Are Wildfires Really Burning More Land?

Summary

More or Less Podcast Summary

Episode Title: Are Wildfires Really Burning More Land?
Date: August 17, 2018
Host: Ben Carter (BBC Radio 4)
Main Theme:
This episode investigates widespread narratives around devastating wildfires, particularly whether current wildfires are truly burning more land than in the past. The episode critically examines how wildfire statistics are used (and sometimes misused) in climate change debates and media coverage.

---

Key Discussion Points & Insights

Wildfire Data in the Media (00:01 - 01:38)

• The Economist's front page depicted the Earth "smouldering" and losing the war against climate change, referencing wildfires across the northern hemisphere.

• Dr. Bjorn Lomborg (author, "The Skeptical Environmentalist") objected to the narrative. He cited data from the US National Interagency Fire Centre (NIFC), stating that the US is "smouldering less, not more," and said 2018's burnt area would be just 1/6th of the US record.

  "Please stop the misleading fire stories. The US is smouldering less, not more. 2018 will likely see burnt area 1/6 of the US record."
  — Dr. Bjorn Lomborg [00:47]

• The NIFC chart showed pre-1950s wildfires burning vastly more land (occasionally as high as 50 million acres a year), but with a sharp drop-off after the 1950s.

---

Data Accuracy and Limitations (01:38 - 04:00)

• Critics on Twitter quickly pointed out that NIFC's own data for years before 1983 is labeled as unreliable and comes with a disclaimer.

  "If you read in the very top the data from before 1983 is inaccurate."
  — Twitter follower via Dr. Lomborg [01:38]

• The NIFC spokesperson elaborated on these uncertainties:

  "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."
  — NIFC spokesperson [01:57]

• Dr. Lomborg argued the sources are, in fact, known (citing a U.S. Census Bureau document), but the NIFC noted possible double-counting and lack of mapping precision, especially before GPS technology.

  "We don't know if some acres were double or triple counted... mapping accuracy has improved by leaps and bounds with advent of gps."
  — NIFC spokesperson [02:55]

• Dr. Lomborg countered with a peer-reviewed article, arguing that if anything, early fire records underestimated total land burned, as "early reporting covered less than 30% of present day area."

• Science reporter Maggie Kurth Baker (FiveThirtyEight) expressed skepticism about trusting pre-1980s data for natural disasters, noting poor record-keeping.

  "I am consistently amazed at the way that our record keeping in a really meticulous, accurate way doesn't go back very far... I shouldn't trust the numbers before the 1980s. That is something you hear a lot with natural disasters."
  — Maggie Kurth Baker [04:00]

---

Modern Wildfire Trends (04:25 - 05:54)

• Maggie Kurth Baker analyzed the last 35 years of U.S. fire data:

  • 2018: Over 40,000 fires by year-to-date, burning 5.6 million acres.
  • The number of fires is 7% below the 10-year average, but area burned is 28% above average.
  • Long-term trend: Fewer fires, but each fire burns more land.

  "...the number of fire is actually lower than average. So right now we're about 7% lower on the number of fires in the 10 year average, while we are about 28% higher on the area burned than the 10 year average."
  — Maggie Kurth Baker [04:40]

• The fire season has lengthened from 138 days in the 1970s to 222 days in the last decade. Individual fires last over 50 days (vs. less than 10 days in the early ’80s).

  "Thirty or 35 years ago, the norm was really to put out as many fires as possible as fast as possible. But forests are supposed to burn occasionally... So without these regular small burns, what we ended up with was this buildup of dry tinder... And over time that has helped to make these fires... bigger and hotter..."
  — Maggie Kurth Baker [05:54]

• In recent years, U.S. fire management has shifted—firefighters now often let some fires burn for ecological reasons and safety.

---

Fact-Checking Political Claims (06:47 - 07:37)

• President Donald Trump claimed California's wildfires were worsened by environmental laws preventing use of water to fight fires (asserting it was being "diverted into the Pacific Ocean").
• Maggie Kurth Baker debunks this:

  "Several firefighting organizations came out and basically said they have all the water they need to fight fires. That's not a problem at all... What he seems to be referencing there is the demands of dry land farmers in California that want more water diverted to them instead of leaving it in the river systems. 'Diverted to the Pacific' means letting the river flow to the ocean."
  — Maggie Kurth Baker [07:15]

---

Wildfire Trends in Europe (07:37 - End)

• Dr. Lomborg extended his argument to Europe, tweeting that fires there are not as bad as media stories suggest:

  "The EU is smouldering less, not more. Today is about half of the burnt area in the 1980s."
  — Dr. Bjorn Lomborg [07:54]

• He used European Environment Agency data, which showed a decline in annual burnt area across Portugal, Spain, France, Italy, and Greece—down from about 600,000 to 300,000 hectares per year.

