Climate change contributes to widespread declines among bumble bees across continents.

[NNadir]

The paper I'll discuss in this post, having the same title as the post, is this one: Climate change contributes to widespread declines among bumble bees across continents (Peter Soroye1,*, Tim Newbold2, Jeremy Kerr1, Science Vol. 367, Issue 6478, pp. 685-688 2020)

Reference to the article is included in a news item in the same issue of science, from which I'll quote before referring to the paper itself, since it is so well written, and makes a trenchant ecological political point. The news item:

Discovering the limits of ecological resilience (Jon Bridle, Alexandra van Rensburg, Science Vol. 367, Issue 6478, pp. 626-627, 2020).

To wit:

n 1949, environmentalist Aldo Leopold wrote that “one of the penalties of an ecological education is that one lives alone in a world of wounds” (1). Seventy years later, biologists no longer witness such wounds in solitude. Instead, millions of people on social media share evidence every day of how the behavior of a wealthy minority (2) has created unsustainable rates of biodiversity loss and climate transformation (3). Now, on page 685 of this issue, Soroye et al. demonstrate widespread declines in bumble bee species that are better explained by the frequency of climate extremes than by changes in average temperatures (4).

The, um, behavior of a wealthy minority...

Of course, here we like to argue that the wealthy minority consists of people, venal people who are not us, you know, Donald Trump, Koch, Koch, Koch, Koch, Adelson, Murdoch, Murdoch...

We're not "rich."

Bridle and van Rensberg continue:

Despite increasingly precise predictions of rises in average temperatures and the frequency of extreme weather events, biologists still cannot predict how ecological communities will respond to these changes. This means that scientists cannot predict where, and at what rates of climate change, ecosystems will stop providing the rainfall, decomposition, and biological productivity on which all economies depend. Another key unknown is to what extent ongoing habitat and biodiversity loss reduces the ability of ecological communities to evolve in response to the climate crisis (3).

To determine these critical rates of biodiversity loss and climate change as well as where they are being exceeded (5), scientists test for shifts in the distribution of species over time and across their geographical ranges. Such studies reveal that the warming climate leaves a footprint: The abundances of many plant, animal, and fungal species have contracted at low latitudes and elevations, and have increased at high latitudes and elevations (6). How these responses to environmental change vary according to species' life histories, ecologies, and their biotic interactions provides a test of which ecosystems and localities are least resilient to global change.

Soroye et al. used long-term datasets to assess changes in the abundance and geographical distribution of 66 bumble bee species in Europe and North America between two periods, 1901–1974 and 2000–2014. Two of their findings are especially alarming. Bumble bee populations showed substantial declines at southern (warming) ecological margins but fewer compensating population expansions at northern (cooler) margins, suggesting widespread declines in bee biodiversity across both continents. Moreover, the causes of these declines apparently depend more on the frequency of extremely warm years than on increases in average temperatures. As prevailing temperatures climb closer to species' physiological limits, extreme climate events will become increasingly associated with biodiversity loss. In addition, their effects will become more pronounced as cooler habitats, where organisms can survive unusually warm periods (e.g., deeper water, higher elevations), become increasingly rare...

The behavior of a wealthy minority...

We're not rich. Really, we're not.

I personally rail quite a bit about a little fact that um, troubles me:

Today, 2.2 billion people lack access to safely managed drinking water services and 4.2 billion people lack safely managed sanitation services. Unsafe hygiene practices are widespread, compounding the effects on people’s health. The impact on child mortality rates is devastating with more than 297 000 children under five who die annually from diarrhoeal diseases due to poor sanitation, poor hygiene, or unsafe drinking water.

United Nations Water: Water, Sanitation and Hygiene

If any of this troubles you, don't worry, be happy.

Head over to the E&E forum where you can read about the wonders of Elon Musk's car for spoiled children, which is built using cobalt mined by real children working for zero wages under the point of guns, um, slaves, in "The 'Democratic' 'Republic' of the Congo"



"Energy Sage"

The annual per capita income of "The 'Democratic' 'Republic' of the Congo" is reportedly $562, less than $2.00/day.

The "cheap" Tesla car costs more than 60 times the per capita income of "The 'Democratic' 'Republic' of the Congo." The, um, luxury model, costs "only" 220 times as much.

Don't worry, be happy. If you own a Tesla car, you're not rich; you're "green."

