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Climate change and us
Victoria Metcalf
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Valentin Druzkinin, Russia
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Breaking the ice
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Coat Star, by Mikhail Zlatovsky, Russia
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What do you value? What are the things that are most
important to you?
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Butterflies, by Constantin Ciosu, Romania.
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When you hear ‘climate change’ what words spring to mind?
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“Politicians discussing climate change” by Spanish sculptor Isaac Cordal
Passivity- Waiting for Climate Change
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Antarctica: a pivotal continent Maintains the health of our planet
Linked to Antarctica are:
Weather
Ocean currents
Ecosystems
Sea level
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Andrei Popov (Russia)
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Antarctica – the present 2x size of Australia
Coldest, windiest, highest and driest place on Earth, biggest desert
Covered in 2160 m ice (90% of world’s ice, as deep as 4km, ¾ of world’s fresh water)
largest solid object in the world
0.5% exposed rock
Frozen seas, ice shelves
Cold temperatures
Unique flora & fauna
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• Polygons
• Dry Valleys
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Ice environments- present
Glaciers
Ice tongues
Lakes
Subglacial Antarctic lake environments
Ice shelves
Sea ice (seasonal growth world’s biggest seasonal change)
Sastrugi
Icebergs
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Southern Ocean –introductionSouthern part of Pacific, Indian and Atlantic oceans, 10% of world ocean
Antarctic Circumpolar Current =world’s longest current, with an estimated journey of 24,000 km.
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The motorTransports the biggest volume of water and connects all other oceans.
Plays the most important part in the global distribution of heat and nutrients around the world
Powerhouse of the planet
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Southern Ocean -present Characteristics:
3000-5000m deep
Temperature < 0ºC (continental shelf -1.87 ºC)
Thermally stable (McMurdo varies from -1.9 - 1.4)
2-3 m sea ice for most of the year
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What lies beneath Oxygen solubility nearly doubles from 20-0ºC
Paradox: Freezing water requires adaptation but increased oxygen solubility supports richness of life
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Not always icy
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Not always frozen
Antarctica above and below water has changed significantly over time due to alterations in climate
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Bob Eckstein (USA)
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Extreme living Organisms in extreme environments are exposed to
strong environmental constraints
Temperature = strong evolutionary driving factor
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Multiple stressors
Ocean acidification
Pollution
Fisheries
Warming
Freshening
Stratification
Deoxygenation
Eutrophication
Accelerated polar warming
Stratification
Wind/current change
Lower oxygen concns
Sea ice loss
Methane venting
Sea level rise
Primary prod. Δ
Range shift
Species invasions
Species turnover
Disease increase
Extinctions
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Multiple stressors acting in Antarctic waters
Ingels et al 2012
Altered food web dynamics
Reduced abundance
Range shifts
Ecological imbalance
Pathogen expansion
Extinctions in Southern Ocean
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Cartoonist: Reynolds, Dan
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Scale of process and rate of change
Peck 2011
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Flux of carbon (atmosphere, biosphere, oceans) in both inorganic (e.g. CO2 ) and organic forms (sugars, complex carbohydrates in the biosphere) = global carbon cycle
Rapid increase in CO2 emissions since industrial age
When CO2 levels in the atmosphere rise, temperature goes up, and vice versa.
IPCC 2007
Carbon cycle
Source of data: Boden, T.A., G. Marland, and R.J. Andres (2010). Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi10.3334/CDIAC/00001_V2010.
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Oceans play a critical role in the global carbon cycle by:
Absorbing 1/4th -1/3rd emitted CO2 from human activities = sink (sponge)
Wikimedia Commons
Carbon in the oceans
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Ocean absorbs > 1/4th of man-made CO2 emissions
Half of emitted CO2 remains in atmosphere (causing global warming)
Half absorbed by ocean & land (trees, plants, and soils) Ocean absorbs 24 million tons of CO2 every day (4 kg per person,
daily)
Increase in atmospheric carbon8.6 + 0.8 – 2.6 – 2.6 = 4.2 Pg C / yr
Global Carbon Project (2013)
2.6 ± 0.5 Pg C/yr2.6 ± 0.8 Pg C/yr0.8± 0.5 Pg C/yr
Deforestation Land uptake Ocean
8.6± 0.4 Pg C/yr
Fossil fuels2002-2013 Carbon budget
•Le Quéré et al 2013; CDIAC data; Global Carbon Project 2013
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The Hand, by TawanChuntraskawvong, Thailand
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Once dissolved in sea water, CO2 is subject to two possible fates:
used by photosynthesis or other physiological processes
or remain free in its different dissolved forms in the water
The latter leads to ocean acidification.
