Trend in Global Fires

Climate alarmists claim that an increase in man-made greenhouse gas emission will cause more fires. For example …

Human-induced climate change promotes the conditions on which wildfires depend, increasing their likelihood …


Funk … says there is very well documented scientific evidence that climate change has been increasing the length of the fire season, the size of the area burned each year and the number of wildfires.


The clearest connection between global warming and worsening wildfires occurs through increasing evapotranspiration and the vapor-pressure deficit.  In simple terms, vegetation and soil dry out, creating more fuel for fires to expand further and faster.

… Global warming will keep worsening wildfires …


Sounds serious. Is it true?

We show that fire weather seasons have lengthened across 29.6 million km2 (25.3%) of the Earth’s vegetated surface, resulting in an 18.7% increase in global mean fire weather season length. We also show a doubling (108.1% increase) of global burnable area affected by long fire weather seasons and an increased global frequency of long fire weather seasons across 62.4 million km2 (53.4%) during the second half of the study period.

— Nature: Climate-induced variations in global wildfire danger from 1979 to 2013

This is just about the most scientific paper I could find on the issue. Why are they obsessed with the length of the fire season? Why can’t they just answer the simple question: Is there more or less fire?

NASA has collected daily data on Active Fires since 2000.

Active Fires, March 2000 [Source]

I downloaded and analyzed all of their Active Fires data. Here’s the result:

Now it all makes sense. Climate scammers need to cherrypick locations and seasons in order to distract from the empirical truth that global fires have been decreasing. Disgusting.

Enjoy 🙂 -Zoe

# Zoe Phin, 2021/02/16
# File:
# Run: source; require; sets; download; index; plot

require() { sudo apt-get install -y gmt gnuplot; }

sets() {
    for y in {2000..2021}; do
        wget -qO- "$y"
    done | awk -F\' '/"viewDataset/{print $4" "$2}' > sets.csv 

download() {
    rm -f wget.log [0-9]*.csv
    awk '{print "wget -a wget.log -O "$1".csv \""$2"&cs=rgb&format=CSV&width=360&height=180\""}' sets.csv >

area() {
    seq -89.5 1 89.5 | awk '{
        a=6378.137; e=1-6356.752^2/a^2; r=atan2(0,-1)/180
        printf "%.9f\n",(a*r)^2*(1-e)*cos(r*$1)/(1-e*sin(r*$1)^2)^2/1416867.06
    }' > .area

avg() {
    awk -F, '{
        for (i=2;i<=NF;i++) { 
            if ($i~/999/) $i=0
            S+=$i; N+=1 }
        printf "%s %.4f\n", $1, S/N
    }' | awk '{ S+=$1*$2 
    } END { printf "%0.4f\n", S }'

index() { area
    for f in $(ls -1 2*.csv); do
        echo -n "${f/.csv/} "
        paste -d, .area $f | avg
    done > .csv

plot() { 
    awk '$2>0.02 {"date +%j -d "$1 | getline t; 
        print substr($1,1,4)+t/365" "$2 }' .csv | gmt gmtregress | tee .trend | sed 1d | tr '\t' ' ' | cut -c-25 > plot.csv
    echo "
        set term png size 740,420
        set key outside top center horizontal
        set ytics format '%4.2f'
        set ytics 0.01; set mytics 5
        set xtics 2; set mxtics 2
        set xrange [2000:2021]
        set grid xtics mxtics ytics
        plot 'plot.csv' u 1:2 t 'Active Fires Index' w lines lw 2 lc rgb '#DD0000',\
                     '' u 1:3 t 'Linear Trend'  w lines lw 3 lc rgb '#440000'		
    "| gnuplot > fire.png 

Published by Zoe Phin

26 thoughts on “Trend in Global Fires

  1. I know it is picky, but the black like is very persuasive, but I’m guessing a bit misleading?
    What is the maths behind the black line?

    When I’ve done a rolling average I extend it timewise eg, a rolling average over 3 years of fires of the rate of fires per month, and I it would be interesting to see that? It is not as clear of course, but tru-er, and hate your good work to be picked apart. It will give a kindof sinusoidal wave I think, growing in the summer, falling in the winter, but overall trend, at a minimum, flat. Extend it over a longer period and it will be flatter, but you probably don’t have that much data.

    Really interesting as always

    Liked by 1 person

    1. The problem with using a Moving Average is that NASA has a few random days missing. Even one missing day means I have to fill in data. I didn’t want to do that. Instead, I use a simple linear regression.


