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Bull Moose |
The biggest threat to the
integrity of environmental science is bad science, exaggeration and fear
mongering. The recent hype about declining moose populations is just one more
example of global warming advocates hijacking and denigrating ecological
science. All organisms act locally, yet global warming advocates quickly
characterize any local wildlife declines as the dastardly work of global
warming.
In northeastern Minnesota,
moose populations reached an historic high abundance of 8,840 in 2006, and then
rapidly declined to 4,230 in 2012. Most recently in a 2013-2014 survey,
estimates dropped to 2,760 moose. Cause for alarm? Perhaps. But moose are a
species known to naturally exhibit booms and busts when their habitat can no
longer sustain a rapidly growing population. Instead of deeper discussions on
the ecological complexities, but reminiscent of the fearful headlines that “childrenwill no longer know what snow is”, the NationalWildlife Federation (NWF) bellowed
“People never forget seeing their first
moose. But due in part to the
effects of climate change, it could well be their last. Moose are being
hurt by overheating, disease and tick infestation – all tied to warming
temperatures.” And to magically save
the moose, the NWF encourages you to sign their petition to the EPA to curb CO2
emissions, and for just $20 to $50 you can adopt a moose from the NWF.
Presumably the $50 moose is in its prime and carries fewer ticks.
The Audubon Society similarly
published MysteriousMoose Die-Offs Could be Linked to Global Warming and climate scientists like MichaelMann, who has hitched his scientific status to “dire predictions”, wrongly
connect declining moose populations to rising CO2. There are so many reasons to
be revolted by their fear mongering and its denigration of ecological science,
it’s hard to know where to start. For instance, the greatest spike in moose
mortality happens in March at the end of severe winters. Milder winters can be
beneficial. While alarmists blame moose deaths on “global warming”, the rapid
decline in northeastern Minnesota has happened in a region experiencing bouts
of record breaking low temperatures. Nearby International Falls, MN broke its
record January low of -37°F set in 2010, by dropping to -41°F in 2014, which followed December’s record setting 8 days with a temperature of less than -30°F. Averaging local temperatures is likely as useless as
referring to the global temperature.
Furthermore moose die‑offs
are not global. In adjacent habitat of southernOntario, moose are stable or increasing. Estimates of moose populations
have traditionally been based on hunters’ harvest and in Scandinavia, the
annual harvest was less than 10,000 in the early 1900s. After a century of
global warming the moose population reached an all time high with annual
harvests increasing20‑fold to 200,000. Similarly in the 1900s, moose from British Columbia expanded
into Alaska and multiplied as the climate warmed. In New England, moose
were once more abundant than deer when the Pilgrims arrived. But due to deforestation
for farmland and overhunting, moose have been absent from Massachusetts and
Vermont for 200 years. In 1901 less than 20 moose were believed to inhabit New
Hampshire. But in contrast to fearful globalwarming theory and species range,
since 1980 moose have migrated south from New Hampshire into Massachusetts
and Connecticut,
despite temperatures that average 4 to 6° F warmer.
Scandinavian biologists
suspect the moose population may begin to decline, but their reasons illustrate
the complex ecology. Increasing moose densities strain food supplies resulting
in lower body mass, lower reproductive success, and lower resiliency. Moose
thrive on vegetation common in regenerating forests that have been cleared by
insect outbreaks, fires or logging. Scandinavian logging increased during the
20th century but has now peaked and will decline, and so moose will
lose habitat as closed forest canopies reclaim the landscape . Except in
eastern Finland, depredation by wolves has been minimal, but wolf populations
are now rebounding.
The beststudied moose population exists just east of Minnesota’s northeast border
on Isle Royale in Lake Superior and illustrates the boom and bust nature of
moose populations. As moose populations globally expanded in the 1900s, they soon
colonized Isle Royale around 1912 and rapidly grew to over 3000 by early 1930s.
Rapid population growth diminished food supplies and a starvation crash happened
in1934. Extensive forest fires in 1936 increased their preferred vegetation and
feasting on young vegetation in a regenerating forest, the population rebounded
until it peaked , followed by increasing winter starvation. To add another
factor governing moose population, in the 1940s wolves colonized Isle Royale.
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Wolves attacking a moose |
Virtually every college ecology text discusses the
predator-prey interactions illustrated by the wolves and moose of Isle Royale.
As observed elsewherein the Great Lakes region, moose populations remained low until they began
increasing in the 1950s. As seen in the diagram below, moose populations rose
but also ebbed and flowed inversely with wolf populations. In contrast to
suggestions that global warming is killing moose, during the rapid warming from
the 80s to 90s, Isle Royale moose doubled their population, approaching a peak
not observed since the 1930s, then suddenly crashing to just 500 in 1997. Moose
have slowly rebounded since 2007 and are now at levels 50% higher than the
1950s.
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Relationship between moose and wolf populations at Isle Royale |
- 16 calves (46%) were killed by
wolves
- 13 calves (37%) calves died due to
mother abandonment. Eleven were caused when the mothers abandoned the calve
during the act of attaching the collars, 2 were abandoned later.
