinds of lies: lies, damned lies, and statistics.'"[2]

    Figures often beguile..... particularly when he (the unskilled) is the one doing the arranging. At which point the unskilled is less inclined to blame himself for any deception or failure, blaming instead the numbers themselves, which is how the general public likes to dismiss the fine art of statistics. This is "attribution bias" where the narrator wishes to direct blame for a failure away from themselves, insinuating the it is the art of statistics itself that is unreliable.

    Twain was no fool and I'm pretty sure he meant to say quite clearly what he did. Statistics only consistently lie when the unskilled arrange them. Not surprisingly, this observation of his is borne out by the actual study of expertise, which has been studied at least as long as climate. Numbers can be arranged in many ways but depending on the objective, only one way is the right way and the odds on the average joe picking the right way are not as easy as it appears. Daniel kahneman covers it quite well in his book Thinking, Fast and Slow where he boils it down to two main requirements to get the numbers arranged properly.

    Adequate skill and "the law of large numbers"

  38. The metrics one chooses, as well as other factors, to assess change really matters. As someone involved for years in a different science domain that had trouble figuring out what metrics were important, and the need for multidimensional metrics and analyses, I know that this is a challenging area.

    One metric that it seems increasingly important to include in assessing potential 'event' changes due to climate change are the frequency and intensity of extreme events, e.g., as discussed here (with original references) re: the extreme rain event during Hurricane Harvey

  39. "One metric that it seems increasingly important to include in assessing potential 'event' changes due to climate change are the frequency and intensity of extreme events, e.g., as discussed here (with original references) re: the extreme rain event during Hurricane Harvey"

    Interesting. Here's a post that provides substantially more analysis on Hurricane Harvey that says the opposite:


    Cliff, what has the VPD been this year for California? Seems like that would be a more direct and better dataset to use for this discussion.

  41. Jim Steele with good points to Belinda et. al. It’s so obviously unscientific when you don’t simply let the science lead where it may. You have to remain dispassionate and objective at all times, even when everything you thought you knew has been falsified by new evidence. When people like Governor Brown turn science in to an emotional and political crusade, they lose every time.

  42. And Cliff, thanks for standing up to the bullying of people like Sarah Myhre. The majority are not swayed by anyone who is trying to leverage current political and cultural trends to buttress their “science.”

  43. "Blogger Craig said...
    Cliff said:

    "Part of the forcing of Santa Ana is the difference in temperature between the interior and the ocean. A very robust finding of virtually all climate models is that the interior of the continent will warm more quickly than the eastern Pacific. Thus, warming should WEAKEN a major forcing mechanism of Santa Anas".

    If the interior is warming faster than the ocean doesn't this increase the temperature difference thus making the winds stronger, not weaker?"

    Craig, the short answer is probably not. Heating in the summer would on a synoptic scale increase onshore winds as the interior of the continent would heat up more. During Santa Ana events in the fall and winter, strong high pressure in the interior helps generate the winds. With increasing winter temperatures the difference between the cold interior and the "hot" Pacific declines resulting in declining winds. At least this would be my thoughts.

  44. Cliff you should really be publishing your arguments, because other people are publishing the opposite and it appears to be accepted in the literature and filtering to the press:

    I recognize this is 2016 wildfires not 2017 but you must get the drift. Publishing only to your blog is not persuading your peers. And if you are publishing, you need to be talking to more reporters.

  45. Yeah......but......wouldn't global warming irritate humans and as a result make them start more fires??

    Daah! seems like it should be so.

  46. "Why not steer the subject ( current wildfire patterns direct relationship to climate change) in a direction that is helpful?"

    That really says it all about the global waming cult: When the facts are against us, just lie through our teeth.

  47. Place Slipper - please, you can do better than that. It really doesn't add to your reputation by stooping to the cowards tactic of a drive by insinuation.

    If you would be so kind, that is assuming you are even capable, explain succinctly and concisely exactly how you conclude that I explicitly or implicitly ever advocated "lying through my teeth".

