Tuesday, April 2, 2019

The Little Ice Age - Back to the Future

published in the Pacifica Tribune's biweekly column What’s Natural?

April 3, 2019

Little Ice Age glaciers threaten villages and farms

The Little Ice Age - Back to the Future 

Extreme scientists and politicians warn we will suffer catastrophic climate change if the earth’s average temperature rises 2.7°F above the Little Ice Age average. They claim we are in a climate crisis because average temperature has already warmed by 1.5°F since 1850 AD. Guided by climate fear, politicians fund whacky engineering schemes to shade the earth with mirrors or aerosols to lower temperatures. But the cooler Little Ice Age endured a much more disastrous climate.

The Little Ice Age coincides with the pre-industrial period. The Little Ice Age spanned a period from 1300 AD to 1850 AD, but the exact timing varies. It was a time of great droughts, retreating tree lines, and agricultural failures leading to massive global famines and rampant epidemics. Meanwhile advancing glaciers demolished European villages and farms and extensive sea ice blocked harbors and prevented trade. 

Dr. Michael Mann who preaches dire predictions wrought by global warming described the Little Ice Age as a period of widespread “famine, disease, and increased child mortality in Europe during the 17th–19th century, probably related, at least in part, to colder temperatures and altered weather conditions.” In contrast to current models suggesting global warming will cause wild weather swings,Mann concluded “the Little Ice Age may have been more significant in terms of increased variability of the climate”.  Indeed, historical documents from the Little Ice Age describe wild climate swings with extremely cold winters followed by very warm summers, and cold wet years followed by cold dry years.

A series of Little Ice Age droughts lasting several decades devastated Asia between the mid 1300s and 1400s. Resulting famines caused significant societal upheaval within India, China, Sri Lanka, and Cambodia. Bad weather resulted in the Great Famine of 1315-1317 which decimated Europe causing extreme levels of crime, disease, mass death, cannibalism and infanticide.The North American tree-ring data reveal megadroughts lasting several decades during the cool 1500s. The Victorian Great Drought from 1876 to 1878 brought great suffering across much of the tropics with India devastated the most. More than 30 million people are thought to have died at this time from famine worldwide. 

The Little Ice Age droughts and famines forced great societal upheaval, and the resulting climate change refugees were forced to seek better lands. But those movements also spread horrendous epidemics. Wild climate swings brought cold and dry weather to central Asia.  That forced the Mongols to search for better grazing. As they invaded new territories they spread the Bubonic plague which had devastated parts of Asia earlier. In the 1300s the Mongols passed the plague to Italian merchant ships who then brought it to Europe where it quickly killed one third of Europe’s population. European explorers looking for new trade routes brought smallpox to the Americas, causing small native tribes to go extinct and decimating 25% to 50% of larger tribes. Introduced diseases rapidly reduced Mexico’s population from 30 million to 3 million.

By the 1700s a new killer began to dominate – accidental hypothermia. When indoor temperatures fall below 48°F for prolonged periods, the human body struggles to keep warm, setting off a series of reactions that causes stress and can result in heart attacks. As recently as the 1960s in Great Britain, 20,000 elderly and malnourished people who lacked central heating died from accidental hypothermia. As people with poor heating faced bouts of extreme cold in the 1700s, accidental hypothermia was rampant. 

What caused the tragic climate changes of the Little Ice Age? Some scientists suggest lower solar output associated with periods of fewer sunspots. Increasing solar output then reversed the cooling and warmed the 20thcentury world.  As solar output is now falling to the lows of the Little Ice Age, a natural experiment is now in progress testing that solar theory. However other scientists suggest it was rising COthat delivered the world from the Little Ice Age. 

Increasing COalso has a beneficial fertilization effect that is greening the earth. The 20th century warming, whether natural or driven by rising COconcentrations, has lengthened the growing season. Famines are being eliminated. Tree-lines stopped retreating and trees are now reclaiming territory lost over the past 500 years. So why is it that now we face a climate crisis?

