Download Understanding Weather and Climate Ch 16

Rapid climate change in the Arctic
and global implications
By: Paul Beckwith (Ph.D program)
Laboratory for Paleoclimatology and Climatology
Department of Geography
University of Ottawa
CMOS luncheon talk
Thursday January 19, 2012
Topics
Climate system of the Earth
Forcings, feedbacks, nonlinearity, timescales, teleconnections
Global changes
Temperatures, precipitation, GHG concentrations, weather
extremes, sea-level rise
Arctic changes
Sea-ice collapse, albedo change, ozone hole, Greenland melt,
permafrost melt (terrestrial, continental shelves), methane
Projections
Tipping points (thresholds), abrupt climate change, biosphere,
geoengineering, fate of society (food supply)
Climate system of Earth
(Ruddiman, 2008)
Climate system of Earth (human timescales)
(IPCC:AR4, WG1, Ch. 1, 2007)
CO2 and CH4 concentrations and growth rates
http://thinkprogress.org/romm/2011/11/21/374141/heat-trapping-co2-new-high-growth-methane-levels-are-risingagain/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+climateprogress%2FlCrX+%28Climate+Progress%29
CO2 and CH4 “hockey sticks”
“Sooner or later, we will all deal with global warming. The only
question is how much we will mitigate, adapt, and suffer.”
(Thompson, 2010)
(AMEG, 2011)
Mean surface air temperature change (oC)
Serreze MC, Barry RG (2011) Processes and impacts of Arctic Amplification:
A research synthesis. Global and Planetary Change, 77,85-96.
(AMEG, 2011)
(AMEG, 2011)
(AMEG, 2011)
Precipitation anomalies
(NOAA, NCDC data, 2011)
Is the Eemian
(120 kyr b.p.)
a good analogue?
No…
Interglacials at 400
and 800 kyr b.p. are
better but resolution
is lower
(Ganopolski and Robinson, 2011)
Sea surface temperature trend
(NOAA, 2010)
Mean surface air temperature change (oC)
(Serreze and Barry, 2011)
(AMEG, 2011)
Influences on sea-ice cover in Arctic
(Carmack and Melling, 2011)
Arctic sea ice extent
(Copenhagen Diagnosis, 2009)
Arctic sea ice measurements
(Kwok et. al., 2009)
Ice transport out of Arctic
(Smedsrudi et. al., 2008)
Great salinity anomalies
(Belkin, 2004)
Arctic sea-ice melt season
(NSIDC, 2010)
Arctic sea-ice yearly minimum volume
Sea-ice volume  0
during melt season
>5% chance of
vanishing by 2013
>50% chance of
vanishing by 2015
>95% chance of
vanishing by 2019
Arctic sea-ice monthly average volume
>50% chance of ice
vanishing by t = 2015
(ice-free duration likely
< 1 month first year)
Ice-free duration 3 months
by t + 1 year (2016)
Ice-free duration 5 months
by t + 3 years (2018)
Ice-free duration all year
by t + 9 years (2024)
Extreme weather connection to reduced sea-ice
Arctic sea ice loss
open ocean releases more heat in fall
and winter
raises 500 mb elevations (hot air
expands)
affects upper-level atmospheric
circulation (smaller ΔT)
 winds reduce, jet stream changes
 increases tendency to contort to
high-amplitude loops (Rossby waves)
 increases probability of persistent
weather patterns in NH
 stalled fronts
more extreme weather (longerduration cold spells, snowstorms, heat
waves, floods, and droughts)
(Francis, AGU 2011); http://thinkprogress.org/romm/2011/12/17/391462/our-extreme-weather-arctic-changes-to-blame/
Recent extreme weather event (meridional jet stream)
Speed of west to east wind patterns reduced
by 20% over less than one decade
Hot Arctic-cold continents pattern  cold
snowy winters in Eastern U.S. and Europe in
2009-2010 and 2010-2011 winters (record
negative AO, NAO)
Less sea ice  more meridional (ridge to
trough amplitude 1600 km)
 abnormally high temperatures under
ridges; abnormally low temperatures above
troughs
Less snow cover in spring
 increased amplitude of Rossby wave by
about 160 km in last decade in summers
(Francis, AGU 2011); http://thinkprogress.org/romm/2011/12/17/391462/our-extreme-weather-arctic-changes-to-blame/
