Wednesday, December 6, 2017

Listing the Bearded Seal as Threatened: A Disturbing Victory for Untestable Hypotheses and Flawed Models

Bearded Seal on typical small ice floe

I’m a longtime supporter of the Endangered Species Act (ESA). When properly abided by, it seeks to prevent extinctions and requires humanity to seek a win-win scenario where both humans and all the other species can thrive. Unfortunately, some organizations like the Center for Biological Diversity have weaponized the ESA in order to manipulate the debate on energy policy and climate change by petitioning the courts to designate perfectly robust species as endangered or threatened from future climate change. Such abuse has understandably caused a growing backlash that ultimately threatens the ESA’s original mission. The listing of the polar bear is a case in point. Despite Center for Biological Diversity assertions that “Arctic sea ice melt is a disaster for the polar bears”, research shows polar bear populations have continued to thrive and increase.

The Center for Biological Diversity also petitioned to list thriving populations of Bearded Seals as threatened or endangered by melting sea ice. In response to their petition, the National Marine Fisheries Service (NMFS) assembled a Bearded Seal Biological Review Team (BRT). The BRT’s report can be read here. Oddly, despite promoting a threatened designation, the BRT reports Bearded Seals have existed for over 1-2 million years, surviving far greater bouts of climate change as the earth bounced between several ice ages and warmer interglacials.

On average, every hundred thousand years for the past half million years, the earth has descended into an ice age. Ice accumulation on land lowered sea level by about 400 feet (120 meters). The Arctic’s presently bountiful shallow seas were left high and dry and passage from the Pacific Ocean to the Arctic Ocean was completely blocked by the resultant Beringia land bridge. Any seals trapped in a frozen Arctic were likely extirpated. During the last ice age, seals also experienced far more rapid changes than they are experiencing now or that are predicted in the future. Despite the extreme cold of the last ice age, the BRT reported “more than 20 so‐called Dansgaard‐Oeschger oscillations have been documented … each with rapid warming to near inter‐glacial temperatures over just a few decades.” 

Melting ice during our recent interglacial, known as the Holocene, has been good for seals. Sea levels rose and flooded coastal areas to create what is now the seal’s prime shallow-water habitat. Our best scientific data has determined Arctic temperatures between 9,000 and 6,000 years ago were a few degrees warmer than today, eliminating remnant glaciers and minimizing Arctic sea ice. Sea levels peaked around 6000 years ago, allowing an increased flow of warm, nutrient-rich “Pacific Water” across the shallow Bering Strait into the western Arctic. Our best scientific evidence reveals periodic warm water inflows coincide with peak marine productivity.

Unaffected by a slight increase in CO2 concentrations, sea levels began to fall as glaciers began to expand over the past 5000 years, the Neoglacial. Glaciers reached their greatest extent during the Little Ice Age 150 years ago. During the Neoglacial, average Pacific Water inflows subsided, average sea ice has increased, and marine productivity decreased. During this cooling trend, there were several warm spikes, usually associated with life-enhancing inflows of both warm Pacific and Atlantic water. High inflows consistently correlate with reduced sea ice and greater marine productivity. If the hypothesized warming from greenhouse gases proves to be true and if it can prevent further descent into another ice age or another little Ice Age, it is more likely than not such a warming effect would benefit the entire Arctic food web that sustains “threatened” bearded seals.

The state of Alaska and the Alaskan Oil and Gas Association correctly challenged the “threatened” designation as an “arbitrary, capricious abuse of discretion, or otherwise not in accordance with law”. A district court agreed concluding that the listing indeed violated the Administrative Procedure Act. In that decision, the court reported it was troubling that the Beringia population of bearded seals was listed as threatened simply based on threats predicted by climate models that would not manifest until the end of the 21st century. However, that ruling was quickly appealed and now reversed, as the courts upheld the “threatened” designation.

