Chicken Littles vs Adelie Penguins

 from What's Natural  column, published in the Pacifica Tribune October 23, 2019

Nesting Adelie Penguins

Throughout recorded history doomsday cults attract thousands of gullible people. Charismatic cult leaders of the Order of the Solar Temple or Heaven’s Gate convinced their followers to commit suicide due to a coming “environmental apocalypse”. To prevent environmental collapse, a recent mass shooter justified his killings as reducing over-population, while a Swedish scientist has suggested cannibalism. Thus, it’s worrisome that charismatic congresswoman Ocasio-Cortez similarly warns our world is doomed in 12 years. Equally disturbing is the carefully orchestrated fear-mongering, such that the United Nations gave ill-informed, 16-year old Greta Thunberg center stage to rage that CO₂ is causing ecosystem collapse. Terrifying children with ‘the sky is falling’ fears will only bring about dire, unintended consequences.

Who is filling our children’s heads with stories of ecosystem collapse? 

For one Al Gore wrote in 2012, “The fate of the Adelie Penguins, A message from Al Gore”: “As temperatures rise along the West Antarctic Peninsula and the winter sea ice blankets the ocean three months fewer per year than 30 years ago, the local ecosystem is in danger. Everything from the base of the food chain – the phytoplankton (microscopic plants and bacteria) and krill (shrimp like creatures), to one of the continent’s most iconic inhabitants, the Adelie penguins, are under threat…There is an important lesson for us in the story of the Adelie penguins.”   

Indeed, Adelie penguins provide an “important lesson”. Don’t trust apocalyptic hype! 

Adelie penguins may be the best studied bird on earth. In 2009, the International Union for the Conservation of Nature (IUCN) estimated between 4 and 5 million adults, happily listing them as a species of “Least Concern”. However, using dubious IPCC climate models, scientists led by ornithologist David Ainley predicted the most northerly Adelie colonies would soon disappear as ice-melting warmth crept southward. They predicted between the years 2025 and 2052, 70% of the total Adelie population would be lost. Bullied by that virtual death count, the IUCN downgraded Adelies from “Least Concern” to “Near Threatened”. 

In real life, by 2016 Adelie abundance had nearly doubled to 7.6 million, and once again Adelies are a species of Least Concern. So how were scientists so misled? 

Adelie Breeding Colony

Ice Age glaciers had forced Adelies to abandon most of Antarctica’s coast. With warming, glaciers retreated and Adelies rapidly returned to breed and multiply.  However, there was one exception. For over 5400 years Adelies avoided ice free coastlines along Antarctica’s northwestern peninsula. Scientists dubbed this the “northern enigma”. Due to the region’s unfavorable weather, breeding Adelies still avoid much of that region, currently labeled the “Adelie Gap”. As might be expected, breeding colonies adjacent to the “Adelie Gap” are the least stable with some colonies experiencing population declines, and those declining colonies were enough to confirm some scientists’ climate fears.

In the 1990s, the northwestern sector of the Antarctic peninsula coincidently experienced rising temperatures and declining sea ice. Although Antarctica sea ice was not decreasing elsewhere, researchers believed the melting ice and warmer temperatures were just what CO₂-driven climate models predicted. But then the peninsula’s winds shifted. The peninsula’s sea ice has now been growing and temperatures have been cooling for over a decade. Furthermore in contrast to Ainley’s models, colonies at the most northerly limits of the Adelies’ range are not disappearing. Those colonies are thriving and increasing such as the Sandwich Island colonies, and northerly colonies on the Antarctic peninsula’s east side. 

Media headlines are guided by the maxim ‘if it bleeds it leads.’ Likewise, scientific journals. Good news about thriving colonies, or no change, fail to capture headlines. But the addiction to eye-catching catastrophes misleads the public and scientists alike. Despite no warming trend at an Emperor penguin colony, David Ainley was so inebriated by global warming fears, he fabricated a warming temperature graph to falsely explain the colony’s decline! Similarly, extreme researchers of polar bear populations wrongly argued, “we're projecting that, by the middle of this century, two-thirds of the polar bears will be gone from their current populations”.  Again, in reality polar bear abundance has increased.

