Preventing Ecosystem Collapse: Seagrass

Seagrass ecosystems enable a wondrous diversity of marine life. Seagrass feeds ancient (but currently threatened) animals like green turtles, manatees and dugongs, sea urchins, parrot fish and geese. Seagrass supports major fisheries of pollock and cod and they’re home to seahorses. The ecosystem serves as a nursery ground for hundreds of species of juvenile fish. Seagrass supports clams, scallops, shrimp and spiny lobsters. Recently, seagrass meadows have also been shown to reduce disease that can infect people, coral or fish. So, recent losses of seagrass have generated great concern and motivated restoration efforts world-wide. Still, they are not doomed to collapse. The good news is most of the human factors that have reduced seagrass meadows can be and are being remedied. Furthermore, rising levels of carbon dioxide will benefit their growth and recovery.

Unlike seaweeds that are anchored to hard surfaces, seagrass thrives on muddy or sandy bottoms where their roots absorb the rich supply of nutrients stored in the sediments. However, storms and heavy waves easily disturb such habitat. So, seagrass prefers sheltered estuaries, coves and bays. Unfortunately, sheltered waters are also prime real estate for humans to harbor their boats. Much seagrass habitat has been lost to dredging of boat harbors. The chains that anchor boats to their moorings can scour the sea floor as the boats shift with the tides and currents. Nets seeking tasty bottom fish are dragged across the seafloor but also plow up seagrass meadows. Fortunately, people are working to prevent such damage by restricting fishing zones or inventing seagrass friendly moorings. The ancestors of today’s seagrasses were flowering land plants that returned to the ocean a 100 million years ago. To photosynthesize, seagrass colonization was limited to shallow coastlines with clear water and adequate sunlight. Most species prefer water that’s only 3 to 9 feet deep. But to remain at the proper depths, seagrass had to be resilient. Ice ages caused sea levels to rise and fall 400 feet eliminating old habitat and creating new ones. None of today’s seagrass meadows existed 6000 years ago. The Everglades’ Florida Bay formed 4000 years ago. Since then, seagrass meadows have flourished and disappeared periodically, but are now at their greatest extent.

It would have been extremely difficult for seagrass ancestors to successfully invade the oceans under today’s atmospheric CO2 concentration and still photosynthesize. Carbon dioxide is quickly converted to less usable ions after entering the water. Under current concentrations, only 1% remains as vital CO2. However, a 100 million years ago, plants flourished under increased atmospheric CO2 that was up to 7 times greater (3000 ppm) than today (410 ppm). The biggest evolutionary hurdle for seagrasses was surviving toxic sediments. Seagrass meadows accumulate organic matter as leaves and shoots are grown and shed. Unfortunately, as bacteria decompose organic matter, they consume all the oxygen. Without oxygen, different bacteria convert sulfur molecules into toxic sulfides that could kill the grass. So, seagrasses evolved channels that transported oxygen from their leaves to their roots, creating an “oxygen shield.” Many species evolved symbiotic relationships with specific bacteria and clams. The clams benefit from the grass’ added oxygen and help aerate the sediment further. Bacteria sheltering in clams then convert toxic sulfides into harmless chemicals. Seagrass success largely depends on generating more oxygen than bacterial decay can consume, and that battle explains many seagrass die-offs, such as recent die-offs in the Everglades’ Florida Bay.

As human populations grew and settled along the coast, they altered seagrass ecosystems by clearing the land for lumber and agriculture, and by overgrazing. Increased soil erosion was carried to the sea creating murky ocean waters that reduced sunlight. Sewage runoff and agricultural fertilizers added nutrients that promoted plankton blooms, which also reduced sunlight. With less light, there is less photosynthesis to generate oxygen. Without enough oxygen, toxic sulfides can invade and kill the seagrass. The good news is such lost seagrass ecosystems are not happening everywhere, and many unaffected regions support prosperous seagrass ecosystems. It is not a global crisis. The losses due to past ignorance of the ecosystem’s natural dynamics are now being repaired. Seagrass meadows with improved water quality are thriving and people are now managing sediment runoff better and developing waste-water treatment to reduce nutrient pollution. A 2010 die-off of seagrass in Australia’s Shark Bay, now a World Heritage site, generated scary headlines in scientific journals and the mass media drumming up fears of an existential crisis. The seagrass died during a “marine heat wave” supporting beliefs that only global warming could kill seagrass in a relatively pristine and protected ocean bay. However, the “marine heat wave” alleged to have killed the seagrass, was caused by a strong La Niña that caused warmer tropical waters to be transported (via the Leeuwin current) down the west coast of Australia. These periodic and natural warm water intrusions have been dubbed the “Ningaloo Niño”. The northerly winds that drove that warm water southward also suppresses the normally cold air arriving from the Southern Ocean region. The normal upwelling of colder deep waters is also suppressed. Once the strong La Nina conditions waned, the regional climate reversed causing several years of cold spells.