Those kids digging cobalt are not afforded the luxury of being green with envy as they admire your Tesla car. They've probably never seen one. They are probably not even aware of what this is all about; since even that would require a rudimentary education. The guns and the whips are all they need to know to understand what this is all about.

Don't worry. Be happy. All that fracking is transitional because soon enough we will drag giant steel posts for wind turbines through every virgin ecosystem on the planet and be "green." We swear. We swear. We'll build those wind farms right on through 500 ppm of CO2, and be so proud of ourselves for being "green."

You're not rich, because you live in a country that is the world's largest debtor, run by a brainless cheap carny hack criminal who is the pet puppy of an ex-KGB agent and who is coddled by a bunch of thugs who used to wrap themselves in American flags and complain about "those commies."

You're not rich. You had nothing to do with those bumble bees and their bumble bee problems.

About the bees, from the introduction to the paper cited at the outset:

Recent climate changes have accelerated range losses among many species (1, 2). Variation in species’ extinction risk or chances of colonizing a new area determine whether species’ ranges expand or decline as new climatic conditions emerge. Understanding how changing climatic conditions alter species’ local extinction (extirpation) or colonization probabilities has proven exceptionally challenging, particularly in the presence of other environmental changes, such as habitat loss. Furthermore, identifying which species will most likely be at risk from climate change and where those risks will be greatest is critical to the development of conservation strategies (3, 4).

Although many mechanisms could alter how species fare as climate changes, discovering processes that strongly affect species persistence remains among the foremost challenges in conservation (5). Climate change could pose risks to species in part by increasing the frequency of environmental conditions that exceed species’ tolerances, causing population decline and potentially extirpation (6, 7). Conversely, climate change may render marginal areas more suitable for a species, making colonization of that locale more likely (1). Understanding and predicting spatially explicit colonization and extinction likelihood could identify which species are vulnerable to climate change and where, identify which species may benefit, and suggest interventions to mitigate conservation risks. Colonization and extinction dynamics, in combination across a regional species assemblage, determine how species richness changes. Among taxa that contribute critically to ecosystem service provision, including pollinators such as bumble bees (Bombus), species richness decline could impair ecosystem services (8).

We evaluated changes in bumble bee species occupancy and regional richness across North America and Europe using a database of ~550,000 georeferenced occurrence records of 66 bumble bee species (figs. S1 and S2 and table S1) (1, 9). We estimated species’ distributions in quadrats that measured 100 km by 100 km, in a baseline (1901–1974) and recent period (2000–2014) (9). Climate across Europe and North America has changed greatly between these time periods (fig. S3). Although the baseline period was substantially longer, there were 49% more records in the recent period. Non–detection bias (difficulty distinguishing among true and false absences due to imperfect detection) in opportunistic occurrence records can reduce measurement accuracy of species distributions and overall richness (10). Consequently, we used detection-corrected occupancy models to estimate probability of occurrence for each species in quadrats in each time period (9). We calculated changes in species’ probabilities of occupancy and generated detection-corrected estimates of species richness change between periods (fig. S4).

We predict greater declines in bumble bee species occupancy and species richness where changing climatic conditions more frequently exceed individual species’ historically observed tolerances. Conversely, we predict greater occupancy and species richness in areas where climate changes more frequently cause local weather to fall within species’ historically observed tolerances.

Figure 1 from the paper:



The caption:

Fig. 1 Change in community-averaged measures from the baseline (1901–1974) to the recent period (2000–2015).

Local changes in (A) thermal and (B) precipitation position indices are shown. Increases indicate warmer or wetter regions and that, on average, species in a given assemblage are closer to their hot or wet limits than they have been historically. Declines indicate cooling or drying regions and that, on average, species in a given assemblage are closer to their cold or wet limits than they have been historically

More text:

...Our measurements of bumble bee species occupancy over time provide evidence of rapid and widespread declines across Europe and North America. The probability of site occupancy declined on average by 46% (±3.3% SE) in North America and 17% (±4.9% SE) in Europe relative to the baseline period (Fig. 2). Declines were robust to detection-correction methods (figs. S6A and S7) and consistent with reductions in detection-corrected species richness (fig. S6B) (9)...

Figure 2:



The caption:

Fig. 2 Percent change in site occupancy since a baseline period (1901–1974) for 35 North American and 36 European bumble bee species.