At the end of the 1300’s Great Famine and the Bubonic Plague epidemic, the earth sustained 350 million people. With today’s advances in technology and milder growing conditions, record high crop yields are now feeding a human population that has ballooned to over 7.6 billion.

So, the notion that cooler times represent the “good old days” and we are now in a warmer climate crisis seems truly absurd. 

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

Wednesday, March 20, 2019

A Sea Level Rise Conundrum – Greenland’s Cycles

After France fell to the Nazis, Britain desperately prepared for an invasion. The United States shuttled hundreds of planes to England via the Snowball Route, a series of secret bases on Newfoundland, Greenland and Iceland. But in 1942 one squadron never completed the journey. A sudden July storm forced 8 planes to land on a slushy glacier surface in southeast Greenland. Although the crews were rescued, later attempts failed to locate the Lost Squadron. The glaciers had ferried the planes miles downstream as they were increasingly buried in ice. One plane was finally recovered in 1992 and the second, recovered in 2018, was under more than 300 feet of ice. Southeastern Greenland had been gaining ice at a rate of 4 feet per year. 

In contrast, climate scientists project Greenland will increasingly lose ice as CO2concentrations increase. Indeed, its melting ice has been the biggest contributor to accelerating sea level rise for 2 decades.  But that is rapidly reversing. City planners along California’s coast are struggling with competing theories. How much sea level rise should we plan for?  Fearing an accelerating rise, some argue we abandon the coast. Others argue, and I agree, we should protect our homes with seawalls. But how high must we build? Understanding Greenland’s contribution is critical.

If we removed all ice from Greenland, the land would reveal a bowl-shape. A ring of mountains paralleling the coastline prevents the ice cap from sliding into the sea, no matter what scary climate stories suggest. Several gaps in those mountains allow glaciers to transport ice from inside “the bowl” to the oceans. Given enough time the Lost Squadron may well have been shuttled out to sea. Whenever more ice accumulates inside the “bowl” than leaks out via glaciers, Greenland gains ice and sea levels fall.  If more ice reaches the ocean than accumulates inland, sea level rises. But predicting any imbalance is difficult.

During the last 100 years, Greenland oscillated between gaining and losing ice. Its greatest loss raised sea level by 0.07 inches in 2012, about half the total sea level rise of 0.12 inches a year. That accelerated loss was trumpeted as just what climate models predict. However, Greenland’s melt rates then declined and by 2017 it was gaining enough ice to slightly reduce sea level rise.

Furthermore, the cause of rapidly melting ice since the 1990s was fewer clouds. Fewer summer clouds allow more solar heating and cycles of atmospheric circulation naturally alter cloud cover. In addition, researchers reported Greenland’s ice-free regions experienced various warming and cooling trends over the past 15 years, but concluded if there was any general trend, “it is mostly a cooling”. They also admitted they “cannot differentiate between anthropogenic forcing [in other words: warming from human added CO2] and natural fluctuations.”

A similar warming and melting episode occurred decades earlier. Climate scientists determined Greenland had warmed most rapidly between 1920 and 1940. As reported by the IPCC, “temperature has risen significantly since the early 1990s, reaching values similar to those in the 1930s.”Regards accelerated rates of sea level rise from melting ice, the IPCC reported “It is likely that similarly high rates occurred between 1920 and 1950.”  Intriguingly, much lower CO2concentrations still resulted in similar warming, melting and rates of sea level rise.

Until Greenland’s temperatures and ice-melt exceed the 1930s episode, scientists cannot distinguish between natural variability and human-caused warming. The current trend is too short to be certain, but the past 2 years suggest Greenland is now entering a cooling cycle. In fact, based on my analyses of published scientific reports regards decades-long cycles of migrating fish into and out of the Arctic, and circulation effects of Atlantic oscillations, I boldly blogged in 2014, we would soon see Greenland begin to gain ice, as it is now doing.

