Gavin Newsom’s Exceedingly Ignorant Climate Claim

 

Scientific evidence reveals there has been no climate effect regards California’s wildfires! None! The data below proves it beyond all doubt. There is no denying that warmer temperatures can cause drier fuels and promote larger fires. But that fact is being misapplied to all wildfires. About 70% of California’s 2020 burnt areas have been in grasslands and dead grass is so dry by the end of California’s annual summer drought that dead grasses are totally insensitive to any added warmth from climate change. Dead grasses only require a few hours of warm dry conditions to become highly flammable. It’s fire weather not climate change that is critical. Furthermore, the century trends in local temperatures where California’s biggest fires have occurred reveal no connection to climate change. In most cases the local maximum temperatures have been cooler now than during the 1930s. Those cooler temperatures should reduce the fire danger. Newsom is either ignoring or distorting the scientific evidence, is totally stupid, or is a dishonest demagogue.

 

Maximum temperatures are typically used by fire indexes to issue red flag warnings because it is the heat of midday that has the greatest drying effect. Minimum temperatures are often low enough to drop below the dewpoint at which time fuel moisture increases. So averaging minimum and maximum temperatures is inappropriate. In addition, referencing a higher global average temperature is meaningless. Only local maximum temperatures determine the dryness of surface fuels during every fire. As in Park and Abatzoglou 2019, the months of March through October are averaged to determine maximum temperatures during California’s dry season.

 

Here are some relevant facts (from the Western Regional Climate Center).  Trust the scientific evidence

 

 

1) The August 2013 Rim Fire centered around Yosemite National Park, was California’s 5th largest fire.

 

 

2) The November 2018 Camp Fire was California’s deadliest fire destroying the town of Paradise. It was also its 16th largest fire.

 

 

3) The 2018 Mendocino Complex Fire was California’s largest fire (since 1932 excluding 2020) .

 

 

4) In the October 2017 wine country fires, the Tubbs Fire was the 4th deadliest. It only burned 37,000 acres but high winds drove embers into the dwellings of the heavily populated outskirts of Santa Rosa.

 

 

 

 

Governor Newsom ignores the data to disgustingly hijack the tragedy of California’s fires and push his climate change agenda. But he is not alone. There are climate scientists pushing catastrophes by ignoring the local maximum temperature trends. Bad analyses promote bad policies and obscure what needs to be done regards fuel management and creating defensible spaces in fire prone California. Newsom must focus on fuel management and fire suppression. As fire ecologist Thomas Swetnam echoed the experts’ growing consensus against fire suppression wrote, “The paradox of fire management in conifer forests is that, if in the short term we are effective at reducing fire occurrence below a certain level, then sooner or later catastrophically destructive wildfires will occur. Even the most efficient and technologically advanced firefighting efforts can only forestall this inevitable result.”

 

 

Further information about California’s wildfires are

Why Worse Wildfires - part 1

 

Why Worse Wildfires?  Part 2

 

Minimizing California Wildfires

 

Wildfires: Separating Demagoguery from the Science

 

 How Bad Science & Horrific Journalism Misrepresent Wildfires and Climate

 

 

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 

 

What’s Natural

 

Minimizing California Wildfires

 

How do we focus our resources to minimize the devastation caused by California’s wildfires? First, we can reduce ignitions. California’s deadliest fire, the Camp Fire and California’s 2^nd largest fire, the Thomas Fire were ignited by faulty powerlines during high wind events. California’s sprawling power grid has rapidly expanded since 1970 to accommodate the influx of 20 million people. Accordingly, powerline-ignited fires increased area burnt by five times relative to the previous 20 years.

 

California’s largest fire (Mendocino Complex), its 3^rd largest (Cedar Fire), 5th largest (Rim Fire), and 7th largest (Carr Fire), were all ignited by accidents or carelessness. Uncontrollably, more people cause more accidents, suggesting California’s wisest course of action requires creating more defensible space.

 

In contrast, the August 2020 fires, which will likely rank in the top 10 of burned area of California, were all naturally started by an onslaught of dry lighting. This prompted Governor Gavin Newsome to blindly blame climate change, implying we need to focus resources on minimizing CO₂ concentrations to improve fire safety. But the science doesn’t support Newsome’s narrative.

