Wildfires in 2021: Don’t Be Lulled Into Complacency by YTD Figures

The upward trend in acres burned is shown below.

Figure 1: Acres burned (black) and acres burned year-to-date (YTD) 28 July (red), and log linear regression fit (gray), forecast based on log first differences regression 2012-18 (purple x) and plus/minus one standard error (light small purple x). Source: NIFC1, NIFC2 , and author’s calculations.

If one were to use year-to-date numbers to infer the severity of the season to come (as has at least one commentator – the same one who also had questions about confidence intervals), one could make a serious error. All one has to do is to absorb the oft-remarked point that fire season is expanding in time, so that it runs later into the year. The trend in divergence between full-year and year-to-data figures — i.e. the gap between black and red line — is consistent with this point.

How to use this fact in order to get a handle on 2021 acres burned? Examination of the first difference of logged variables is illuminating.

Figure 2: First difference of log acres burned (black) and of acres burned year-to-date (YTD) 28 July (red). Source: NIFC1, NIFC2 , and author’s calculations.

The correlation breaks down for 2019 and 2020, but overall seems otherwise strong. I use that correlation between 2012-18.

The regression equation is:

d(log(ACRES)) = 0.046 + 0.894×d(log(ACRES_YTD))

bold denotes significance at 1% msl using HAC robust standard errors. Adj.-R2 = 0.86. DW = 2.45, n=7.

Hence, even without believing in any regression results, one should be circumspect in using YTD numbers this early in the fire season to infer final annual numbers, particularly in the new climate normal I believe we are in.


47 thoughts on “Wildfires in 2021: Don’t Be Lulled Into Complacency by YTD Figures

  1. ltr


    December, 2008

    Target Atmospheric CO2: Where Should Humanity Aim?
    By James Hansen, Makiko Sato, Pushker Kharecha, David Beerling, Robert Berner, Valerie Masson-Delmotte, Mark Pagani, Maureen Raymo, Dana L. Royer and James C. Zachos


    Paleoclimate data show that climate sensitivity is ~ 3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, * is ~ 6°C for doubled CO2 for the range of climate states between glacial conditions and ice-free Antarctica. Decreasing CO2 was the main cause of a cooling trend that began 50 million years ago, the planet being nearly ice-free until CO2 fell to 450 ± 100 ppm; barring prompt policy changes, that critical level will be passed, in the opposite direction, within decades. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm ** to at most 350 ppm, but likely less than that. The largest uncertainty in the target arises from possible changes of non-CO2 forcings. *** An initial 350 ppm CO2 target may be achievable by phasing out coal use except where CO2 is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO2 is not brief, there is a possibility of seeding irreversible catastrophic effects. ****

    * Surface reflectivity of sun’s radiation

    ** Currently 419 ppm

    *** Net change in radiant emittance or irradiance

    **** http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf

    1. rjs

      since you brought it up, the infrastructure bill currently making its way through the Senate will have the largest carbon footprint of any domestic policy initiative since Eisenhower built the interstates…just start with the concrete and asphalt we’ll use for road building & repair..

      concrete is made of various combinations of sand, gravel and cement…all the various types of cement have lime (CaO) as their basic material…that lime is produced by heating limestone (CaCO3) in a big kiln (often by burning coal) to produce lime and carbon dioxide (CaCO3 > CaO + CO2); hence, cement production itself emits 0.654 tons of CO2 per ton of cement produced, not including the CO2 emitted in generating the needed 1300 C degree temperatures…

      meanwhile, the basic material for making asphalt is bitumen, also known as tar…bitumen is the thick goo that’s left over from oil refining…trouble is, oil from shale is so light (sometimes it’s almost like gasoline) there’s little bitumen left over from refining it, so most bitumen now has to be mined from somewhere…we’ve got a few deposits, like in Utah, Kentucky, & California, but for any quantity we’d have to import it from the tar sands of Canada or Venezuela..

      then there’s bridges, which will need steel…like cement production, steel making has CO2 emissions from both the process (using coking coal) and the electricity needed to make it….CO2 emissions from steel manufacturing are almost double the amount of steel produced: 1.85 tons of carbon per ton of steel.

      i could go on, but you get my gist…if i thought there was still hope, the infrastructure bill would be something that would gravely concern me..

  2. pgl


    I know it is easy to mock Andrew Clyde but please remember he replaced fast talking Doug Collins who represented the 9th Congressional district of Georgia. This is the far northeast corner of the state which is the polar opposite of Atlanta. Yes we are talking about KKK country. In their neck of the woods any tourists who happen to be black get lynched. So when the Trump tourists as he calls them saw Capitol police who happened to be black of course they had to resort to extreme violence. That is indeed Andrew Clyde’s view of the world.