Climate change impacts extreme weather statistics
(McGregor, 2005)
Extreme weather events in 2010
Climate  0.5 oC warming since 1970; 4% increase in moisture since 1970
-
2010 warmest year on record (since 1800s); tied with 2005
19 countries (20% of global land mass) set all time record highs including
Pakistan (53.5 oC in May 2010)
2010 wettest year over land (13% higher than previous 1956 record)
record low AO, NAO over Arctic  extreme change in jet streams
Canada (warmest, driest winter on record); US (coldest in 25 years, many record
snowfalls broken)
NY (3 of top 10 snowstorms on record); record snowfalls in Europe
strongest high pressure ridge ever measured mid-altitude
2nd most extreme shift from El Niño (start of 2010; oceans +3oC) to La Nina (end
of 2010; oceans -2oC)
2nd worst coral bleaching overall; worst in Caribbean, SE Asia
(Jeff Masters, Wunderground blog, 2011)
http://thinkprogress.org/romm/2011/12/07/384524/wp-content/uploads/2011/11/Munich-Re.gif
Extreme weather events in 2010 and 2011
-
-
worst natural disaster in Pakistan history (flooding in most of country)
deadliest heat wave in human history in Russia (55,000 deaths); 30 days with
maximum temperatures > 30 oC in Moscow; 40% or Russian wheat crop lost
Strongest storm ever in SW U.S. history (January 20 – 21, 2010); caused massive
flooding, tornadoes, hail, hurricane force winds, and blizzard conditions
Strongest non-coastal storm in U.S. (Minnesota, Oct 26, 2010)
flood (1:1000 years) in Nashville, TN (greatest disaster in state since civil war)
Amazon rainforest drought in 2010 (worse in 2005); 2 billion ton/year carbon sink
became 3 billion ton/year source in these drought years; net 5 billion tons is ~20%
of global emissions
No monsoon low pressure region in India (2nd time in 134 years)
Australia record flooding in 2010; record high SST
2010 most extreme year since 1816 “year without a summer” (Tambora, 1815
eruption)
(Wunderground, 2011)
http://thinkprogress.org/wp-content/uploads/2011/12/billion-dollar-graph-Nov-2011.gif
Extreme weather events in U.S. in 2011
(AON Benfield (reinsurance company), 2011)
Arctic Oscillation Index (AO)
Defined by pressure difference between Icelandic low (L)
and Azores high (H); reflects strength of the polar vortex
+AO  strong polar vortex; zonal upper atmospheric
winds; cold air confined to Arctic (2011-2012 winter)
-AO  weak polar vortex; meridional upper atmospheric
winds; cold air excursions to lower latitudes (2009-2010
and 2010-2011 winters)
(NOAA/ESRL/Climate Prediction Center, 2011)
Precipitation anomalies in U.S.
56% of U.S. had either a
top-ten driest or top-ten
wettest year (unprecedented)
Fraction of country that was:
-extremely wet (32% versus
norm of 10%)
-extremely dry (22% versus
norm of 10%)
(NOAA/HPC
http://water.weather.gov/ahps/ )
Climate is “messing with Texas (1/100 or 1/1000 year drought)
(John Nielsen-Gammon, Texas state meteorologist, 2011)
(Jeff Masters, Wunderground blog, 2011)
Loaded climate dice
(Hansen, 2011 report) http://www.columbia.edu/~jeh1/mailings/2011/20111110_NewClimateDice.pdf
Jun-Jul-Aug surface
temperature anomalies over
land relative to 1951-1980
mean temperature
(units: local standard
deviation of temperature)
Numbers above maps are
percentages of areas in
specific legend respectively
(7 bins)
(Hansen, 2011 report) http://www.columbia.edu/~jeh1/mailings/2011/20111110_NewClimateDice.pdf
Day-to-day precipitation more extreme
More fluctuation in days between
dry and rainy (fewer in-between
days with both dry and rain or
drizzle)
Possible negative consequences for
ecosystems, plants, solar-energy
production they depend upon
consistent weather
Effect on atmosphere of a small
amount of rain every day versus one
large rain event every week?