By perpetuating bogus claims of a world ending in 12 years, the Chicken Littles are doing far more harm than blinding children to scientific evidence that many species, from polar bears to Adelie penguins, are thriving. Our children miss the “important lesson” that a “climate crisis” is only a theory supported by scary narratives, not facts. So how do we protect our children from Chicken Littles who seek to enroll vulnerable minds into their doomsday cults? How do we motivate our children to be good critical thinkers, and not blind group thinkers mesmerized by fear and ‘end of the earth’ scenarios? 

Foxy Loxy invites Chicken Little into the "safety" of his den

We tell children fairy tales to alert them to the real dangers, such as Crying Wolf. In the original Chicken Little tale,  Foxy Loxy offered Chicken Little and friends the shelter of his den so they would be safe from the falling sky. Once inside Foxy's den, they were never heard from again!

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

Ask John Interviews Jim Steele on Climate

Click to Watch entire interview

Marvelously Resilient Coral

 

Low tide bleaching of Heron Reef

Published October 2, 2019 in California’s Battle Born Media newspapers - the Pacifica Tribune, the Novato Advance, the Sausalito Marin Scope, the Mill Valley Herald, the Twin Cities (Larkspur and Corte Madera) Times, the San Rafael News Pointer and the Ross Valley Herald. 

What’s Natural? 

Marvelously Resilient Coral

Imagine if today’s magnificent coral reefs all dried up and died - from the surface down to a depth of 400 feet. Horrifying! But that was exactly the case 20,000 years ago when growing glaciers of the Last Ice Age lowered sea level 400 feet. Yet coral reefs fully recovered as the earth warmed. So, what makes coral so resilient? 

To survive, coral must also withstand lethal effects of modern cyclones, coral-eating crown-of-thorns starfish, and El Niño related bleaching.  Rapid growth has allowed most reefs to fully recover within 7 to 30 years. For example, due to the 1998 El Niño event 12 reefs on the Seychelles, experienced greater than 95% mortality. Yet 6 reefs fully recovered within 7-12 years, and within 16 years coral cover had increased by 135% to 305% of pre-bleaching values. The others continued to recover but at a slower pace.

In contrast to climate crisis claims, cyclones cause the greatest coral mortality. Cyclones have caused 48% of lost coral cover, while crown-of-thorns feeding caused 42%, and bleaching just 10%. Yet regardless of cause, coral growth quickly restored most damaged reefs within 10 years. Known as the Phoenix effect, remnant living tissues can expand, regenerating tissue that covers dead skeletons. After several years of regeneration, plus growth of surviving colonies, coral then produce massive amounts of larvae (young coral) and complete the reef’s recovery. 

Disturbingly, an extreme advocate of a coral climate “crisis”,Terry Hughes argued global warming has impaired recruitment of new coral to the Great Barrier Reef,  despite only 2 years since the 2016 bleaching event. Internet media outlets, eager for ‘click-bait headlines’ wrote, “Great Barrier Reef suffers 89% collapse in new coral” and CNN hyped “Dead Corals Don’t Make Babies”. 

But such reduced larval production is normal whenever adult corals are reduced. For example, after a western Australian reef suffered 70 to 90% mortality, larval production was reduced by 96% for the first 6 years. Nonetheless surviving coral increased their abundance by 5-fold over a period of 12 years. After the first 6 years of increasing coral, larval production rapidly increased. Likewise, in the northern Great Barrier Reef, which was heavily bleached in 2016, an 89% decrease in larvae is expected. And consistent with the potential for rapid recovery, surviving coral in the northern Great Barrier Reef have now increased by 16%. Thus, its highly likely we will witness large increases coral larvae within four years.

Media outlets have also misleadingly conflated coral bleaching with dead coral prompting ridiculous headlines proclaiming the Great Barrier Reef is dead. But bleaching is not always lethal. When over 90% of the coral on the Palmyra Atoll experienced bleaching, there was no loss of coral on the reef flats, and only a 9% loss on the fore reefs. Similarly, despite the severe 2016 bleaching in the Coral Sea Marine Park, researchers reported total coral cover was not significantly reduced by 2017. Most bleached corals survived.  

