Climate Change: Adaptation Isn’t the Answer

 

(Image by makieni777 from Pixabay) Pika

First, the rallying cry was to “Stop Global Warming!” and whatever would be the particular dire results du jour resulting from that environmental disaster. Then, as the ominous 350 ppm of CO2 in the atmosphere drew closer, was reached, then surpassed, the mainstream dialogue shifted from one of halting climate change to one of adapting to climate change. Was this movement to pragmatism over idealism driven by the realization that there were already too much climate altering GHGs in the system to avoid some impacts on the planet? Or was it driven by the very uniquely human selfish unwillingness to face hard choices and make the sacrifices necessary to stave off disaster? The answer would be fodder for those far wiser and with much more time to ponder than I. What I do know for certain is that not everyone, not every species, is able to sign on for the adaptation option.

 

(Image by Peter Fischer from Pixabay) Polar Bear

Adaptation isn’t an option if you’re an American pika, Ochotona princeps, whose habitat consists of alpine terrain above the tree line on mountains, and whose body is very well adapted to these cold conditions. Any significant warming or drying of the environment will cause your body to overheat. Since your habitat is already so high on the slopes, there’s not much room left to migrate upward in altitude before you run out of mountain. Of course, that’s also assuming the alpine meadows upon which you rely for sustenance will adapt rapidly enough to colonize higher up. Unfortunately, the time frames extrapolated from the most recent IPCC findings offer little hope for species in predicaments similar to the American pika. There simply won’t be enough time for organic evolution to enable pikas to adapt to warming temperatures (or for primary succession to establish new alpine meadows) before the species simply runs out of space and food, and disappears forever. For instance, in Glacier National Park, the pika may disappear not long after the last glacier is predicted to melt away in 2030.

 

The polar bear is in much the same predicament. So much of Ursus maritimus’s life cycle is tied to the Arctic sea ice — it’s a marine mammal — that the shrinking and eventual disappearance of that vital component of its environment is already negatively impacting the species’ chances of survival. Although the polar bear is thought to have diverged from the Brown bear (Ursus arctos) between 400,000 and 600,000 years ago and has survived past episodes of climate warming, proving itself capable of adapting to some degree, that was before the ubiquitous presence of technologically intrusive humanity. Today, when polar bears seek out new sources of food — new territories — they inevitably risk encountering humans, which, just as predictably, will always end badly for the bears. 

 

White Lemuroil Ring Tail Possum

In an article by Scott Waldman in the February 15, 2017, edition of Scientific American (reprinted with permission from Climatewire), a survey of 130 previous studies determined that climate change has had a particularly devastating impact on threatened and endangered species — and that this impact has been vastly underestimated. Of all the species maintained on the International Union for the Conservation of Nature, close to half of the mammals and a quarter of the birds have suffered increased threat due specifically to climate change. The studies show that the most impacted are those with highly specialized diets or very restricted habitats.

 

Of course, it makes perfect sense that a species already on the brink — or close to it — without accounting for the myriad alterations to its environment wrought by climate change, could much more easily fall over the edge into oblivion than a species that wasn’t already in such a weakened state. But even those robust, adaptable generalists are not immune to environmental changes.

 

What are some of the threats posed by climate change that impact our co-inhabitants of planet earth so dramatically? Patrick Barkham’s piece in The Guardian (January 19, 2017), while examining the ten species most endangered by climate disruption, also highlighted many of the threats. Rising sea levels will eradicate species whose habitat consists solely of areas just a few meters above sea level. Increasing ocean temperatures and acidification spell disaster for corals and all species dependent on them, as well as for any marine organism with a shell or exoskeleton. Then there is the ubiquitous interplay of phenology and synchronicity. Evolution has honed and fine-tuned interdependence among species and with the environment over many thousands of years. Now climate change is abruptly intruding on this symphony with cacophonous results.

 

(Photo by Skitterphoto from Pexels) Ringed Seal

Animals with very restricted habitats due to metabolic mandates, such as the white lemuroid ringtail possum (Hemibelideus lemuroides), will soon disappear in a warming world. And while the polar bear may be able to adapt to an altered earth, including by interbreeding with its brown bear cousins (something that happens infrequently already, but will increase in frequency as the planet warms), one of its primary food sources, the ringed seal, is not so fortunate. The ringed seal depends on the sea ice for denning, for raising its pups, for the krill living on its lower surface — no more ice, no more seals.

