The National Oceanic and Atmospheric Administration (NOAA) continues to cite billion dollar damage (BDD) events as a proxy for the intensity of climate change despite the statistic’s numerous flaws.
The agency stated that the increasing frequency of BDD weather events is a sign of worsening climate change in a January press release and blog post recapping 2023, and then subsequently defended the use of the stat in communications with the Daily Caller News Foundation.
However, the statistic does not relate directly to atmospheric conditions, and it has several other serious flaws that call into question NOAA’s claims that 2023’s 28 BDD events demonstrate that climate change is accelerating and causing more severe natural disasters as a result.
“For millions of Americans impacted by a seemingly endless onslaught of weather and climate disasters, 2023 has hit a new record for many extremes,” NOAA Chief Scientist Sarah Kapnick said of 2023’s BDD statistics, according to the press release.
“Record warm U.S. temperatures in December, a record-setting number of U.S. billion-dollar disasters in 2023 and potentially the warmest year on record for the planet are just the latest examples of the extremes we now face that will continue to worsen due to climate change.”
“According to NOAA’s Chief Scientist, Dr. Sarah Kapnick, climate change is known to increase the probability and magnitude of extreme weather events,” a NOAA spokesperson told the DCNF. “The vulnerability of our built environment leads to damages. When vulnerability grows or weather and climate events become more extreme, it can lead to more billion–dollar disasters.”
However, Roger Pielke, Jr., a professor at the University of Colorado who has extensively studied and written about climate change, extreme weather and BDD event data, is far from convinced that BDD events are a suitable metric for analyzing climate change. While Pielke, Jr. takes issue with NOAA’s use of BDD events as a proxy for climate change’s intensity, he does believe climate change to be a real and serious threat.
“There is no peer reviewed science that attributes any part of increasing disaster losses to changes in climate,” Pielke, Jr. previously told the DCNF. “To see evidence of changes in climate, look at climate data, not economic data.”
For its part, NOAA told the DCNF that there is scientific evidence that justifies the use of BDD events as an indicator for climate change. While it did not directly name any specific studies, the agency referred the DCNF to chapter two of the Fifth National Climate Assessment (NCA5) for more details.
However, the NCA5 credited more than two dozen ostensibly conflicted authors and contributors, many of whom are actively affiliated with environmental activist organizations. Kate Marvel, who works for a group called Project Drawdown, is credited as the chapter lead for chapter two, titled “Climate Trends,” while Katharine Hayhoe of the Nature Conservancy and Texas Tech University and Zeke Hausfather, whose employer has invested millions into carbon removal technology, according to CNBC, are credited as authors.
The NCA5’s analysis of BDD events in chapter two primarily cites NOAA’s “Billion-Dollar Weather and Climate Disasters” website, which itself cites two peer-reviewed studies in addition to a host of technical reports. There are three authors credited in total for those two peer-reviewed studies, respectively published in 2013 and 2015, and two of those three authors are listed as NOAA scientists in the studies.
Notably, the agency’s recap of last year’s BDD events cites numerous events that occurred over time and space as distinct occurrences. In some cases, such as Hurricane Idalia, this may make more sense than it does to classify “California flooding” between January and March as a single BDD event. Additionally, the agency cites the August 2023 Maui wildfires as a climate or weather-related disaster, but human error and government incompetence appear to have had much more to do with that tragedy than climate change.
Pielke, Jr. contends that NOAA could be inflating the number of BDD events using disaster accounting methods that group together multiple smaller, discrete events into one larger incident that meets the $1 billion threshold, according to a paper on the subject that he authored earlier in January. However, the paper makes clear that it is not possible to discern whether NOAA has changed the way it sources its dataset, specifically since 2008, due to a lack of transparency on that particular point.
Beyond any potential gimmicks in defining a BDD event, there is a separate underlying trend that complicates NOAA’s use of BDD events as a proxy for the intensity of climate change. In fact, NOAA acknowledges as much, as does chapter two of the NCA5.
“The evidence clearly shows that the number and cost of disasters are increasing over time due to a combination of three things: increased exposure (i.e., values at risk of possible loss), increased vulnerability (i.e., where we build; how we build) and climate change that is increasing the frequency of some types of extremes that lead to billion–dollar disasters,” a NOAA spokesperson told the DCNF. “More specifically, these trends are further complicated by the fact that much of the growth has taken place in vulnerable areas like coasts and river floodplains. Vulnerability is especially high where building codes are insufficient for reducing damage from extreme events.”
In other words, there are more people living in areas that tend to be more prone to natural disasters now than there were several decades ago, regardless of whether or not climate change is intensifying. The concentration and value of assets that can be lost to damages have similarly increased, meaning that the same exact storm in the same exact place several decades apart would have significant differences in the amount of damage caused in terms of dollars and cents.
Pielke, Jr. ran his own analysis in a January 2023 piece — which described NOAA’s use of BDD events as a “national embarrassment” — to express North American catastrophe losses in terms of U.S. gross domestic product (GDP). He found that “North American catastrophe losses as a proportion of U.S. GDP clearly show no upwards trend.”
The agency is planning to start expressing disaster costs as a percentage of GDP at some point in the future, a spokesperson for the agency told the DCNF. NOAA also includes this context on its BDD website and “regularly” provides context about factors involved in BDDs, the spokesperson added; the January press release makes no mention of that type of context, though the blog post linked inside the press release does.
“NOAA uses aggregated damage costs for shock value. NOAA knows as well as anyone with common sense that more people living in storm-prone areas means that damages are going to be higher,” Steve Milloy, a senior legal fellow for the Energy and Environmental Legal Institute, told the DCNF. “In Florida, for example, population has increased since 2005. Adjusted for GDP (a proxy measure for stuff at risk), there is no trend in aggregate storm damages. NOAA is just being dishonest.”
While NOAA does not express disaster costs as a percentage of GDP, its January blog post depicts data that reflects disaster costs per capita, adjusted for changes in the consumer price index.
Notably, disasters of the past can become classified as BDD events retroactively since NOAA adjusts the damages for inflation. This means that a hypothetical hurricane that caused $900 million in damages in 1985 would be recorded later as a BDD event for that year once that figure is translated into 2024 dollars.