    Hint: No, it will not help your case by putting my sentence back in the context you surgically removed it from which only means you will have to use a context that only your own fertile imagination can provide.

    So lets hear it! I'll make popcorn....

  48. You are a global warming zealot. Every single non-average weather event is now evidence of your religion. Time was when your crowd would piouly caution about the difference between climate and weather. When that didn't work, your crowd dropped the pose and went into full b.s. scare mode.

    All that's happened is that normal people now laugh at you. This has nothing to do with climate. You're part of one more doomsday cult, except that now you want $00 trillion. The answer is "no."

  49. Hi Cliff.

    Very interesting article, and since you're a climatologist, I'll trust your data. It goes totally against my intuitive sense. Intuitively it seems that global warming will of course be the cause of recent California wildfire activity. But then again, all the other causes you mention (more human activity that starts fires, building homes further out, aging electrical infrastructure) are happening as well, so we trust you scientists to examine this. I grew up in Southern California and don't remember wildfires being this bad, so I read this with interest.

    If those headlines aren't based on facts, then all they're doing is scaring people (even the New York Times, a newspaper I trust, is doing this!).

    By the way, do you know Robb Wills? He's my nephew (my husband's brother's son). We figure you know him since he's working at University of Washington.


  50. Thank you for your post. Starting in 1995, decades of increasingly alarming bipartisan state and federal reports warn about accumulation of wildfire fuels due to fire suppression policy put in place in 1910, and the critical need to reduce fuels, and to amend environmental laws to allow people to reduce wildfire fuels to safe levels, to avoid the kind of catastrophic wildfires we are seeing today.

    In 2009 one of those papers, A Call To Action, warned, "Business as usual is not working! To the U.S. citizen 'The nation's fire service is about to lose its ability to put out unwanted wildfires and help you protect yourself and your properties.'" As we see in the news, that time has now come.

    You can download a paper with quotes from and links to some of those reports from Google Drive with this link

    Despite those decades of warnings, Congress and California's Legislature have not amended environmental laws to allow and facilitate wildfire fuel reduction work.

    Saying the wildfire problem is caused by climate change rather than wildfire fuel accumulation works for politicians.

    California government averages about $1.6 billion per year auctioning carbon credits, which is supported by saying wildfires are caused by climate change.

    Moreover, blaming wildfires on climate change avoids the need to confront environmental activists about environmental laws contributing to the wildfire fuel accumulation problem.

    I believe the root cause is that most people now live in cities and do not see in their daily life the vast quantity of fuel that is accumulating. They are the source of the power environmental groups have over legislators, giving environmental groups unquestioning support.

    In California the 2010 Census reports that 95 percent of Californians live in urban areas, on about 5.3 percent of California's land. Table 2 on page 2 of this document

    Interesting is seeing the change in California's population going from primarily rural to primarily urban over time. Table 1 in that same Census document.

    A Forest Service official I spoke with explained that what he called urban bias is the cause of many problems in rural areas. Most people live in urban areas, so most legislators live in urban areas, so most laws are written and enacted by urban legislators, which reflect the biases of urbanites, which can cause real problems in rural areas.

    As I see it, the wildfire problem will not be solved until millions of minds are changed to support amending environmental laws so they clearly allow and facilitate wildfire fuel reduction work instead of adding costs, delays, requirements, limitations, and threats of fines or jail time that act to discourage the work. Not likely any time soon.

    In the meantime, I don't understand why more people don't see the obvious fact that climate does not burn, only fuel burns, and fuel density is the only thing we can readily change with existing technology, especially as wildfires continue to release massive quantities of greenhouse gases into our atmosphere.

    Cliff, implying that people should not be allowed to live in rural areas subject to wildfires seems imprudent.

    Already, very little land in California is available for Californians to own and live on outside cities on non-farmland.

    About half of California is owned by government, mostly federal. And much is owned by lumber companies, public utilities, and railroads, and much of what remains is farmland we need to grow food on. People living in rural areas could be part of the solution, if they are allowed and encouraged to thin wildfire fuels to safe levels without regulatory hindrance, and allowed to live in rural areas where the work needs to be done.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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