The judge wrote the court was required to “defer to the agency’s [NMFS] interpretation of complex scientific data so long as the agency provides a reasonable explanation for adopting its approach.” The court also ruled that the ESA requirement for proving an imminent threat in the “foreseeable future” only required a scenario that it was “more likely than not” seals could be endangered.

The court ruling maintained that “as long as the agency states a rational connection between the facts found and the decision made [for listing] it must be upheld.”  Unfortunately judges who decide the validity of a Center for Biological Diversity claim, rarely have any background in biology or climate science. Those judges must rely on what lawyers assert are “the best available scientific data”. But lawyers and advocacy scientists only present the “best available scientific data” that supports their arguments, and ignore equally valid scientific data that contradict their claims. Unfortunately all the known facts were not presented. So even though 2 million years of climate history illustrated bearded seals are highly resilient, the court was swayed by a limited selection of models and untestable predictions. So, as Paul Harvey would say, here’s the rest of the story.

Defining Sea Ice as Critical Habitat

Although the Biological Review Team acknowledged “there is ample evidence that bearded seals have
adapted successfully many times to both large and rapid ecological changes” they argued “history is not, on its own, an assurance that bearded seals can adapt to the changes projected for the foreseeable future.” To make the case bearded seals were threatened, the BRT argued sea ice is a critical habitat required for birthing, nursing, molting and for resting while over prime foraging habitat. Because global climate models predict critical sea ice habitat will disappear as CO2 concentrations rise, they argue the seals are ultimately endangered. However ample evidence suggests sea ice is not a survival requirement.

When Bearded Seals do haul out onto sea ice, they prefer tiny floes of thin first-year ice. Climate change, whether natural or anthropogenic, will not eliminate that first-year ice. As the BRT reported, “sea ice will always persist from late fall through mid‐summer due to cold and dark winter conditions.”  Much of the Bearded Seal’s habitat encompasses seasonal ice zones where first-year sea ice is renewed every winter but melts completely every summer. The Bering Sea, Barents Sea, Baffin Bay, the Sea of Okhotsk, and Hudson Bay are all seasonal ice zones. Renewed winter ice reaches its maximum in late March about the time of the solar equinox. Simultaneously whelping (giving birth) begins in March and peaks in April followed by 2 to 3 weeks of nursing, a time with plenty of ice. The loss of thick multi-year ice over the deep Arctic basin in September has no effect on bearded seals survival.

Heavy sea ice is a bigger threat to bearded seals, so they avoid regions where sea ice cover is more than 90%. Heavy sea ice acts as a barrier that prevents access to their feeding grounds. Each winter bearded seals in the Pacific sector migrate southward as winter ice prevents access to their favored feeding grounds. As sea ice recedes with increasing spring and summer insolation, feeding grounds once again become available. Bearded seals are in competition with other benthic (sea floor) feeders, walrus and gray whales, who likewise migrate into the Arctic as the ice melts. Due to the advantage of accessing the sea floor as soon as dwindling sea ice permits, bearded seals are frequently associated with 70 to 90% sea ice concentrations. Although resting on floating ice above their feeding grounds imparts a small energetic benefit, it is not a life-saving requirement.

For example, although the sample size has been very small, studies of radio-collared seals in the Bering and Chukchi Seas observed those seals rarely hauled out at all, on land or sea ice, even when occupying ice covered areas. The BRT concluded that “at least in the Bering and Chukchi Seas, bearded seals may not require the presence sea ice for a significant part of the year”.

The BRT then manufactured an untested sea-ice threshold based solely on circumstantial evidence to assert whelping and nursing required sea ice concentrations over 25%. As the BRT stated, “Research suggests that, during the time of whelping and nursing, bearded seals prefer areas where the percent concentration of sea ice is >25%. Lacking a more direct measure of the relationship between bearded seal vital rates and ice coverage, the BRT assumed that this preference relationship reflects the species requirements for sea‐ice coverage.” Based Solely on that assumption wherever climate models projected ice falling below 25% concentration, they deemed it “inadequate for whelping and nursing.” [all emphasis mine]

