Wednesday, February 12, 2020

The Monarch Abundance Roller-Coaster

Monarch caterpillar and milkweed flower

published in the Pacifica Tribune February 12, 2020

What’s Natural

The Monarch Abundance Roller-Coaster- part 2

Indeed, some Monarch populations have declined in recent decades. However, the species as a whole is not endangered.  Monarchs experience booms and busts as do many insects. So, we still need to determine if recent population declines are part of natural cycles or due to human disturbance.  Counter-intuitively, humans purposefully and unwittingly have both increased and decreased monarch populations.

Eighteen thousand years ago, most of the breeding habitat for North America’s eastern monarch populations was covered in ice sheets and permafrost. Unfortunately the monarchs main food plants, Common Milkweed and Showy Milkweed, are frost intolerant.  Today those milkweeds die back each autumn, forcing monarchs to migrate south. Habitat south of the ice sheet was covered with dense forests, which also limited the milkweed species that require warm open habitat, and disturbed ground. As the earth warmed and ice retreated, milkweed migrated northward colonizing glacially disturbed landscapes. Likewise, monarch populations expanded.

However, some scientists suggest the monarch’s awe-inspiring abundance really boomed during the past 200 years after European colonists began extensively logging America’s dense southern and eastern forests. Logging created more open fields and pastures, more farms and roadways; habitat milkweeds still favor today. More milkweeds, more monarchs.

In addition, gardeners adored showy milkweed flowers, so began planting milkweed across the globe. Again, the monarchs followed. Suddenly monarchs expanded out of North America and across the globe. Around 1850 monarchs reached Hawaii likely as stowaways on trading ships, then spread to several Pacific Islands. With optimally warm climates monarch populations boomed, feeding on introduced milkweeds and closely related native species. But monarchs often decimated their food plants causing island monarch populations to bust.

Monarch butterfly's global expansion

By the turn of the century monarchs were found in Australia, New Zealand, Indonesia, the Philippines and southeast Asia. They also spread across the Atlantic to the Azores, Canary Islands, Spain, Portugal and Morocco. In many regions, monarch populations are now stable. Where warm temperatures permitted milkweeds to grow all year, monarchs no longer migrated. Having successfully colonized much of the suitable regions of the world, insect experts don’t fear monarch extinction. However, concern remains for the USA’s eastern population that winters in Mexico.

The wintering population in Mexico was first surveyed in 1993. By 1997, the population boomed, tripling its abundance. But then winter populations worrisomely declined. Paradoxically, surveys of monarchs in their midwestern breeding habitats found no evidence of declining populations. But such surveys were done in “natural” habitat, not agricultural fields. It now appears the rise and fall of milkweed in agricultural fields drove the booms and busts of 20th century monarchs.

Having successfully colonized roadway ditches and any open disturbed landscapes, milkweed species began invading the open fertilized ground between rows of crops. Monarch populations boomed, while the farmers’ crops suffered. Studies estimated milkweed competition reduced harvests of wheat and sorghum by 20% and most states declared milkweed a noxious plant. But when farmers tried to eradicate milkweed by mowing, they only stimulated its underground roots promoting a greater infestation. Likewise, for herbicides that only eliminated stems and leaves. Tilling the fields only fragmented milkweed roots, again causing milkweed to multiply.  The growing battle to eliminate milkweed started the monarch’s mid 20th century decline. With the 1970s discovery that the herbicide glyphosate killed the whole plant, the loss of milkweeds in the monarch’s human-made breeding grounds accelerated.

Still, there was room for optimism. Monarchs continue to breed throughout their traditional habitats. More efficient agriculture allowed more land to revert to “natural” states.  Furthermore, the federal Conservation Reserve Program (CRP) was successfully compensating farmers to take environmentally sensitive land out of crop production. The good news was the majority of Midwest monarch breeding habitat was found on lands enrolled in the CRP.  But fossil fuel fears reversed all that promise. The 2005 Energy Policy Act and the 2007 Energy Independence and Security Act instituted subsidies and quotas that rewarded biofuel production.

As a result, U.S. corn harvests for ethanol rose from 6% in 2000 to 43% percent in 2012. The monarch’s remaining “natural” breeding habitat was increasingly eroded as corn acreage increased by 17 million acres since 2006. Lured by lucrative biofuel subsidies, farmers increasingly abandoned the CRP program. Soon thirty percent of the CRP’s sensitive lands converted back to growing corn and soybeans for biofuels.

Perhaps the loss of milkweed in agricultural lands, will only reduce monarch populations to their “natural’ levels of the 19th century, before modern agriculture opened the land for more milkweeds. Monarchs may become less common, but not endangered. For monarch lovers, our best safeguard is to halt the spread of biofuels and plant more milkweed in our gardens.

Saturday, February 8, 2020

Media’s Horribly Dishonest Antarctica Propaganda

Attempting to reinforce the climate crisis narrative, a recent high temperature record in Antarctica has been misleadingly ballyhooed as an example of global warming by the world’s largest media outlets – New York Times, BBC, the Guardian, etc.  Although the NY Times tries to sell their paper with the slogan “The Truth is Worth It”, their misleading articles suggest you should spend your money elsewhere.  These media giants seem more intent on scaring the public and manufacturing a false climate crisis, than educating the public about the real physics that cause weather changes causing Antarctica’s temperature record!

