Climate Change is Not Decimating Bees
Several media outlets -- namely National Public Radio -- are touting a tall tale that climate change is decimating bee populations throughout North America. The (false) alarm is based on a February 7 study published by the American Association for the Advancement of Science (AAAS). The study, however, is deeply flawed and does not change the very low likelihood of climate change seriously impacting bee populations.
After examining the study, titled “Climate change contributes to widespread declines among bumble bees across continents” -- one immediately notices that there is a key issue missing that is not discussed in the paper at all: Colony Collapse Disorder (CCD). In non-scientific jargon, CCD occurs when entire hives suddenly experience population crashes. CCD has been called the honeybee’s biggest enemy by scientific researchers.
The U.S. Environmental Protection Agency says:
“There have been many theories about the cause of CCD, but the researchers who are leading the effort to find out why are now focused on these factors:
- Increased losses due to the invasive varroa mite (a pest of honeybees).
- New or emerging diseases such as Israeli Acute Paralysis virus and the gut parasite Nosema.
- Pesticide poisoning through exposure to pesticides applied to crops or for in-hive insect or mite control.
- Stress bees experience due to management practices such as transportation to multiple locations across the country for providing pollination services.
- Changes to the habitat where bees forage.
- Inadequate forage/poor nutrition.
- Potential immune-suppressing stress on bees caused by one or a combination of factors identified above.”
Needless to say, the many causes of CCD identified above don’t get a single mention in this new study, which cites climate change as the overwhelming “cause” of declining bee populations.
The study’s methods are quite dubious. In effect, they took a trove of bee population data, tossed out a bunch of facts and figures they didn’t like, put it into the world’s most complex gridded climate model, compared data, and somehow claimed correlation with climate change.
Here is an example of their questionable methodology. The authors noted that if their limited examination of parts of a 3,600-square-mile area found some types of bees -- but not a particular species of bee they were looking for -- then the bee does not exist in the 3,600-square-mile area. That is a huge leap in (faulty) logic. In 3,600 square miles, it would be quite likely to identify one, or three, or even five types of bees while not identifying another type that is only present in a smaller segment of those 3,600 square miles.
Such methodology is troublesome. In much of their analysis, the authors are not really dealing with actual observations. They start with those, but then they create a model that gives them “occupancy probability” -- or educated guesses based on their limited actual observations. Instead of looking at the effects of a changing climate on actual bee numbers, they speculate about the effects of a changing climate on “occupancy probability.”
Then, there is this interesting statement:
“Occupancy, extirpation, and colonization. Consistent with measured declines in occupancy (Figure 2), observed distributions declined on average by 54% (±3.4% SE) in North America and 18% (±7.2% SE) in Europe relative to the baseline period (Figure S6A).”
Yet the researchers fail to explain why bee populations more than halved in North America, while European bee populations dipped only one-third as much as North America. They don’t even try to explain why global warming doesn’t impact bees the same way globally.
It is difficult to understand how this study passed the peer review process. This is especially so, considering scientists who study species extinctions are not at all concerned when it comes to the studied bees.
The International Union for Conservation of Nature (IUCN) has published the IUCN Red List on the European bumblebee that was tracked in the study. The IUCN Red List categorizes the European bumblebee as “Least Concern.” That is the absolute lowest level of concern that the Red List contains. For the American version of the same bee, IUCN says “Data deficient” -- meaning they don’t have enough data to even assign a concern level. You’d think if populations were collapsing due to climate change, researchers would be feverishly counting bee populations. But they aren’t, and that speaks volumes.
This overhyped climate-blaming study seems merely an exercise in numerology and “climate click-baiting.” Neither the U.S. Environmental Protection Agency nor the International Union for Conservation of Nature believe a climate-caused bee crisis is on the horizon.
It appears AAAS got stung after publishing this deeply flawed study.
Anthony Watts (AWatts@heartland.org) is senior fellow at The Heartland Institute. He is a former broadcast meteorologist and operates the world’s most-viewed climate website, WattsUpWithThat.com. He is also a member of the American Association for the Advancement of Science.