Reef building corals depend on energy from photosynthesizing symbiotic algae.  But their symbiotic relationship requires careful maintenance. So coral naturally add and subtract symbiotic algae as the seasons change. During the winter, coral increase their symbiotic algae as lower light reduces photosynthesis. Each summer as light intensity increases, they expel symbionts. Bleaching is just an extreme of that behavior. After bleaching, coral can quickly replace their symbiotic algae within days or months with no resulting mortality. 

Scientists are increasingly observing that coral can acquire very different symbiotic algae with different genetics. To adapt to changing climates corals don’t require thousands of years to evolve. Coral get instantaneous genetic upgrades simply by acquiring new symbiotic algae. Acquiring different symbiotic algae allowed coral to adapt to dramatic temperature changes as Ice Ages came and went. And acquiring new symbiotic algae now allows coral to rapidly adapt to 60-year changes caused by ocean oscillations.

Under La Niña like conditions, warm water accumulates over the “coral triangle” in the western Pacific, promoting more rains and heavier cloud cover. This condition can dominate for 30 or more years. However, during El Niños as in 2016, that warm water sloshes towards the Americas causing sea levels to dramatically fall. Falling sea levels expose coral to drying winds and shallower bays will more rapidly heat. Furthermore, during an El Niño, the rains and cloud cover moves eastward. With less clouds, the Great Barrier Reef is exposed to more sunshine and more heatwaves. Scientists now recognize a strong connection between ocean heat waves and El Niños. Coral bleaching correlates best with El Niños. 

Climate models do not agree on how El Niños will change in the future. But there is good news. Michael Mann, who promotes “dire predictions” due to rising CO₂, also published that during past warm periods, the oceans remain in more La Niña-like conditions. And La Niña-like conditions are good for the Great Barrier Reef.

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

Amazon Fires and Biofuels

What’s Natural 

Brazil’s Fires and Biofuels. 

published September 11, 2019

Trends on Amazon Deforestation

From leaf cutting ants that cultivate fungus gardens to flowers that fool potential pollinating insects into having sex, the magic of rainforest ecology always inspired my love for nature’s creativity. So, it’s no surprise that any and every report of burning rainforests would rally deep concerns across the globe. Nonetheless I am disturbed by dishonest gloom and doom regards recent Amazon fires. NASA reports since 2003 the square kilometers of forest burned each year has dropped by roughly 25 percent. But such good news doesn’t get headlines. 

Although the NY Times wrote the fires have no climate connection, meteorologist Eric Holthaus, who writes numerous catastrophic climate articles for Slate and the New York Times, suggested the fires show, “We are in a climate emergency”.  As of August 16, 2019, an analysis of NASA satellite data indicated that total fire activity across the Amazon basin this year has been close to the average in comparison to the past 15 years, but Holthaus dishonestly tweeted, “The current fires are without precedent in the past 20,000 years.” 

fungus garden ants

To heighten global hysteria, French president Macron and actor Leonardo deCaprio, tweeted photographs of forest infernos. But those photos were taken 20 years ago. Likewise, Madonna tweeted wildfire photos taken 30 years ago, and others tweeted flaming photos from regions far from the Amazon. 

Activist vegetarians denounced meat-eaters for deforestation, arguing forests are burnt to create pastures for cattle. But they failed to mention pastures previously created for grazing without deforestation, are now being usurped by biofuel cultivation. Indirectly, it’s the biofuel fad that has driven cattle grazers to carve out new pastures in the rain forests.  

Left-wing politicos blame the fires on Brazil’s rightwing president Jair Bolsonaro, a climate skeptic. They argue Bolsonaro’s views emboldened land grabbers. But the number of Brazilian fires, and rates of rainforest deforestation were far worse before Bolsonaro, peaking in 2004 under a corrupt leftist Workers Party. It seems every tragedy is just an opportunity to demonize one’s opponents, no matter the facts. 

