Bjorn Lomborg: ‘Stop these silly, undocumented claims of ever-increasing fire’ Claims ‘based on anecdotes, not data’ – Reality is Global & U.S. fires declining
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 smoldering. From Seattle to Siberia this summer, flames have consumed swathes of the northern hemisphere”
This is based on anecdotes, not data.
As I’ve shown in previous days, the US burnt area was much higher in the early part of last century, and the EU burnt area has declined by half over the past 36 years.
So: No, the US is not smoldering more – it is smoldering much less than it used to in the first part of the 20th century.
And no, the EU is not smoldering more – it is smoldering much less over the past 36 years.
Let’s finally look at the global perspective. While many of these fire scare stories are based on news from the US and the EU, the Economist claim was explicitly global.
Yet, the data does not support the argument that things are burning more and more.
The graph shows the estimated area burnt globally per year from 1900-2010. And it shows a steady decline.
It is from the article “Spatial and temporal patterns of global burned area in response to anthropogenic and environmental factors: Reconstructing global fire history for the 20th and early 21st centuries” One important point is to recognize that there is absolutely not enough data to do this only based on reported burning.
This is one of the reasons I started off with the US (where we have solid (if likely underreported) data from 1926) and the EU. But clearly, the evidence for the global trend is unmistakable.
We see a similar pattern from the 2018 Nature article “Reduction in global area burned and wildfire emissions since 1930s enhances carbon uptake by land” which (as the title suggests, finds a strong decline in area burnt since 1930 (figure 2).
We also see declining area burnt from 1900-2000 from the article “Human impacts on 20th century fire dynamics and implications for global carbon and water trajectories”, figure 4b.
In a very recommendable (and freely available) overview article “Global trends in wildfire and its impacts: perceptions versus realities in a changing world” they clearly write that people (like the journalist at the Economist) who believe there is more fire now, that is is worse and have higher impact, are likely wrong:
“Many consider wildfire as an accelerating problem, with widely held perceptions both in the media and scientific papers of increasing fire occurrence, severity and resulting losses. However, important exceptions aside, the quantitative evidence available does not support these perceived overall trends. Instead, global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago.”
Beyond better fire prevention an important reason might be that more people and higher population densities perhaps surprisingly means *less* fire. The paper “Impact of human population density on fire frequency at the global scale” shows that “at the global scale, the impact of increasing population density is mainly to reduce fire frequency.”
So: Stop these silly, undocumented claims of ever-increasing fire, please.
Sources: Graph from “Spatial and temporal patterns of global burned area in response to anthropogenic and environmental factors: Reconstructing global fire history for the 20th and early 21st centuries” https://agupubs.onlinelibrary.wiley.com/…/10.1…/2013JG002532.
“Reduction in global area burned and wildfire emissions since 1930s enhances carbon uptake by land” https://www.nature.com/articles/s41467-018-03838-0
“Human impacts on 20th century fire dynamics and implications for global carbon and water trajectories” https://www.sciencedirect.com/…/artic…/pii/S0921818117303910
“Global trends in wildfire and its impacts: perceptions versus realities in a changing world” http://rstb.royalsocietypublishing.org/cont…/…/1696/20150345 (not embargoed)
“Impact of human population density on fire frequency at the global scale.” https://www.biogeosciences.net/11/1085/2014/
US fire data: https://www.facebook.com/…/a.2217582089…/10157044699208968/… and additional data set here: https://www.facebook.com/bjornlomb…/posts/10157044718363968…