The greatest diversity of seagrass species thrives in the warmest waters. So normally, scientists would expect that organisms exposed to a constantly changing climate, induced by periodic warm Ningaloo Niño, would have adapted to those natural temperature fluctuations. Indeed, the immediate seagrass killer now appears not to have been warmer temperatures. Years of heavy grazing by non-native cattle and sheep made the watershed that drained into Shark Bay increasingly vulnerable to erosion. La Niña’s coincidentally increase rainfall during Australia’s monsoon season. Those heavy rains and eroding soil combined to produce a murky river discharge that flowed 10 miles out into the bay. The closer Shark Bay’s seagrass meadows were to the river delta, the greater the die-off. Seagrass meadows escaping those light?reducing waters were typically still thriving. Hopefully the wrong analysis that blamed global warming, will not lead to bad remedies and misguide any efforts to protect Shark Bay from further lethal river discharge. Lastly, the legacy of seagrass reproduction created one other problem. In the 1930s along the coast of Virginia, hurricanes and disease had completely denuded several seagrass meadows. Seventy years later the seagrass had yet to return. Without flowering grasses there are no local seeds to initiate recovery. Seagrass seeds are heavy and quickly fall to the seafloor, so many seagrasses spread slowly. Without a very nearby seed supply, a denuded meadow may take centuries to recover. The good news is people are now harvesting seeds from distant healthy patches and sowing them where seagrass once thrived. By maintaining good water quality and minimizing boat-related damage, seagrass meadows are on the mend. Dependent fish and scallops are slowly recovering. Florida’s manatees have increased 6-fold and are no longer rated as endangered. But manatees need warm winter refuges. So, counter-intuitively, the biggest threat to manatees living in Florida’s seagrass ecosystem is the loss of power plants and the warm water discharge that has served as a manatee winter sanctuary.

12/31/2020 modified online version to be printed in BattleBorn Media newspapers Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism Contact: naturalclimatechange@earthlink.net

Preventing Ecosystem Collapse: Pt 2 Caribbean Coral

Media headlines have been promoting unrealistic fears of ecosystem collapse due to climate change. Such fears get supported when the International Union for the Conservation of Nature (IUCN) designates some ecosystems as endangered, such as Caribbean Coral Reefs. But reefs are resilient and the human factors threatening individual reefs can be remedied.

 

The Caribbean reef ecosystem consists of thousands of individual reefs spanning from the east coast of Mexico and Central America to Florida and the Bahamas and south to the coast of Venezuela. Fifteen thousand years ago these reefs did not exist because sea level had fallen by 400 feet during the ice age. Modern reefs became established 8,000 years ago by colonizing newly flooded coastlines.

 

Caribbean Coral Reef Boundary

Based on one IUCN criterion the Caribbean reef ecosystem was designated “Least Concern” due to the widespread occurrence of individual reefs. In contrast, the loss of 59% of total coral cover between 1971 and 2006 prompted the IUCN to designate the reef system as “Endangered”.

 

Coral cover naturally fluctuates with seaweeds (macro-algae). Coral are killed by hurricanes, disease or bleaching,  which allows seaweeds too colonize the vacated space. The seaweed is gradually reduced by algae-eating animals which allows coral to return to their former dominance. Coral usually recover within 15 to 20 years, but recently their recovery has been extremely limited thus reducing coral cover. Unlike the demonized sea urchins that threaten Alaska’s kelp forest, algae-eating urchins are vitally important in maintaining the balance between seaweeds and Caribbean coral. The recent lack of coral recovery is largely attributed to a new disease that devastated urchin populations in the 1980s and minimized the urchins’ consumption of seaweeds.

 

Caribbean corals had been decimated in the 1980s by the novel White Band disease. However, that disease only affected two coral species from the genus Acropora - staghorn and elkhorn coral. Those species are now considered endangered. Acropora’s evolutionary strategy was to quickly colonize vacated shores produced by natural disturbances like hurricanes. These coral species thus dedicated their energy to rapid growth to out compete the seaweeds. That adaptation allowed staghorn and elkhorn coral to rapidly colonize flooded coasts as sea level recovered from the last Ice Age and dominate modern Caribbean reefs. But that strategy required diverting energy from building stronger reefs or resisting disease.  

 

Because Acropora require shallow habitat they’re vulnerable to storm damage. So, they evolved a reproductive strategy that produced new colonies by cloning new coral from storm damaged fragments. However, cloning reduces genetic diversity which also made them more vulnerable to new diseases.

 

Mortality from bleaching also reduced coral cover. Bleaching from unusually warm temperatures during summer 2005 and the 1998 El Nino is often highlighted. Surprisingly, fatal cold weather bleaching is rarely mentioned. Yet in January 2010 along the Florida Keys, cold weather killed 11.5 percent of the coral, which was 20 times worse than the 2005 warm weather mortality. Understanding why both warm and cold weather causes bleaching provides insight into how coral have successfully adapted to ever changing climates over the past 220 million years.

