Celebrating America’s Environmental Stewardship

published in the Pacifica Tribune July 10,2019

What’s Natural? 

Celebrating America’s Environmental Stewardship

I resent the one-sided mis-characterization of humanity as “destroyers of our environment”. Humans certainly had negative impacts on most ecosystems. However, in contrast to a recent United Nations report insinuating we are threatening one million species with extinction, humans have been working hard to restore nature and prevent further extinctions. Most endangered species are still staggering from disruptions initiated centuries ago. But now humans are correcting past mistakes.

Islands have been extinction hotspots. Sixty-one percent of all known extinctions have occurred on islands and 37% of today’s critically endangered species are found only on islands. The main driver of island extinctions has been purposeful or unintentional introductions of alien species. Introduced species are implicated in 81% of all island extinctions. With no natural predators, Island species did not evolve needed behaviors to avoid introduced rats, cats and stoats.  Researchers now suggest eradication of rats and other introduced mammals could prevent the extinction of up to 75% of threatened island birds, reptiles and mammals. 

Similarly, past introductions of disease decimated island species whose immune systems were ill-prepared to combat alien pathogens. For example, after sailors inadvertently introduced mosquitos into Hawaii in the early 1800s, mosquitos began transmitting avian malaria. By the late 1800s Hawaii’s lowland birds were noticeably disappearing, even in undisturbed habitat. Mosquitos were restricted to warmer lowlands, so cooler high elevations served as a refuge. But high elevation birds regularly migrate to the relative safety of lowland valleys during winter storms, so are still threatened by malaria. Due to landscape changes, introduced predators and introduced diseases, Hawaii became known as the extinction capital of the world. Unfortunately eradicating introduced diseases will be extremely difficult.

Extinct Hawaiian Akialoa lanaiensis

In 1750 Russian fur farmers began introducing red and arctic foxes to the Aleutian Islands. Breeding birds that once thrived in predator-free environments were deemed fox food. By 1811 native Aleuts complained foxes were reducing once abundant seabirds but populations continued to plummet. The Aleutian goose was soon considered extinct until a few pairs were found on 3 fox-free islands. Humans embarked on programs to eradicate introduced foxes allowing seabirds and geese to recover. The Aleutian goose recovery has been so rapid, that along the coast of northern California where the geese winter, they are now considered a pest in local parks.

Arctic Fox

Lost habitat has caused many extinctions, especially species dependent on rapidly disappearing wetlands. For centuries wetlands were being drained and converted to croplands and pastures. However, in the United States that trend is being reversed. Due to more efficient farming methods, the extent of land covered by crops decreased 18% between 1938 and 1992, allowing most of that land to return to more natural habitat. Due to improved wildlife management and incentives to conserve wetlands, wetland-dependent birds have increased by over 30% since 1968. Unfortunately, the incentives to protect wetlands have been counteracted by misguided government subsidies for biofuels in the name of fighting climate change. As a result, some farmers have been enticed to drain their wetlands to grow corn.

The probability of extinction by chance is greatly enhanced when a species’ range is extremely small, and their original abundance is low. Minor habitat disturbances can then cause extinctions. For example, most extinct plant species in California were found in only one or two counties, and due to low abundance were known only from one or two collections.

Nonetheless people are still striving to restore wetlands. We preserve habitat by establishing land trusts. My research prompted restoration of a Sierra Nevada watershed that was initially degraded over 100 years ago. Meadows then stayed wetter during California’s 3-year drought than had been the case before the drought and before restoration. Furthermore, bird populations significantly increased. Colleagues are now restoring other meadows as are several other non-profit organizations. 

The United Nations’ report hyping one million extinctions in the near future should be regarded with extreme suspicion. It engages in fearmongering that only evokes a sense of helplessness. It repeatedly argues their environmental goals for 2030 and beyond “may only be achieved through transformative changes across economic, social, political and technological factors.” Their proposed remedy smells of a hidden political agenda. It ignores the tremendous strides humans have taken towards being better environmental stewards. 

Bald Eagle

Our situation is not hopeless. Simply funding the eradication of invasive species on islands would save a significant number of threatened species. America’s regulations have promoted the recovery of several endangered species now listed as species of “least concern”: bald eagles, humpback whales, brown pelicans and many more. Improved agricultural practices and our efficient economy have allowed more land to convert from cropland back to natural habitat despite feeding a growing human population. Learning from past mistakes, we are now on a trajectory to create win-win situations for both humans and the environment.