  3. pgl

    I was wondering why you picked on Princeton Steve here but then I noticed his hit parade of incredibly dumb comments on such a variety of topics. But at least he sort of got around to noting interest rates have something to do with housing prices – finally!

  4. ltr


    January 15, 2021

    Atmospheric Concentration of Carbon Dioxide, 1980-2020

    (Parts per million by volume)

    1980 ( 338.76) (Low)
    1981 ( 340.12)
    1982 ( 341.48)
    1983 ( 343.15)
    1984 ( 344.85)

    1985 ( 346.35)
    1986 ( 347.61)
    1987 ( 349.31)
    1988 ( 351.69)
    1989 ( 353.20)

    1990 ( 354.45)
    1991 ( 355.70)
    1992 ( 356.54)
    1993 ( 357.21)
    1994 ( 358.96)

    1995 ( 360.97)
    1996 ( 362.74)
    1997 ( 363.88)
    1998 ( 366.84)
    1999 ( 368.54)

    2000 ( 369.71)
    2001 ( 371.32)
    2002 ( 373.45)
    2003 ( 375.98)
    2004 ( 377.70)

    2005 ( 379.98)
    2006 ( 382.09)
    2007 ( 384.03)
    2008 ( 385.83)
    2009 ( 387.64)

    2010 ( 390.10)
    2011 ( 391.85)
    2012 ( 394.06)
    2013 ( 396.74)
    2014 ( 398.87)

    2015 ( 401.01)
    2016 ( 404.41)
    2017 ( 406.76)
    2018 ( 408.72)
    2019 ( 411.66)

    2020 ( 414.24) (High)

  5. ltr


    January 15, 2021

    Annual Mean Atmospheric Carbon Dioxide Growth Rate, 1980-2020

    (Parts per million by volume)

    1980 ( 1.68)
    1981 ( 1.43)
    1982 ( 0.86)
    1983 ( 2.36)
    1984 ( 1.51)

    1985 ( 1.21)
    1986 ( 1.47)
    1987 ( 2.06)
    1988 ( 2.24)
    1989 ( 1.24)

    1990 ( 1.20)
    1991 ( 1.05)
    1992 ( 0.49) (Low)
    1993 ( 1.36)
    1994 ( 1.95)

    1995 ( 2.01)
    1996 ( 1.24)
    1997 ( 1.91)
    1998 ( 2.97)
    1999 ( 0.92)

    2000 ( 1.62)
    2001 ( 1.62)
    2002 ( 2.51)
    2003 ( 2.26)
    2004 ( 1.59)

    2005 ( 2.57)
    2006 ( 1.69)
    2007 ( 2.31)
    2008 ( 1.54)
    2009 ( 2.00)

    2010 ( 2.30)
    2011 ( 1.92)
    2012 ( 2.65)
    2013 ( 1.99)
    2014 ( 2.22)

    2015 ( 2.90)
    2016 ( 3.03) (High)
    2017 ( 1.93)
    2018 ( 2.88)
    2019 ( 2.48)

    2020 ( 2.31)

  6. ltr


    July 29, 2021

    Over 1.6 bln doses of COVID-19 vaccines administered in China

    BEIJING — Over 1.6 billion doses of COVID-19 vaccines have been administered in China as of Wednesday, the National Health Commission said Thursday.

    [ Chinese coronavirus vaccine yearly production capacity is now 5 billion doses. Along with over 1.6 billion doses of Chinese vaccines administered domestically, another 600 million doses have been distributed internationally. A number of countries are now producing Chinese vaccines from delivered raw materials. ]

  7. macroduck

    I don’t know much about wildfire prevention and suppression, but I remember some stuff from grade school. The necessary conditions for fire are Fuel + Heat + Oxygen. Those conditions exist over vast area. Aren’t we pretty much screwed when it comes to wildfire? Higher temperatures and drier conditions due to normal variation would result in normal variation in wildfires. Persistently higher temperatures and drier conditions due to climate change looks unbeatable.

    Grass fires get less press than forest fires, though grass fires often burn more acreage. Peat fires don’t get as much attention at all in the U.S., but peat fires in Asia, Africa and Europe are growing more common and are very hard to put out. Peat, permafrost and frozen methane present the potential for sudden, massive increases in greenhouse gas release. It’s a tipping point problem, with some evidence that tipping points may have been reached.