Most 2019 fires have been ignited on land cleared long ago. To clear agricultural stubble or to prevent forests from encroaching on existing farms and pastures, Brazil’s farmers set fires as soon as the dry season begins. According to NASA, Brazil’s “agricultural fire season” traditionally peaks in July and August and ends by early November. To date, there is no data determining the extent of area burnt on existing farms and pastures, versus how much rainforest has actually been lost to fire. 

As the saying goes, the road to hell is paved with good intentions. Between 2000 and 2005 an estimated 45,000 square miles per year of rainforest were lost worldwide as biofuel production ramped. Currently only 2.3% of Brazil’s agricultural lands grow biofuels. But that will increase as governments require fuels blended with increasing percentages of biofuels. Most projections suggest biofuels will dominate 36% of arable lands by 2030. More encroachment on rainforests is likely.

Brazil leads all developing countries in biofuel production. Thus, Brazil is at the center of scientific disputes regards biofuels and deforestation. Brazil is the leader in sugarcane production for biofuels. Sugarcane is typically cultivated on disturbed fields far from rainforests, so, there is no evidence of direct deforestation. But there are definitely indirect impacts. As sugar cane fields expanded throughout southern Brazil, soybeans increasingly grown for biodiesel were pushed northward into central Brazil. In turn, usurped pastures pushed cattle grazers further northwards into rainforests.

Nearly 55 million Brazilians live in poverty. Slash and burn agriculture is often practiced by poor farmers. To achieve a win-win solution for rainforests and humanity, we need more efficient land use. But fields once growing food, are being transformed into fields for biofuels. To make-up for lost food production, pristine lands elsewhere are cleared and burnt for new agriculture.

Still there’s hope. America’s early colonists deforested the land and drained wetlands. Marginal farms deforested 80% of Vermont by 1900. But as more efficient land use evolved, marginal farms were abandoned, and Vermont is now 80% re-forested. Similarly the UN’s State of the World’s Forests 2018 reports global net loss of forest area continues to slow, from 0.18 percent per year in the 1990s to just 0.08 percent over the last five-year period. If Bolsanaro’s pro-agriculture advocacy generates greater agricultural efficiency, Brazil’s forests should likewise benefit. 

Deforestation Index

Although there have been admirable attempts by the international Amazon Fund to promote sustainable rainforest agriculture, it has not been enough to raise Brazilians out of poverty. Worse, In the name of fighting climate catastrophes, biofuel subsidies and incentives encourage destruction of Brazil’s rainforests and savannahs, while displacing small farms. We must wait and see but having a newly elected skeptical president in Brazil might be a godsend. Better agricultural practices may evolve if Brazil’s government is not blinded by the false promises of biofuels!

Addendum September 13, 2019:

Having more closely examined the photo I downloaded from the internet of cattle and burning forests, I suspected the red line in the photo suggested it may have been photoshopped. I was just contacted by another scientist suggesting the same thing.

Although it doesn't affect the issue of biofuels, it is likely  another example of how photoshopped pics can be easily and incorrectly used. Although it nicely juxtaposes the fires with cattle,  I warn viewers that the picture is likely photoshopped and I apologize for having used it.

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

Listen to the Trees

published in the Pacifica Tribune August 20, 2019

What’s Natural? 

Listen to the Trees!

This summer I taught a class on the Natural History of the Sierra Nevada for San Francisco State University’s Sierra Nevada Field Campus. The first day we taught students how to identify the trees. Once students know their trees, they can easily see how tree species vary with elevation, temperature, moisture, and snow pack. They can see which species colonize open sunny areas and which trees need shade before they can invade. Old time naturalists used trees to identify “life-zones” where different species of mammals, birds, insects and other plants can be found. Furthermore, when you listen to the trees, you can see change.

The class explored forests along the North Yuba River. Free from politics, trees tell us about changes in fire frequency, logging, climate change and ecosystem resilience. Photographs taken during the late 1800s during California’s gold rush days, revealed the total devastation of local forests. Gold miners needed wood for heating and cooking, for their metal forges, and for timbers to reinforce their mines. They needed wood to build flume boxes that altered river courses to expose riverbeds. Flume boxes also carried water from high to low elevations where giant water cannons completely washed away hillsides in their search for gold.

