US Fires Nowhere Near Record

Fires in California and elsewhere are devastating. But US fires are nowhere near the record. More likely about one-fifth of the records in 1930 and 1931.

Reuters (along with many others), tell us the current US fires are historic: "The year’s wildfire season is one of the worst in history in the United States, with nearly 8.6 million acres burned as of Oct. 13, according to the National Interagency Fire Center.”(https://reut.rs/2wVWPP2)

But that is because of the National Interagency Fire Center curiously – and somewhat conveniently – only shows the annual burnt area back to 1960, when fire suppression indeed was going strong, and hence we had some of the lowest amounts of burnt forests ever.

Yet, the official historical data of the United States tells a different story. Look at the Historical Statistics of the United States - Colonial Times to 1970, p537:(https://bit.ly/2hGp7XF). There we have statistics for area burnt since 1926 and up to 1970. Reassuringly, the data for 1960-1970 *completely overlap*. This is the same data series. 

And when you look at the whole data series, *every year* from 1926-1952 – over a quarter of a century – saw higher, and mostly much higher forest areas burnt than the modern record set in 2015.

This is not (as some have suggested) an artifact of the US gradually being deforested (and hence having less land to burn). The USDA Forest Service in their Historical overview (https://bit.ly/2jtVew8, p7) finds that the US “forest area has been relatively stable since 1910” – if anything slightly increasing since 1910 (which would help push up the burnt area slightly).

This matters, because many wants to blame the current forest fires (like so many other bad effects) on global warming. Hence the clamor for arguing that these are ‘record-setting’ fires. Many news outlets pointed out that "2015 becomes worst US wildfire year on record" (https://bit.ly/2ypFJfV) or "2015 was a record setter... the first time wildfire acreage burned has crossed the 10-million acre threshold" (https://bit.ly/1O6rexy).

Now, it appears probable that global warming will lead to somewhat more forest fires. 

But it is important to get a sense of proportion. US fires were *much* more destructive in the first part of last century.

And this is also true globally. Because climate models need estimates for forest fires (because they emit CO?) there are many and good models going far back. In one recent overview, run with 124 simulations, shows that while global warming will increase fires, we are now at a historic *minimum* of fires. Since 1900, fire activity has decreased about 20%. And even with the most damaging CO? increases over this century, “wildfire emissions start to rise again after ca. 2020 but are unlikely to reach the levels of 1900 by the end of the 21st century.”(https://www.biogeosciences.net/13/267/2016/)

Note on data: 2017 estimated from area burnt from January 1 to October 13, as documented here:https://www.nifc.gov/fireInfo/nfn.htm. Comparing area-burnt-to-date for 2008-2016, on average these years had 91.6% of the burnt area before October 13 (from 85-96%), so the area-burnt-to-date for 2017 is multiplied by 100%/91.6% (=1.091) to create the most likely, comparable burnt area for all of 2017.