Posts
World
Food Security in the Cross Hairs of Human-Caused Climate Change:
Mangled Jet Stream, Ocean Heat and Melting Sea Ice To Deliver 500
Year Drought to California? Brazil, Turkey, Australia and More
to Follow?
(California
Snow Pack for January 18 2013 vs the California Snow Pack for January
18 2014. Note the near-zero snow cover for this drought-impacted
region. Image source: NASA/Lance-Modis)
5
February, 2014
“We
are on track for having the worst drought in 500 years.”
— B. Lynn Ingram, professor of earth and planetary sciences at the
University of California, Berkeley.
Remember
the historic drought that swept the US in 2011-2013? It was the worse
drought in 50 years for some areas. Thankfully,
the blocking pattern, excess heat and evaporation that set off this
drought and that almost ran the Mississippi River dry abated and
lessened, shifting westward and, instead delivered wave after wave of
wet and stormy weather to the Eastern US.
Not
so with the American West. There the high amplitude Jet Stream
pattern remained, keeping regions locked in warm, dry conditions
throughout the winter of 2012-2013, on through the end of 2013 and
into the early months of 2014.
Looking
further back, it was not just these years that had delivered dry
weather to the US West Coast. California, ground zero for the current
climate change related emergency, has endured dry, hot weather ever
since the Pacific Decadal Oscillation (PDO) went negative ten years
ago suffering drought years with almost bi-annual frequency.
Now,
as Dr. Ingram notes above, California is currently ramping up to its
worst drought in 500 years.
A
long emergency for California
We
only have to scratch the surface for the symptoms of systemic climate
crisis in California to crop up. California water authorities failed
to honor contracts for the first time in 54 years. Sacramento, as of
December was experiencing its worst drought in 130 years even as
conditions continued to worsen through January and February.
According
to the New
York Times,
as of February 1rst, 40,000 people were at risk of losing access to
water within the next 60 to 120 days. And State officials warned that
this number was likely to rapidly rise as The State Water Project
announced on January 31rst that it did not have enough water to
supplement the fading supplies of local providers to a total of 25
million customers. Meanwhile, State emergency planners were laying
out contingencies that included shipping water over land by truck to
parched communities.
The
drought is also having a devastating impact on local farmers with
about 1/3 of California’s farmland expected to lay fallow, at least
25,000 farm laborers expected to be laid off work, and agricultural
businesses expecting losses to mount into the tens of millions of
dollars. Already, livestock owners in both New Mexico and California,
unable to support their animals, have been forced to sell, as fields
that used to support four foot high grass are brown and cracked.
Tim
Quinn, executive director of the Association of California Water
Agencies noted:
“I
have experienced a really long career in this area, and my worry
meter has never been this high. We are talking historical drought
conditions, no supplies of water in many parts of the state. My
industry’s job is to try to make sure that these kind of things
never happen. And they are happening.”
Climate
change, climate change, and climate change
Far
flung and dynamic changes to the Earth System appear to have resulted
in a variety of factors that have amplified the California drought.
First, increasing
global temperatures have amped up the rate at which water evaporates
into the atmosphere by about 6%,
this increased rate of evaporation results in more extreme conditions
when heat and dryness do occur. So a drought that may last a year is
likely to be even more intense, due to enhanced evaporation, than a
comparable drought that occurred 50 or 100 years ago.
In
addition, loss of sea ice, snow, and permafrost plays a key roll in
re-shaping the Jet Stream. According
to Dr. Jennifer Francis and other polar researchers, receding sea ice
cover is likely to result in more powerful and long-lasting Rossby
Wave type blocking patterns.
This happens as more heat becomes concentrated in the polar regions,
causing the Jet Stream to meander in great swoops and whirls. These
large waves can become fixed into blocking patterns for extended
periods. In the up-slope of these waves, warmth and heat predominate.
In the trough or down-slope, stormy, wet and cool conditions prevail.
And
just such a blocking pattern has dominated the US West Coast for 11
months running. The result is extraordinarily intense dryness, even
during the rainy season of November through March.
Sadly,
according to climate models, we can expect this kind of dryness to
intensify over the US Southwest as human caused global warming grows
more extreme. A report conducted by PNAS in 2010 and authored by
Seager and Vecchi confirmed other model findings that the US
Southwest would continue to dry as the climate warmed — the upshot
being that the wet season for the West would eventually evaporate.
Above,
the PNAS drought model shows evaporation beginning to increase during
the first two decades of the 21rst Century. Then, by about decade 2,
precipitation rates rapidly fall and evaporation rates gradually rise
through to 2100. The red line shows the compounding effects of
evaporation increase and precipitation decrease over 24 separate
climate model essays.
It
is worth noting that on a positive, and slightly hopeful, note, the
current blocking pattern over the US West Coast and related Pacific
Ocean waters has weakened somewhat. This should allow some moisture
to flow into the parched west over the coming days and weeks. And, in
the forecast, we do see a proper storm or two emerging from this new
pattern. Unfortunately, we’d typically expect about 20-30 storms of
this kind during a typical winter season and with March bringing in
the end to this year’s rainy season, along with the northward
retreat of the moisture flow, it appears likely that California will
have to endure at least another 6 months of dry conditions before
seeing any hope of major storms returning next fall/winter. A remote
potential to say the least given both long-term trends and current
conditions.
‘Like
a microwave on full blast drying the Earth:’ drought, drought, and
more drought
“The
extra heat from the increase in heat trapping gases in the atmosphere
over six months is equivalent to running a small microwave oven at
full power for about half an hour over every square foot of the land
under the drought. No wonder wild fires have increased! So climate
change undoubtedly affects the intensity and duration of drought, and
it has consequences.”