(average same in both cases)
Day-to-day precipitation variability change (%) from 1997 to 2007
(Medvigy and Beauliau, 2011)
Day-to-day sunshine more extreme
Blacked out area  lack of
consistent data
Most studies use averages  miss
these fluctuations (or they look at
daily fluctuations on a regional or
city scale for forecasting)
Green areas: less partly cloudy
days; in other words: more days
with all clouds or all sun (all or
nothing, less of both)
Atmosphere is a fluid
 severe weather punches hole
 affects other regions
 less heat and rain equilibrium
 impairs photosynthesis
Day-to-day solar radiation (sunshine) variability change (%) from 1984 to 2007
(Medvigy and Beauliau, 2011)
Weather: 2010 and 2011 (meteorologist anecdotes)
“… the wild roller-coaster ride of incredible weather events during 2010, in my
mind, makes that year the planet’s most extraordinary year for extreme weather
since reliable global upper-air data began in the late 1940s. Never in my 30
years as a meteorologist have I witnessed a year like 2010–the astonishing
number of weather disasters and unprecedented wild swings in Earth’s
atmospheric circulation were like nothing I’ve seen.”
(Masters, Jeff, 2011)
“…it is highly improbable that the remarkable extreme weather events of 2010
and 2011 could have all happened in such a short period of time without some
powerful climate-altering force at work. The best science we have right now
maintains that human-caused emissions of heat-trapping gases like CO2 are the
most likely cause of such a climate-altering force.”
(Joseph Romm blog Climate Progress, 2011)
Ozone hole in the Arctic (winter 2011)
Higher greenhouse gas concentrations
warming troposphere
cooling stratosphere
temperature crosses threshold of
-79 oC
formation of polar stratospheric clouds
(PSCs)
on surfaces of ice crystals chlorine
catalyzes ozone destruction
chain reaction occurrs; destroyed
about 40% of ozone layer
Ice sheet mass balances
a) Greenland ice loss
b) Antarctica ice loss
c) Total ice loss (Greenland +
Antarctica)
Uses Mass Budget Method (MBM)
(solid black circles) and GRACE
time‐variable gravity (solid red
triangles), with associated
error bars (Gt/year)
(Rignot, 2011)
Sea-level “hockey stick”
1) Expansion of water; 2) mountain glacier melt; 3) ice caps;
4) Greenland and Antarctic ice sheet melt (present rate of rise 3.4 mm/year);
projected rise of 1 foot by 2050, up to 2 meters by 2100
Paleorecords: 121 kyr ago (Eemian); rise 50 cm/decade for 5 straight decades
(Blanchon et. al., 2009)
Ocean acidification “hockey stick”
(Synthesis Report, 2009)
Carbon stocks in northern cryosphere
(McGuire et. al., 2009)
Terrestrial permafrost
Wetland drying  more severe peatland wildfires
 9x more carbon released into atmosphere
(New York Times article,
“Frozen carbon”, Dec 16, 2011)
(AMEG, 2011)
(AMEG, 2011)
(AMEG, 2011)
Global warming potential of methane
xxx
(AMEG, 2011)
Terrestrial permafrost methane
(Schaefer et. al., 2011)
Thawing permafrost will turn Arctic from carbon sink to source in 2020s,
releasing 100 billion tons of carbon by 2100
18.8 million km2 of northern soils hold about 1,700 Gtons of organic carbon
4x all carbon emitted by humans; 2x atmospheric concentration of carbon
(AMEG, 2011)
East Siberian Arctic Shelf: plume diameters of tens of meters several years ago;
now diameters of 1000 meters; 100s of plumes in study area
(AMEG, 2011)
Methane hydrates on sea floor
(Archer, 2008)
Methane from Arctic continental shelf
(Shakhova, 2010)
Methane from Arctic continental shelf
(Shakhova, 2010)
Methane in the Arctic
Albedo flipping as sea-ice leaves
Present sea-ice forcing 0.1 W/m2; sea-ice gone for one month 0.3
W/m2; eventual disappearance 0.7 W/m2
Rate of warming in Arctic
Now about 2 oC/decade (~6x global rate); rate will increase
significantly with ice disappearance
Methane sources
Terrestrial permafrost 1700 Gtons C; ESAS permafrost 1750 Gtons
(50 Gtons in precarious state, liable to sudden release; would cause
surge in atmospheric methane level by 11x current level 
catastrophic feedback loop  warming spiraling up  world food
production spiraling down); release of only 15 Gtons over 10 years
would dominate CO2 forcing (no chance at 2oC stabilization)
Methane in the Arctic
Recent methane emissions in Arctic
estimated to be quite small (10-20 Mtons carbon)
Very recent escalation of emissions
Apparent from ESAS (100s of plumes tens of meters in diameter
a few years ago to 100s of plumes as large as 1 km in diameter
for study area); increase between 22x and 33x estimated?