• However, 2017 was an outlier with 895,000 hectares burned. When factoring this in, the reduction is closer to a third, not a half—something Lomborg accepted.

---

Notable Quotes & Moments

• "Early fire data is likely to be severely underestimated." — Dr. Bjorn Lomborg [03:25]
• "I am consistently amazed at the way that our record keeping... doesn't go back very far." — Maggie Kurth Baker [04:00]
• "We are about 28% higher on the area burned than the 10 year average." — Maggie Kurth Baker [04:40]
• "Several firefighting organizations came out and basically said they have all the water they need to fight fires. That's not a problem at all." — Maggie Kurth Baker [07:15]
• "The EU is smouldering less, not more. Today is about half of the burnt area in the 1980s." — Dr. Bjorn Lomborg [07:54]

---

Key Takeaways

• Historical wildfire data (pre-1983, especially pre-1950s) is highly unreliable and should not be directly compared with post-1983 figures due to inconsistent methods, possible double-counting, and lack of precise mapping.
• Modern wildfire “trends” show fewer fires but larger areas burned. The size of wildfires has increased in recent decades, and the fire season is much longer.
• Past fire suppression strategies led to a buildup of flammable material, which now feeds larger, hotter fires. Recent fire management often allows fires to burn naturally for ecosystem health.
• Claims suggesting wildfires are always worse than the past can be misleading, as both data limitations and management strategy changes complicate direct comparison.
• Media and political rhetoric often distort or oversimplify the true trends. For both US and European wildfires, the situation is nuanced and doesn't always support dramatic headlines.

---

This summary provides a comprehensive look at the episode’s discussion on wildfire data, interpretation, and the complexities involved in measuring and communicating trends over time.

Transcript

[Ben Carter]

Hello and welcome to More or Less on the BBC World Service with me, Ben Carter. Earlier this month, the Economist newspaper ran a front page which caught the eye of a number of people on Twitter. The text read in the line of Fire Losing the War Against Climate Change, Earth is smouldering. From Seattle to Siberia this summer, flames

[Maggie Kurth Baker]

have consumed swathes of the northern hemisphere.

[Ben Carter]

On August 4, Dr. Bjorn Lomborg, author of the book Skeptical Environmentalist, which set him up as perhaps the world's best known critic of the dominant scientific view of global warming, tweeted a picture of the Economist's front page and drew attention to the situation in the United States.

[Dr. Bjorn Lomborg]

Please stop the misleading fire stories. The US is smouldering less, not more 2018 will likely see burnt area 1/6 of the US record Dr. Lomborg attached

[Ben Carter]

a chart produced by the National Interagency Fire Centre in the United States which showed the annual number of acres burned by wildfires in the US from 1926 to 2018. The chart showed that between the 1950s and present day there were very few years that wildfires had exceeded more than 10 million acres per year of damage. But before the 1950s it was not unusual to see annual numbers over 30 million and on a couple of occasions as high as 50 million. But a Twitter follower commenting on Dr. Lomborg's tweet posted the following in response,

[Dr. Bjorn Lomborg]

you forgot something important, did you not? If you read in the very top the data from before 1983 is inaccurate.

[Ben Carter]

What this tweet was referring to was the fact that the National Interagency Fire Centre's data on its website does come with an explicit warning prior to 1983,

[National Interagency Fire Centre Spokesperson]

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.

[Ben Carter]

This doesn't mean the data before 1983 is definitely inaccurate, as the tweeter described it, but it does mean that numbers before 1983 shouldn't be compared with the ones after. For the reasons given, Dr. Lomborg argued on Twitter that the National Interagency Fire Centre was wrong to claim that they didn't know where the figures prior to 1983 came from, and cited a 1975 document published by the U.S. census Bureau which contains numbers for the years 1926 to 1967 which were provided by the U.S. forest Service. I asked the National Interagency Fire Centre why they had claimed that the sources of the figures prior to 1983 were not known and a spokesperson told me,

[National Interagency Fire Centre Spokesperson]

yes, the Forest Service provided those numbers, but the raw data I've seen came from multiple sources and we don't know if some acres were double or triple counted. Further, it's only been in more recent times that mapping accuracy has improved by leaps and bounds with advent of gps. Tens of millions of acres is a massive amount of land. And up through the middle of the last century, the tools, manpower and time it would take to actually map those fires were not available.