But breeding seals’ ice association is not a matter of preference or a requirement!  To maximize the time spent over accessible foraging grounds, pups are born in the spring when winter sea ice begins its retreat. As the BRT reported, bearded seals prefer foraging in open ice cover where the sea floor is less tan 100 meters deep. Thus, to whelp in April and still remain for over shallow feeding grounds, seals are coincidentally surrounded by extensive winter sea ice. Figure 1 below illustrates the Pacific sector’s potential foraging grounds. White regions mark shallow areas, typically 50 to 100 meters depth. Because bearded seals cannot forage in deep waters (illustrated by the dark blue color), they cannot breed in ice free waters located south of the shallow Bering Sea.

The illustration’s colored lines represent the “ice front” position each month. In March, sea ice concentrations less than 15% are found to the south of the light green line. By peak whelping time in April, heavy sea ice concentrations (turquoise line) largely remain as in March. Thus, during the optimal season for whelping, 99% of their foraging habitat is covered by ice concentrations greater than 15% and as high as 100%. Seals do not prefer to breed in this heavy ice! They are forced to if they want access to required shallow feeding grounds. Consistent with this analysis, the BRT reports during the spring in the eastern and northern Bering Sea, the Chukchi Sea, and the Laptev Sea, where much of the first-year sea ice is heavily compacted, breeding bearded seals are not found in any significant numbers.

Bearded seals forced to breed in heavy ice
Figure 1. Monthly location of west Arctic ice front

On the other hand, bearded seals are definitely adapted to survive in ice free waters. Mating always happens in the water. Native Arctic hunters observe seals giving birth in the water. Furthermore, bearded seal pups are well adapted to enter the water immediately after birth. Harp Seals for example require weeks of development on the ice. To thermo-regulate harp seal pups are born with a white fur called the lanugo. The lanugo provides excellent protection from cold air, which is why baby Harp seals were heavily hunted for the fur trade. But the lanugo provides little insulation when wet. So after a few weeks, Harp seals molt their lanugo and gain a protective layer of fat so they can enter the sea. In contrast, most Bearded Seal pups amazingly molt their lanugo within the uterus. They are also born with a thicker layer of blubber and begin foraging in the sea right after birth. So, birthing on an ice floe is more likely a convenience, but not a requirement.

Although it has not yet been reported, newborn pups are probably capable of nursing underwater as well. Based on the amount of time spent in the water right after birth this seems likely. Marine mammals such as whales and manatees must nurse underwater. And although California Sea lion pups primarily nurse on land, they too have been observed nursing underwater.

In habitat where sea ice either melts completely or recedes beyond the limits of shallow-water feeding grounds, bearded seals simply come ashore. Observations of seals on dry land have been documented for the White and Laptev Seas, the Bering, Chukchi and Beaufort Seas, for Svalbard, the Hudson Bay and the Okhotsk Sea. The Okhotsk and Kamchatka populations thrive in the most southerly part of the seal’s range where ice melts completely each summer. There, bearded seals form numerous shore rookeries comprised of tens to hundreds of individuals, during a time that overlaps with molting.

Finally, their preferred small ice floes do not offer protection from the seals’ 2 major predators. Polar bears are well adapted for surreptitiously swimming up to floating ice and snatching an unwary seal. Killer Whales readily grab a seal from floating ice or tip that ice over, dumping the seal into the water where it is no match for the Orca. Thus, many lines of evidence suggest it is “more likely than not” that observations of bearded seals resting on sea ice platforms is only evidence of a convenience, not a survival requirement.

Small ice floes do not protect bearded seals from their predators

The IPCC Models

The Biological Review Team included one climate scientist, James Overland and he predicts the Arctic will be ice free within the next decade or two. (By “ice free” he means September ice will be reduced to about 1 million square kilometers.). Although there is a general consensus among models that rising CO2 will drive warming and continued ice melt into the future, IPCC models failed to predict the current level of rapid sea ice reduction. Because IPCC models projected currently observed sea-ice reduction would not occur until 2070, Overland believes IPCC models were simply too conservative. However other evidence suggests the models are flawed because they did not accurately incorporate natural variability. Nonetheless, Overland used a select group of 6 IPCC models to convince the courts rising CO2 concentrations threatened to destroy and modify the seals’ sea ice habitat.

