The Cascade Mountains of central Oregon, where the average, annual snowpack is less than in decades past.
Biodiversity is Nature’s backup system and thus the bedrock foundation of social-environmental sustainability. Backup systems, in the biological sense, comprise the various functions of different species that act in concert as an environmental insurance policy.
To maintain this insurance policy, an ecosystem needs three kinds of diversity: biological, genetic, and functional. Biological diversity is the richness of species in any given area. Genetic diversity constitutes different degrees of flexibility whereby a species can adapt to change. The most important aspect of genetic diversity, from our human point of view, is that it buffers the extremes in the variability of the way ecosystems behave, particularly in the medium and long term. And functional diversity equates to the variety of biophysical processes the species richness of an area allows to take place. The upshot is that healthy ecosystems act as shock absorbers in the face of potential, catastrophic disturbance—those disturbances that negatively affect the quality of our human life.
OUR HUMAN INFLUENCE
Human societies of all types continue to develop and use a broadening array of technologies, while assuming these technologies will do little or no harm to the interactive atmosphere (air), the litho-hydrosphere (the rock that constitutes the restless continents and the water that surrounds them), and the biosphere (the life forms that exist within the other two spheres), which together sustain all life—including us humans. The day has come, however, when the life-support systems themselves are being disrupted by increased use of technologies with the cumulative power to disarrange ecosystems to such an extent that the biophysical services we require are in peril—unlike anything faced by humanity until the 20th century. Such is the newest and greatest threat faced by us in the world we inhabit.
The melting of glaciers around the world is a fact because it is irrefutably observable and measurable. This indisputable increase in global warming is caused by an array of gases in the atmosphere that trap heat radiated outward from Earth’s surface—the “greenhouse effect.” Carbon dioxide has to date received the most attention, but other gases are involved, including water vapor, ozone, nitrous oxide, chlorofluorocarbons (CFCs), and methane.
For example, the Union of Concerned Scientists found in a case study that a single 500-megawatt coal plant produces 3.5 billion kilowatt-hours per year, enough to power a city of about 140,000 people. To produce this amount of electricity, it burns 1,430,000 tons of coal, uses 2.2 billion gallons of water, and 146,000 tons of limestone. It also puts out annually:
•10,000 tons of sulfur dioxide. Sulfur dioxide (SOx) is the main cause of acid rain, which damages forests, lakes and buildings.
•10,200 tons of nitrogen oxide. Nitrogen oxide (NOx) is a major cause of smog, and also a cause of acid rain.
•3.7 million tons of carbon dioxide. Carbon dioxide (CO2) is the main greenhouse gas, and is the leading cause of global warming. There are no regulations limiting carbon dioxide emissions in the U.S.
•500 tons of small particles. Small particulates are a health hazard, causing lung damage. Particulates smaller than 10 microns are not regulated, but may be soon.
•220 tons of hydrocarbons. Fossil fuels are made of hydrocarbons; when they don’t burn completely, they are released into the air. They are a cause of smog.
•720 tons of carbon monoxide. Carbon monoxide (CO) is a poisonous gas and contributor to global warming.
•125,000 tons of ash and 193,000 tons of sludge from the smokestack scrubber. A scrubber uses powdered limestone and water to remove pollution from the plant’s exhaust. Instead of going into the air, the pollution goes into a landfill or into products like concrete and drywall. This ash and sludge consists of coal ash, limestone, and many pollutants, such as toxic metals like lead and mercury.
•225 pounds of arsenic, 114 pounds of lead, 4 pounds of cadmium, and many other toxic heavy metals. Mercury emissions from coal plants are suspected of contaminating lakes and rivers in northern and northeast states and Canada. In Wisconsin alone, more than 200 lakes and rivers are contaminated with mercury. Health officials warn against eating fish caught in these waters, since mercury can cause birth defects, brain damage and other ailments. Acid rain also causes mercury poisoning by leaching mercury from rocks and making it available in a form that can be taken up by organisms.1
The consensus among scientists is that global warming, at some unknown intensity, is occurring at an unprecedented rate, as evidenced by the massive melting of the world’s continental glaciers and oceanic ice. Moreover, sea levels are rising as the ice melts and ocean temperatures warm, the latter causing the water to expand and contribute to rising sea levels. Further discussion is unnecessary for those who accept the compounding evidence of global warming and a waste of time for those who cling steadfastly to informed denial.