The NY Times wrote,  “Antarctica, the coldest, windiest and driest continent on Earth, set a record high temperature on Thursday, underscoring global warming” But the fact that Antarctica is the coldest place on earth, has nothing to do with a  temperature record at a single weather station, Esperanza. Esperanza is located at the warmest, most northerly part of the mountainous Antarctica peninsula. Esperanza is most sensitive to El Nino warming. It most sensitive to the southward flow of warm moist subtropical winds.  And Esperanza’s topography always amplifies temperatures when winds from the northwest cause foehn wind events. What happened at Esperanza has nothing to do with Antarctica’s overall climate trends, never mind any global warming trend.

The Guardian wrote, Antarctica “is one of the fastest warming places on earth, heating by almost 3°C [5.4°F] over the past 50 years”. However, the Guardian hides the fact they are using zombie data. Recent research shows a cooling trend since the year 2000 and that contradicts any CO2 driven global warming theory.

In the 2016 peer-reviewed paper “Absence of 21st century Warming on Antarctic Peninsula consistent with Natural Variability”,  Antarctic climate experts documented that from 1979–1997, Antarctic had indeed experienced the globe’s fastest warming temperatures, increasing by 3.2 °C [5.8 °F] per century. In contrast, from 1999–2014, temperatures then decreased at a rate 4.7 °C [8.5 °F} per century. This strong cooling trend is rarely reported or referred to by media alarmists. Dishonestly, the Guardian ignores the recent cooling trends to suggest a recent one day Esperanza temperature record is “a sign that warming in Antarctica is happening much faster than global average” and “is the foreshadowing of what is to come.”  Likewise the NY Times dishonestly claims, “The high temperature is in keeping with the earth’s overall warming trend, which is in large part caused by emissions of greenhouse gases.

The Guardian’s author Graham Readfearn engages in his typical alarmist distortions to write, “Previous research from 2012 found the current rate of warming in the region was almost unprecedented over the past 2000 years.”  Really? Almost unprecedented? The paper he refers to actually stated, “Although warming of the northeastern Antarctic Peninsula began around 600 years ago, the high rate of warming over the past century is unusual (but not unprecedented) in the context of natural climate variability over the past two millennia.

The BBC gets the prize for going completely off the rails stating, “Scientists warn that global warming is causing so much melting at the South Pole, it will eventually disintegrate - causing the global sea level to rise by at least three metres (10ft) over centuries.” But there has been no warming trend at the south pole nor in east Antarctica as exemplified by the Dumont D’Urville weather station.

For those readers who only trust peer reviewed papers, I suggest reading, “Foehn Event Triggered by an Atmospheric River Underlies Record-Setting Temperature Along Continental Antarcticawhich thoroughly investigated the causes of the previous 2015 record-setting temperature at Esperanza.

What is a foehn event? Foehn events cause rapid extreme temperature jumps simply due to changes in the air pressure as winds descend from a mountain top. During the 2015 foehn event, Esperanza’s daily temperature jumped from 0°C [32°F] 2 days before, to a record setting 17.5°C [63.5°F]. Elsewhere, Antarctic foehn winds are common and have been extensively studied, often raising maximum temperatures by 10+°C [18+°F]  above normal.

As seen in figure “c” below, weather systems in 2015 had driven a warm and humid subtropical air flow from the northwest onto the northern Antarctic Peninsula. That warm air flow raised the western peninsula’s temperatures above normal. Then those winds rose up and over the peninsula’s mountain range amplifying temperatures even further on the east side of the peninsula. As the air rose, its water vapor condensed, both releasing precipitation and releasing latent heat that had further warmed the air.  As that warmer and drier air passed over the mountain crest and descended onto Esperanza, temperatures warmed further as air pressure increased temperatures at a rate of over 5°F for every 1000-foot drop in altitude. A typical foehn event.

Warm humid atmospheric river headed to Antarctic Peninsula 2015

As happens in all the earth’s mountainous regions, foehn winds warm the air due to simple physics and well-established gas laws. Warming does not require any added heat from the sun or CO2. During Esperanza’s 2015 record warmth, temperatures had hovered around 0.5°C [32.9 °F] the day before. But as winds from the northwest increased air flow over the peninsula’s mountains, those foehn winds increased Esperanza’s temperatures by 17.5 °C [31.5 °F]. Those same dynamics were in play during the February 2020 record temperature.

In contrast to several paragraphs trying to implicate global warming, the Guardian did offer one sentence hinting at a foehn wind warming, quoting Dr. Renwick: “higher temperatures in the region tended to coincide with strong northwesterly winds moving down mountain slopes – a feature of the weather patterns around Esperanza in recent days.”

Also a quote from Dr Steve Rintoul, an Antarctic expert at CSIRO, admitted: “This is a record from only a single station, but it is in the context of what’s happening elsewhere and is more evidence that as the planet warms we get more warm records and fewer cold records.” 

But Rintoul is not sharing all the facts. The current context for the Antarctica Peninsula is that for over a decade it has experienced cooling temperatures driven by natural variability. In fact, glaciers in Esperanza’s region have also expanded.  Esperanza’s record temperature simply happened due to foehn winds despite a cooling trend. Unfortunately, the media would rather scare the public to promote a climate crisis, than honestly educate them about the causes of natural climate variability.

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