 

Shallow water corals depend on photosynthesizing symbiotic algae (aka symbionts) that provide over 90% of the coral’s energy. However, those corals will remove one symbiont species and acquire a new symbiont that is better adapted to the changing weather conditions. During the winter, colder temperatures and less light reduce photosynthesis. So, coral increase their density of symbiotic algae to counteract reduced productivity. But if it is too cold, the symbionts keep their energy supply for themselves. As a result, coral remove the “freeloaders” causing bleaching. A more productive cold?tolerant symbiont must then be acquired, or the coral die.

Coral polyp with inner symbiotic algae 

 

In contrast during the summer, more light and higher temperatures produce so much energy, coral reduce their number of symbionts. Because photosynthesis also produces potentially harmful chemical by-products, coral remove symbionts to reduce the production of harmful chemicals. That too causes coral to bleach, and unless a better adapted symbiont is  acquired, the coral will die. Despite that mortality risk, research now shows by switching their symbionts, coral can quickly adapt to warmer or cooler climates and enhance the species survival.

 

Studying fossil reefs, scientists determined that Caribbean corals had been declining decades before widespread bleaching and disease outbreaks occurred. Growing human populations cleared the land for farms, sugarcane and banana plantations. Resulting soil runoff reduced water clarity required for efficient photosynthesis. Increased sewage also reduced clarity and introduced pathogens. Those stressors made coral more susceptible to subsequent bleaching and disease. Soil runoff also added nutrients that tipped the ecological balance to favor seaweed growth, while overfishing removed seaweed?eating fish that once restricted seaweed dominance.

 

We can, and are controlling soil runoff and treating sewage. Fishing regulations are restoring the ecosystem that had balanced seaweeds and coral. And with those protections, naturally resilient coral will steadily recover.

Preventing Ecosystem Collapse: Alaska’s Kelp Forests

Over the past few years the media, such as the NY Times, have hyped a coming apocalypse and an existential crisis as ecosystems collapse. Inside Climate News, one of the more egregious fear mongers suggests “Global Warming Could Collapse Whole Ecosystems, Maybe Within 10 Years”. In contrast, most scientists agree ecosystems are very complex and still not well understood. By understanding each ecosystem’s unique pressures from humans, other organisms and natural climate change, perhaps we can make ecosystems more resilient and prevent the alleged "crises".

The International Union for the Conservation of Nature (IUCN), the foremost scientific organization evaluating threats to species and ecosystems, has created the “Red List of Ecosystems” that provides assessments that characterize threats to individual ecosystems.  To date, only one ecosystem has collapsed, central Asia’s Aral Sea. It’s the world’s fourth largest inland water body. Landlocked, its fate is determined by the balance between inflowing water and evaporation. But 2000 years of irrigation has disrupted that balance. Between 1950 and 2007, irrigation nearly quadrupled causing the Aral Sea to largely dry up, eliminating most of its species. The Aral Sea has been sacrificed in order to feed a growing population. However most other ecosystems have a more optimistic future.

 

The first IUCN Endangered ecosystem I’ll examine in a series of articles is Alaska’s giant kelp forests. The fate of kelp forests is largely determined by the interactions between urchins, otters, humans and killer whales.  Hungry kelp-eating urchins can quickly convert a kelp forest into an urchin barren stripped of kelp. However, urchins are regulated by their primary predator, sea otters. Before Alaska’s fur trade began in the mid 1700s, otter populations and kelp forests flourished. One hundred and fifty years later overhunting exterminated or reduced all otter populations, urchins proliferated and kelp forests declined. Alarmed, a 1911 international treaty forbade hunting otters. To further their recovery, otters were re-introduced to islands where they had been eliminated. With improved human stewardship, otters rebounded to their pre-hunting abundance by 1980. With fewer urchins, kelp forests flourished again. But then killer whales began overhunting otters.

FIg 1.  Extent of Alaska's kelp forests: From the Aleutian Islands in the west to southeastern Alaska.

Each killer whale population has a specialized feeding strategy. Some strictly eat fish while others feed on marine mammals. Some congregate around Alaska’s eastern Aleutian Islands near Unimak pass to prey upon migrating gray whale calves. In the 1980s some killer whales began reducing Steller sea lion and harbor seal populations along Alaska’s Aleutian Islands. An autopsy of one killer whale revealed 14 research tags originally attached to endangered Steller sea lions. As seal and sea lion populations declined, killer whales increased their intake of otters, which allowed urchins to again multiply.  