For the BRT analysis, Overland culled the most flawed IPCC models. His chosen models had to simulate the seasonal changes in ice cover to demonstrate an accurate sensitivity to changes in solar insolation. In addition, chosen models had to simulate (hindcast), within 20% accuracy, September sea ice extent observed from 1980 to 1999. The number of IPCC models fitting this selection criteria was reduced to six. However, the time span to accurately test the models’ reliability was far too short. IPCC models attempting to replicate 20th century Arctic air temperatures have failed to reproduce the rapid warming from 1920 to 1940. Furthermore, those 6 models failed to accurately simulate observed sea ice extent for individual Arctic basins.

Of Overland’s 6 best models, all 6 only simulated past sea ice correctly in the Chukchi and Siberian seas. Four models correctly simulated sea ice in the eastern Bering seas.  Only one model could simulate recent sea ice in the western Bering and Barents sea. None of the models satisfactorily simulated sea ice in the Sea of Okhotsk, Hudson Bay and Baffin Bay, the Canadian Archipelago, or Greenland, Kara and Laptev Seas. As the BRT correctly cautioned, “loss of summer sea ice in the Arctic cannot be extrapolated to the seasonal ice zones which are behaving differently than the Arctic. For example, the Bering Sea has had 4 years of colder than normal winter and spring conditions from 2007‐2010, with near record sea‐ice extents, rivaling the sea ice maximum in the mid‐1970s, despite record retreats during summer in the Arctic.”

From Gillett 2008: IPCC models fail to simulate natural Arctic warming 1920-1940

As seen in the graph above from Gillett 2008, IPCC model simulations based solely on known natural factors (the blue line labeled NAT), erroneously reported no change in 20th century Arctic temperatures. Observations revealed (the black line labeled OBS) temperatures had naturally oscillated. Actual temperatures compared to model results were as much as 0.6 C degrees higher in the 1930s and 40s but then lower after the 1960s. More disconcerting, when models added the effects of CO2 and aerosols to natural factors (the red line labeled ALL), discrepancies between models and 1940s observations worsened. A modeling study by Johannessen 2004 failed similarly. In contrast to flawed CO2-driven models, it is well-documented that warming from 1920-1940 as well as the current sea ice loss is more parsimoniously attributed to changes in atmospheric and ocean circulations that pump warm southerly air and water into the Arctic. Although judges believed they were presented with the “best scientific models”, those best scientific predictions had failed to simulate past natural climate change.

The BRT did not inform the courts of research that shows a small Arctic cooling trend for the period 1901 to 1997, a trend contrary to the CO2 global warming hypothesis. A similar cooling trend was reported in the 1993 paper, “Absence of Evidence for Greenhouse Warming over the Arctic Ocean in the Past 40 years”. Nor did the BRT discuss research detailing how the loss of sea ice in the 1990s was not caused by warmer air, but by a shift in the Arctic Oscillation resulting in below-freezing winds that pushed thick insulating ice out into the Atlantic.

Furthermore, it’s not obvious that the BRT advised the judges that our best scientific data has observed that past and recent reductions of sea ice have coincided with intrusions of relatively warm Atlantic and Pacific waters. Fishery data shows warming in the 1930s coincided with the arrival of fish normally found further south. Recent analyses show similar northward fish migrations are associated with intruding warm Atlantic waters, driven by natural shifts in the North Atlantic Oscillations and Atlantic Multidecadal Oscillation. In the Atlantic sector, the greatest loss of Arctic ice occurs in the Barents Sea and associated with the pathways of intruding warm water.