Nevertheless, the inviolate, biophysical principles ultimately bind together the universal commonalities, while simultaneously allowing the novelty of differences, such as those found in large populations of organisms. The predominant commonality in today’s world, however, may well be the variability of our changing climate. As climate is altered, so are the effects of the biophysical cycles.
CLIMATE: THE GLOBAL ARBITER
Climate has been dynamic throughout the various scales of geological time, and it will continue to be the main driver of our planet’s story of novelty within and among the three, interactive spheres of our earthscape: the atmosphere, litho-hydrosphere, and the biosphere.
There have been five major episodes of plant and animal extinctions over the last 440 million years, and each time it took upward of 10 million years to recover species richness—each time with a different compositional arrangement of species and biophysical processes. Alteration of the global climate was a factor then, and it’s a factor now in that climate change since the late 1970s has shifted the distribution and abundance of numerous species—and continues to do so.
The consensus among biologists is that we are now moving toward a potential sixth great extinction, ranging from the extinction of the smallest microorganisms to that of large mammals—some without our ever having known they existed. This episode will be caused predominantly by the activities of a single species, however, us humans. Although scientists estimate that a minimum of 10 million species inhabit today’s world, they are disappearing between 1 and 10 thousand times faster than they did over the past 60 million years.
Today, only a small fraction of the world’s plants have been studied in detail, but as many as half of the species are threatened with extinction, primarily in the diverse tropical forests of Central America and South America, Central Africa and West Africa, and Southeast Asia. Moreover, according to the International Union for Conservation of Nature’s Red List survey of the world’s flora and fauna, of 64,000 species monitored, the number threatened with extinction in the coming decades of this century rose from about 11,000 species of plants and animals in 2000 to roughly 20,000 species by this year (2012)—and the trend continues.
Throughout most of geological history, new species seem to have evolved faster than existing ones became extinct, and so the planet’s overall biological diversity has increased. But, now evolution seems to be falling behind, in large measure because of our modern-day economic thinking.2
Because climate is still the primary mechanism through which the distribution of species and ecosystem processes are controlled, new 21st -century-climatic conditions may promote the formation of heretofore-unseen associations of species and other ecological surprises. Novel climates are projected to develop primarily in the tropics and subtropics, whereas disappearing climates will be concentrated in tropical montane regions and the pole-ward portions of continents. Consequently, species with limited abilities to disperse will experience the loss of existing climate and the occurrence of novel ones.3
This said, caution is vital in making predictions because all models are linear by design, but no ecosystem is. Therefore, while novel climates will become a reality, generalized models will neither capture nor account for the “micro-climatic buffering” of topography, besides which they often do not consider the full capacity of plants and animals to acclimate to changing conditions.
CLIMATE AND BIODIVERSITY
Nevertheless, predicting the fate of biodiversity in response to complexities wrought by climate change, especially when combined with habitat fragmentation, is a serious undertaking, one that is fraught with caveats, nuances, and total unknowns. Although every measure must, of necessity, be put in place to reduce further fragmentation of reserves and landscapes in general, we must determine what represents a positive, sustainable intervening matrix in these human-modified landscapes.
What’s more, the growing combination of climate change and habitat destruction will see novel ecosystems becoming increasingly common. Their conservation will require a whole new definition of what is “natural,” considering that most ecosystems are now sufficiently altered in structure and function to qualify as novel ecosystems. It is critical for this recognition to be the starting point in understanding ecosystems into the future, especially under the emerging biogeochemical configurations, coupled with human activities in the form of an ongoing experiment that blurs the line between basic and applied research in all disciplines.4
According to a piece in American Forests magazine, recent (2012) studies show that forests are increasingly threatened with simplification due to a loss of biodiversity through various human influences. Here, the crux of the issue is that a significant loss of species from an ecosystem can have the same level of impact as climate change.5
WHEN HABITATS CHANGE
Sometimes habitats evolve slowly and gradually, sometimes quickly and dramatically, but regardless of the way they do it, all habitats change. When they do, there is a general reshuffling of plants and animals. More adaptable species may for a time survive a change in habitat, even a relatively drastic one, but in the end they too must change, migrate elsewhere, or become extinct. That not withstanding, all habitats form a continuum of ever-changing novelty in a variety of ways that elicit the migration of species to new areas or a shift in behavioral synchronicity between and among species.