    1. Each pixel has an intensity. To make the math easier, I include water as well. Since water is not vegetation, the maximum possible value is ~0.29, since water is ~71% percent of Earth.

      A value of 0.145 could means 50% of land is heavy vegetation OR 100% of land is light vegetation.

      Vegetation intensity is mixed in with area coverage.


      1. I was talking about the fire index. It seems that it is approximately 0.05 on average. Does this mean that on average 5% of the vegetated area is on fire? I now understand that the greening index does not necessarily reflect the amount of area covered with vegetation as intensity is also a factor. Even so, I guess the following question is still relevant: is the vegetated proportion of land area assumed by NASA to be constant over the period for the fire data?


        1. The two indicies are not related, but they are computed the same way. Fire pixels have intensity. 0.05 could mean 5 % of Earth has strong fire, or 10% has medium fire. It also can not exceed 0.29. Don’t know what else to say.


  2. LOL! Just take other years and your linear regression has a positive slope.

    Got this blog recommended by a friend. I guess I was a bad tutor for his math class if he still falls for stuff like this.

    To everyone else: Just because someone can make graphs doesn’t mean they are good for anything. Apparently, she doesn’t even know what her active fire index means!

    > Fire pixels have intensity. 0.05 could mean 5 % of Earth has strong fire, or 10% has medium fire. It also can not exceed 0.29. Don’t know what else to say.

    At the beginning of 2000 the “active fire index” is over 0.1. So 10% of Earth has strong fire or 20% has medium fire A maximum value of 0.29 would mean that over 1/3 of the land was on fire?


    1. You can cherrypick small subsets to get a positive slope. Why would you do that?

      What are you failing to understand? Each pixel has an intensity of 0 to 1. Only 29% of pixels is land. I guess it might even be less if you don’t count ice cover. If you have issues with the data, you should take it up with NASA. The main point is that there is a consistent measure throughout whole time period.

      You really believe fires should increase, don’t you? Your scientific method is not empirical but wishful expectation.


  3. Great job Zoe! I’ve been wanting to get updated NASA global burned area data for a while, the last of which I’ve seen was through 2015. However after contacting NASA it wasn’t a straightforward download and I didn’t have the computer savy to do what you did. Again, well done!

    Liked by 1 person

    1. No idea how they normalized it.

      I couldn’t stop laughing at:
      There are really two separate trends,” said Randerson. “Even as the global burned area number has declined because of what is happening in savannas, we are seeing a significant increase in the intensity and reach of fires in the western United States because of climate change.”

      This shows that if we ever go into global cooling, they will still be cherrypicking warming spots.


  4. Zoe,
    what bothers me is that the data you’re showing doesn’t differentiate between intentional slash burning, a wildfire in chaparral or grassland, or a fire in towering old growth – flames reaching hundreds of feet into the sky.


  5. An acre burned here will be green again the following spring:

    But an acre of severely burned old growth may take decades, if not centuries to fully recover. Again, the NASA data sees no difference between the two.

    Point being, Earth’s last remaining ancient forests are under increasing threat of severe fire due, in part, to global warming. A product lumping every sort of fire into one basket, and showing fewer acres burned, does not refute this.


      1. Let’s say that twenty years ago, a hundred acre forest would, on average, see 5 acres burn per year. And let’s say that today, because of global warming, we would expect 10 acres to burn each year. (Just making up numbers for the sake of argument)

        Now, what happens if 80 of those acres are cleared and replaced by an irrigated corn field?

        A time series would show decreasing fires,
        but that decrease would have no bearing on the wildfire risk to the remaining 20 acres of forest.

        Liked by 1 person

  6. Thanks for presenting this analysis. It is interesting a see a downward trend.

    It is interesting that people are still commenting that fires in the Western US are caused by climate change since Cal Fire’s report clearly stated that the cause was poor forest management practices. When I mover to California from the East Coast 30 years ago, I was shocked by the fact that there were no fire breaks in California forests. Estimates are that there are more than 150,000,000 dead trees standing in California forests. Until recently controlled burns were rarely done because of multiple government mandated hurdles.

    Since the Cal Fire report, the state has begun a shift to active fire prevention rather than simply responding to fires. It will take decades to complete the shift to active forest management, but anything is a positive step forward.

    Liked by 1 person

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