 

Some researchers blame global warming, regardless of increased ignitions. They argue warmer temperatures dry out the vegetation more quickly, so more of California burns. Indeed, warmer drier weather creates a higher fire danger. But fire experts only found that correlation within forests. They found no such correlation along California’s central coast where the August 2020 lightning fires have been raging. The experts stated, as California’s summer drought proceeds, “grasslands and coastal chaparral are usually already hot, so they are not as sensitive to the extra heat from global warming.” And it was grasslands and chaparral the lightning ignited.

 

More resources must be focused on managing invasive grasses, or California will continue to experience larger fast-moving fires, regardless of climate change. Grasslands and chaparral provide an abundance of insensitive “fine fuels” that dry out within a day. Grasses grow quickly and unless managed provide more fuel for hotter fires. Fine fuels act as kindling that can ignite larger logs in cooler habitat. Invasive grasses increased ground fuels in desert regions, promoting more frequent fires that were once uncommon because the deserts’ lacked enough fuel. Along California’s coast invasive grasses have likewise usurped areas of  shrublands. Furthermore, grasses provide a corridor for grassland fires to spread into chaparral and forests. The greater the abundance of grasses the faster and further fires spread.

 

 

Finally does dry lightning increase with climate change? Dry lightning usually occurs when the lower 1000 feet of the atmosphere is warm and dry and is overlain by unstable air at mid-elevation between 1000 and 5000 feet. The greatest occurrence of dry lightning happens in New Mexico and Arizona. Moisture pumped northward from the Gulf of California and Mexico causes mid-elevation air to become unstable and turbulent, generating lightning and precipitation. However, while the lightning reaches the ground the precipitation doesn’t, evaporating in the dry desert air. In the Sierra Nevada, dry lightning causes 69% of the lightning fires, peaking in August. But lightning is uncommon along California’s coast because the ocean provides a cool marine layer that inhibits convective turbulence.

 

However, in August 2020 a high-pressure system centered over the Southwest pushed the marine layer offshore. Simultaneously the high-pressure system carried air northward along the California coast, while entraining a seasonally unusual layer of moisture from a decaying tropical storm and setting the stage for dry lightning.  Such coastal events are so uncommon and erratic weather models have great difficulty simulating and predicting them. Thus, it’s impossible to attribute coastal dry lightning to climate change and resources would be best spent on fuel management.

 

 

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 

  

The Oceans Won’t Suffocate!

harbor fish kill

 

What’s Natural?

Published in Pacifica Tribune August 12, 2020

 

The Oceans Won’t Suffocate!

 

There is a saying in the journalistic community: ‘Bad news is  good news! Good news is no news!” Bad news sells papers. It’s internet click-bait. So, we’re bombarded with a disproportionate amount of fearful news. Unfortunately, scientific journals also succumb to the same profit incentives. Indeed, pictures of thousands of suffocated fish floating belly-up is very disturbing. However, media outlets amplified our fears with headlines like “A Horrifying New Study Found that the Ocean is on its Way to Suffocating by 2030”. Only slightly less sensational, the Smithsonian promoted one of their researchers articles as “Why Our Oceans Are Starting to Suffocate”, while the NY Times suggests “World’s Oceans Are Losing Oxygen Rapidly”.

 

 

Changing oxygen concentrations is determined by the balance between oxygen addition versus consumption. Oxygen is only added at the surface, via diffusion from the atmosphere or via photosynthesis.  The chemical wizardry of photosynthesis uses sunlight to break apart water molecules and generate new oxygen while creating organic matter. Although this organic matter forms the base of the ocean food web, its digestion and decay consumes oxygen.  Paradoxically, wherever the surface ocean food web is most bountiful, the waters below lose the most oxygen.

 

To analyze natural- versus human-caused losses of oxygen, we must consider how the supply of nutrients for photosynthesis differs between the open ocean and coastal oceans. In the open ocean digestion and decay of sinking organic matter consumes oxygen and releases nutrients  to be recycled. Those nutrients must then be upwelled from dark subsurface waters back into sunlit waters.

 

In contrast, the supply of nutrients to coastal waters is greatly affected by river discharge. In the early 20^th century, chemists learned to convert atmospheric nitrogen into biologically useful nitrogen fertilizer. Starting around 1950, agriculture doubled, then tripled their use of synthesized fertilizer. While greatly benefitting  human food supplies, increased fertilizer use coincided with decreasing coastal oxygen.