Wide-ranging species of plants and animals, which incorporate large, diverse portions of landscapes within their normal patterns of habitat use, tend to be more adaptable than species with narrow tolerances that live within relatively restricted habitats. Nevertheless, climate change is ultimately forcing species of both plants and animals in the Northern Hemisphere to migrate northward in latitude or upward in elevation as the climate warms, whereas those in the Southern Hemisphere migrate southward in latitude or upward in elevation. That is, provided they are adaptable enough in either case to accommodate a somewhat different habitat and they can compete with the existing species. Otherwise, they become extinct. Although there are thousands of examples worldwide, I have chosen a miniscule sampling as illustrative.
Both plants and animals tend to thrive in a narrow temperature range, which means they are forced to seek cooler ground when temperatures rise. Therefore, a three-degree Fahrenheit rise in temperature in mountainous areas would mean that subalpine and alpine plants would have to migrate upward in elevation about 1,600 feet to compensate for the increased warmth. This magnitude of a migration would lead to a reduction in both the number of subalpine and alpine habitats in the foreseeable future, as well as their size, and would drastically affect the animals of some of those habitats.
The challenge of global warming for species that live on mountains is either that they cannot migrate upward quickly enough or that they will run out of a mountaintop, cannot go any higher, and so will become extinct. To illustrate, populations of the American pika (also known as a “rock rabbit,”) have moved upslope at an average of 43 feet per decade for most of the 20th century. Since the late 1990s, however, they have migrated upward far faster, climbing 475 feet per decade.
An American pika in its rocky habitat, taken on Steamboat Mountain, Skamania County, Washington, in July 1973.
Local extinctions will indeed be the dilemma in the Great Basin of the North American West if the temperature rises just two degrees Fahrenheit over the next 50 years. Ten to 50 percent of the animals living in the subalpine and alpine habitats of the Great Basin occupy “habitat islands” on the very tops of isolated mountains. One of these is the American pika, which lives in subalpine rockslides at the base of cliffs. The warming climate is rapidly destroying its habitat, as it did at the close of the Wisconsin Glaciation 10,000 years ago on these same mountains. But, at that time, the pika simply migrated upward in elevation as the glaciers melted and revealed new areas in which its food plants could grow. Today, however, the pika, its food plants, and the other species living on these isolated mountains are already as high at they can go because there are no glaciers to retreat and create new habitat, so now local populations are becoming extinct.6
Steen’s Mountains in the Great Basin of the American West, where American pikas are at the apex of their habitat and on the verge of extinction, if they are not already extinct, from this mountain island.
On the other hand, I studied Royle’s pika on Phulung Ghyang, Newakot District, in Himalayan Mountains of Nepal at 11,500 feet in elevation in the mid-1960s. There, shrubs were found as high as 12,000 feet, and the subalpine habitat was above that. In this case, the royle’s pikas have greater flexibility in migrating upward because the Himalayas are not only vast and connected but also are much higher and more rugged than the isolated mountains of the Great Basin.
Home of Royle’s pika on Phulung Ghyang, Newakot District, at 11,500 ft. in the Himalayas of Nepal. I took this photo in May 1967.
This difference offers a considerably higher elevational gradient into which the pikas and their food plants can move, much of which is still occupied by melting glaciers, where new habitat is being created and thus can accommodate the pikas’ upward migration. In addition, there are numerous, protected, colder habitats on steep, north-facing slopes within the pikas’ current elevational distribution, which may for a time delay the necessity of its having to migrate upward.
Lang Tang Peak the Nepalese Himalayas; taken from Phulung Ghyang, Newakot District, at 11,500 ft., May 1967. This photo shows the potential for Royle’s pika to migrate upward in elevation as glaciers melt and new habitat is created due to global warming.
With respect to marine mammals, a species’ geographical distribution is generally related to a specific range in water temperature. There is, however, a kind of double-edged sword hidden within this relationship, one that depends on whether a species’ distribution is linked directly to the water temperature and the species’ ability to regulate its own body temperature, or whether other ecologically similar species can better regulate their body temperatures and thus have a competitive advantage.
