Could we please stop with the misleading fire stories?

From Bjørn Lomborg.

"Could we please stop with the misleading fire stories?

The Economist cover story, like so many other stories these last weeks, claim that forest fires are exceptional and record-breaking: "EARTH is smouldering. From Seattle to Siberia this summer, flames have consumed swathes of the northern hemisphere"
This is based on anecdotes, not data.

Here is the data for area burnt in US forest fires from 1926 up until today. (2018 is estimated on area burnt until August 3, which over the past 10 years was 59.8%, scaling 2018 similarly.)
As is evident, US burnt forest area has dramatically *declined* since the 1920s, 1930s and 1940, after which widespread fire suppression was introduced. As more burnable mass is piling up, fire is going up slightly.

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 CO₂) 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 CO₂ 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/

Overall, 2018 will likely see burnt area of one-fifth of the average burnt area in the US in the 1930s.
The US is smouldering less, not more.

Data: https://www.nifc.gov/fireInfo/fireInfo_stats_totalFires.html
, 2018 based on burnt area until August 3: https://www.nifc.gov/fireInfo/nfn.htm
Since 1900 US foreests have remained stable at 745m acres ±5% with a low point in 1920 at 735m acres, https://www.fia.fs.fed.us/slides/major-trends.pdf
. Similar stories here: "World on Fire", http://theweek.com/articles/788224/world-fire

See my story on US forest fires last year, https://www.facebook.com/…/fires-in-cali…/10156121084368968/

See similar EU data for the last 36 years: https://www.facebook.com/…/a.2217582089…/10157018315208968/…

  Some people have pointed out that the National Interagency Fire Center writes that “Prior to 1983, sources of these figures are not known, or cannot be confirmed, and were not derived from the current situation reporting process. As a result the figures prior to 1983 should not be compared to later data.”

This is convenient, since the NIFC for the longest time didn’t even want to acknowledge that there were data before 1960 (https://web.archive.org/.../fireInfo_stats_totalFires.html). I’ve consistently pointed out that we had early data and where the data starting in 1926 comes from; it is the Wildfire Statistics from USDA, summarized in the official Historical Statistics of the United States - Colonial Times to 1970, p537: http://bit.ly/2hGp7XF.

So, we all know, very well, where this data is from.

Interestingly, what the NIFC forgets to tell us is that the earlier data was based on reporting from *much* less land – about 200m ha of 700m ha burnable land (http://www.publish.csiro.au/WF/WF14190). So, if anything, it is reasonable to argue that the early estimates should multiplied by 3.5 (divided by 2/7th), which indeed is what this article did  
(https://esajournals.onlinelibrary.wiley.com/.../07-1183.1): “Littel et al. (2009) recognised the reporting bias and, as part of their analyses of fire–climate relationships in the western US, multiplied the USFS-reported WFAB estimates ‘by the ratio of the total area protected in 2003 to the area protected in a given year’.”

There are other, legitimate concerns, such as the inclusion of intentional burning in the early years, which may have added millions of acres to the numbers in the early part of the century (4-10% too much). But still, this does not in any way jeopardize the general trend of the data. This is of course why this data has been used by many academic publications, including Houghton, R. A. (03.2000). "Changes in terrestrial carbon storage in the United States. 2: The role of fire and fire management". Global ecology and biogeography (1466-822X), 9 (2), p. 145.

If anything, the graph that I’m showing is likely *underestimating* the amount of burning in the early part of last century.

One way to see this is comparing the graph to the US estimate from forest fires in the global carbon budget from “Fire history and the global carbon budget” (https://onlinelibrary.wiley.com/.../j.1365-2486.2005.00920.x). They estimate the burnt area in Eastern and Western US (here added together) in decades from 1900-2000. It is very clear that not only is the graph broadly right, but early fire, from where we have no or very spotty data, is likely to have been even greater, compared to the present.

The likely 2018 burnt area will be about 9% of the burnt area each year in the decade 1900-1910.

 

(it is burnt area in million acres up the vertical axis)"