Intruding dense salty warm water also generates a reservoir of Arctic heat stored between 100 and 900 meters depth. That heat reservoir can melt all Arctic sea ice several times over. Indeed, the most recent scientific research reveals that warm reservoir has been rising closer to the surface and thinning sea ice. Researchers called this dynamic the atlantification of the Arctic Ocean.

In 2007, the greatest reduction of sea ice happened in the Chukchi Sea. Research by Rebecca Woodgate using mooring and satellite data, documented that the volume and heat content of intruding warm water. She reported Pacific water passing through the Bering Strait into the Chukchi had doubled since 2001. The inflowing Pacific Waters spread across half the Arctic Ocean with a heat equivalent equal to, and up to twice as great, as possible heat estimated from CO2 back-radiation. The amount of heat carried by those intruding waters was comparable to the solar heating of the entre Chukchi Sea.

The resulting enhanced loss of summer and winter sea ice resulted in feedbacks, associated with Arctic Amplification, which has raised Arctic air temperatures at a rate twice the global average. Less insulating ice allows the heat reservoir to more easily ventilate, cooling the ocean but warming the air. Furthermore, researchers show the loss of sea ice reconnects the oceans with the winds causing a stirring effect that brings warmer water to the surface. Less ice lowers the ocean’s albedo allowing more solar heat to be absorbed. Finally, the re-formation of lost ice, releases more latent heat. All those warming effects caused by increased inflows, have been myopically attributed to rising CO2.

Less ice benefits the food web. As outlined by Grebmeir 2015, the productivity in the Chukchi Sea (and likely the entire Arctic ocean) depends on the inflows of nutrient rich waters. The same intrusions of warm water through the Bering Strait that reduces sea ice, also bring vital nutrients that increases productivity, as well as bringing warmth that enhances faster growth. Our best scientific evidence suggests that if the Arctic becomes ice free by mid-21st century, more open water will enhance photosynthesis so that marine productivity will increase by 67%. Thus, it is “more likely than not” that the dynamics that are now reducing Arctic sea ice are also increasing the food supply, not just for bearded seals but for the whole food web. Because bearded seals currently consume a huge variety of fish and invertebrates, it is highly likely bearded seals will easily adapt to any foreseeable changes in the food web.

When the “rest of the story” is told, it seems highly unlikely bearded seals will be endangered by reduced sea ice or warming temperatures. It is the Endangered Species Act itself that is endangered because the Center for Biological Diversity and their ilk abuse the ESA to promote climate fear. Instead what should rightfully evoke our greatest concern is how climate change alarmism is eroding objective science, allowing untestable hypotheses and flawed models to become codified in our legal system.

Friday, October 27, 2017

Deconstructing the Climate Demagoguery of the Wine Country Wildfire Tragedies

Wine Country Fire October 2017

As sure as the winds will blow, climate demagogues hijack every human tragedy to amplify fears of rising CO2 concentrations. Despite the fact that other critical factors were the keys to understanding the devastation of the Wine Country fires, politicians like Hillary Clinton, Al Gore and Governor Jerry Brown were quick to proclaim climate change had made the fires worse than they would have been.

Climate researcher Kevin Trenberth has long tried to undermine the foundations of science by discarding the null hypothesis. Without formal testing whether a tornado, hurricane or wildfire event is within the expectations of natural variability, Trenberth simply asserts every tragedy is made worse by rising CO2. Accordingly, he is interviewed by climate change propagandists after every weather tragedy. In an interview with InsideClimateNews a few months before the Wine Country wildfires Trenberth continued to proselytize his views, “Whatever conditions exists, they're always exacerbated by climate change. There's always that heat variable, the increased risk.”

Indeed heat is always a variable, but usually it has nothing to do with CO2. Sadly, due to his extreme beliefs Trenberth often confuses climate with weather.

Similarly, Daniel Swain who authors a good California Weather Blog, unfortunately strays when he tries to interject CO2-climate change into an otherwise good weather analysis. Writing the fires should also be looked at from “the long-term climate context,” he argued the “record-hottest summer” dried out the vegetation exacerbating the fire conditions. But he too failed to separate natural climate and weather events from his hypothesized contributions from CO2. As will become clear from a more detailed analysis, climate change played no part in the wildfire devastation.

