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 

  

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