Deforested mountains - Downieville, CA late 1800s

Still, by comparing catastrophic photos of forests during the gold miners’ days to our current forest conditions, I was filled with optimism. The forests had totally recovered and again are quite dense. So dense, that local inhabitants fear there’s too much fuel on the forest floor that could feed catastrophic fires. Nevertheless, the lush re-growth is testimony to our forest’s amazing resilience. 

We counted tree rings and determined a majority of trees were no more than 170 years old. Those trees began their lives shortly after the gold miners had cut down all their older relatives. Occasionally we found a few larger trees, 300 years or older, that fortuitously avoided the miners’ ravenous saw blades.

Scientists determine the natural frequency of fires by reading tree rings and fire scars. Low elevation trees like Ponderosa Pines naturally endured wildfires about every 25 years. At higher elevations, where temperatures are colder and the snow pack lingers, fire scars suggest wildfires naturally happen about every 100 years. In contrast to media hype, fire scars in living and fossil trees suggest wildfires were far more common during the cool Little Ice Age.

Tree stumps tell us that trees once bordered Arctic shores 9000 years ago. Since then, cooler temperatures have pushed trees to lower latitudes and warmer elevations. Hikers in the Sierra Nevada often encounter dead trees several hundred feet above our current tree line. Accordingly, researchers determined that for the last 3 thousand years, tree line was mostly higher than today because temperatures were much warmer. However, during the Little Ice Age, between 1300 AD and 1850 AD, it got so cold, tree line dropped and tree seedlings in the Ural Mountains couldn’t germinate for hundreds of years. Ancient tree lines suggest if temperatures increase over the next century, it will not be a crisis. Trees will simply reclaim their former habitats. 

Trees reveal past rainfall patterns. California’s Blue Oaks are very sensitive to changes in precipitation. In drought years they generate narrow rings contrasting with wider rings during wet years. A recent tree ring study of Blue Oaks finds no rainfall trend over the past 700 years, but it suggests Californians can expect extreme droughts and extreme rainfall 3 to 4 times a century. More concerning, tree stumps at the bottom of Lake Tahoe dating back 6000 years ago, suggest Californians can naturally expect far more extreme droughts than living humans have yet to experience. 

Trees tell us how climate has changed. Fossil trees indicate Antarctica once experienced subtropical temperatures 40 million years ago. Similarly, trees tell us about recent temperature changes. Tree rings have correlated accurately with instrumental temperatures for over 100 years. However, since the 1960s, tree ring temperatures suggest a much cooler global climate in contrast to thermometers and models. 

Tree ring temperatures 

Tree rings indicate the warmest decades of the 20^thcentury were the 1930s and 40s, and temperatures have yet to surpass those decades. This divergence between thermometers and trees is best explained by the fact that instrumental temperatures are biased upwards when taken at hot airports or in areas recently suffering from growing urban heat island effects. In contrast, trees measure temperatures in natural habitat.

There are too many fear mongering politicians pushing an “existential climate crisis”. I find the climate history told by the trees far more trustworthy, and the trees are whispering there is no crisis. 

  

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

Ten Causes of Warming: The Layperson’s Checklist

published August 7, 2019 

What’s Natural? 

Ten Causes of Warming: The Layperson’s Checklist

All temperatures are not created equally. Rising temperatures have many causes. Good science demands we explore alternative hypotheses before reaching any conclusions. Below is a list of common causes of warming trends and heat events that everyone should consider in addition to any possible increased greenhouse effect.

1.     Heat trapping surfaces: Asphalt and cement not only heat up much faster than natural habitat during the day, those materials hold the heat longer, increasing temperatures at weather stations situated near buildings and near asphalt. More asphalt, more warming, more record temperatures.

2.     Loss of Vegetation: During the summer the temperature of a dry dirt road can be 60°F higher at noon, than ground shaded by trees. That’s why our pets instinctively seek the shade. Plants also bring moisture from below the ground that cools the air by evaporative cooling. Increasing deforestation or lost vegetation due to landscape changes cause regional warming trends.