The Ignition Component

Fire danger rating systems analyze 1) an ignition component, 2) a fuel component and 3) a spread component to determine how to allocate fire-fighting resources and when to issue public alerts. Natural fires are caused by lightning, and thus good weather models can forecast the short-term probability of lightning fires. Lightning fires are also more likely during warm and moist seasons enhancing their window of predictability. Unfortunately, Cal Fire reports 95% of California fires are unpredictably ignited by humans.

Climate alarmists like Dr. Trenberth have blithely suggested global warming is increasing the fire season stating, “In the West, they used to talk about a fire season, the fire season used to be 60 days, then 90 days, and now they think it's year-round. There's no pause." Tragically that uncritical belief in a climate-related extended fire season has been parroted by lay person and scientists alike. But the facts show the observed extended fire season is due to human ignitions. Blaming climate change is fake news!

In a 2017 paper researchers reported that across the USA from 1992 to 2012, “human-caused fire season was three times longer than the lightning-caused fire season and added an average of 40,000 wildfires per year across the United States. Human-started wildfires disproportionally occurred where fuel moisture was higher.” Furthermore “Human-started wildfires were dominant (>80% of ignitions) in over 5.1 million km2, the vast majority of the United States, whereas lightning-started fires were dominant in only 0.7 million km2.”

We can reduce some human caused ignitions. The Wine Country fires were not ignited by lightning but all observations suggest they were started by downed power lines in high winds. A year ago, California legislators introduced a bipartisan bill aimed at reducing wildfire ignitions from powerlines. Although governor Brown hypes the unsubstantiated dangers of climate change, he vetoed the bill which would have promoted real action to prevent well-known human causes of wildfires. Preventing powerline ignition could have prevented the Wine Country tragedy.

The Fuel Component

Fire ecologist will estimate a fire’s potential intensity by calculating the Energy Release Component (ERC), a measure of the potential heat energy per square foot. ERC is a function of the biomass both dead and alive, and the biomass moisture content. As fuels increase and as fuels dry the ERC increases. Live fuels are modeled such that maximum moisture content coincides with the peak growing season, and declines thereafter as the plants go dormant. Moisture content of dead fuels are modeled according to their diameters.

Depending on their diameters, dead fuels will lose moisture as they equilibrate with their dry surroundings at rates that vary from 1 hour to 1000 hours or more. To aid in firefighting management decisions, fuels are categorized into 4 groups as described in Gaining an Understanding of the National Fire Danger Rating System published by the National Wildfire Coordinating Group 

1-Hour Time-lag Fuels “consist of herbaceous plants or round wood less than one-quarter inch in diameter.  Also included is the uppermost layer of litter on the forest floor.” The ERC of these fuels and thus the fire danger, can change throughout the day. Dead grass as well as twigs and small stems of chaparral shrubs are 1-hour fuels, and those fine fuels sustained the rapid spread of the Wine Country fires. Assertions that recent and past summer droughts or decades of climate change had dried the fuels and exacerbated the Wine Country fire danger have absolutely no scientific basis. The approach of the hot, bone-dry Diablo Winds would have extracted all the possible moisture from the dead grasses and chaparral twigs within hours, regardless of past temperatures. Trenberth and Swain simply confused rapid weather changes with climate change.

The critical “long-term context” they never discussed is that a century of fire suppression allowed destructive levels of fuel loads to develop, increasing the biomass component of the ERC estimate. As populations grew, so did the demand to suppress every small fire that could threaten a building. Natural small fires reduce the fuel load, whereas fire suppression allows fast drying fuels to accumulate. Unfortunately, fire suppression only delays the inevitable while stocking more fuel for a much more intense blaze. Local officials and preservationists have long been aware of this problem, and controlled burns to reduce those fuels were being increasingly prescribed. Tragically, it was too little too late.