    1. macroduck

      By the way, “Several recent studies indicate that those models are underestimating the total amount of carbon that will be released from soil in a warming climate.” Those same studies also indicate that schemes to sequester large amounts of carbon in the soil won’t work. Turns out that humus isn’t what we thought it was. Still delicious, though.

      The good news is that with improved knowledge comes the opportunity to develop schemes which might work.


      1. Moses Herzog

        I think all of your points are valid and frighteningly well stated. You know “the unknown” here that is scaring me?? I’m not sure if we’ve seen any solid estimates of the environmental damage coming from lithium-ion battery production for cars?? I’m not against lithium-ion batteries for cars, but to say that it’s definitively better don’t we need some estimates on the immediate negative externalities from their production?? Alongside with the fact these probably aren’t 100% recyclable once the individual units become obsolete. So where do they go when they can’t be recycled??

        I’m very happy to be told by anyone that this is a non-worry, but I haven’t seen convincing research or publicly available data to convince that it is a non-worry.

        1. macroduck

          Uh, wish I could help, but I can’t.

          Many popular “remedies” for carbon-induced climate change assume the goal should be the continuation of consumption patterns we have adopted during a period of remarkable divergence from historical patterns of resource use. We have to keep driving, just in cars that don’t directly consume hydrocarbon-based fuels. Producing the cars consumes massive amounts of hydrocarbons. Generating electricity consumers massive amounts of hydrocarbons. Building and maintaining roads consumes massive amounts of hydrocarbons. But that’s cool if the cars don’t actually burn hydrocarbons. The batteries? Well, they don’t burn hydrocarbons, do they? So what could go wrong?

      2. baffling

        in addition, recent estimates indicate the rain forests, such as in the amazon, are no longer working in our favor. deforestation is doing two things. the slash and burn is putting carbon in the air. and the loss of rainforest takes away a valuable tool which removes carbon from the air. i am hearing concerns that the rainforests are no longer a carbon capture sink.

      1. sammy


        Yes, I forgot.
        Any data that refutes manmade CO2 induced Global Warming being responsible for natural catastrophe is de facto incorrect.
        My bad.

        1. Menzie Chinn Post author

          sammy: So, you’re in favor of using inconsistent data w/o caveats. Who knew.

          Why don’t you go back to arguing like the other clearly insane people:

          ” Biden got the highest percentage of the vote of any challenger to an incumbent president, 51.3%, since FDR beat Hoover in 1932. He even did better than Reagan against Carter.”

          Truly, I feel sorry for you, and the fact that you are in this mentally incapacitated state.

          This is one of the reasons for the scepticism.

          We are supposed to believe that this creepy senile dotard, with no meaningful accomplishment in 40+ years in the national legislature, who failed miserably in every other presidential run, with an obviously evident payola scheme through his drug addicted son, who campaigned from his basement and when he did emerge, didn’t draw flies, with record low voter enthusiasm…yeah that guy…..

          1. sammy


            So I believe differently than you. How do you know that I am wrong? The fact that you choose to attack me personally reveals the weaknesses of your arguments.
            Only time will tell.

          2. Moses Herzog

            @ sammy
            Admittedly, I lean to the left, so that might color my views (however I have been labeled as both “sexist” and “racist” by people on this blog who cannot hold their ground with logic/data, so maybe that makes me a Republican, I don’t know).

            But from my view, Menzie has been amazingly tolerant in general with comments here. and it speaks to both his, and Professor Hamilton’s credit and ethics. I’ve been filtered here (98% of the time correctly, sometimes I was semi-grateful I was filtered)) I’ve disagreed with Menzie a decent amount, I doubt someone could view me as sycophant. Maybe 85% I agree with Menzie and the other 15% I’m pretty stubborn about.

            He’s allowing the comments you are making now up on the blog which are hardly flattering. Would you do the same if you were the blog host and someone stated those things about you?? I’m doubtful.

          3. CoRev

            Sammy, YUP! “The fact that you choose to attack me personally reveals the weaknesses of your arguments.
            Only time will tell.”

            Remember, Menzie repeatedly lists the MEASURED temperature data from 1880 as valid without thinking it is worst than the early fire data: “Forest fires today are about 1/5 of the 1920’s and 30’s”

          4. Menzie Chinn Post author

            CoRev: Thank goodness you’ve stopped kvetching about moving averages, and whether a 13 month centered moving average is a good idea for analyzing climatic change. Have you figured out what an HIP filter is?

            Please, please, please tell me what institutional features mean we should anticipate a structural break or breaks in the data series. This will also give you another opportunity to regale us with you massively error-ridden discourses on the superiority of satellite-based temperature measurement.