More text:

...Declines among bumble bee species relate to the frequency and extent to which climatic conditions approach or exceed species’ historically observed climatic limits, particularly for temperature. We modeled change in probability of site occupancy with phylogenetic generalized linear mixed models using thermal position variables (baseline, change since baseline, and the interaction between these), precipitation position variables (baseline, change since baseline, and the interaction between these), the interaction between baseline thermal and precipitation position terms, and the interaction between change in thermal position and change in precipitation position. We controlled for continent (9). The models support our predictions: Probability of occupancy decreases when temperatures rise above species’ upper thermal limits (Fig. 3A, fig. S8A, and table S2), whereas warming in regions that were previously near species’ cold limits is associated with increasing occupancy. Evidence for precipitation influencing site occupancy was mixed, but declines were more likely in sites that became drier (Fig. 3B, fig. S8B, and table S2)...

Figure 3:



The caption:

Fig. 3 Change in probability of occupancy in response to change in thermal and precipitation position from the baseline (1901–1974) to the recent period (2000–2014).

Thermal (A) and precipitation (B) positions range from 0 to 1, with 1 indicating that conditions at a site are at a species’s hot or wet limit for the entire year and 0 meaning that conditions are at a species’s cold or dry limit for the entire year during the historic period. For ease of visualizing the significant interaction between baseline thermal position and change in thermal position, the continuous baseline thermal position variable has been split at the first and third quantile to show sites that were historically close to species’ hot limits (red; n = 969 sites), cold limits (blue; n = 2244 sites), and the middle of their observed climatic limits (purple; n = 11,793 sites). Rug plots show the distribution of observations. Confidence intervals (±95%) are shown around linear trendlines.

More text:

Bumble bee species richness declined in areas where increasing frequencies of climatic conditions exceed species’ historically observed tolerances in both Europe and North America. An analysis of covariance that modeled the response of detection-corrected richness to community-averaged measures of climatic position revealed that, consistent with observed trends in species-specific occupancy change, richness was more likely to decline in regions experiencing warming, especially when species present were in the warmest parts of their historical ranges (table S2)...

...Projections suggest that recent climate change has driven stronger and more widespread bumble bee declines than have been reported previously, especially in Europe (Fig. 4). European estimates of observed richness rely particularly on observations from well-sampled regions that were cooler in the baseline period and that have experienced less warming subsequently (9), which may have contributed to underestimation of recent species richness decline across that continent (figs. S6B, S9, and S10). These findings contrast with those for other taxa that predict widespread range expansions and increasing species richness toward warming environments in the north (13, 14).

Figure 4:



The caption:

Fig. 4 Climate change–related change in bumble bee species richness from a baseline (1901–1974) to a recent period (2000–2014).

Predictions are from a model projecting percent change in detection-corrected bumble bee species richness as a function of mean community-averaged thermal and precipitation position.

Some concluding remarks from the paper:

Climate is expected to warm rapidly in the future (20). Using a spatially explicit method of measuring climatic position and its change over time, we show that risks of bumble bee extirpation rise in areas where local temperatures more frequently exceed species’ historical tolerances, whereas colonization probabilities in other areas rise as climate changes cause conditions to more frequently fall within species’ thermal limits. Nevertheless, overall rates of climate change–related extirpation among species greatly exceed those of colonization, contributing to pronounced bumble bee species declines across both Europe and North America with unknown consequences for the provision of ecosystem services. Mitigating climate change–driven extinction risk among bumble bees requires efforts to manage habitats to reduce exposure to the growing frequency of temperatures that are extreme relative to species’ historical tolerances.

The bold is mine.

...efforts to manage habitats...

Don't worry. Be happy. It's not your problem, those bumblebees. Transitional gas...solar roof...wind turbine...Elon Musk...Your SpaceX ticket to Mars...not your problem...you're for all of it. aren't you?.

You know what? Some of those bumble bees are nasty anyway. They can sting you. Some of them are boring insects and they can drill holes in the wood in your deck from which you can admire the view, and cost you thousands of dollars, way more than $2/day.

...efforts to manage habitats...

The whole world is a habitat.

I am a member of that awful Baby Boomer generation. When we were kids we used to huddle in front of black and white televisions with tiny screens and watch those Japanese monster movies - "science" fiction - where all the world's political leaders would call upon the world's scientists - who were always deeply respected and whose advice was always taken.

I actually used to believe the world worked like that, but then again, I was eight years old and now we are all eight years old, in a very different world.

Don't worry. Be happy.

History will not forgive us, nor should it.

TGIF tomorrow. Enjoy it.