Prescribed Control Burn

10-Hour Time-lag Fuels are “dead fuels consisting of round wood in the size range of one quarter to one inch in diameter and, very roughly, the layer of litter extending from just below the surface to three-quarters of an inch below the surface.” The fuel moisture of these fuels vary from day to day and modeled moisture content is based on length of day, cloud cover or solar radiation, temperature and relative humidity.

100-Hour Time-lag Fuels are “dead fuels consisting of round wood in the size range of 1 to 3 inches in diameter and, very roughly, the forest floor from three quarters of an inch to four inches below the surface.” Moisture content of these fuels are also a function of length of day (as influenced by latitude and calendar date), maximum and minimum temperature and relative humidity, and precipitation duration in the previous 24 hours. 

Much of the chaparral shrubs produce twigs and stems in size ranges of the 1-hr, 10-hr and 100-hr fuels. These fuels were most likely the source of burning embers that high winds propelled into the devastated residential areas. Again, these dried out fuels are the result of a natural California summer drought and short term weather conditions such as the bone-dry Diablo Winds that arrive every year. 

Figure 2  Moisture content of 3-8 inch diameter fuels from March to December

1000-Hour Time-lag Fuels are “dead fuels consisting of round wood 3 to 8 inches in diameter or the layer of the forest floor more than about four inches below the surface or both”. These larger fuels are more sensitive to drought conditions that existed months earlier, so it could be rightfully argued that a hotter drier July and August made these fuels more flammable in October and exacerbated the fires.

Fire ecologists planning prescribed burns to reduce fuel loads, wait until the 1000-Hr fuels’ moisture content is reduced to 12% or lower. If these larger fuels are dry, it is certain the smaller fuel categories are dry as well, so that all fuels will be highly flammable. As seen in the graph above (Figure 2) 1000-hr fuels reach that critical dryness threshold by July 1st and remain below that threshold until mid-October when the rains begin to return. Contrary to Trenberth’s blather, California’s fire season has always lasted 90+ days. Undoubtedly the unusually hot and dry 2017 summer would have lowered 1000-hr fuel moisture content even further. Nonetheless those fuels become naturally flammable every summer. Furthermore, these larger fuels were less often burned and thus insignificant factors regards the fires rapid spread. The rapid spread of the fires was due to consumption of the rapidly drying fuels.

Swain is fond of finding a “record setting” metric to bolster his climate change assertions. As such, he noted the “record-hot summer had dried out vegetation to record levels” and linked to a graph tweeted by John Abatzoglou showing October ERC values for the past 30 years were at a record high in 2017 (in part because of delayed rains). However, that “record” was also largely irrelevant. The ERC calculation is heavily biased by the greater biomass of the larger 1000-hr fuels that would indeed get drier as the autumn continued without rain. Still those larger fuels were insignificant contributors to the rapidly spreading fire. As seen below (Figure 3), the grasses have been entirely burnt while the larger shrubs and trees, as well as the woody debris near the base of the trees (in the upper left) have not been consumed. In fact many of the trees are still alive. The potential energy estimated by the “record ERC” was only partially realized. It was the fast-drying dead grass and chaparral shrubs that turned potential ERC into meaningful fiery heat.

Figure 3

The Spread Component

“The spread component is defined as “the theoretical ideal rate of spread expressed in feet-
per-minute.” Wind speed, slope and fine fuel moisture are key inputs in the calculation of the spread component, thus accounting for a high variability from day-to-day." Thus, a combination of dry fuels and high winds typically result in fire-watch and red-flag warnings one day and no warnings days later as the winds subside. Forest rangers are well aware that September and October bring the powerful Diablo Winds to Santa Rosa as well as the Santa Annas to southern California, and with those winds comes the highest fire danger.