Wikimedia Commons
Carbon fate in the oceans
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=Decrease in pH of the oceans
Does not need to be acidic state; in fact that will not occur
Wikimedia Commons
Ocean acidification
http://youtu.be/Wo-bHt1bOswAnimation- excellent basic NGO vid
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CO2 = an acid gas (produces acid when combined with water)
Each of us adds 4 kg CO2 per day to the ocean (increasing acidity, reducing pH)
Ocean acidity up by 30% since start of industrial age
Most of that only in last 40 years
deforestation Land uptake océan
Schematic: Sam Dupont, University of Gothenburg
More atmospheric CO2 means more ocean acidity
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Data: Bates (2007)Dore et al. (2009)Santana-Casiano et al. (2007) Gonzàles-Dàvila et al. (2010)
Change in pH from ocean acidification already measurable
IPCC AR5 WG1 Report, Chap. 3 (2013)
Station ESTOC
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• overwhelms natural variations (last 800 000 years)
• may be 10 times faster than natural event (55 million years ago)
• rate may be unprecedented (over last 300 million of years)
• 30% increase in acidity (H+) during industrial era
• 100% increase (or more) projected by 2100
Barker and Ridgwell (2012)
Today’s rate of ocean acidfication may be unprecedented
Current change:
average glacial pH
futuregeological past
1900 2000 21001002003004006007008007.7
7.8
7.9
8.0
8.1
8.2
8.3
surf
ace
pH (t
otal
sca
le)
200
300
400
500
600
700
900
Atm
osph
eric
CO
2(p
pm)
YearAge (thousands of years)
average interglacial pH
500
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Carbonate ions [carbonate ion] in oceans largely determines whether there
is dissolution or precipitation of calcium carbonate (CaCO3) Two forms of calcium carbonate: aragonite and calcite
Surface waters are super saturated with respect to aragonite and calcite, meaning that carbonate ions are abundant.
OA shifting this saturation horizon and state Calcium carbonate essential for biomineralising organisms
Wikimedia Commons
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RS report 2005
Ocean Acidification
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RS report 2005 (Figures courtesy Scott Doney, Woods
Hole Oceanographic Institution)
RHS Wikimedia Commons
Ocean AcidificationRelative proportions of the three inorganic forms of CO2 dissolved in seawater.
Green arrows indicate narrow oceanic range of pH at present
0.1 pH unit change = 30% more H+
ions
LGM176620072100
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Models project that cold waters soon will become corrosive to aragonite, a (CaCO3) mineral in some marine shells & skeletons
Corrosivity of waters to aragonite
(when < 1, aragonite dissolves)
Polar oceans will become corrosive to shell material within decades
Confirms original warnings: Orr et al. (2005), Caldeira & Wickett (2005), Steinacher et al. (2009)
Latest model projections (IPCC AR5 WG1, 2013)
AnimationCopyright: James C. Orr
see also Bopp et al. (2013)
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If projections hold, in much of the 2099 ocean, many organisms from plankton to corals, could be gone!
Major impacts by 2030-2050
Making shells is/will be chemically difficult in much of the Southern Ocean
Impacts on many species that play key roles in food webs especially polar + coral reefs BUT what effects?
Irreversible for 1000’s of years
(Figures courtesy Scott Doney, Woods Hole
Oceanographic Institution)
CaCO3 levels in the oceans
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Day 16
Day 2
Day 1
Orr et al. (2005)
Fabry et al. (2008)
Comeau et al. (2009; 2011; 2012)
Lischka et al. (2011); Lischka & Riebesell (2012)
Bednarsek et al. (2012)
These corrosive conditions dissolve shells of sea butterflies
Image: Victoria Fabry, California State University San Marcos
Sea butterfly shells (CaCO3) exposed to corrosive conditions expected by 2100
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Wikimedia Commons
Where shell building happens
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Granite Harbour
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Experimental setup
Sentinel Antarctic benthic bivalves (circum Antarctic)
• Laternula elliptica (clam)
• Adamussium colbecki
(scallop)
pCO2 levels of:
• natural environment (430 μatm, pH 7.99)
• predicted for 2100 (735 μatm, pH 7.78)
• glacial levels (187 μatm, pH 8.32).