[Ben Carter]

When I told Dr. Lomborg this, he maintained that the early numbers were accurate, citing a peer reviewed article on biases in the early data which did not support claims of double counting. Instead, he says it shows that early reporting covered less than 30% of present day area. So early fire data is likely to be severely underestimated. But science reporter Maggie Kurth Baker, who regularly writes on natural disasters, says she's been surprised at how high hard it's been to get accurate data prior to the 1980s.

[Maggie Kurth Baker]

I am consistently amazed at the way that our record keeping in a really meticulous, accurate way doesn't go back very far. I did a story a couple years ago about tornadoes in the US and over and over, basically I was told that I shouldn't trust the numbers before the 1980s. That is something that you hear a lot with natural disasters.

[Ben Carter]

Maggie has written about the wildfires for FiveThirtyEight. Com, a website that crunches the numbers, much like more or less. She looked at the numbers over the last 35 years and she started by focusing on the number of fires in the US this year.

[Maggie Kurth Baker]

We have had more than 40,000 fires total this year. Year to date, we have burned more than 5,600,000 acres. One of the things that I think is really interesting about this is that the number of fire is actually lower than average. So right now we're about 7% lower on the number of fires in the 10 year average, while we are about 28% higher on the area burned than the 10 year average. So the amount of land that's getting burned is bigger and bigger and bigger, but the number of fires is smaller. And that's in keeping with these long term trends that we've kind of seen over the last 30 years or so.

[Ben Carter]

But why is this happening? Well, one reason might be that the fire season, which is the time elapsed between the first large fire ignition and last large fire control, has increased from 138 days in the 1970s to 222 days in the last decade. Individual fires today burn for more than 50 days. In the early 80s, they burned for less than 10. Maggie Kurt Baker explains why 30 or

[Maggie Kurth Baker]

35 years ago, the norm was really to put out as many fires as possible as fast as possible. But forests are supposed to burn occasionally. You know, you have some of these trees that actually need fire to reproduce. So without these regular small burns, what we ended up with was this buildup of dry tinder leaves and sticks and branches down on the forest floor. And over time that has helped to make these fires. We couldn't put out bigger and hotter and spread them further. And at the same time, you know, we just stopped trying to put them out so quickly. Particularly in the last 15 years or so, it's become more normal to just let fires do their thing. You know, we have a more natural means of fire management now, which is better for these forests. It's also better for the firefighters who were putting their lives at risk trying to keep these fires small unnecessarily.

[Ben Carter]

It might not come as a massive surprise to hear that US President Donald Trump tweeted about California's wildfires on August 6. He said that the wildfires are being magnified and made so much worse by the bad environmental laws which aren't allowing massive amounts of ready available water to be properly utilized. He said that it was being diverted into the Pacific Ocean. I asked Maggie whether there was any truth to this claim.

[Maggie Kurth Baker]

No. Several firefighting organizations came out and basically said they have all the water they need to fight fires. That's not a problem at all. What he seems to be referencing there is the demands of dry land farmers in California that want more water diverted to them instead of leaving it in the river systems. Diverted to the Pacific means letting the river flow to the ocean.

[Ben Carter]

Maggie Kurth Baker from FiveThirtyEight. Com A day after Dr. Longborg tweeted about US wildfires, he tweeted again with the same Economist front page and a comment about fires in Southern European countries.

[Dr. Bjorn Lomborg]

Please stop the misleading fire stories. The EU is smouldering less, not more. Today is about half of the burnt area in the 1980s.

[Ben Carter]

He was referring to European Environment Agency data that looked at how much land had been burnt in Portugal, Spain, France, Italy and Greece between 1980 and 2016. He cited the fact that the trend line showed a reduction in the annual number of burnt hectares and from roughly 600,000 to 300,000. However, in 2017, 895,000 hectares were burnt, the second largest number on record. And if we factor that number into the equation, then the reduction is closer to a third than a half, something that Dr. Lomborg accepts. That's all we've got time for this week, but if you've got any questions, email more or lessbc.co.uk or tweet @BBC. More or less.