In addition to temperature, such oceanographic features as the physical and chemical characteristics of the water, which define water masses and the boundaries of oceanic currents, often determine where populations of prey species accumulate and thus their availability. Therefore, while marine mammals are observed widely across the world’s oceans, their actual occurrence within their geographic distribution is often patchy, with some areas being used more frequently than others, presumably for feeding and reproducing. However, the most likely direct effects of changes in the water temperature to a species geographic distribution are based on the species mobility and its ability to regulate its core body temperature.7
As previously stated, animals in the Northern Hemisphere migrate northward to cooler clines and animals in the Southern Hemisphere migrate southward. For example, a colony of Galápagos fur seals has migrated 932 miles from the Galápagos Islands in the South Pacific Ocean (just south of the equator and 687 miles west of Ecuador) southward to northern Peru, where the sea surface has consistently risen over the last decade from an average temperature of 62.6 degrees Fahrenheit to 73.4 degrees Fahrenheit. This temperature is much closer to that around the Galápagos Islands, which averages about 77 degrees Fahrenheit. The conditions of the sea around northern Peru are now so similar to the Galápagos that more fur seals and other marine species may begin migrating.8
In addition, both direct and indirect effects of climate change on prey species can have several indirect effects on marine mammals, such as changes in their distribution, abundance, and migratory patterns, as well as the structure of their communities, susceptibility to disease and contaminants, and reproductive success. Climate change can also affect marine mammals through competition, as they are forced to shift their geographic distributions and migratory patterns, which create novel contacts among the various species that heretofore, had no contact.
Mismatched synchronicity occurs when one species responds to day length and another to temperature. For example, the caribou in West Greenland synchronize their seasonal migration to their calving grounds based on day length, but the food plants on which they depend respond to temperature. As the temperatures of the calving grounds have risen more than 32.9º Fahrenheit, plants have started to grow earlier, which means the caribou are now arriving after the peak foraging time. The result is a diminished food supply, which translates into fewer calves being born and a higher mortality of those that are.9
THE CASCADING EFFECT OF GLOBAL WARMING
Here, an example from the Gulf of Alaska is apropos. In the early 1980s, the Gulf of Alaska rose by 2 degrees Fahrenheit and severely altered the marine ecosystem. Orcas (also known as “killer whales”) living near the Aleutians traditionally ate Stellar sea lions and seals, both rich in blubber and loaded with calories. However, the sea lions and seals soon disappeared, leaving just the sea otters, which caused the orcas to change their diet. It took only four orcas less than a decade to kill and eat 115,000 sea otters. Once the otters vanished, the number of sea urchins skyrocketed. The sea urchins, in turn have eaten most of the massive 18-foot-tall kelp forests, formerly the otter’s habitat. In addition, rising ocean temperatures killed the plankton, which fed the copepods and krill, which in turn fed the shrimps and Alaska king crabs. Shrimps, crabs, capelin, and herring are gone. A once-brimming, diversified ecosystem has today been reduced to sea urchins, cod, pollack, and sharks. The speed in which these species have been lost has been likened to that of the great extinction of the dinosaurs. Such is the cascading effect of global warming, as it alters one ecosystem another.10 Although this example is from the ocean, the same dynamic is ongoing in both freshwater and terrestrial ecosystems.
A CLOSING COMMENT
Finally, I hope it is clear that we human beings, as relative newcomers within the world, are redrafting the evolutionary play. We are choosing the characters who will survive to perform again, those who will meet their extinction in which act, and those relative unknowns who will come from backstage to command the spotlight of the future.
Why? Because five things plague us in Western culture: (1) linear thinking; (2) impatience with Nature’s time table and production schedule; (3) always wanting more; (4) constantly “living” in fear of the future, while ignoring the eternal now; and (5) fierce competition based on an unrelenting desire for instant gratification. We therefore spend most of our time looking for new areas of the world to exploit. In so doing, we gear our science and technology to efficiently wringing the “last drop” of monetary wealth out of whatever dwindling resources we find—all the time ignoring the intrinsic, biophysical processes (the true wealth) that sustains us in a good quality of life. And the decisions we make today in our continual competition for control of the world’s material goods will echo through the years and the lives of people for generations to come—a legacy of irreversible consequences.