Cliff Mass is an atmospheric scientist at the University of Washington and author of the superb Cliff Mass Weather and Climate blogs. An October 16th post provides an excellent summary of the metorological conditions that created the fierce winds driving the Wine Country fires. In essence, a strong approaching wind flow (the Diablo Winds) coupled with a thermal inversion near the top of the mountains that border the Santa Rosa valley, accelerated winds into a 60 to 90 mile per hour downslope wind event, a phenomenon known as a mountain wave.  Those high winds snapped power line poles and ignited fires. The regional topography also funneled the winds and fire down the valley, taking dead aim at the heart of Santa Rosa. The topography had guided a similar fire in 1964, the Hanley fire, which was started by a carelessly discarded cigarette. Unfortunately without much concern, most of the burnt homes in the Tubbs fire had been built on top of the burnt grounds of that previous Hanley fire, despite public protests.

Were those high winds perhaps exacerbated by climate change? Highly unlikely!

The Diablo Winds affecting Santa Rosa or the Santa Annas of southern California are driven by cooling seasonal temperatures in the high deserts to the east. The inner continent cools faster than the oceans, setting up a pressure gradient driving the winds toward the coast. The winds then heat adiabatically rising 5 degrees Fahrenheit for every 1000 feet of elevation descent. An adiabatic rise in temperature means no added heat from any source and basic physics tells us temperatures can rise adiabatically simply due to compression. Thus an air mass that originated near Flagstaff Arizona at a 6900 foot elevation, could adiabatically warm by 30 degrees as it reaches sea level.

The flow direction of winds are largely driven by unequal seasonal changes in temperatures. During the summer the interior heats faster than the oceans, such that a cooling onshore wind reduces interior temperatures. This pattern reverses in the autumn as the interior lands cool faster than the ocean creating an inland high pressure that drives the Diablo and Santa Anna winds toward the coast.  Despite declining solar insolation, this autmn wind flow causes coastal California to experience some of its hottest days of the year in September and October, commonly referred to as Indian summer. Similarly a pressure system that inhibited the cooling onshore winds around San Francisco, resulted in a record hot summer temperature. By simultaneously opposing cooling sea breezes while bringing warm winds that were adiabatically 5 to 10 degrees warmer, temperatures rise and relative humidity falls. The result is bone-dry hot Diablo winds that suck the moisture from land and vegetation where ever the winds pass.

To restate the forces driving the winds, the Diablo winds are the result of a pressure gradient resulting from an interior that cools faster than the ocean. If CO2 is warming the earth to any significant extent, then we would expect that warming to prevent the inner continent from cooling as quickly as it did decades ago. Thus CO2-global warming would predict a decline in that presure gradient and a weakening of these winds.

Devastated Neighborhoods in Santa Rosa

To summarize, none of the fire components - ignition, fuels, or spread – had been affected by climate change.

Finally, keen observers will notice that entire blocks of houses, and entire neighborhoods were completely burnt to the ground, in contrast to neighborhood trees that often remained relatively unscathed. This suggests that the high winds rapidly carried burning embers from the grassland and chaparral into these developments. While the trees did not trap the embers, the buildings did. I would expect we will soon hear about investigations inquiring into why these residences were not required to erect more fire safe structures, especially when built in a known fire-prone habitat and a high wind corridor. The simple requirement of constructing eaves in such a manner that prevents the trapping of burning embers and fire-proof roofs may have saved many homes.

Indeed there are many lessons that will allow us to prevent such wildfire disasters in the future if we have accurately determined the causes of these fires. Cliff Mass notes that our short-term weather models had accurately predicted the time and place of the fiercest winds. That information could be used to temporarily shut down the electrical grid where power lines are likely to ignite fires. We can bury power lines below ground. We can remove the high fuels loads that accumulated during a century of misguided fire suppression. Insurance companies can demand higher rates unless proven precautions are undertaken. It is those lessons that Gore, Clinton, Brown should be promoting to inform the public. Trenberth and Swain should be informing the people of the natural weather dangers that are inevitable. There is no evidence that climate change, whether natural or anthropogenic, exacerbated the ignition, fuels or spread components of these deadly fires.  And worse their obsessed belief that rising CO2 concentrations worsen every tragedy only distracts our focus from real life-saving solutions.