 

Coastal populations and sewage also increased. Sewage and fertilizer run-off combined to stimulate coastal algal blooms that produced excessive organic matter which sank to shallow (< 100 meters) ocean floors, where its decay consumed bottom water oxygen. Along the Texas-Louisiana coast, the term “dead zone” was first used by shrimp fishermen to describe the resulting seasonal disappearance of shrimp and other invertebrates from the ocean floor.

 

The good news is people are now preventing and restoring dead zones. Sewage treatment plants extract solids and recycle it as fertilizer and farmers are engaging in more judicious use of fertilizers.

 

In contrast, the open ocean contains natural, permanent “oxygen minimum zones” (OMZ) at depths between about 200 and 800 meters. OMZs are maintained by the constant supply of sinking organic matter but OMZ size fluctuates. While some researchers blame global warming for any OMZ expansion, the evidence points to natural climate change that affects upwelling and ocean circulation.  

 

 

 

For example, in the eastern Pacific natural El Nino events reduce photosynthesis which decreases the supply of organic matter. Less decay causes OMZ’s oxygen to increase. Conversely during a La Nina, enhanced upwelling stimulates photosynthesis and organic matter production. Increased decay then expands the area of depleted oxygen.  Similarly, during the Little Ice Age, upwelling and photosynthesis off the coast of Peru was reduced and oxygen increased. Since the mid 1800s, upwelling has increased and Peru boasts one of the world’s largest fisheries. However, the increase in decaying organic matter has steadily consumed oxygen, and Peru’s expanding OMZ is also the world’s largest.

 

 

 

Open ocean OMZs are ancient, allowing a highly diverse ecosystem to evolve and adapt to the low oxygen environment.  A great diversity of jellyfish, squid, krill, sea snails, and other invertebrates inhabit the OMZs. Sperm whales (i.e. Moby Dick) evolved to hunt abundant squid at those depths. Researchers estimate that 95% of the global ocean fish mass inhabits OMZ depths. Most of these abundant organisms migrate nightly to feed in surface waters, then during the day migrate back to depths where they digest their food, further reducing the oxygen.

 

Finally, the claim that global warming is causing OMZ’s to expand and oceans to suffocate is largely based on simplistic physics that less oxygen will dissolve from the atmosphere into warmer waters. Although that is true, the scientific consensus still finds most of the oceans’ surface is supersaturated with oxygen. That’s because warmer waters also stimulate photosynthesis and produce more oxygen. Some researchers found photosynthesis could contribute 2.4 times more new oxygen than is absorbed from the atmosphere.  Accordingly, scientists estimate  50% - 80% of the earth’s oxygen is produced by ocean plankton. Based on natural ocean dynamics and its historical changes, we can breathe easy. Global warming is not suffocating our oceans!

 

 

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism.

 

Contact: naturalclimatechange@earthlink.net

 

 

 

  

Turtle-paced Recoveries

 

Green Turtle

Published in the Pacifica Tribune July 28, 2020

What’s Natural?

Turtle-paced Recoveries

Many humans are working hard to prevent any further extinctions of our plants and animals and with growing success. Pelicans are increasing and no longer endangered. Humpback whales are increasing at a rate of 12% per year. Mountain lions and bald eagles are increasingly abundant. In 1982 the California Condor had dwindled to just 25 individuals. A captive breeding program began and today there are about 325 individuals and condors are expanding back into their historical range. This summer, condors were seen in Sequoia National Park for the first time in 50 years.

Over-harvesting, loss of habitat and introduced species are the main causes of endangered species. The green sea turtle, prized for its meat and eggs, was seriously over-harvested and endangered. Their numbers continued to fall as beach resorts disturbed their traditional nesting sites. Many others were killed as by-catch in fishing nets. But several new studies report seeing an uptick in green turtles around the world. One of the world’s largest nesting rookeries, Raine Island off northeastern Australia, just experienced the most abundant nesting season as ~64,000 breeding turtles have arrived. What is the reason for these higher numbers?

Green Turtles nesting on Raine Island

There is a degree of certainty conservation efforts have been effective. Many countries have banned harvesting eggs or turtles for meat, although poaching remains a threat. Fishermen have developed Turtle Exclusion Devices that prevent turtles from being captured in their nets.  Still, it is extremely difficult to reliably measure the success of sea turtle conservation.