Of course, that prediction was attacked by the ill-informed. They claimed my analyses of published scientific observations was cherry-picking, pseudo-science and I ignored the (mythical) 97% consensus.  My response is always, there is absolutely no consensus regards climate’s sensitivity to a doubling of CO2. Some IPCC experts predict 1 degree warming, others predict as much as 5 degrees. Nonetheless the scientific method demands, to prove rising CO2is causing an effect like melting Greenland ice, we must show current changes exceed past natural variability. But most people are unaware that has yet to happen. 

We are an adaptable people. Seawalls we build to protect our coastal homes for the next hundred years, likely need to plan for just 8 inches of sea level rise, but certainly not 5 or 10 feet. Yet to be confident, we need another 20 years to determine the contribution of natural cycles.

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

Wednesday, March 6, 2019

Scary Climate Campfire Stories

Scary Climate Campfire Stories

Several politicians and a few scientists tell us we are facing a climate crisis. They warn if we do not act now, we’ll leave our children an uninhabitable world. Naturally nobody wants that. But throughout history, the public has been bamboozled by various “end of the world” stories. I’m reminded of the Heaven’s Gate Cult. Highly educated members were conned into believing a spaceship, hiding behind the approaching Hale-Bopp comet, was coming to save them from our deteriorating world. On March 26, 1997, 39 followers committed mass suicide. Its disturbing how easily end of the world fears override basic critical thinking. 

My whole professional career I’ve advocated for wise environmental stewardship. My research in the Sierra Nevada restored a watershed and increased wildlife. I’ve warned that landscape abuse destroys ecosystems. I’ve pointed out how over-hunting and invasive organisms endanger species. I’ve noted island extinctions occurred when humans imported rats, cats and mosquitoes that attacked ill-prepared native species. But, in contrast to abundant media hype, I have yet to verify a single climate-change induced extinction. 

Understandably, to most people, a one degree change in global temperature over the past 150 years, does not seem fatal. I studied micro-climates. Over a distance of a few hundred feet from bare ground to forest shade, summer temperatures will vary by over 20 degrees. We endure a greater temperature change between night and day. Still some scientists and politicians push a narrative that just a one-degree change in global temperature over a period of 100 years has been deadly. But what’s their evidence?

The first highly publicized climate “tragedy” was Camille Parmesan’s claim that global warming had caused population extinctions that pushed California’s Checkerspot butterfly’s range northward and upward. Such a catastrophic assertion attracted the Intergovernmental Panel on Climate Change (IPCC). So, Parmesan became one of just 4 biologists on the IPCC in 2001. The Union of Concerned Scientists’ website also hyped Parmesan as a climate change heroine! In contrast, every other butterfly researcher argued it was California’s growing sprawl and resulting landscape changes that decimated the Checkerspot’s prime habitat.

Hoping to separate landscape changes from climate change, I tried to replicate Parmesan’s iconic study. But she never published her data. In a gross violation of scientific process, she refused to share her data. We battled, but it was finally admitted many populations that she had claimed had been extirpated by climate change, were now thriving. Unfortunately, such good news was never publicized. That was my first taste of dishonest climate fear-mongering. 

In 2010 so-called experts suggested polar bear populations were declining. They claimed global warming would extirpate two thirds of all polar bears by 2050. But today no populations are in decline. Basic biology argues less sea ice allows more photosynthesis which increases plankton abundance. More plankton support more fish and seals, which in turn feed more polar bears. Like the Inuit who steadfastly claim it is the “time of the most polar bears”, my 2012 analyses found polar bear populations were increasing. Accordingly, the global population has now increased from about 25,000 to 30,000 and researchers from Norwayto Alaska are reporting very fat polar bears.

Fat Polar Bears

In Antarctica, a few scientists hyped penguins were “marching to extinction.” In 2009 both Emperor and Adelie penguins were considered healthy and “species of least concern”. Oddly, despite larger populations, both species were downgraded in 2012 to “near threatened” based only on climate change predictions. Nonetheless with the discovery of new colonies and the robust growth of known colonies, Adelie penguin abundance increased from 4 million to 8 million. Perhaps climate change benefitted Adelie penguins? So, in 2016 experts reverted their status back to “species of least concern”.