 

Mostly due to killer whale predation, otter populations declined by 50% to 80% and kelp forests declined by 50% between 1980 and 2000  Those declines prompted the designation of kelp forests as Endangered and possibly Critically Endangered. However more recent surveys evoke hope. Along the coast of Alaska from the peninsula south, otter populations have been steadily increasing at a rate of 12-14% a year and there kelp forests dominate. However depleted otter populations throughout Alaska’s Aleutian Islands still remain at 50% of their 1980 abundance. There, with fewer otters sea urchin barrens became more common.

 

 

 

Although these biological interactions control ecosystem shifts between kelp forests and urchin barrens, climate factors play a role, and in a most positive way. Otters are limited by ice. In places like Glacier Bay where ice has retreated, otter habitat is expanding. Likewise, kelp benefit from less sun-blocking ice while greater concentrations of carbon dioxide enhance photosynthesis and promote more growth. Life is good.

 

published in Battle Born Media What's Natural column

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and member of the CO₂ Coalition

Contact: naturalclimatechange@earthlink.net

Children and the Insect Apocalypse

The American Psychological Association reports young people are suffering from  “a chronic fear of environmental doom”. A recent national survey reported “eco-anxiety” is causing 43 percent of our youth to feel hopeless. Psychologists warn such hopelessness leads to suicide, drug addiction and anti-social behavior. Why such eco-anxiety?  Their hopelessness is driven solely by media narratives. Young people lack the scientific knowledge, lack years of observation, and have yet to acquire the critical thinking skills needed to detect any ecosystem collapse. Its headlines like the Guardian’s, “Plummeting insect numbers 'threaten collapse of nature”, that induce paranoia that “insects are hurtling down the path to extinction, and threatening a “catastrophic collapse of nature’s ecosystems”.

 

In contrast, most scientists studying insects readily admit science lacks the data to make such apocalyptic claims. Science has only identified about one million of an estimated 6 to 10 million insect species worldwide, and only a small percentage of those named species have enough data to evaluate their biology, behavior, or changes in abundance. Nonetheless “the last 3 years have seen a global outbreak of media headlines predicting a global insect apocalypse” and scientists are concerned that such “confusing and inaccurate science” will negatively affect support for insect conservation”. Many have published critiques exposing “the insect apocalypse myth.” 

 

Worse, apocalyptic myths are damaging our children’s mental health. Competing for readership with supermarket tabloids, the New York Times announced, “The Insect Apocalypse Is Here”. The Guardian fearmongered, “Insect apocalypse’ poses risk to all life on Earth”. And despite her lack of the requisite scientific knowledge, the United Nations invited 16-year old Greta Thunberg to lecture the world that “entire ecosystems are collapsing. We are in the beginning of a mass extinction”. 

 

How do we protect our children from succumbing to bogus  “chicken little science”? We must teach them to be good critical thinkers. My parents always warned, “believe half of what you see and none of what you hear.” The world’s oldest scientific motto advises, “Take no one’s word.” To maintain objectivity, us scientists were advised to entertain “multiple working hypotheses”. Likewise, adults must teach children to question all fearful claims. But due to the politicization of science, many adults refuse to read anything outside their beliefs. Many indiscriminately share catastrophic headlines without any critical analysis. For the sake of our kids’ mental health, many “psychologists warn parents and guardians against being climate change alarmists."

 

The apocalyptic NY Times headlines were prompted by a severely flawed German study claiming 75% of flying insects declined in 27 years. That study surveyed insects at 69 different locations, but 37 locations were surveyed only once, and 20 locations were surveyed just twice. Such snapshots of abundance at one location in just one or two years can never determine a meaningful  trend. Never! That’s bad science. Yet the media eagerly elevated a flawed study from just one small region of Germany to suggest a global insect Armageddon.

 

The media simultaneously highlighted another single study by Dr Lister in a Puerto Rican forest to implicate a “global climate crisis”. Researchers claimed higher local temperatures devastated insect abundance and collapsed frog and bird populations that feed on insects. However the media ignored longer term research in the same forest that refuted the temperature claim. It reported that after a destructive hurricane new and more edible vegetation began regenerating and enabled an abnormally higher abundance of opportunistic forest insects, frogs and birds. Unfortunately, Lister’s first survey happened in the 1970s when insect populations had spiked. His second survey happened in 2015 after the forest had matured and insect abundance dropped to normal pre-hurricane numbers. Lister had misinterpreted half of a natural population fluctuation as a catastrophic decline driven by climate change.

 

Giving less attention to optimistic studies is not unusual. Where were media headlines that moths more than doubled in Great Britain over the past 50 years? Why no media fanfare for the 2020 peer-reviewed study that found no change in US insect abundance since 1980?  That study evaluated a network of Long-Term Ecological Research sites established by the National Science Foundation. They found at some sites insect abundance and diversity increased or was unchanged, while at other locations there was a slight decrease. The result? No net change.