 

Not as much attention has been paid to Antarctic species, but the Adelie penguin numbers have declined significantly since 1970. Warming ocean water provides fewer fish for their diet, meaning they switch to less nutritious krill, and earlier melting at nesting sites brings higher infant mortality — eggs can’t survive sitting in pools of melt water.

 

(Image by Sarah N from Pixabay) Adelle Penguin

Sea turtle species will suffer a variety of deleterious impacts from a warming planet. More powerful storms will pummel and erode nesting grounds. Warming oceans will shift the currents and alter the abundance and location of food sources. Also, since more than one factor determines the gender of a sea turtle, warming sands will ensure an increasing predominance of females in the populations — until the sands become too hot and whole clutches of eggs fail. Once the percentage of females in the population reaches a critical point, the species will be beyond recovery.

 

With respect to abrupt climate change, phenology — or the timing of events — is, in a way, the Achilles heel of evolution and the handmaiden of extinction. The biosphere consists of a multiplicity of interconnected relationships that have evolved over thousands — even millions — of years. The fact that plants were able to colonize nearly every part of exposed land on the planet was due not just to the evolution of vascular tissues, but also to the development of a relationship — a symbiosis — with a group of Mycorrhizae fungi (and Rhizobium bacteria in legumes). Some of these relationships are broad, but many are very specific, examples of what is known as co-evolution.

 

(Image by Dorota Wrońska from Pixabay) Baird's Sandpiper

In these relationships, timing can be everything. If you’re a Baird’s sandpiper (Calidris bairdii), an arctic wading bird, the warmer temperatures induce you to mate earlier, but that means your eggs hatch before the peak season for the insects that are your primary nutrition source. Thus, your chicks are less hardy and less likely to survive to adulthood. If you’re a Yucca moth, your life cycle is intimately tied to the Yucca plant. If the plant blooms too early, you’ll fail to pollinate it, fewer plants will exist in the next generation and less food will be available to the next generation of Yucca moths.

 

No species exists in isolation — including Homo sapien sapien. Everything is interconnected and interdependent. Humans tend to think of ourselves as set apart from the rest of life on the planet. We’re somehow unique, solitary and extraordinary, as if an enlarged cerebrum, self-reflective awareness, language, etc., give us the right to determine the fate of all other life on the planet. That strikes me as the extreme of self-centered narcissism and hubris.

 

As a prime example of this tendency, we need look no further than plans for adaptation being touted in various halls of power. For some, the answer to adaptation appears to be throwing multiple, rapidly developed, insufficiently vetted technologies (carbon capture and storage, various forms of geo-engineering, tampering with the ocean) at a vast global problem engendered by

(Photo by Richard Segal from Pexels) Sea Turtle

centuries of willful ignorance about our impact on and interrelationships with all other living things. For others, the problem becomes one of structurally altering existing infrastructure to meet the demands of the altered environment for those already fortunate enough to be living there. For most of humanity, it will mean becoming climate refugees and hoping the 3% will have compassion for the 97%. None of these responses gives any priority to rest of the living biosphere.

 

I hate to disagree with Paul Simon and Art Garfunkel, but we aren’t rocks or islands, we are each, ourselves, ecosystems — microbiomes — and repositories of evolutionary history. Each human being contains roughly the same number of non-human cells (bacteria, archaea, fungi and viruses) as human cells, and this doesn’t include the microinvertebrates, bacteria and fungi that reside on the surface of the body. Some of our non-human residents actually exist as historic relics in our genomes, while others are helping us today by producing substances we need (our E. coli synthesizes Vitamin K for us).

 

It would therefore be prudent for us, before embarking on a self-centered adaptation crusade, to examine if and how climate disruption might directly affect our own micro-symbionts. The “other” is not only outside in the sky, the ocean and the forest, it’s also inside in the stomach, mouth, kidneys and lungs.

 

(Image by tdfugere from Pixabay) Yucca Plant

Granted that humans are fairly resilient, but as climate change creates more and more refugees, and population centers become more congested, it’s important to remember another group of organisms that will be on the move thanks to a warming planet — infectious disease vectors. Diseases that were previously confined to tropical and subtropical regions of the world will shift north and south. The microbiomes of people living in those areas will not have encountered these pathogens and will be vulnerable, as will their human hosts. We may discover adaptation to be less viable than originally thought.

 

Each species lost to extinction weakens the entire biosphere, which is an organic, living system. It’s capable of responding to extinctions — even to mass extinctions — but it’s uncertain if there has ever been one of this magnitude that occurred so abruptly.