        2. macroduck

          No, no. Any data which is sourced to Bjorn Lomborg is de facto incorrect. See, for instance, this site regarding the errors in just one of his publications:


          Citing Lomborg on the environment is like citing John Lott on gun control. These guys aren’t just wrong — they willfully insist that wrong is right after being caught out as wrong.

          You can fool some of the people all of the time. You are apparently one of those people.

          1. pgl

            Damn – this is a great source for all of his distortions. This paragraph nails it:

            When experts in the fields covered by Lomborg check his texts, they most often find that the evidence has been distorted. Danish biologist Kåre Fog has systematically over many years checked Lomborg´s texts against his sources and references and against other scientific literature. His conclusion is that Lomborg´s texts are systematically manipulated to fit a certain agenda.

            This is exactly why Sammy made this clown his new hero. Two peas in a pod!

    1. Barkley Rosser


      As rhe person who called you out on your lies on the election (yes, Biden did indeed do better than any challenger of an indumbent president since FDR beat Hoover, even better than Reagan over Carter), and also as someone who has actually published on forest fires, I guess I need to step in to correct your errors here. Menzie has pointed out how unreliable the data in general for the US as a whole is prior to 1983 and especially prior to 1960, but you have just dismissed that.

      So, there is a more reliable data source, although it does not cover the whole US. It is what has happened on US Forest Service land, which covers a substantial portion of the total U?S forest land, and they have kept much more reliable track of what went on with their land going back to the beginning of the 2oth century, and it does not remotely correspond with this figure you pulled from a tweet by John Miltmore, whose provenance is some random weirdo who showed up to testify before Congress in 2014.

      So, go check the report for the US Forest Service by McKelvey and Busse, “Twentieth Century Fire Patterns on Forest Service Lands” available at fs.fed.us/psw/publications/mckelvey/mckelcey3.pdf . Then check out Figure 41.2.

      So it is true that there was a peak of fires in the late 19 teens followed by much lower levels for many decades. But then we get to 1983 and rhe level is back up to just about the same level as the late teens. And we have the data since then, with fires at that level or higher. So, sorry sammy, your link is bs. Fires were more in the teens than for much of the 20th century, but they have been back up to that level more recently.

      So, why did the amount of fires decline in the 1920s and after for so long? Because the Forest Service began combating them vigorously. The Smoky Bear program got going and the Forest Service adopted a “no tolerance” policy that has since come under criticism for overdoing it, with more recently some fires allowed to burn and even some being set in controlled burns.

      So, big surprise there were so many fires before 1920, although not that much more than now. Nobody was bothering to fight them.

      1. sammy

        ” Because the Forest Service began combating them vigorously. The Smoky Bear program got going and the Forest Service adopted a “no tolerance” policy that has since come under criticism for overdoing it, with more recently some fires allowed to burn and even some being set in controlled burns.”

        Hmmm….. so forest management is a variable here? I thought the fires were due to the few extra CO2 molecules in the atmosphere

        1. pgl

          What a pathetically childish reply. Good to know you do not even try to have an honest conversation.

        2. pgl

          “so forest management is a variable here?”

          The CoRev soybean BS. There he accuses us of denying weather is a factor which NONE of us have ever done. Of course in CoRev’s world weather is the only factor … which is just stupid.

          Forest management can help but it can not overcome the disasterous impacts from global warming. A smart approach would be to adopt both. But of course using the term smart in reference to anything form Sammy is sort of silly.

      2. pgl

        “Nobody was bothering to fight them.”

        If we keep following Sammy’s agenda of cutting the taxes of the rich and slashing government spending, we will no longer have the funds to fight forest fires. This agenda is about as rational as refusing to take the vaccine or wear masks. Which of course Sammy also advocates.

        1. Menzie Chinn Post author

          pgl: Better yet, do the Trump thing, and like the response to rising Covid cases, stop measuring forest fires at all. That’ll solve the problem!

          1. Moses Herzog

            Good point, what is it with this Covid-19 testing and Delta tracking stuff?? You know none of these states would have high rates of Delta if we stopped the testing and tracking. donald trump keeps on dropping these pearls of wisdom to public health experts. When will they learn? The way to have zero Delta cases is stop testing and tracking.

            FDR said it years ago. “The only thing we have to fear is……. testing of viruses”

  8. sammy

    Bjorn Lomborg is an AGW believer:

    “Global warming is real – it is man-made and it is an important problem. But it is not the end of the world.”[37]

    I guess that last sentence makes him heretical?