Green turtles feed primarily on low-calorie sea grass. The good news is sea grass thrives under higher concentrations of CO2. However, that diet limits turtle growth and it takes 10 to 25 years before turtles reach sexual maturity. So, even if today’s conservation efforts are successful, we won’t see today’s benefits for at least another 10 years when hatchlings return to their birth sites as breeding females.

Despite increasing populations, some researchers have been needlessly gripped by a global warming fear. Like several reptiles, a turtle’s gender is determined by the temperature of the incubating egg. Eggs at the top of a nest are warmed the most and become females. Just a 4° F cooler temperature will create males. Furthermore, sex ratio of turtles from nests along the northern Great Barrier Reef have averaged 88% to 99% females, while populations from the cooler southern Great Barrier Reef average about 66% female. So the fear is, if the earth warms only females will be born and the population goes extinct. But gender determination by temperature is not a fragile system.

Turtles evolved during the age of dinosaurs over 250 million years ago when global temperatures were much warmer. Palm trees grew along the coast of Antarctica and crocodiles roamed the Greenland coast 55 million years ago. Since then temperatures cooled and ice ages ensued, yet turtles did not become all males. Nonetheless, cooler temperatures are an immediate threat. Along the USA’s east coast, many turtles travel northward as waters warm with summer heat. But if they do not return south in time, autumn’s cooler temperatures paralyze them, stranding hundreds on east coast beaches. (Again, humans help out by flying rescued turtles back to warmer waters).

During the Holocene Optimum 6000 to 9000 years ago, temperatures were bout 1.8° F warmer than today without causing extinctions. In 1957, the Whittaker brothers petitioned Australia’s Queensland government to commercially harvest female turtles on Raine Island. They cited surveys that found over 99% of the turtles were female. That high percentage of females has remained despite 60 years of climate change and Raine island remains one of the world’s most abundant nesting sites.

There are good scientific reasons why 99% females are beneficial. Only female turtles go on shore to nest. Males remain offshore mating with every available female. One male fertilizes several females. On shore females suffer more mortality. They come ashore in the evening to avoid the deadly effects of the sun. If they do not return to the sea by early morning, they often die of heat exhaustion. Some females get disoriented or fall into pits, becoming stranded in the midday sun. Some flip over on uneven ground and cannot right themselves. On crowded beaches, some females become so exhausted from jostling with other females they return to the ocean without laying their eggs.

Nesting turtles can flip and die

Females may lay 2 to 5 clutches, each with 100 eggs, during the breeding season. This greatly depletes their energy. So, females only breed every 3 to 5 years, allowing time to replenish their body condition. Finally, it is estimated only 1 of every 1000 successfully hatched turtle ever survives to maturity. So the high percentage of females is certainly not a sign of impending global warming doom. It is an ancient breeding system that maximizes egg production and ensures the species’ survival.

Hatchling Ridley Turtles

Acid Oceans? & Oyster Shells

from What’s Natural?

Published July 14, 2020 in the Pacifica Tribune

(I also wrote a white paper for the CO₂  Coalition, providing more details and references to peer reviewed science regards how marine life counteracts ocean acidification. That paper can be downloaded here )

Search the internet for “acid oceans” and you’ll find millions of articles suggesting the oceans are becoming more corrosive due the burning of fossil fuels, and “acid oceans” are threatening marine life. Although climate modelers constantly claim the oceans’ surface pH has dropped since the 1800s, that change was never measured, as the concept of pH was not created until the early 1900s by beer-makers.

In 2003 Stanford’s Dr. Ken Caldeira coined the term “ocean acidification” to generate public concern about increasing CO₂  . As New Yorker journalist Elizabeth Kolbert reported, “Caldeira told me that he had chosen the term ‘ocean acidification’ quite deliberately for its shock value. Seawater is naturally alkaline, with a pH ranging from 7.8 to 8.5—a pH of 7 is neutral—which means that, for now, at least, the oceans are still a long way from actually turning acidic.” Nonetheless Caldeira’s term “ocean acidification” evoked such undue fears and misunderstandings, we are constantly bombarded with catastrophic media hype and misdiagnosed causes of natural change.