Elsewhere a few scientists argued global warming was pushing adorable rabbit-like pikas off mountain tops into extinction throughout the western USA.  Instead, further research proved pikas are actually expanding into lower and warmer elevations. 

In 2008 climate scientists claimed children would no longer know what snow is. Yet in 2019 snowfall from Hawaii to Wisconsin has been breaking records. Inconsistent with global warming theory, in the northern hemisphere, winter and autumn snow cover has increased. Only spring-time snow cover has decreased.

For several decades, bogus catastrophic climate-change claims have come and gone. Claiming the world is destined for climate hell in 12 years is just another scary campfire story. In contrast, scientists are observing that rising CO2has a fertilization effect promoting a greening of our planet! If we truly care about nature, rising CO2is not the problem. There are far more important problems to address!  Detrimental changes to our ecosystems are driven by overhunting, invasive species and loss of habitat.

Wednesday, February 20, 2019

The Scientific Baloney Detection Kit

published in What’s Natural? column of Pacifica Tribune February 20, 2019
Dealing with the Climate Uncertainty Monster

Politicians from all sides manufacture “crises” and “demons” to promote their agendas superficially designed to fight those crises.  In his book “The Demon Haunted World”, Carl Sagan famously published his Scientific Baloney Detection Kit; a “do and don’t” list to guide honest scientific inquiry. Sadly, climate science has been too politicized. But Sagan’s advice can help separate the politics from honest science regards claims of a “climate crisis”.
The very foundation of scientific inquiry demands a vigorous skeptical challenge to every hypothesis. Several different hypotheses can explain the same phenomena. Anyone, scientist or layperson, can make assertions and models. But claims are not reliable science until rigorously tested and well vetted. Based on this understanding, our oldest scientific society, the Royal Society of London for Improving Natural Knowledgethat Sir Isaac Newton once presided over, made “Nullius En Verba” its motto. It means take “no one’s word for it’.
We are all naturally blinded by our beliefs. To overcome our biases and strive for a greater scientific truth, our discussions will be well served if guided by Sagan’s principles. Below I paraphrase the most pertinent points in Sagan’s Scientific Baloney Detection Kit. (I add my comments in parentheses)
1.    Do: Encourage substantive debate on the evidenceby knowledgeable proponents of all points of view. 
(Saying there’s no more debate triggers the Baloney alert)
2.    Don’t: Avoid arguments from authority. They carry little weight  - “authorities” have made mistakes in the past.
(Unable to refute Einstein’s ideas, his antagonists claimed authority via consensus and published “100 against Einstein”. Evoking the mythical “97% of all scientists agree” is a similar tactic.)
3.    Don’t: Don’t attack the arguer, attack the argument.
(Mud-slinging dominates politics. Dismissing valid arguments by calling the arguer a “denier” muddies the science.)
4.    Do: Spin more than one hypothesis. Think of all the different ways in which something could be explained. Think of tests by which you might systematically disprove each of the alternatives.
(Climate change is extremely complex and governed by many variables. The aim of the What’s Naturalcolumn is to delve into all those complexities. Detailing natural climate change is not denying a greenhouse effect.)
5.    Don’t: Don’t get overly attached to a hypothesis just because it’s yours. Compare it fairly with the alternatives. See if you can find reasons for rejecting your favored hypothesis. If you don’t, others will.
6.    Do: Ask whether a hypothesis can be, at least in principle, falsified.
(Unfortunately, predictions generated by climate change theory cannot be falsified or verified by simple experiments or short-term weather events.)
7.    Don’t: Don’t argue via adverse consequences.
(Claiming we will be “underwater in 70 years” or the world will be “irreversibly destroyed in 12 years”, are common adverse consequences; scare tactics that set off a Baloney alert)
8.    Don’t: Don’t “appeal to ignorance”. In other words, don’t claim that whatever has not been proved false then must be true.
(The earliest claim that 97% of all scientists agree, was an appeal to ignorance. It was assumed if authors did not explicitly disagree with CO2 driven climate change theory, then they must all agree. In subsequent surveys, only 22 to 32% of scientists ever replied. Of those responding, only 49% believed humans are causing more than 50% of observed climate change. That means only 16% have actually agreed.)
9.    Don’t: Don't confuse correlation with causation.
(A recent extreme weather event happening when CO2 concentrations are high, may or may not have been worsened by high CO2. Far worse weather events happened over the past thousand years.)
10.  Don’: Don'ttuse straw man arguments — caricaturing a position to make it easier to attack.
(A common straw man attack I encounter has been ‘Jim Steele ignores the effect of rising CO2only pointing out other possible reasons for climate change’. I do indeed point out natural causes to provide a greater climate perspective. But I never ignore the greenhouse effect. Clearly climate has been changing since the 1800s. CO2concentrations are unprecedently high and CO2 is a greenhouse gas. Those are undeniable facts on which we all agree.
But there is absolutely NO scientific consensus regards how “sensitive” the earth is to a doubling of CO2concentrations. IPCC estimates of how global temperature will respond to a doubling of CO2range greatly from 1°to 5°C. To accurately determine the earth’s sensitivity to higher levels of CO2, we must accurately assess natural climate change.)
11.  Don’t: Don't just count the “hits” and forget the “misses” when evaluating a hypothesis. 
(There are many hits, yet many misses by both CO2 global warming theory and natural climate change theories.  The science is not settled and the time for rigorous debate has not passed.)
Jim Steele authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