3.     Transport of heat: Natural climate oscillations alter air and ocean circulation patterns that can drive more heat from the tropics towards the poles. Europe’s recent heat wave was largely caused by air heated over the baking Sahara Desert and then driven into Europe. Similarly, the latest research finds variations in Arctic sea ice has been dominated by transport of warm Atlantic water heated in the tropics and transported northward via the Gulf Stream.

4.     Less cloud cover: Recent research suggests a trend of less cloud cover resulted in increased solar heating of land and oceans. The added solar energy normally reflected by clouds was 2 times greater than what’s believed to be added by increasing carbon dioxide. Two decades of declining cloud cover was similarly shown to cause Greenland’s rapid ice melt between 1995 and 2012.

5.     Less Cooling: Windy conditions cool the oceans. The unusually warm ocean conditions that occurred in the northwestern Pacific Ocean, known as the Blob, were caused by decreased winds that reduced normal cooling. 

6.    Suppressed Convection: Surface temperatures are cooled by rising convection currents that carry away the heat. Roll up the windows of your car and immediately the temperature rises simply because convection is prevented. Suppressed convection is the reason temperatures are warmer inside agricultural greenhouses. Weather-people predict a heat wave when they see a looming dome of high pressure that will suppress cooling convection.

7.     Drier conditions: It takes 5 times more energy to heat water 1 degree than it does to heat sand. Furthermore, it takes 500 times more energy to evaporate water than it does to raise water one degree. Without evaporation to consume the heat, most extreme temperature events are associated with dry conditions. The trend in lost wetlands increases temperatures.  

8.     Ventilating stored heat: Oceanographers from Harvard and MIT have suggested heat stored in the deep oceans thousands of years ago, when temperatures were warmer than today, is still ventilating. Likewise, El Niños ventilate previously stored heat. Similarly, Arctic temperatures rose after a change in wind direction blew thick insulating ice out of the Arctic allowing subsurface heat to ventilate.

9.     Descending winds: For every 1000 feet of elevation that an air mass descends, its temperature rises over 5°F. California’s hot Santa Anna and Diablo winds can raise downslope temperatures 25°F in a matter of minutes. Descending air in a high-pressure dome suppresses convection causing heat waves. Despite temperatures far below freezing, bouts of descending winds from Antarctic’s peaks rapidly heat the ice and generate melt ponds.

10.  Misleading Averaging: The average temperature is calculated by adding the maximum and minimum daily temperatures and dividing by 2. Due to heat trapping surfaces, higher minimum temperatures cause the average temperature to rise even when maximum temperatures have not increased or sometimes cooled.

Good stewards of the environment should never mindlessly blame rising CO₂concentrations for a heat wave or a warming trend unless all the other warming dynamics are considered. Restoring a wetland or planting trees might be the best option to lower regional temperatures.

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism. He writes regular column for Battle Born Media newspapers -- the Pacifica Tribune, the Novato Advance, the Sausalito Marin Scope, the Mill Valley Herald, the Twin Cities (Larkspur and Corte Madera) Times, the San Rafael News Pointer and the Ross Valley Herald. 

Contact: naturalclimatechange@earthlink.net

California Dreaming and Erosion “Crises”

published in the Pacific Tribune July 24th 

What’s Natural? 

California Dreaming and Erosion “Crises”

California's Undulating Coastline

California’s spectacular coastline attracts tourists from around the world. Headlands of granite or basalt resist erosion, defiantly jutting out into the sea. Pocket beaches form where focused wave energy bites into softer sandstones and uncemented stream sediments. Relentless waves undermine and steepen cliffs bordering 70% of California’s shoreline. Over hundreds and thousands of years, natural erosion sculpted our awe-inspiring undulating coast. 

But beauty is in the eye of the beholder - likewise the magnitude of a “coastal crisis”. The Los Angeles Times recently published ‘California coast is disappearing under the rising sea. Our choices are grim’. They inaccurately painted natural erosion as a recent crisis due to CO₂ induced climate change. However, California’s erosion “crisis” must be understood within a greater timeframe.