For example, for nearly a decade the media has hyped the 2006-2008 die-off of larval oysters in hatcheries along Washington and Oregon. They called it a crisis caused by rising atmospheric CO₂  and the only solution was to stop burning fossil fuels. But it was an understanding of natural pH changes that provided the correct solutions. Subsurface waters at a few hundred meters depth naturally contain greater concentrations CO₂  and nutrients and a lower pH than surface waters. Changes in the winds and currents periodically bring those waters to the surface in a process called upwelling. Upwelling promotes a burst of life but also lowers the surface water pH.  Not fully aware of all the CO₂  dynamics, the hatcheries had made 3 mistakes.

upewlling

First, they failed to recognize not all oyster species are well adapted to the low pH of upwelled water. The larvae of native Olympia oysters naturally survive intense upwelling events along the Washington coast because that species “broods” its larvae. The larvae initiate their shells protected inside their parents’ shells where pH is more controlled. However, the Olympia oysters were over-harvested into near extinction in the 1800’s.

So, fishermen imported the Japanese oyster, which is now the mainstay of the Washington and Oregon fisheries. Japanese oysters did not evolve within an intense upwelling environment similar to Washington’s coast. Each Japanese oyster simply releases over 50 million eggs into the water expecting their larvae to survive any mild changes in pH during initial shell formation. Hatcheries didn’t realize the Japanese oyster’s larvae had a 6-hour window during which the larvae’s initial shell development and survival was vulnerable to low pH.

Second, because cooler waters inhibit premature spawning, hatcheries pumped cool water from the estuary in the early morning. As measured in coral reefs, photosynthesis raises pH during the day, but nighttime respiration drops pH significantly. By pumping early morning water into their tanks, they imported estuary water at its lowest daily pH. Finally, they failed to recognize natural upwelling events transport deeper waters with naturally low pH into the estuary, further lowering the pH of water pumped into their tanks.

Now, hatcheries simply pump water from the estuary later in the day after photosynthesis has raised pH. Scientists also developed a metering device that detects intrusions of low pH waters, so hatcheries avoid pumping water during upwelling events. As for most shellfish, once the shell is initiated, a protective layer prevents any shell corrosion from low pH conditions. Problem easily solved and crisis averted!

The simplistic idea that burning fossil fuels is causing the surface ocean to become more acidic is based on the fact that when CO₂  interacts with water a series of chemical changes results in the production of more hydrogen ions which lowers pH. Unfortunately, all catastrophic analyses stop there. But living organisms then reverse those reactions. Whether CO₂  enters the surface waters via the atmosphere or from upwelling, it is quickly utilized by photosynthesizing plankton which counteracts any “acidification”. A percentage of the organic matter created in the sunlit waters sinks or is actively transported to depths, further counteracting any surface “acidification’. Some organic matter sinks so rapidly, CO₂  is trapped at depths for hundreds and thousands of years. The dynamics that carry carbon to ocean depths largely explains why the oceans hold 50 times more CO₂  than the atmosphere.

To maintain marine food webs, it is essential that upwelling bring sunken nutrients back into the sunlight to enable photosynthesis. Upwelling also brings stored CO₂  and low pH water to the surface. Wherever upwelling recycles nutrients and lowers surface pH, the greatest abundance and diversity of marine life is generated.

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism.

Contact: naturalclimatechange@earthlink.net

Hopefulness Despite 2.9 Billion Lost Birds

What’s Natural

Hopefulness Despite 2.9 Billion Lost Birds

In 2019 bird researchers published Rosenberg et al “Decline of the North American Avifauna”, reporting a decline in 57% of the bird species. They estimated a net loss of nearly 2.9 billion birds since 1970, and urged us to remedy the threats, claiming all were “exacerbated by climate change”, and we must stave off the “potential collapse of the continental avifauna.” Months before publication the researchers had organized an extensive media campaign. Typical doomsday media like the  New York Times piled on with “Birds Are Vanishing From North America” and Scientific American wrote, “Silent Skies: Billions of North American Birds Have Vanished.”

