Patrick Brown: When Science Journals become Activists

From NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood

Spinning climate data to fit a policy agenda undermines public faith in science.

Public trust in many mainstream publications continues to consistently decline. Part of the reason for this seems to be that media outlets cater more and more to the ideological tastes of specific groups, sacrificing their credibility to a wider audience in the process. I have criticized the New York Times, for example, for exaggerating the impacts of climate change, but this type of criticism may be in vain if they are covering climate exactly how their audience wants them to. 

It is in a media environment like this, however, that we desperately need reputable sources of scientific information. Sources that will avoid the same temptation to cater to their audiences and prioritize dispassionate reporting of facts instead. 

Nature magazine has a reputation as one of the most reliable sources of information on earth. Their publication has a section of peer-reviewed articles as well as softer sections dedicated to science news and the like. I have criticized the landscape surrounding high-impact peer-reviewed scientific studies published in places like Nature, but I won’t elaborate on that here. Here, I want to bring attention to Nature’s science news section. Sadly, this section now appears to be engaged in similar levels of spin on climate information as outlets like The New York Times.

Two recent articles serve to illustrate the point. 

The first is titled: 

Surge in extreme forest fires fuels global emissions. Climate change and human activities have led to more frequent and intense forest blazes over the past two decades.

The second is titled:

Climate change is also a health crisis—these graphics explain why…Rising temperatures increase the spread of infectious diseases, claim lives, and drive food insecurity.

Between these two news articles, we have four claims: one on wildfires, one on infectious disease, one on deaths, and one on food security. Let’s scrutinize each claim one by one. 

Are wildfires and their carbon emissions increasing? 

The title and subtitle of the first article conveys the impression that global wildfire activity is increasing, which in turn increases CO2 emissions from wildfires. This idea is also communicated several times in the text of the article (emphasis added):

“Global forest fires emitted 33.9 billion tonnes of carbon dioxide between 2001 and 2022…Driving the emissions spike was the growing frequency of extreme forest-fire events.”

“Xu and her colleagues found that the growth in emissions had been mostly fuelled by an uptick in infernos on the edge of rainforests between latitudes of 5 and 20º S and in boreal forests above 45º N.”

“The increased numbers of forest fires was partially driven by the frequent heatwaves and droughts caused by climate change”

The article also goes on to raise the concern of a self-reinforcing feedback loop:“In turn, the CO2 emitted by forest fires contributes to global warming, creating a feedback loop between the two.”

There are, of course, many positive and negative feedback loops in the climate system (i.e., responses to warming that either amplify or counteract the initial warming). The relative sizes of these feedback loops are systematically documented in synthesis reports like those from the Intergovernmental Panel on Climate Change. According to the IPCC, the CO2 feedback associated with fires is very small relative to other feedbacks. To put it in perspective, it is only about three percent as large as the water vapor feedback (as the atmosphere warms, it can “hold” more water vapor, which is a greenhouse gas, that further enhances warming). Thus, a self-perpetuating cycle of warming leading to more fires and more CO2 emissions is not exactly at the top of our list of concerns.

Second, and more importantly, despite what is communicated in the article, global CO2 emissions from wildfires are not actually increasing! 

The Nature article covers a recent non-peer-reviewed report by the Chinese Academy of Sciences that contains one figure on changes in wildfire CO2 emissions over time (with emissions separated by region):

This figure does not indicate an increase in global emissions over the study period (2001-2022).

Independently, the most well-known estimate of CO2 emissions from wildfires comes from the Copernicus Atmosphere Monitoring Service (CAMS), Global Fire Assimilation System (GFAS). This estimate shows a decrease in global wildfire carbon emissions over its record (dating back to 2003):

This reduction in carbon emissions is also in line with a long–term observed decrease in the annual amount of global land area burned by wildfires:

Since all these numbers seem to contradict what is communicated in the Nature article, I emailed the author to get some clarification. She told me that:

“Based on my interview with Xu Wenru, a co-author (of the Chinese Academy of Sciences report), extreme forest fires became more frequent over the past 22 years in areas prone to forest fires (on the edge of rainforests between 5 and 20º S and in boreal forests above 45º N), and their CO2 emissions increased rapidly.”

But this amounts to saying that CO2 emissions from wildfires are increasing…where CO2 emissions from wildfires are increasing. And it completely leaves out the important context that global CO2 emissions from wildfires are decreasing.

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