Wednesday, February 13, 2019

Changing Sea Levels: Sinking Lands vs Rising Sea

(web version of column article published in Pacifica Tribune February 13, 2019 )

What’s Natural? 

Changing Sea Levels - Part 1

Flooded Sinking Land in New Orleans after Hurricane Katrina

Local sea levels appear to rise when ocean volumes increase, but also when the land sinks. Scientists increasingly warn that coastal cities are sinking much faster than ocean volumes are rising. Pumping out groundwater not only causes lands to sink, it increases the oceans’ volume. China’s Huanghe Delta is sinking 10 inches a year. Southeast Asian cities battle sinking rates of 1.2 to 2.4 inches per year. Regions around Houston, Texas had sunk 10 feet by 1979; a disaster waiting to happen where hurricanes commonly generate 15-foot storm surges. Likewise, New Orleans was doomed by sinking 1.4 inches per year. Built on marshland, San Francisco’s airport sinks 0.4 inches per year.

In contrast, ocean warming plus added glacial meltwater are estimated to have only added 0.06 inches per year to sea level from 1850 to 1990, punctuated by decades that accelerated sea level rise to 0.14 inches a year. Still, that fastest rate of modern sea level rise remains only one-tenth of New Orleans’ sinking rate. 

Better water management could minimize the primary causes of sinking coastlines. But even if climate policies could reduce our carbon footprint, natural sea level rise that began in the 1800s will likely continue. To what degree rising CO2concentrations are accelerating sea level rise is still debated. Prominent climate scientist Dr. Michael Mann gives scant attention to the critical issue of sinking lands. He prefers scary models supporting his theory regards a rising CO2effect on sea level, “We’re talking about literally giving up on our coastal cities of the world and moving inland.”  Likewise, at California’s local coastal planning meetings, Mann’s followers similarly advocate moving inland, otherwise known as “managed retreat”. 

Intriguingly, San Francisco and North America’s west coasts have not experienced a rising sea level trend since the 1980s. Equally curious, using the average estimates from all researchers the 2007 Intergovernmental Panel on Climate Change (IPCC) reported known contributing factors only explained 40% of 20thcentury sea level rise. So, there is still much to learn.