Today, in the United States alone, 592 species of plants and animals are threatened with extinction11 due to habitat fragmentation and other anthropogenic barriers to migration, such as cities, both of which are being made progressively worse by the effects of global warming. And we in our arrogance and informed denial of the problems continue to direct our impromptu play—with a script governed by our economic/political blindness and thus devoid of any ecological notion of what we’re staging! And once again, the children of all generations will reap the consequences of our thoughts, decisions, and actions—in that they have no choice because we adults give them none. The question is, will they be able to respond in a viable manner to circumstances we leave them in our passing?
The grandeur of Zion Canyon, Utah, masks our human-caused simplification of its biodiversity—both large and small.
Series on Biodiversity:
1. Quoted by permission, Union of Concerned Scientist, http://www.ucsusa.org/about/contact-us.html
2. (1) The preceding four paragraphs are based on Chris D. Thomas, Alison Cameron, Rhys E. Green, and others, “Extinction Risk from Climate Change,” Nature 427 (2004):145–148; (2) Janet Larsen. The Sixth Great Extinction: A Status Report. March 2, 2004, Earth Policy Institute, http://www.earth-policy.org/Updates/Update35.htm; and (3) The IUCN Red List of Threatened Species.TM 2012. http://www.iucnredlist.org/about/summary-statistics
3.The discussion of climate is based on: John W. Williams, Stephen T. Jackson, and John E. Kutzbach, Projected Distributions of Novel and Disappearing Climates by 2100 A.D. Proceedings of the National Academy of Sciences USA, 104 (2007):5738–5742
4. The forgoing two and a half paragraphs are based on: (1) Kathy J. Willis and Shonil A. Bhagwat. Biodiversity and Climate Change. Science, 326 (2009):806–807; (2) Timothy R Seastedt, Richard J Hobbs, and Katharine N Suding. Management of Novel Ecosystems: Are Novel Approaches Required? Frontiers in Ecology and the Environment, 6, (2008):547-553; (3) Robin L. Chazdon, Celia A. Komar, Oliver Harvey, and others. Beyond Reserves: A Research Agenda for Conserving Biodiversity in Human-modified Tropical Landscapes. Biotropica, 41 (2009):142-153; (4) Daniel B. Botkin, Henrik Saxe, Miguel B. Araújo, and others. Forecasting the Effects of Global Warming On Biodiversity. Bioscience, 57 (2007):227-236; and (5) Christophe F. Randin, Robin Engler, Signe Normand, And Others. Climate Change and Plant Distribution: Local Models Predict High-Elevation Persistence. Global Change Biology, 15 (2009):1557–1569.
5. Effects of Less Biodiversity. American Forests, Fall (2012):12.
6. Discussion of the American pika in the Great Basin is based on: Erik A. Beever Chris Ray, Jenifer L. Wilkening, and Others. Contemporary Climate Change Alters The Pace And Drivers Of Extinction. Global Change Biology 17 (2011):2054–2070
7. The preceding two paragraphs are based on: Derek P. Tittensor, Camilo Mora, Walter Jetz, and others. Global Patterns and Predictors of Marine Biodiversity Across Taxa. Nature 466 (2010):1098–1101
8. (1) Endangered Galapagos Seals Migrate to Peru. http://www.andeancurrents.com/2010/02/endangered-galapagos-seals-migrate-to.html and (2) Dan Collyns. Galapagos Fur Seals Head for Peru Waters. http://news.bbc.co.uk/2/hi/americas/8503397.stm
9. Alison Donnelly, Amelia Caffarra, and Bridget F. O’Neill. A Review Of Climate-Driven Mismatches Between Interdependent Phenophases In Terrestrial And Aquatic Ecosystems. International Journal of Biometeorology 55 (2011):805–817.
10. J. A. Estes, M. T. Tinker, T. M. Williams, and D. F. Doak. Killer Whale Predation on Sea Otters Linking Oceanic and Nearshore Ecosystems. Science 282 (1998):473–476.
11. Jean-Christophe Vié, Craig Hilton-Taylor and Simon N. Stuart (editors). Wildlife In A Changing World: An analysis of the 2008 IUCN Red List of Threatened Species.TM http://data.iucn.org/dbtw-wpd/edocs/RL-2009-001.pdf
Text and Photos © by Chris Maser 2012. All rights reserved.