As I have now been sheltering in place, I finally had ample time to thoroughly peruse Rosenberg’s study. I had a very personal interest in it, having professionally studied bird populations for over 20 years and had worked to restore their habitat. I also had conducted 20 years of surveys which were part of the study’s database.  Carefully looking at their data, a far more optimistic perspective is needed. So here I join a chorus of other ecologists, as reported in Slate, that “There Is No Impending Bird Apocalypse”. As one ecologist wrote, it’s “not what’s really happening. I think it hurts the credibility of scientists.”

First consider since 1970 many species previously considered endangered such as pelicans, bald eagle, peregrine falcon, trumpeter swan, and whooping crane have been increasing due to enlightened management. Despite being hunted, ducks and geese increased by 54%. Secondly, just 12 of the 303 declining species account for the loss of 1.4 billion birds, and counterintuitively their decline is not worrisome.

Three introduced species - house sparrows, starlings and pigeons - account for nearly one half billion lost birds. These birds were pre-adapted to human habitat and are considered pests that carry disease and tarnish buildings and cars with their droppings. Across America, companies like Bird-B-Gone are hired to remove these foreign bird pests. Furthermore, starlings compete with native birds like bluebirds and flickers for nesting cavities, contributing to native bird declines. The removal of starlings is not an omen of an “avifauna collapse”, but good news for native birds.

Flicker

When European colonists cleared forests to create pastures and farmland or provide wood for heating, open-habitat species “unnaturally” increased. Previously confined to the Great Plains, brown‑headed cowbirds quickly invaded the newly opened habitat. Unfortunately, cowbirds parasitize other species by laying its eggs in their nests. A cowbird hatchling then pushes out all other nestlings, killing the parasitized species’ next generation. The loss of 40 million cowbirds only benefits our “continental avifauna”.

Several bird species had evolved to colonize forest openings naturally produced by fire, or floods or high winds. Those species “unnaturally” boomed when 50% to 80% of northeastern United States became de-forested by 1900. Still, eastern trees will reclaim a forest opening within 20 years, so open habitat species require a constant supply of forest openings. However as marginal farms and pastures were abandoned, fires were suppressed and logging reduced, forests increasingly reclaimed those openings. With a 50% decline in forest openings, their bird species also declined; now approaching pre-colonial numbers. Accordingly, birds of the expanding forest interior like woodpeckers are now increasing.

White-throated Sparrows and Dark-eyed Juncos quickly colonize forest openings but then disappear within a few years as the forest recovers. Those 2 species alone accounted for the loss of another quarter of a billion birds; not because of an ecosystem collapse, but because forests were reclaiming human altered habitat. Nonetheless those species are still 400 million strong, and juncos remain abundant in the open habitat maintained by suburban back yards. If environmentalists want to reclaim the abundance of their boom years, they must manage forest openings with logging or prescribed burns.

Insect outbreaks also create forest openings. For hundreds of years forests across Canada and northeastern US have been decimated every few decades by spruce bud worm eruptions. So, forest managers now spray to limit further outbreaks. Today there are an estimated 111 million living Tennessee Warblers that have specialized to feed on spruce bud worms. But the warbler’s numbers have declined by 80 million because insect outbreaks are more controlled. Still they have never been threatened with extinction. Conservationists must determine what is a reasonable warbler abundance while still protecting forests from devastating insect infestations.

The grassland biome accounted for the greatest declines, about 700 million birds. Indeed, natural grasslands had been greatly reduced by centuries of expanding agriculture and grazing. But in recent times more efficient agriculture has allowed more land to revert to “natural” states.  However fossil fuel fears reversed that trend. In 2005 federal fuel policies began instituting subsidies to encourage biofuel production. As a result, 17 million more acres of grassland have been converted to corn fields for ethanol since 2006.

Although still very abundant, just 3 species account for the loss of 400 million grassland birds: Horned Larks, Savannah Sparrows and Grasshopper Sparrows. Horned Larks alone accounted for 182 million fewer birds due to a loss of very short grass habitats with some bare ground. To increase their numbers, studies show more grazing, mowing or burning will increase their preferred habitat.

Horned Lark

It must be emphasized that the reported cumulative loss of 2.9 billion birds since 1970, does not signify ecosystem collapses. But there are some legitimate concerns such as maintaining wetlands. And there are some serious human-caused problems we need to remedy to increase struggling bird populations. It is estimated that cats kill between 1 to 3 billion birds each year. Up to 1 billion birds each year die by crashing into the illusions created by window reflections. Collisions with cars and trucks likely kill 89 to 350 million birds a year. Instead of fearmongering ecosystem collapse, our avifauna would best be served by addressing those problems.