Under
such conditions, we would expect both drought and wildfires to
proliferate. And, in fact, this is exactly what we are seeing. As
major
wildfires impacted both California
and Arctic
Norway during winter time,
Brazil, Turkey, China, Argentina and Australia were also all
experiencing some of their worst or most intense droughts on record.
In
Brazil, the
least rain in two decades is spurring a cattle sell-off that would be
very familiar to livestock farmers in California and New Mexico.
The expected summer rains did not come and Brazil, a heavily
meat-dependent nation was left with soaring food prices after the
sell-off as stocks first surged, then plummeted. The epic drought for
this region is also causing a number of other impact such as coffee
shortages and a related reduction in hydro power as rivers run dry.
Nearby
Argentina also saw severe drought-related shocks in recent months as
a December drought inflicted serious harm upon Argentina’s corn
crop.
In a typical year, Argentina produces about 32 million tons of corn.
But this year’s drought is estimated to have wiped out about
between 7 and 14 million tons of the crop. Argentina is the third
largest producer of corn and with the US revising estimates down for
its 2013-2014 crop, supplies of the grain are being drawn ever-lower.
Though very intense, the December drought had abated by mid-January,
providing a respite for other crops such as soybeans.
In
Turkey, Lake
Sapanca, which provides water for hundreds of adjacent farms, was
within a half meter of ‘dying’ as a combination of drought and
water drilling had pushed the lake to its limits.
Local farmers have, for decades, drilled the land to provide
irrigation water for farms and livestock. Now, the drilling is
sapping the lake bed. A period of drought had, as of late January,
left the lake in such a state that local officials were claiming the
lake would be dead after another half-meter fall. The lake which is
nourished both by springs and ground water has been deprived of flows
both by human climate change induced drought and by human drilling
into the lake’s spring-bed.
In
Australia, drought
conditions are now worse for some locations than at any time since
2003,
a tall order since the 2003 to 2009 drought was Australia’s worst
in 1,000 years. For Sydney, that means the lowest rainfall totals in
more than 70 years. This particular drought hit both hard and fast
with Australia seeing normal conditions before Christmas, but after,
very intense heat and dryness resulted in a rapid scorching of
farmlands, crops, and grazing fields. The dire drought situation has
resulted in government relief funds being released to affected
farmers. NSW Minister for Primary Industries, Katrina Hodgkinson
noted to the Sydney Morning Herald:
“Seasonal
conditions are now deteriorating at a rapid rate across a large
portion of NSW and both the severity and speed at which this drought
is moving is astonishing. Primary producers in some parts of NSW have
simply not had the opportunity to prepare for another severe downturn
in seasonal conditions so quickly after the Millennium drought
broke.”
(A
mostly full Lake Poyang as seen from Satellite on the left during May
of 2012. A parched and almost completely dry lake Poyang as seen from
Satellite during January of 2014. Image source: NASA/Lance-Modis.)
And,
in China, the largest lake for that populous nation has now dried up.
Poyang, a massive lake usually spanning 3,500 square miles has been
turned into a sprawling field of earth parched and cracked by a
combination of drought and water diversions resulting from the
construction of the Three Gorges Dam. According to reports from
The Guardian and Chinese News Sources,
a drought stretching from 2012-2014 in the region of Poyang is now
the worst in at least 60 years leaving lake refill almost non
existent as upstream river flows to the lake were periodically cut
off by water storage operations at the Three Gorges Dam. The result
was an extreme lowering of lake levels and dry bed conditions that
have driven farmers and fishermen in the region out of business.
Implications
for world food security
Major
droughts during 2011-2012 impacted many of the world’s primary
agricultural basins, resulting in forward food supply dropping to as
low as 72 days.
Since that time, food supplies have slightly recovered but are well
below previous levels last seen in the 1990s at 104 days. Food
insecurity and failure to distribute food to the malnourished remains
a priority at international agencies like the UN which has identified
numerous countries including Cameroon, the Central African Republic,
Somalia, Syria, Mali, Sudan and Nigeria, among others, as extreme
risks for hunger and famine. Relief agencies have allocated billions
of dollars to address this problem but the UN continues to identify
climate change as a major threat to global food security with the
potential to wipe out all previous progress moving forward.
The
droughts in California, Turkey, Australia, China, Argentina and
Brazil so far for 2014 put the world at risk for another bout of food
insecurity later this year should major weather and climate related
crop disruptions emerge in other primary food producers such as the
bread baskets of the US, Russia, and Europe (The US, Brazil, China,
Russia, and Europe are top food producers). It is worth noting that,
in large part due to the ongoing southwestern drought, the US has
revised a number of its crop projections downward for end 2014.
With
polar amplification playing havoc with the Northern Hemisphere’s
weather systems, with Australia sitting in a pool of expanding warm
Pacific Ocean water that makes drought more likely there, and with
the Eastern Pacific edging closer to La Nina, conditions warrant a
continued monitoring of both weather and the state of world food
supplies. The added global heat engine also impacts soils and crop
growth in ways to which we are currently unaccustomed, resulting in
more extreme instances of flash drought as well as flash flood. In
this respect, the examples of Australia and Argentina are of
particular concern.
Though
global crisis has not yet returned, it lurks at the edges as drought,
extreme weather and over-use of ground water supplies continues to
threaten a wide swath of productive zones. So, at this point, the
situation is one best described as tenuous with ongoing regional
impacts over the Sahel region of Africa and in other sporadically
vulnerable locales.
Links:
No comments:
Post a Comment
Note: only a member of this blog may post a comment.