 

Although transforming natural habitat into agricultural land greatly benefitted people, it did reduce insect populations. However due to better conservation efforts and efficient farming practices, agricultural lands that once covered 63% of America in 1949 were reduced to 51% by 2007. (Unfortunately, due to biofuel subsidies, agricultural land increased in the Corn Belt.) Additionally, genetically modified plants continue to reduce the indiscriminate spraying of insecticides once practiced in the days of aerial crop dusting.

 

To trust the science, we must examine all the science. We can then honestly tell our children why there’s great hope for our future.

 What’s Natural?

 

Sea level rise and Antarctica

 

California and other American coastal towns are engaged in divisive arguments regards rising sea levels. Although observed sea levels rose less than 8 inches (0.08 inches per year) since 1900, some modelers forecast much bleaker futures. They predict a 2.4-foot rise for every 1°F rise above preindustrial temperatures, then accelerating to nearly 4.5 feet for every 1°F additional increase. Why a dramatic acceleration in sea level? It’s based primarily on dire models, typically presented to coastal planning commissions as ‘best science’, suggesting increasing ice instability and Antarctica ice sheet collapse. “Antarctica has the potential to contribute more than 3.3 feet of sea-level rise by 2100 and more than 49 feet by 2500.”

 

Those models have prompted some citizens to argue we must abandon the coasts via managed retreat. Others argue we should build better sea walls. But how high? Others rightfully ask, “how trustworthy are those models?” Model predictions of a collapsing Antarctica ice sheet are not based on observations.  Models of Antarctica’s catastrophic ice collapse are attempts to explain ancient sea levels such as the 30-foot higher levels 120,000 years ago.

 

There are good reasons to question catastrophic models. For one, away from the coast Antarctica’s surface temperatures average −70 °F. Antarctica’s extremely cold surfaces require global warming to increase many, many times more before surface glaciers could ever melt. For another, although greenhouse theory predicts increasing CO2  concentrations will raise temperatures, greenhouse theory also predicts added CO2  has a cooling effect on Antarctica (Wijngaarden & Happer 2020, Schmithüsen 2015).

 

Up to a point, increasing greenhouse gases  act like a blanket that warms your body by slowing your loss of body heat. Although CO2  absorbs then rapidly releases heat in less than one-thousandth of a second, at colder altitudes it releases that heat more slowly. Because warner bodies release more heat than colder ones, the higher and colder atmosphere absorbs the heat released from warmer surfaces faster than it can release heat to space generating the greenhouse effect. In contrast Antarctica’s surface is much colder and the air miles above is warmer.  Warmer greenhouse gases in the air above release heat back to space faster than can be absorbed from the colder surface. Thus, the atmosphere over Antarctica cools faster than if there were no greenhouse gases.

 

Still, researchers do observe regions of retreating ice. The Antarctic Peninsula was once designated one of the earth’s most rapidly warming regions in the 1980s and 90s, but researchers debated whether melting was caused by global warming or shifting winds. Indeed, warmer winds had been frequently blowing from the north. But the British Antarctic Survey now reports the peninsula has rapidly cooled since the 1990s due to frequent southerly winds from the mainland that can be 50°F to 70°F  colder.  Researchers attribute shifting winds to “extreme natural internal variability”. Similarly periods of accelerating ice melt in Greenland is attributed to natural changes in the winds

 

Strong winds also cause turbulence that sporadically pulls warmer air from above down to the cold surface resulting in occasional “warming” spikes. Furthermore, strong winds moving over mountains can heat the air simply due to increasing pressure as the winds descend (known as foehn storms).  Without adding heat, the increasing air pressure alone can raise regional temperatures in excess of 72°F eventually causing dry, ice-free regions or causing melt ponds that promote ice shelf collapse.

 

Finally, because air temperatures rarely reach the melting point (other than during foehn storms), there is no significant melt of Antarctica’s surface ice. However, some glaciers that extend past the coast terminate below sea level and are indeed losing ice. Antarctic oceans consist of a relatively fresh cold layer of surface water that overlays a thick layer of relatively warm salty water known as the Circumpolar Deep Water (CDW).

 

Antarctic winds can push cold surface water towards the coast and then deeper.  That also pushes the warmer CDW downward and minimizes glacier melting. At other times the winds can  shift and cause surface water to move away from the coast and simultaneously draw up warmer CDW toward the surface. The warm CDW then accelerates the melting of submerged glaciers. Natural oscillations such as El Nino or the Antarctic Oscillation (aka SAM) can shift the winds and induce decades of rapidly retreating glaciers alternating with decades of stable or growing glaciers.

Antarctica’s research community is split 50-50 on whether observed changes are mostly natural or driven by human additions of CO2. But to date there’s no evidence of an ice sheet collapse that would accelerate sea level rise, and many researchers are walking back the extreme claims of Antarctica’s sea level contributions. Coastal planning commissions would be wise to plan on the same average sea level rise witnessed for the past 100 years but be mindful of Antarctica’s shifting winds and shifting scientific claims. 