- 4 calves (11%) were eaten by bears
- One calf drowned and 1 calf died of
unknown causes.
- Of the 19 adults, 10 (53%) were
killed directly or indirectly by wolves.
Oddly given those results, biologist
received a new $750,000 grant to study the effects of “global warming” on
declining moose. I suspect it is politically more convenient to blame declining
moose on global warming rather than to blame natural boom and busts, rebounding
wolf populations, or researcher induced casualties.
Similar fear mongering blamed global
warming for recent declines in New Hampshire’s moose. On a PBSNewshour, the interviewer interspersed interviews with researchers and Eric
Orff of the National Wildlife Federation who insinuated that it’s all about
climate change. Like the debunked claims of Parmesanthat global warming is killing animals in the south, Orff highlighted
dwindling moose populations on the southern end of their range, concluding, “we
need to put this earth on a diet of carbs, carbon, and bring back winter.” But New
Hampshire’s average temperature has little meaning. Moose can respond to
temperature changes by moving to different microclimates. Between a gravel
road, open shrub lands, ponds, and closed canopies of deep evergreen forest,
temperatures will vary by 20° to
40°F. A mosaic of habitats
is more critical than a 1°
degree change in average temperature.
In addition, Orff failed to mention that moose have been
migrating from New Hampshire southward and thriving where climates averaged 4°F to 6°F
warmer and winters are much milder. Orff also failed to inform the public about
normal population boom and busts. New Hampshire’s moose population stagnated at
fewer than 15 individuals since the mid 1800s and did not begin to rebound
until the 1970s. As the climate warmed numbers exploded, by 1988 growing to
1600, and then 7500 by the late 1990s. That increase resulted in more moose‑car
collisions and a public clamor for increased moose hunts. Perhaps because the public would be
less likely to “adopt a moose” that needed to be hunted, Orff failed to mention that according to Fishand Game about half of New Hampshire’s recent population drop from 7500 to
4000 moose was due to a public safety management decision to increase hunting.
New Hampshire’s remaining decline has been blamed on moose
ticks, which some suggest have increased due to milder winters. Perhaps. But
moose also survive better during milder winters. On average moose are covered with 30,000
ticks and each tick can lay a thousand eggs. When moose populations explode so
do the ticks. Unprecedented tick abundance coincides with unprecedented moose
populations. Besides biologists have observed such parasite‑driven booms and
busts for over a century.
Growing up in Massachusetts, moose were unheard of so far
south. We travelled north to Baxter State Park in Maine to canoe the streams
with hopes of seeing moose. Moose are indeed sensitive to warmer temperatures,
so why would moose migrate southward to a warmer region that was also
experiencing rapid “global warming”. Homogenized data suggested a rapid warming
trend but as an ecologist, I knew homogenized temperatures are worthless for
wildlife studies because the process eliminates natural temperature variations and
alters the actual mean temperatures. However I also understood that trends determined
from raw data can suffer from changes in instrumentation and/or changes in
location.
I first looked at minimum temperatures for the only 2 USHCN
weather stations in western Massachusetts where moose populations had been
thriving since the 1980s. Both stations exhibited peak warming around the 1950s
in the raw data, but after homogenization, that peak was lowered. For Amherst
the peak dropped by 4°F. Onto
the graphs downloaded on January 10 from the USHCN, I superimposed changes in
instrumentation (designated by the vertical red lines) and changes in location
(designated by the blue arrows). But those changes did not logically or
intuitively explain the newly fabricated warming trend or the cooling of the
1950s peak. (raw data on left, homogenized on right)
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Raw (left) and Homogenized (right) Minimum Temperatures for Great Barrington and Amherst MA |
So I looked for a USHCN station with
no such changes. Only one Massachusetts station, West Medway (below), had not
moved and did not change thermometers. I assumed it would serve as the best
standard with which to constrain any trend adjustments at other stations. Yet West Medway was also homogenized (below
on right) creating the same virtual warming trend. More importantly, West
Medway’s raw minimum temperature trend had the same basic curve as the 2
western stations.
The homogenization process for both
NOAA and BEST creates a “regional expectation” based on similarities among
neighboring stations, which in turn guides their temperature adjustments. But
if USHCN stations are deemed to be of the highest quality with the fewest gaps
and relocations, what data (likely much less reliable) was being used to
re-create West Medway’s warming trend. If West Medway’s raw data shared similar
trends with nearby stations, wouldn’t Medway’s trend be a reliable “regional
expectation”? More troubling, the homogenization process undeservedly altered
observed temperature peaks. Like Amherst, homogenization lowered West Medway’s
1950’s peak by 3 to 4°F, a
lowering that was also applied to many other stations such as the Reading station
(raw data left, homogenized right).
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Raw and Homogenized Minimum Temperatures at West Medway, MA |
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Raw and Homogenized Minimum Temperatures at Reading MA |
So I was curious how the
raw data from West Medway’s nearby USHCN stations compared and affected the
regional expectation. The Blue Hill Observatory (below left) sits just 28 miles
east of West Medway and is a historical landmark that has not moved. Its trend
agrees with West Medway, peaking in around 1950 and then cooling until 1980.