San Francisco Sea Level (data from NOAA)

So, does Mann’s disaster scenarios represent an extreme climate doomsday cult? Or is he offering sage scientific advice we should heed?

Some researchers and politicians argue any accelerating rate of sea level rise must be the fingerprint of a human contribution as some models predict. But that is simply not true. In a 2007 peer-reviewed paper, On the Decadal Rates of Sea Level Change During the Twentieth Century, researchers reported rates of sea level rise accelerated up to 0.2 inches/year every 10 years, followed by a decade of deceleration. Sometimes sea levels fell.  Some of Mann’s followers believe it’s impossible for sea levels to fall in an age of climate warming. But they are ill-informed. 

20th Century changing rates of global sea level rise

Sea level remains un-changed when the same amount of water evaporating from the ocean returns to the ocean. However, when more rainfall remains on the land, sea levels fall. During the last Ice Age, rainfall stored in ever-growing glaciers caused global sea level to fall by 400 feet. Although those melting glaciers then raised sea level back to its current level, sea levels have yet to fully recover. Large amounts of meltwater that sank into the ground are still flowing slowly but surely back to the oceans.

Furthermore, water need not be stored as ice. When rains fall over land-locked landscapes with no outlets to the ocean, that precipitation similarly returns to the ocean via slow-moving sub-surface flows or evaporation. Rainfall over Nevada that sinks into the ground requires thousands of years to reach the Pacific. A similar fate befalls snowmelt and rainwater entering Lake Tahoe, and melt-water from Sierran glaciers draining into land-locked Nevada. Analyses of global sea level change have yet to fully incorporate the fact that over 13% of the earth’s land surface consists of landlocked basins slowly supplying ancient groundwater to today’s oceans.

Since the 1990s, satellites likewise detected a 10-year cycle of accelerating and decelerating sea level rise. A period of more El Niños followed by more La Niñas likely explains the 10-year accelerated rise followed by a 10-year deceleration. During the most recent deceleration, from 2010 to 2011 a La Niña amplified monsoons carrying above average rainfall into Australia’s landlocked basins. This caused global sea level to fall by nearly 0.3 inches. Amazingly, global sea level fell despite Greenland simultaneously experiencing its greatest ice melt. Conversely, during earlier El Niños, above average rains fell back onto the ocean, accelerating sea level rise. 

There is still no consensus regards Greenland and Antarctic contributions to sea level. There is also significant debate regards what adjustments need to be applied to satellite data. However, that discussion must wait for part 2. Until then, I urge local planning commissions to wait at least 20 more years for more data before “giving up on our coastal cities of the world and moving inland”.

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


Wednesday, January 30, 2019

Climate Fish Tales

from the column What’s Natural? published in the Pacifica Tribune and 5 other SF Bay Area papers January 30, 2019

American folk lore is filled with stories of how Native Americans observed changes in wildlife and foretold future weather changes. I was fascinated by an 1800s story of Native Americans inhabiting regions around Marysville, California who had moved down into the river valleys during drought years. They then moved to higher ground before devastating floods occurred. Did they understand California’s natural climate cycles? Could changes in salmon migrations alert them? 

Observing salmon has certainly improved modern climate science. In the 1990s climate scientists struggled to understand why surface temperatures in the northwest sector of the Pacific Ocean had suddenly become cooler while temperatures in the eastern tropical Pacific suddenly warmed.  Climate models predicted no such thing. However, fishery biologists noted salmon abundance in Alaska underwent boom and bust cycles lasting 20 to 40 years. When Alaskan salmon populations boomed, their populations from California to Washington busted. Conversely, decades later when Alaskan populations busted, those more southerly populations boomed.

Scientists soon realized the observed alternating patterns in fish abundance not only coincided with those puzzling changes in ocean surface temperatures, but also with regional drought-flood cycles, glacier growth and retreat, and tree-line advances and retreats. Tree rings and lake sediments also recorded cycles of 5 major Sierra Nevada droughts alternating with wetter decades during the past 300 years. This all convinced scientists of the existence of a natural “ocean oscillation” driving climate change. This climate see-saw was finally named the Pacific Decadal Oscillation (PDO) in 1997. (Science uses the term “oscillation” to describe repeating cycles with general, but imprecise time periods.)