Humpback Whale

Jim Steele is retired director of the Sierra Nevada Field Campus, SFSU

and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

Contact: naturalclimatechange@earthlink.net

How Cold Air Caused a Heatwave

From What’s Natural? Column

published in Pacifica Tribune June 26, 2019

Worst Heatwaves During the 1930s Dust Bowl Years

I was recently asked if the record June 2019 heat in the San Francisco Bay Area validated CO₂ driven climate models. Surprisingly climate scientists have now demonstrated the heat wave was largely due to an intrusion of record cold air into the Pacific Northwest. How?

Basically, the winds’ direction controls the San Francisco Bay Area’s weather. In summer, California’s inland regions heat faster than the ocean, so the winds blow inland from the cooler ocean. Those onshore winds bring cooling fog, our natural air conditioner. Later, as the sun retreats southward in the fall, the land cools faster than the ocean. Seasonal winds then reverse and blow from the cooling land out to sea. Those winds keep the fog offshore. Without fog, San Franciscans finally enjoy pleasantly warm days in September and October. In northern California those strong offshore winds are called the Diablo winds. Although Diablo winds bring welcome warmth, those winds also increase wildfire danger.

Typically, inland California heats up in June drawing in the fog. But that temporarily changed when a surge of record cold air briefly entered Washington state and then moved down into northeastern California and Nevada. Dr. Cliff Mass, a climate scientist at the University of Washington, studies the Diablo winds. On his popular weather blog,  he discussed how that intruding cold air created an unseasonal burst of Diablo winds that then kept the fog offshore. Without cooling fog, solar heating increased temperatures dramatically. According to Accuweather, San Francisco’s maximum temperature on Friday June 7^th was 67 °F, skyrocketed to a record 97 °F by Monday and then fell to 61 °F three days later as onshore winds returned. 

Such rapid temperature change is never caused by a slowly changing greenhouse effect.  Nevertheless, the media asks if rising CO₂ concentrations could have contributed to the higher temperatures or made the heatwave more likely? 

Although definitions vary, the World Meteorological Organization defines a heat wave as 5 or more consecutive days of prolonged heat in which daily maximum temperatures are 9+ °F higher than average. Assuming the rise in CO₂  concentration increased all temperatures relative to the 20^thcentury average, it is believed maximum temperatures are more likely to exceed that 9 °F threshold. But heatwaves are not caused by increasing greenhouse gases.

The science is solid that greenhouse gases can intercept escaping heat and re-direct a portion of that heat back to earth. That downward directed heat reduces how quickly the earth cools, and thus the earth warms. However, heat waves typically occur when greenhouse gas concentrations are greatly reduced.  Eighty percent or more of our greenhouse effect is caused not by CO₂, but by water vapor. Satellite data shows the dry conditions that accompany a heat wave actually reduce the greenhouse effect because drier air allows more infrared heat to escape back to space. However, like less fog, less water vapor and less clouds allow more solar heating. So despite the increase in escaping heat, increased solar heating dominates the weather and temperatures rise. 

The important contribution of dryness to heat waves helps explain why the USA experienced its worst heat waves during the 1930s Dust Bowl years (see EPA Heatwave Index above). Furthermore, the EPA’s heat wave index appears totally independent of rising CO2 concentrations.  Dryness also helps to explain why the hottest air temperature ever recorded anywhere in the world happened over a century ago in Death Valley on July 10, 1913; a time of much lower CO₂ concentrations.

To summarize, an intrusion of record cold air into the Pacific Northwest generated unseasonal Diablo winds in northern California.  Those offshore winds prevented the fog from reaching and cooling the land. In addition, because the Diablo winds are abnormally dry, solar heating of the land increased. Those combined effects caused temperatures to temporarily jump by 30 °F. 

Lastly, not only can Diablo winds cause heatwaves, Diablo winds will fan small fires into huge devastating infernos such as the one that destroyed Paradise, California. Fortunately, there were few wildfire ignitions during this heat wave. To be safe, Pacific Gas and Electric had shut off electricity to areas predicted to have high wind speeds. So Dr. Mass mused, that because colder temperatures generate the destructive Diablo winds, climate warming may have some benefits.

Jim Steele is retired director of the Sierra Nevada Field Campus, SFSU

and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

Contact: naturalclimatechange@earthlink.net