Contact: naturalclimatechange@earthlink.net

Cold Weather Kills Most Birds

Dead Birds Falling

On October 8th a resident of Pacifica California reported that 2 birds fell dead from the sky onto his deck. That would startle anyone and raised grave concerns. People began suggesting possible causes: a mid-air collision, West Nile virus, rat poison, wildfire smoke, and of course the climate crisis. Some pointed out they had found a dead bird in their yard. Others referenced a massive die-off of migrating birds in early September over Colorado and New Mexico suggesting thousands, maybe a million birds had died. The speculated cause of death was wildfire smoke, starvation and a cold snap that dropped temperatures from 90°F to near freezing in a matter of hours. Sky-is-falling fears and fearing a “ bird flockalypse” one person wrote, “if birds are dying, we humans are next”.

 

Good scientists must examine all likely factors. So, I investigated the stories behind most documented bird die-offs.  For the case of a single dead bird found in someone’s yard, that bird may have died from disease, flown into a window, or simply died of old age. Most of our sparrows, warblers and hummingbirds don’t live longer than 13 years. Twenty-five to fifty percent of young birds die in their first year.

 

California asks people who find dead birds to report them to local vector control agencies so the birds can be tested for disease, West Nile Virus in particular. For the year 2020, to date about 5200 dead birds have been reported in California, a fourth of which were tested. Only 320 have had the virus, while most died of unknown causes. (Mass die-off of 10 or more birds are not included in their reports.) Los Angeles county reports the most dead birds, while rural Sierra County reports none. That suggests higher population centers with more eyes find more dead birds.

 

In contrast, the die-off of hundreds and thousands of birds, often during migration requires very different explanations. Good scientists must place such unusual events into a historical context. Was the September 2020 die-off in the southwest so historically rare that we can attribute it to how humans have recently altered our environment? Or, are such die-offs relatively common occurrences. Scientists calculate millions of birds die each year during migration in North America. We just don’t know all the causes, or what percentage of dead birds are actually observed.

 

A 2007 scientific paper reviewed reported bird die-offs across the globe and major die-offs were observed more than once a decade for the past 120 years. Some happen during spring or fall migration, other die-offs happen while on the breeding grounds. Most are associated with cold weather. On New Year’s Eve night in 2011, people reported dead black birds “raining” from the sky around an Arkansas town. People blamed everything from secret military testing and UFOs to bad weather. Investigations later determined 5000+ birds had died from blunt force trauma, which confirmed reports that birds were flying into buildings and towers. Apparently, someone attempted to scare away a roost of a million black birds, which are agricultural pests, with fireworks. Black birds have poor night vision which explains their collisions with houses.

The most common cause of other cases of bird deaths was bad weather - heavy rains, cold or snow. For example, a sudden cold spell across southern Germany, Austria and Hungary caused birds numbed by the cold to fall from the sky. Residents eagerly brought still living birds inside to warm, then loaded 89,000 birds onto planes and trains, sending them south to a warmer Venice, from which birds continued their migration.

 

In March 1904, a small town in Minnesota reported dead birds falling. Investigations determined nearly a million birds, all Lapland Longspurs, died during a heavy rainstorm. Over 750,000 birds were counted on just 2 small lakes that were still covered with winter ice. Autopsies determined most birds died from blunt force trauma as birds crashed into the ice or buildings.

Migratory deaths of thousands of birds this September in southwest USA likewise, appear to be driven by a cold snap. USGS experts have indeed told me that the best explanation is still a sudden cold snap that dropped temperatures from the 90s to near 30 F, killing birds already stressed by the rigors of migration. My analysis of archived EPA air quality doesn’t suggest smoke particulates coincided with that die-off, but officials have not yet ruled out wildfire smoke. Corpses are still being autopsied and whether or not there is lung damage could implicate wildfire smoke. 

I suspect the most likely cause of the 2 birds falling dead from the sky in Pacifica was due to exhaustion from flying out over the ocean and trying to return to land. I have been on pelagic bird trips miles from shore where exhausted land birds flop down on our boat. Several studies have been performed on the Farallon Islands which are 26 miles offshore due west of Pacifica. Several studies note weather conditions, such as offshore winds that we naturally experience this time of year (ie Diablo Winds that also spread human ignited fires), cause birds to veer off course and fly out to sea. They can be further confused by the offshore fog bank. Many of the birds having arrived on the Farallons are later observed to be headed back to shore, suggesting they are guided to our coast if they can see land when not obscured by fog. Furthermore most of the Farallon birds are young birds born that summer and are typically less efficient at finding food and more likely to become emaciated after an extended overseas flight. 

Of course as for all tragedies, media like the Guardian always blame the “climate crisis”, and downplay cold weather.  They push flockalyptic fears even though there is no support to suggest the sky-is-falling or ecosystems are collapsing. Birds have indeed suffered from loss of habitat, overhunting and window crashes. Fortunately, people are working to change that. I removed my bird feeder because it attracted birds that flew into my windows. But it is natural weather events that have caused most major die-offs. Yet still birds have risked bad weather events for thousands of years in order to enjoy the benefits of migration.