The newly characterized PDO had yet to be included in climate models. But progress in climate researchrecently argues the PDO largely explains western North America’s last 100 years of climate change. So how do we separate naturally caused weather extremes from human contributions? Unfortunately, few Americans are aware of these “cycles”. But if we don’t educate our children about natural climate change, the next generation will surely fall victim to every Chicken Little climate story told by scientifically illiterate politicians or by journalists who profit from sensationalism; if it bleeds, it leads!

Similar fish tales have been reported globally. In the Atlantic, a similar oscillation was officially recognized in 2000. But according to fishery records, that oscillation has been noted since the 15thcentury. Norwegian fisheries documented 30 to 60-year boom and bust cycles for herring, sardines and anchovies. In the 1930s Greenland experienced a warming rivaling today’s temperatures. Simultaneously Danish Arctic ice records showed extensive sea ice melt. This all coincided with intrusions of warm Atlantic waters that brought Atlantic cod and herring northwards. Fish retreated decades later coinciding with cooling temperatures and recovering sea ice. Today’s Arctic warming and reduced sea ice has likewise coincided with greater intrusions of warm Atlantic water. Will there be a return cycle of retreating Atlantic waters that causes sea ice to rebound again?

Finally, contrary to recent claims of “unprecedented” rapid warming, Greenland’s air temperatures warmed more rapidly during the 1920s to 30s causing melting around Greenland’s ice cap. After warm waters retreated, Greenland gained ice from the 1960s to the 90s. A new period of rapid melting began in the 90s but peaked in 2012. Since then, Greenland’s melting gradually subsided and Greenland gained ice in 2017 and 2018, perhaps signaling a new cooling phase. 

And there is a truly optimistic fish tale. Monterrey Bay Aquarium Research Institute’s senior scientist Dr. Francisco Chavez is a Peruvian oceanographer who studies the PDO and upwelling effects on marine life. The upwelling region off the coast of Peru is known as the most productive fishery in the world because robust upwelling brings nutrients from dark ocean depths up to the sunlit layers increasing photosynthesis. During the cold Little Ice Age - 1300 to 1850 AD - marine life off Peru’s coast was at a low point. Starting in the late 1800s as temperatures warmed, plankton rapidly increased, which promoted rapid increases in fish abundance. This dramatic improvement in marine life is well documented in preserved sediments.

To promote plant growth, commercial greenhouses add an additional 1000 ppm to the current 400 ppm of atmospheric COconcentrations. So, did marine life also increase due to rising levels of CO2? Or perhaps, because land temperatures warm faster than ocean temperatures, did stronger winds increase ocean upwelling? Whatever the drivers of the observed increases in ocean life, it appears likely that rising COcontributed definitive benefits. 

If we are to truly understand climate change and discern human contributions, these fish tales all suggest we must first account for natural oscillations that have surely been operating for millennia. So, to rephrase Mark Twain, ‘reports of the earth’s imminent death within 18 years, via rising CO2, are likely greatly exaggerated’.

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

Wednesday, January 16, 2019

Disentangling California Droughts

Devastating droughts are a great concern. Droughts disrupt ecosystems, agriculture, and drinking water supplies. Contrary to headlines suggesting we have only 12 years before descending into climate hell with more severe droughts, historically, Californians are not experiencing more severe droughts. Despite low stream flows and withering plants, there’s no agreement on how to best define drought. Different methods suggest different severities for the same drought. Thus, the Intergovernmental Panel on Climate Change’s recent assessment, downgraded their ability to detect the causes of drought to “low confidence”.