Questioning Bird Models

Population estimates for most land birds are based on data from the US Geological Surveys Breeding Bird Surveys (BBS). I conducted 2 BBS surveys on the Tahoe National Forest for 20 years. Each survey route consists of 50 stops, each a half‑mile apart. At each stop for a period of just 3 minutes, I would record all observed birds, the overwhelming majority of which are heard but not seen. Many birds can be missed in such a short time, but the BBS designers decided a 3-minute observation time allowed the day’s survey to cover more habitat. Each year on about the same date, the BBS survey was repeated.

Each BBS route surveys perhaps 1% the region’s landscape. To estimate each species’ population for the whole region, the survey’s observations are extrapolated and modeled. However, models rely on several assumptions and adjustments, and those assumptions that can inflate final estimates. For example, in 2004 researchers estimated there were 6,500,000 Rufous Hummingbirds. By 2017, researchers estimated there were now 21,690,000. But that larger population cannot be deemed a conservation success. That tripling of abundance was mostly due to new adjustments.

Because singing males account for most observations, the number of observed birds is doubled to account for an unobserved female that is most likely nearby. Furthermore, it is assumed different species are more readily detected than others. The models assume that each stop will account for all the birds within a 400‑meter radius. Because a crow is readily detected over that distance, no adjustments are made to the number of observed crows. But hummingbirds are not so easily detected. The earlier surveys assumed a hummingbird could only be detected if it was within an 80‑meter radius. So, to standardize the observations to an area with a 400‑meter radius, observations were multiplied by 25. Recent survey models now assume hummingbirds can only be detected within 50 meters, so their observations are now adjusted by multiplying by 64.

Thus, depending on their detection adjustments, one real observation could generate 50 or 128 virtual hummingbirds. That number is further scaled up to account for the time‑of‑day effects and the likely number of birds in the region’s un-surveyed landscapes.  

Setting aside assumptions about the regional homogeneity of birds’ habitat, one very real problem with these adjustments that has yet to be addressed. If one bird is no longer observed at a roadside stop, the model assumes that the other 127 virtual birds also died.

Survey routes are done along roadsides and up to 340 million birds are killed by vehicles each year.  Many sparrows and warblers are ground nesters and will fly low to the ground. Many seed eating birds like finches will congregate along a roadside to ingest the small gravel needed to internally grind their seeds. Every year I watched a small flock of Evening Grosbeaks ingesting gravel from the shoulder of a country road, get picked off one by one by passing cars. Roadside vegetation often differs from off-road vegetation. Roads initially create openings that are suitable for one species but are gradually grown over during the lifetime of a survey to become unsuitable habitat. So, it should never be assumed that the loss of roadside observations represents a decline for the whole region.

The larger the models’ detectability adjustments are for a given species, the greater the probability that any declining trend in roadside observations will exaggerate a species population loss for the region. The greatest population losses were modeled for warblers and sparrows and most warbler and sparrow data are adjusted for detectability by multiplying actual observations 4 to 10-fold. It is worth reporting good news from recent studies in National Parks that used a much greater density of observation points and were not confined to roadsides. Their observation points were also much closer together and thus required fewer assumptions and adjustments. Of the 50 species they observed, all but 3 populations were stable.

Pushing a fake crisis, Rosenberg et al argued that declining numbers within a species that is still still very abundant doesn’t mean they are not threatened with a quick collapse. He highlighted the Passenger Pigeon was once one of the most abundant birds in North America and they quickly went extinct by 1914. That doomsday scenario was often repeated by the media. But comparison to the Passenger Pigeon’s demise is a false equivalency. Passenger Pigeons were hunted for food when people were suffering from much greater food insecurity.

Rosenberg et al summarized their study with one sentence: “Cumulative loss of nearly three billion birds since 1970, across most North American biomes, signals a pervasive and ongoing avifaunal crisis.” But it signals no such thing. Wise management will continue. With better accounting of the natural causes of each species declines, plus more accurate modeling, it will be seen that Rosenberg’s “crisis” was just another misleading apocalyptic story that further erodes public trust in us honest environmental scientists.

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism.

Contact: naturalclimatechange@earthlink.net