 

from What’s natural? column

Published in Battle Born Media October 28, 2020 

 

Greenland and the 1950s Climate Consensus

Glaciers around the world reached their greatest size in four thousand years by 1850. Then abruptly the world began to warm. Arctic sea ice lost 40% of its thickness by 1940. Around the Arctic island of Spitsbergen melting sea ice allowed shipping season to lengthen from 3 months to 7 by 1940, meanwhile 400 additional square miles of sea ice was melting along the Russian coasts. By 1950, 96% of Europe’s glaciers were retreating and small glaciers had simply disappeared. In the tropics, Africa’s Kilimanjaro’s iconic glaciers were also shrinking alarmingly.

 

In the far north, pine forests couldn’t reproduce between 1850 and 1900 due to the cold. But with warming, all age classes of seedlings proliferated. Tree-line rose by about 70 feet in a few decades. Plants were flowering earlier, and seeds and berries ripened earlier. Atlantic cod moved northward creating a new Greenland fishery and several southern bird species moved into Iceland.

 

 

This warmth was an extraordinary climate reversal and scientists sought to understand that change. By the 1950s a foremost glacier expert, H.W. Ahlmann, stated the growing consensus the dramatic warming was due to “an increased transfer of heat through the atmosphere by a strengthening of the winds carrying heat from southern parts to the Arctic."  Today’s top climate scientists are observing similar natural climate change that pushes warm winds and warm ocean currents northward, melting the Arctic once again. 

 

To be fair, In the 1940s the British engineer G.S. Callendar also suggested CO2-global warming was melting glaciers. But he was a lone voice and peer-reviewers had refused to publish his paper attributing CO2-global warming for Kilimanjaro’s melting glaciers.

 

Today there is growing scientific support for the theories that changing winds cause decades of warming or cooling in the Arctic. One measure of naturally shifting winds is called the North Atlantic Oscillation (NAO) index. The NAO alternates between a positive phase in which westerly winds increase, bringing warmer winters to western Europe. Switching to its negative phase, the westerly winds decline causing western Europe to cool, but that phase also causes warmer winds to blow from south to north more frequently.  Scientists admit that as much as 100% of observed climate change could be due to that natural variability.

 

As political battles over who controls energy policies intensified, interest in fossil fuels and CO2-global warming theory was revived. Scientists promoting CO2-global warming exhumed Callendar’s private papers and elevated his status to a founding hero of global warming theory. A few scientists believed that rising CO2 could affect the winds and the phase of the NAO. Because the  positive NAO had produced strong westerly winds that warmed much of Europe and Asia, they predicted the current positive NAO would continue and further intensify global warming.

 

But that hypothesis failed quickly. The NAO reversed to its negative phase as the 21st century began. That caused westerly winds to weaken. That produced more persistent blocking high pressure systems and a wavier jet stream as seen in the diagram.  Blocking weather systems are slower moving than normal storms and force the prevailing winds and other storms to move around them. This was outlined, again, in the 1950s by climate scientists who pioneered our present understanding of blocking systems. Weather satellites now confirm those weather effects. They also showed when early 20th century blocking systems forced warm air from the south to pass over Greenland, surface temperatures rose 10° to 12°C above normal. 

 

 

 

In the diagram orange colors are warmer and blue colors are cooler. Blocking systems in the Pacific push warmer air (orange) into Alaska and draw cold air into the southern USA. Thus, Alaskan temperatures are sometimes higher than northern Florida. Likewise, blocking in the Atlantic pushed warm air over Greenland causing extreme melting but brought a cold snap to Europe. Americans became aware of the power of a negative NAO and blocking when a weak hurricane was prevented from normally moving out to sea. Instead it was diverted into New Jersey, transforming into the devastating Superstorm Sandy. In 2019, a warm air mass from the baking Sahara Desert moved northward. Crossing Europe, the Saharan air brought record high temperatures. Continuing northward, that warm air then caused Greenland’s 7th greatest period of melting since 1978.

 

The theory that the NAO and shifting winds create the conditions that drive Greenland’s warming and cooling is supported by all observable evidence. Greenland lost ice in the 1930s then gained ice in the 1970s and 80s. Although Greenland’s ice has been melting extensively in recent decades, that melt rate is now slowing and the shifting NAO suggests the ice will rebound. In contrast, the competing CO2-global warming theory suggests as CO2 continues to rise, Greenland’s ice will increasingly melt and dramatically raise sea levels. That theory has prompted calls to abandon our coastlines and invest in managed retreat. But before you panic, know your climate history and listen to the science. All the science!

