WS More or Less: Are Wildfires Really Burning More Land?

Episode Summary

Executive Summary: The episode examines whether wildfire trends in the US and southern Europe are worsening, focusing on claims by Bjorn Lomborg and corrections from fire data experts. It argues that older US fire data are not directly comparable to modern records, that current US fires are fewer but burn more area, and that Europe’s burned area shows volatility rather than a clear decline.

Main Topics: US wildfire data and comparability (Priority: 5/5): The program scrutinizes Lomborg’s use of historical US wildfire acreage figures and the National Interagency Fire Center’s warning that pre-1983 data should not be compared with later records. Accuracy of historical fire records (Priority: 5/5): Experts explain that earlier fire data may have been incomplete, inconsistently sourced, or potentially double-counted, making long-term comparisons unreliable. Current US fire trends (Priority: 4/5): Reporter Maggie Kerth Baker outlines that the number of fires is below average while acres burned are above average, consistent with longer-term changes in fire behavior. Why fires are burning longer and larger (Priority: 5/5): The segment explains how fire suppression, fuel buildup, longer fire seasons, and more natural fire management contribute to larger, longer-lasting fires. Trump’s wildfire water claim (Priority: 4/5): The episode checks President Trump’s claim that environmental laws are limiting water for firefighting in California and finds no support for it from firefighting groups. European wildfire trends (Priority: 4/5): Lomborg’s claim that EU burned area has halved is tested against European Environment Agency data, which show large year-to-year swings rather than a clear downward trend.

Key Arguments: Older US wildfire acreage figures should not be compared directly with post-1983 records because the underlying sources and methods differ. The National Interagency Fire Center acknowledges that pre-1983 fire data may involve double or triple counting and lack modern mapping accuracy. Current US fire activity is characterized by fewer fires overall but more acreage burned, indicating larger, more intense fires. A major cause of larger fires is decades of aggressive suppression, which allowed fuels to accumulate on forest floors. Longer fire seasons and longer individual fire durations suggest changing fire behavior even if fire counts are lower. Trump’s claim that water is being withheld from firefighters is unsupported; firefighting agencies say they have sufficient water. European wildfire data do not support a simple claim of halving burned area; the trend is volatile and non-linear.

Data Points: US wildfire burnt area (2018 projection by Lomborg): one-sixth of the US record - Claim made by Bjorn Lomborg in response to Economist wildfire coverage US wildfire annual acreage, historical peak years: over 30 million acres; on a couple of occasions as high as 50 million - Shown in a chart Lomborg used from the National Interagency Fire Center US wildfire acreage after the 1950s: very few years exceeded 10 million acres per year - Historical chart cited in the transcript Pre-1983 reliability warning: data prior to 1983 should not be compared with later data - National Interagency Fire Center website warning US fires year-to-date: more than 40,000 fires - Maggie Kerth Baker describing current US fire season US acres burned year-to-date: more than 5,600,000 acres - Maggie Kerth Baker describing current US fire season US fires vs 10-year average: 7% lower - Current number of fires compared with the 10-year average US area burned vs 10-year average: 28% higher - Current acreage burned compared with the 10-year average Fire season length in the 1970s: 138 days - Comparison of historical fire seasons Fire season length in the last decade: 222 days - Comparison of historical fire seasons Early-1980s fire duration: less than 10 days - Typical duration of individual fires in the early 1980s Current fire duration: more than 50 days - Typical duration of individual fires today European burned area in early 1980s: around 600,000 hectares - Baseline used in Lomborg’s EU wildfire claim European burned area in 2013: 300,000 hectares - Lomborg’s endpoint for claim of halved burned area European burned area in 2017: 895,000 hectares - European Environment Agency data showing a spike 2017 Europe rank: second largest on record - 2017 burned area in the EU dataset

Pivotal Quotes: "Please stop the misleading fire stories. The US is smoldering less, not more." — Bjorn Lomborg: Tweet criticizing Economist coverage of US wildfires "No. Several firefighting organizations came out and basically said they have all the water they need to fight fires." — Maggie Kerth Baker: Response to Trump’s claim that California wildfires are worsened by lack of water "You know, we have a more natural means of fire management now, which is better for these forests." — Maggie Kerth Baker: Explanation of why longer-term fire suppression policies have changed fire behavior

Implications: Listeners should be cautious about comparing wildfire trends across eras without checking methodology. Current fires may be fewer but more destructive, and simplistic political claims about climate, water, or trends can mislead policy debate.