Ocean circulation determines how much rain reaches the land. Each summer, California naturally experiences months of drought because storms carrying ocean moisture are blocked. Every few years, a rainy El Niño year alternates with drought producing La Niñas. But 20 years of more frequent La Niñas can cause 20 years of drought. To address natural precipitation shifts, California constructed ~1400 dams, storing water during wet years that can be released during drought years. Yosemite’s Hetch Hetchy reservoir supplies about 25% of San Francisco’s drinking water and 17% of its electricity. Misguided attempts to remove its dam would be disastrous for humans with scant environmental benefits.

NOAA scientists analyzed California’s 2011-2014 drought concluding it was dominated by a La Niña and natural variability. In contrast, their models suggested any greenhouse contribution was “very small”. Similarly, drought-sensitive tree rings suggested the extremely low precipitation was not unprecedented nor “outside the range of natural variability”. For 1200 years, extremely low rainfall happens a few times every century. 

However, because higher temperatures can theoretically increase evaporation and dry the land, some researchers define drought by calculating the Palmer Drought Severity Index (PDSI). Despite using the same tree rings, the PDSI transformed a natural California drought into the worst in 1200 years, evoking global warming fears. 

What to trust? 

Most scientists agree the PDSI is biased towards worse droughts, because it assumes higher temperatures always dry the land. However, the opposite is also true! Without moisture to absorb heat, drier conditions produce higher temperatures.  Studies using more accurate measurements than the PDSI find no increase in global droughts. 

Before significant COwarming was possible, Dust Bowl years from 1928-1939 and the 1950s drought were the most severe 20thcentury American droughts. La Niña-like ocean temperatures blocked rain storms and triggered the Dust Bowl while plowing up native grasses made it worse. More concerning is 2 century-long megadroughts between 900 AD and 1400 AD. Trying to survive increasing dryness Native Americans created dams and irrigation canals. But those droughts finally led to the demise of once thriving Pueblo Cultures such as Mesa Verde.  

Will our modern water infrastructure protect us if drought history repeats? 

Reducing our carbon foot print or whacky plans to shade the earth from the sun to lower global temperatures will have no effect. Lower temperatures may in fact increase major droughts. Droughts during the 1750s, 1820s, and 1850s-1860s were similar to the 1950s. During the cool 1500s, the southwestern United States and Mexico suffered decades long droughts of “epic proportions”.

Coincident with the Pueblo Culture’s demise, drought is detected in sediments of San Francisco Bay. Droughts reduce stream flows that normally flush the bay, allowing salty ocean water to encroach deeper into the Bay’s delta. Past droughts caused the Bay’s Suisun Marsh to become 40% saltier. Suisun Marsh is now considered the only sustainable habitat for a critically endangered fish, the Delta Smelt. The current theory for the Delta Smelt’s demise is agricultural diversions of freshwater raised salinity to intolerable levels. That perceived competition for freshwater has pitted farmers against efforts to save the smelt.  Learning how the smelt survived a thousand years of much higher salinity might provide a win-win solution. 

Agricultural and urban needs also compete with salmon survival. One promising win-win solution is having juvenile salmon develop in irrigated rice fields after hatching. Experiments show young salmon grow much bigger in rice fields. Additionally, low stream flows hamper salmon migration. But when enough water is naturally stored as groundwater, seasonal groundwater release can maintain adequate summer stream flows.  Unfortunately, landscape changes have caused stream channels to cut downwards, draining local groundwater and drying the land. Restoring streams and groundwater would provide great benefits.

During my research in the Sierra Nevada, a meadow we were monitoring began to dry; willows died, and bird populations crashed. Many suggested it was just what global warming models predict. However, we determined a railroad track built over 100 years ago had caused the meadow’s stream channel to cut downwards, draining its groundwater. I initiated a watershed restoration. Vegetation quickly recovered, and wildlife increased. Despite California’s years of extreme drought, the restored meadow remained wetter than it had before restoration and before the drought. 

So, I warn: knee-jerk reactions simply blaming climate change for devastating dryness, blind us to real causes and real environmental solutions.