    1. noneconomist

      I’m still laughing at Democrats choosing to be vaccinated because of their “fealty” to government. Possibly the single stupidest or most stupid) comment made this month. But you still have another day, Sammy. Go for it. You can do it!

      1. pgl

        Sammy and his ilk are so devoted to Herr Trump they would rather die a painful death that cross their master.

      2. baffling

        yes, i got my vaccine because the government did a mind meld on me. it had nothing to do with protecting myself and loved ones from the virus. i probably would have even swallowed bleach if the government had been more aggressive in promoting that remedy as well.

    2. macroduck

      You really have no concept of “fact” or “truth”, have you? All of your attempted “gotchas” are based on the assumption that everybody is like you, basing their positions on allegiance rather than fact and analysis. (It’s that “every accusation a confession” trap folks like you fall into.)

      OK, sammy, I know this is a difficult concept, but there are people who start from facts, work their way through analysis and come to conclusions, without first checking with their ideological brethren. Really. There are.

      Heresy isn’t Lomborg’s problem, because we (the “we” who care about facts) aren’t taking a position based on received views, as you apparently are. Honesty is the problem. People who care about facts care about honesty. That’s why they rarely get into the short of “Oh, yeah, well your mother” kind of dreck that you employ.

    3. pgl

      Ah yes – Sammy appeals to the Skeptical Environmentalist without letting us know his book has been heavily criticized as in this critique:


      I tried to pull up a couple of rather devastating reviews from Scientific American but Google right now says there are temporarily available.

      Hey Sammy – pretty clever work there. Hiding the fact that your boy is almost as dishonest as you are. Good show!

  9. Anonymous

    Lot of possible causes here. For example the well-known change in fire response methods. Or just increased population. Could be climate too, but you have too small of a change (in both cause and result) to make very certain inferences, given all the other confounding factors.

    FWIW, lower 48 US temparature has been pretty stable. Global warming occurs more at the poles. It might be interesting to look at AK alone. Of course even more noise (given reduction in size). Still, you might see a more genuine climate signal. Also, better chance that forestry management and population change are less confounding factors (given how remote AK is).

    1. macroduck

      “Since 1901, the average surface temperature across the contiguous 48 states has risen at an average rate of 0.16°F per decade (see Figure 1). Average temperatures have risen more quickly since the late 1970s (0.31 to 0.54°F per decade since 1979). Eight of the top 10 warmest years on record for the contiguous 48 states have occurred since 1998, and 2012 and 2016 were the two warmest years on record.”


      So, no, temperatures in the lower 48 haven’t been stable. They’ve been rising, and the rise has accelerated since 1970.

  10. Moses Herzog

    sammy says: “So I believe differently than you. How do you know that I am wrong?”

    This reminds one of the MAGA/Republican stance that “there are no hard truths” or some news media’s stance that “there are two sides to every story”. No, on a clear day, around 2 pm, near almost any place on Earth (with yes, some rare rare exceptions) the sky is blue. There is no “other side” to the story when on a clear day at 2pm in the afternoon the sky turns to light orange or dark green. There is no “other side to the story”. The damned sky is just blue, PERIOD. We don’t need the NYT “sit down interview with Steve Bannon”. We already know Bannon is an A$$-wipe. There is no alternative view. What did sitting down with Bannon and tossing up softballs get the NYT?? Other than turning their profession into a carnival game money-grab, what did the sit down with Bannon get NYT?? Quit the false equivalency BULLCRAP!!!!!

    1. sammy


      In your besotted state you fail to distinguish between fact and conjecture. To disagree with a fact, like the sky is blue, is unreasonable. To disagree with a conjecture, an opinion or conclusion based on incomplete information, particularly about the future, is reasonable.

      1. baffling

        sammy, what you and others tend to disagree about is not conjecture or opinion. you disagree with recorded data. in the scientific world, when you disagree with recorded data, that is tantamount to disagreement with the facts. and you do it ALL of the time. corev is a prime example. corev wanted to argue for a hiatus, even though the data did not support that assertion. and when the data continued to show a lack of a hiatus, he simply argued against the data. foolish disagreements with the facts.

      2. pgl

        To conjecture on the basis of zero evidence but a strong political desire to have utter nonsense become Alternative Facts is sammy to a tee!

  11. sammy


    In your besotted state you fail to distinguish between fact and conjecture. To disagree with a fact, like the sky is blue, is unreasonable. To disagree with a conjecture, an opinion or conclusion based on incomplete information, particularly about the future, is reasonable.

Comments are closed.