Note: (simple area ratio (1000 m/20 m)2 = 2500x larger)
Methane in the Arctic
Causes of escalation
1) warming of ocean currents and river flows into ESAS
2) increased mixing/churning of warm water with cold water to heat
water layer above sea-floor as sea-ice cover vanishes and water is
exposed to storms
3) recent switch of Beaufort gyre direction (normally cw; fresh water
from Siberian rivers hits TransArctic drift current and is exported
to Arctic); with shift fresh water accumulated in Canadian Arctic
(freshest there in 50 years, saltier on Russian side)
Outlier measurements of methane at Barrow and Svalbard
Suggest that significant amounts of methane are reaching the
atmosphere
Methane in Arctic atmosphere
ftp://asl.umbc.edu/pub/yurganov/methane/Yurganov_LondonCH4.pdf
http://www.skepticalscience.com/arctic-methane-outgassing-e-siberian-shelf-part2.html
Methane in Arctic atmosphere
Hemispheric mean methane (NH – northern hemisphere)
ftp://asl.umbc.edu/pub/yurganov/methane/Yurganov_LondonCH4.pdf
Hemispheric mean methane (NH – northern hemisphere)
ftp://asl.umbc.edu/pub/yurganov/methane/Yurganov_LondonCH4.pdf
Effect of climate change on biodiversity loss
By 2100: 40 % of “major ecological community types” i.e. biomes (forest, grassland, tundra…) will have
switched (100% change) to a different state; most will have changed by 30% (Bergengren et. al., 2011)
Global croplands (green)
http://earthobservatory.nasa.gov/IOTD/view.php?id=76605&src=eoa-iotd
Projected Palmer Drought Severity Index (PDSI)
Anthropogenic warming change that will likely impact the most people in coming decades?
Extended or permanent drought over presently arable and inhabited regions; “eye opener” for rich Western
countries; many people feel that climate change will not directly affect them; since 1950: global
percentage of dry areas has increased by about 1.74% of global land area per decade
http://www2.ucar.edu/sites/default/files/news/2010/2060-2069wOceanLabels.jpg
The race is on for “smoking gun”…
(Lenton et. al., 2008)
xxx
(Dakos et. al., 2008)
(Arctic Methane Emergency Group (AMEG), 2011)
AMEG recommended actions
1. Support a government “declaration of a planetary emergency” to
alert other governments around the world
2. Set up an emergency task force to recommend temporary
international measures that could have a beneficial effect on
Arctic temperature this year
3. Support the initiation of a number of parallel geo-engineering
projects for large-scale deployment, singly or in combination, by
spring 2013
4. Reassure the public about the “low risk of SRM” (solar radiation
management) geoengineering compared to the high risk of abrupt
climate change (when the magnitude of the hazards are taken into
account.
John Nissen (Chair of Arctic Methane Emergency Group)
www.arctic-methane-emergency-group.org
Procrastination to action: climate Pearl Harbors?
Drivers of serious government action: “bad things must be happening to regular people
right now”; media must report them as being a result of climate change; requires a
change in “world view”
1)
2)
3)
4)
5)
6)
7)
8)
ice-free Arctic by 2020 or earlier
extremely rapid warming over next decade
methane surges
mega-drought hitting US southwest
more Katrina like superstorms
heatwave hitting US breadbasket
accelerating sea-level rise, visible ice shelf collapses
Amazon rainforest collapse
“Owing to past neglect, in the face of the plainest warnings, we have entered upon a
period of danger…. The era of procrastination, of half measures, of soothing and
baffling expedience of delays, is coming to its close. In its place we are entering a period
of consequences…. We cannot avoid this period, we are in it now….”
– Winston Churchill, Nov. 12, 1936, British House of Commons
(Boyd, 2008)
Paleo-temperatures from ice cores (Greenland and Antarctica)
Average temperature swings of 8 to 10 oC in < 1 decade seen… (Jouzel et. al., 2007)
Bristlecone pine (White Mountains, California)
“Methuselah”
Habitat:
- high altitude
- near tree line
- cold, dry, high winds
- short growing season
- poor soils
 grows very slowly
Oldest living organism
on planet:
4789 years old
Will trees live this long in the future?