Since the end of the last ice age, sea level has risen 400 feet. Over 18,000 years, San Francisco’s regional coastline marched 25 miles inland, advancing 7 feet a year - more than twice California’s average. My beautiful home town of Pacifica was featured in that Times’ article because it lost several homes unfortunately built on loosely cemented sand and gravel deposited 100,000 years ago when sea level was 20 feet higher. Although the ocean’s landward march has slowed over the past 5000 years, northern Pacifica’s fragile coastline still retreated by over 7 feet per year between 1929 and 1943. Despite a warming world, the average rate of cliff retreat then markedly declined since 1943.

The ill-fated Ocean Shore Railway, initiated in 1905, foreshadowed California’s erosion problems. To give tourists awesome views, tracks were laid on a ledge dug into steep coastal cliffs. But landslides were common, and costly repairs forced the railway to close. Today, only 25% of the railway ledge built by 1928 still exists. Undeterred, designers of California’sscenic Pacific Coast Highway hoped to give automobile travelers similar breath-taking views. Again, landslides were common. Only 38% of the highway constructed by 1956 still remains. Geologists tell us such landslides constantly altered California’s modern coastline for hundreds of years.

There are few straight lines in nature. Our coastlines undulate. Likewise, our climate oscillates, and coasts erode episodically. Between 1976 and 1999 (the warm phase of the Pacific Decadal Oscillation), California experienced more frequent El Niños. Over 70% of California’s 20^th century disappearing coastline eroded during El Niño events. El Niños bring more storms and more destructive waves. El Niños bring more rains that saturate soils and promote landslides.  The Pacific Decadal Oscillation then switched to its cool phase. It brought more La Niñas and more drought, but fewer winter storms and less erosion. In 1949, also a time of less erosion, Pacifica’s government believed homes setback 65 feet from the edge of a bluff would be safe. They never suspected a single El Niño event would move the cliff edge 30 feet landward 50 years later.  

Pacifica California's  eroding coastline

There are some who see human structures as a blight on California’s natural coastline. In response to natural erosion, they suggest we abandon the coast. They argue California’s only choice is “managed retreat” versus “unmanaged retreat”.  Although well engineered seawalls can protect homes and businesses, some environmentalists called seawalls a coastal “crisis”. California’s Coastal Commission recently pledged seawalls will “only be permitted if absolutely necessary”. But the Commission’s policy only fosters a mishmash of emergency fixes. Randomly armored properties deflect destructive waves downstream, accelerating erosion in a neighbor’s unprotected property. Coastal cities must construct well-engineered sea walls, without any gaps.

Because sea walls prevent erosion, the Commission ill-advisedly fears local beaches will be lost if denied locally eroded sand. The Times parroted that belief writing, ‘for every constructed seawall, a beach is sacrificed’. But is that true? San Francisco’s O’Shaughnessy sea wall built in 1929 prevents erosion of the fragile sand dunes supporting Golden Gate Park. Yet SF’s north ocean beach continues to grow. Without a seawall, San Francisco’s south ocean beach rapidly eroded, and threatened infrastructure now requires a sea wall.

Sources of beach sand fluctuate, and simplistic sea wall analyses are very misleading. Sand is stored and transported to beaches in many ways. Streams and rivers supply the most sand needed to nourish a beach, but mining SF bay’s sand has deprived nearby coastal beaches. Furthermore, ocean oscillations shift winds and the direction of currents that transport sand. Beaches grow for decades then suddenly shrink. Although some argue our beaches face a rising sea level “crisis”, archaeologist determined that despite more rapidly rising sea levels 5000 years ago, many California beaches grew when supplied with adequate sand.

Lastly, it’s interesting to note scientists suggested Pacific islands also face an erosion crisis due to rising sea levels. But the latest scientific surveys determined 43% of those islands remained stable while land extent of another 43% has grown. Only 14% of the islands lost land. So, I fear exaggerated crises only erode our trust in science.

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