Published in Battle Born Media newspapers 10-13-2020 

Contact: naturalclimatechange@earthlink.net

 

  

Restoring Scientific Debate

 

 The political genius of Abraham Lincoln’s efforts to unify the country during America’s most divisive time has been attributed to assembling a “team of rivals”. Likewise, scientific research is published so rivals and supporters of a hypothesis can independently and critically examine it. The great benefits of a team of rivals is also the basis for convening red team/blue team debates.

 

In 2017, Dr Steve Koonin, a physicist who served as Obama’s Undersecretary for Science in the US Department of Energy, urged convening red-team blue-team debates for climate science in his article A ‘Red Team’ Exercise Would Strengthen Climate Science.  “The national-security community pioneered the “Red Team” methodology to test assumptions and analyses, identify risks, and reduce—or at least understand—uncertainties. The process is now considered a best practice in high-consequence situations”.

 

Unfortunately, the public climate science debate has been framed as “deniers” versus “alarmists”, or “honest saintly scientists” versus “corrupt perpetrators of a hoax”.  The media pushes exaggerated claims of a crisis while some scientists misleadingly shield their hypotheses claiming the “science is settled”.  But science is a process and never settled. However, all sides do agree carbon dioxide is a greenhouse gas and concentrations have increased. All sides agree the climate is changing. That science is indeed settled. But complex climate dynamics are not driven solely by CO2 and many unsettled questions remain.  Scientists still debate whether climate has a higher or lower sensitivity to rising CO2. Answering that question depends on the unsettled science regards competing contributions from natural variability and landscape changes. And because rising CO2 and warmth benefits photosynthesizing plants, scientists debate the beneficial contributions of rising CO2.

 

Climate models could not replicate recent warming when only natural climate change was considered. But models could simulate recent warming since 1970s after adding CO2. That was the only evidence that supported the notion that increasing CO2 caused observed warming. However, there’s a flaw in such reasoning. Models limited to just natural climate dynamics failed to explain recent changes simply because our understanding is still incomplete. For example the Pacific Decadal Oscillation, a major driver of natural climate change was only recently characterized in 1997, but has been shown to account for 100 years of changing climate along the coasts of the north eastern Pacific.

 

Abundant peer-reviewed research shows changes in landscapes dampen or amplify warming. Regional modeling studies determined landscape changes could generate extreme temperatures similar to a doubling of CO2 concentrations.  Urban heat islands and deforestation undeniably amplify temperatures and alter regional climates. Such landscape effects best explain why 38% of US weather stations display cooling trends, and why the best tree ring science suggests natural habitat temperatures haven’t exceeded the warm spike of the 1930s and 40s. The misleading downplaying of such important landscape changes in climate models led to the resignation of climate scientists from the Intergovernmental Panel on Climate Change.

 

Unable to model the 1940s warming spike, climate scientist Tom Wigley, emailed colleagues suggesting “It would be good to remove at least part of the 1940s blip”. Subsequently the “40s warm blip” was removed from many data sets arousing widespread distrust. Public red team/blue team debates examining such data adjustments could clarify the reasons for those adjustments.

 

 

 

In 2016, climate scientist Michael Mann co-authored a paper titled Science and the Public: Debate, Denial, and Skepticism correctly arguing, “science is debate” and “public debate and skepticism are essential to a functioning democracy.” But schizophrenically, Mann opposed red team/blue team debates as a “disinformation campaign aimed at confusing the public and policymakers”.

 

Mistrust for Michael Mann and his colleagues in the “high CO2 sensitivity and catastrophic climate change” school of thought increased as they campaigned to denigrate skeptics as “deniers” or “contrarians” who can’t publish in peer-reviewed journals. Simultaneously however, Mann worked to suppress skeptical publications. Two Harvard astrophysicists, Dr Soon and Dr Baliunas, published a peer-reviewed paper synthesizing 240 scientific papers and suggested recent temperatures are similar to the Medieval Warm Period. With his hypotheses threatened by such research,  Mann railed “the peer-review process at Climate Research [the journal] has been hijacked by a few skeptics.”  

 

Trying to suppress skeptical science publications he emailed colleagues, “I think we have to stop considering Climate Research as a legitimate peer-reviewed journal. Perhaps we should encourage our colleagues in the climate research community to no longer submit to, or cite papers in, this journal.” They then discussed how to rid any editors tolerant of skeptical arguments to prevent further skeptical publications.  

 

Undeniably, some climate scientists have been covertly marginalizing honest skeptical scientists. Trust the science, but only when it agrees with their hypotheses. They have argued don’t debate skeptics because “debate actually gives alternative views credibility”. But the scientific process demands thoroughly examining alternative explanations. It is the rigorous vetting by rivals that makes science trustworthy but such biased gatekeeping erodes public trust. Hopefully developing transparent public red team/blue team debates can restore our trust and more accurately guide public policies.

 

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

 

Contact: naturalclimatechange@earthlink.net

 

Published in the Pacifica Tribune, What's Natural column,  September 30, 2020