However after 1980, due to changes in instrumentation, it is not clear how much
of the exaggerated rising trend is due to climatic factors (natural or CO2) or
the result of a warming bias caused by new instruments.
Taunton (below right) is
located 29 miles southeast of West Medway. It too exhibits a peak around 1950 and a cooling trend to
1980. However once again the cause of the subsequent warming trend is obscured
by the change in the measuring system. However there was one nearby station,
Walpole that maintained the same equipment.
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Raw Minimum Temperatures at Blue Hill Observatory and Taunton MA |
Walpole (below) is situated just 12 miles east of
West Medway and just west of the Blue Hill observatory. But Walpole exhibited a
warming trend more similar to Massachusetts’ homogenized trend. Of which of
those stations should anchor a “regional expectation”? Walpole’s raw data had
an odd curve not shared by most of the other stations. Although all stations
experienced a warming spike during the 1972-74 El Nino/La Nina event, that peak
was typically a degree lower than the 1950s. However Walpole reported an
unusually higher 70s peak suggesting that after 1950 the weather station had
moved to a warmer microclimate. But NOAA’s
metadata did not specifically mention any relocation. Thinking I had missed
that information, I rechecked. Although a relocation was not specifically
mentioned, the GPS coordinates revealed a significant move in 1973. Yet
comparing the raw data (below left) to the homogenized data (below right red), Since
1915 Walpoles raw data remained un-homogenized. Did the warming bias from the
1980s instrumental changes, create a confirmation bias for Walpole?
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Raw Minimum Temperatures(left) and Quality Controlled vs Homogenized TMIN at Walpole |
What I assume is a most reasonable method to
quality control for a location change,
I compared the differences between West Medway (the only unaltered site)
and Walpole’s minimum temperatures before and after Walpole’s location change.
Between 1905-1973 Walpole averaged 0.3596 +/- 1.07°F warmer than Plymouth. Walpole could vary between 2° cooler one year to 4.6° warmer another. This great variability is natural and expected.
Depending on how far east winter storm tracks travel up the east coast, the
battle line between cold arctic air masses to the west and warm Atlantic air to
the east causes significant temperature changes. Depending on the depth and
extent of the cold air mass, the overriding warm Atlantic air can cause
different parts of the state to simultaneously experience rain, freezing ice,
sleet and snow.
After the station moved, between
1974-2004 Walpole temperatures averaged 2.89 +/- 1.29F warmer than Medway, but
with similar year-to-year variability ranging between 1.5 cooler one year to 4.5 warmer another. It is
impossible to adjust for such local variations. But to extract a climate trend,
it is reasonable to subtract the difference in mean temperatures before and
after the relocation. So I subtracted 2.53 F (2.89-0.35) from all Wapole
temperatures after 1973 to create my “quality controlled” trend (blue) and
plotted that against the USHCN homogenized trend (red in graph above right).
Unsurprisingly Walpole’s “quality controlled” data and West Medway’s raw data exhibit
very similar trends with peaks and valleys coinciding with the Atlantic
Multidecadal Oscillation (AMO).
So I more carefully checked the
data from Plymouth about 52 miles to the southeast. Unfortunately data from the
Plymouth weather station does not extend back to the landing of the Pilgrims,
which marked the beginning of the end for moose in Massachusetts. But after
adjusting for Plymouth’s 2 obvious location changes, in 1966 and 1990 (blue
arrows), Plymouth’s “quality controlled” data revealed a trend very similar to
West Medway and a “regional expectation” related to the AMO. Most interesting,
once Plymouth’s location change was accounted for there was no instrumental
warm bias. As discussed by Davey
and Pielke, a warming bias if often associated with MMTS temperature
instruments, because new instruments and a new location happened
simultaneously. Insignificant location changes could cause a warming bias when
weather stations were moved closer to a building and subjected to a warmer
micro-climate.
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Raw Minimum Temperatures(left) and Quality Controlled vs Homogenized TMIN at Plymouth MA |
It is highly likely that
due to its effect on storm tracks and competing air masses, the AMO can explain
most of the east coast’s temperature trends in a manner similar to how the
Pacific Decadal Oscillation controls the USA’s west coast trends as published
by Johnstone
2014. Unfortunately this
relationship has been obscured by a highly questionable homogenization process.
To be clear, I am not
suggesting a conspiracy of data manipulation by climate scientists. I am
arguing that the homogenization process is ill-conceived and erroneously
applied. Many local dynamics are overlooked by a one-size fits all digital make over. Monthly homogenization
can amplify those mistakes and has changed trends from one year to the next (as
discussed for Death Valley). Homogenization has failed to adjust for
documented location changes, yet created adjustments to untainted data where
none were needed. Before we conclude that global warming is killing moose and
creating unusually warmer winters, we need examine more closely local dynamics
and their relationship to landscape changes and natural ocean cycles much more
closely. Understanding local micro-climates are more important that a nebulous
global climate. While it may be wise to think globally all organisms react
locally, as do all weather stations.
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NOAA's Atlantic Multidecadal Oscillation Index |