Rod Budd, NIWARod Budd, NIWA
Vond
a C
umm
ings
, NIW
AVo
nda
Cum
min
gs, N
IWA
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Upregulation of HSP70 gene expression indicating a stress at both low + high pH
Negative correlation between pH & chitin synthase expression (calcification gene)
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Respiration as a proxy for metabolic rate
Energetically more stressful for Laternula to function at pH values not currently experienced
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Acidification will change marine ecosystems
see also Kroeker et al. (2013)
Organisms react differently
Corals and shell builders (molluscs, echinoderms) decline
Seagrasses may increase
Synthesis of existing experimental studies
Wittmann & Pörtner (2013)
Photos: Jean-Louis Teyssié Photo: Ana Laangova*Photo: J.-L. Teyssié
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Acidification will change marine ecosystems
see also Kroeker et al. (2013)
Seagrasses may increase
Fish become disoriented, larval fish sensitive
Prey loss affects predators, potential fish catch decline
Synthesis of existing experimental studies
Wittmann & Pörtner (2013)
Photos: Jean-Louis Teyssié Photo: Ana Laangova*Photo: J.-L. Teyssié
Temperature exacerbates effects
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Ocean areas naturally rich in CO2 confirm expected future trends• Less biodiversity, palatibility
• Fewer calcifiers
• More fragile shells
• More invasive species
• More seagrasses, degraded corals
Photo: Jason Hall-Spencer, University of Plymouth
CO2 bubbles rise from seafloor at Ischia, Bay of Naples, a natural lab to study acidification
Photo: Steve Ringman, Seattle Times
Another natural CO2 vent site in Papua, New Guinea, used to study effects of acidification on corals
Hall-Spencer et al. (2008)
Rodolfo-Metalpa et al. (2008)
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Ocean acidification will also affect humans• Fish is primary source of animal
protein for 1 billion people, mostly in developing countries (FAO)
• Coral reefs provide
- home for millions of species- storm protection for coastlines- income from tourism- biodiversity legacy for future
• Ocean acidification already affecting oyster industry (U.S. west coast)
• Ocean acidification may generally affect aquaculture, fisheries, and human livelihoods
Photo: Rodolfo Quevenco, IAEA
Photo: Jean-Louis Teyssié, IAEA
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http://www.cbc.ca/news/canada/british-columbia/acidic-ocean-
deadly-for-vancouver-island-scallop-industry-1.2551662
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936 ppm
670 ppm
538 ppm
450 ppmA
tmos
pher
ic C
O2
(ppm
)
Year
The intensity of ocean acidification depends on us
Intensity of ocean acidification (change in pH) varies by a factor of 3
Future atmospheric CO2
(latest IPCC scenarios)
pH (t
otal
sca
le)
IPCC AR5 WG1, Technical Summary (2013)Year
RCP8.5
RCP4.5
RCP6.0
RCP2.6
see also Bopp et al. (2013)
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OA may also speed the rate of global warming As pH decreases it lowers the concentration of dimethylsufide (DMS) The Problem? - marine emissions of DMS are the largest source of
atmospheric sulfur SO2 isn’t a greenhouse gas BUT higher atmospheric levels can reduce solar energy reaching Earth Flip that around and OA may add 1 deg C to global warming
OA will make climate change worse
http://commons.wikimedia.org
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11 944 climate abstracts from 1991-2011 analysed
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A new study finds overwhelming odds that humans have contributed to higher global temperatures – so how much are we willing to gamble that it’s wrong? Kraevski Vitaly/Shutterstock
4 September 2014
99.999% certainty humans are driving global warming:
new study
The Conversation
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Antarctica 34-50 million yrs ago CO2 > 1000 ppm, global ave temp 10 to 15 ºC
higher than present
Ice free
Surrounding oceans are warmer than 15 ºC
Global sea level ~60 metres higher than today
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Back 33.9-23 million years ago CO2 > 750 ppm (fluctuates), global ave temp 8 to 10 ºC
higher than present
Ice is spreading across the land
Forests clinging to the coast
Drake Passage forms, contributes to cooling
As water becomes trapped in the growing Antarctic ice sheet, sea levels drop by about 50 metres.
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Why the drop in CO2? Rock weathering processes draw CO2 out of the
atmosphere and into the ocean. CO2-laden rains are acidic
Algal blooms also suck CO2 from the air and into the ocean
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Milankovitch cyclesEarth has normal cycles for climate
Change triggered by Milankovitch cycles
3 different cycles – repeating every 100,000 years, 41,000 years and 21,000 years –change the amount and distribution of solar energy Earth receives.
http://channel.nationalgeographic.com/channel/videos/ice-age-cycles/
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Back 23-3.4 million years ago CO2 drops to 400ppm (same as now)
Global ave temp 2-3 deg higher than now
Ice, no forests, tundra
Growth of ice sheets triggers wind and ocean current changes
Sea levels fluctuate but high enough to flood major cities
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Back 3.4 million years ago-1760 The ice age
CO2 180-280ppm (lowest in >50My), LGM was 3-5deg cooler than now
Ice in the Northern hemisphere
Repeated glacial cycles
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The Anthropocene – 1760-now Earth should be cooling but temperatures are rising
For first time in human history CO2 = 400ppm
(Last time this happened temps were 2-3deg warmer, sea level 20m higher)
http://www.climatecommunication.org/climate/the-
problem-800k-years-video/
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What will make a difference?
Knowledge is power
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Wang Rui Sheng, China