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

The Escalator to Extinction Myth

In Life on the Mississippi Mark Twain wrote, “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” Unfortunately, conjecture based on limited facts has produced “research” trumpeting catastrophic fears of extinction. The “escalator to extinction” theory argues organisms must migrate to higher elevations where a cooler altitude will offset global warming temperatures. But there is scant evidence that is happening.

  

For example, in 1985 researchers spent 33 days surveying the wondrous bird diversity along a narrow ascending 5-mile trail in southern Peru. They recorded an amazing 455 unique species. In 2017 they repeated the survey, but for only 22 days. Still they observed 422 species consisting of 52 additional species never observed in 1985, but they also failed to detect 71 species that had been documented in 1985. Clearly, more extensive surveys are needed to accurately detect all species and determine their abundance. Nonetheless, because 8 ridgetop species (i.e. Crested Quetzal) that were previously observed only at the highest elevations but were not detected in 2017, researchers conjectured the “escalator to extinction” eliminated those 8 species. Additionally, they asserted similar local extinctions must be happening along ridgetops all across the earth’s tropical mountains.

 

Modeled temperatures had risen by 0.8°F between the two surveys, so they concluded those missing 8 species were extirpated by global warming because birds already at the ridgetop could no longer flee upwards to cooler temperatures. For most people, the idea that a 0.8°F rise in ridgetop temperatures could be deadly greatly strains the imagination. Moreover researchers in nearby regions of Manu National Park, found the alleged “extirpated species” thriving at lower elevations where temperatures are 3-5 °F warmer than their ridgetop. Falsely asserting most Peruvian birds are “highly sedentary” and don’t migrate, the scientists argued it was unlikely they missed any birds during their 10 days on the ridgetop due to migration. Thus, the birds must be locally extinct.  Not having the critical eye of a Mark Twain, mass media journalists - BBC, the Atlantic, and Yale Environment 360 - promoted those extinction fears. Regretfully only good investigative journalism has become extinct.

  

It is well documented that about 24% of Peru’s birds are “elevational migrants”. Elevational migrants are typically on the move between different elevations during August and September, the same months of the 1985 and 2017 surveys. The high chance of not observing randomly migrating species prudently explains why their short-term surveys each missed detecting 12% and 16% of the region’s species. And there’s good news to counter their extinction conclusions. The International Union for the Conservation of Nature determined those “extinct” 8 species are relatively abundant elsewhere and categorized as species of Least Concern.

 

A global warming explanation only obscures complex movements within ecosystems elsewhere. Researchers comparing early 20th century bird surveys in California’s mountains found as many species were moving downslope as species “fleeing” upslope. Furthermore, the same species moved differently in different regions. But fearmongering media journalists don’t find such facts newsworthy.

 

 

The theory that global warming relentlessly pushes species up mountain slopes to their eventual extinction, has been preached by climate scientists like James Hansen to add urgency to his catastrophic theories.  Unfortunately, such theories have constrained the objectivity of several researchers to the point they manipulated observations to fit the theory.

 

For example, pika are rabbit-like creatures that live in rockslides of western America’s mountains. By comparing the elevations of territories documented in the early 1900s to their current elevation Dr. Beever argued global warming was causing a “five-fold increase in the rate of local extinctions.” However, of the 25 pika territories surveyed, 10 were now inhabiting lower and warmer elevations. To preserve a scary theory, Beever eliminated those observations from his calculations, guaranteeing a statistical upslope retreat. But recent US Forest Service surveys also found 19% of the currently known pika populations are at lower elevations than documented during the cooler 1900s, as well as a few thriving pika territories that Dr. Beever had deemed locally extinct.

 

Dr. Camille Parmesan’s 1994 Edith's Checkerspot butterfly study made her an icon for climate change catastrophe. Featured on the Union of Concerned Scientists' website Parmesan stated,  "The latest research shows clearly that we face the threat of mass extinctions in coming years," For promoting global warming catastrophe, she earned an invitation to speak at the Clinton White House and to join the IPCC. I tried to replicate her study, but she refused to supply the necessary data and she never published a methods section. However,  it was privately admitted the Checkerspot butterfly had been increasing through the 2000s and many butterfly colonies she designated extinct, were now thriving. But such good news was never published.

What is truly worrisome is all these misleading  claims have both poisoned the scientific literature and duped the public into a hysteria regards climate “extinctions”.

 

 

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 my  What’s Natural column, Pacifica Tribune

September 15, 2020

 

My interview with the Cornwall Alliance for the Stewardship of Creation: Ocean Acidification: Real Threat or Fake News

 

My interview with the Cornwall Alliance for the Stewardship of Creation: 

Ocean Acidification: Real Threat or Fake News

 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