Download 5 Climate Change - University of St. Thomas

Science of Natural Disasters:
Climate Change
4 May 2016
Rebecca Clotts
Department of Geology, University of St Thomas
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Why is there weather?
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How the atmosphere creates weather:
Atmospheric Circulation
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How the atmosphere creates weather:
The Jet Stream
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How the atmosphere creates weather:
The Jet Stream
Actual location
depends upon:
– the location of high
and low pressure
systems
– warm and cold air
– seasonal changes
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What is climate?
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How is climate measured?
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What controls Earth’s temperature?
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What controls Earth’s temperature?
1) Amount of incoming solar radiation
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What controls Earth’s temperature?
1) Amount of incoming solar radiation
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What controls Earth’s temperature?
1) Amount of incoming solar radiation
http://www.wwnorton.com/college/geo/egeo2/content/animations/18_2.htm
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What controls Earth’s temperature?
1) Amount of incoming solar radiation
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What controls Earth’s temperature?
1) Amount of incoming solar radiation
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This figure shows the variations in Earth's orbit, the resulting changes in solar energy flux at high
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latitude, and the observed glacial cycles
http://earthobservatory.nasa.gov/Features/Milankovitch/milankovitch_3.php
Precession
Obliquity
Eccentricity
After Scott Rutherford, 2000
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Earth’s temperature?
5°C or 41°F
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What controls Earth’s temperature?
2) Amount of energy reflected
http://www.uwsp.edu/geo/faculty/ritter/images/atmosphere/energy/albedo.gif
ALBEDO = the reflectivity of a surface
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Earth’s temperature? −18°C or 0°F
Snowball Earth
Earth as we like it!
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What is in the atmosphere?
• Gases
• Water Vapor (H2O) – Clouds!
• Areosols – Tiny solid and liquid
particles
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http://www.nasa.gov/images/content/140537main_aerosol_particles.jpg
What controls Earth’s temperature?
3) Greenhouse Effect
Degree to which
atmosphere retains
heat radiated from
Earth
• What are some
greenhouse gases?
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What are some greenhouse gases?
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How much does the greenhouse effect warm Earth?
Earth’s temperature? 15°C or 59°F
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Where do greenhouse gases come from?
Natural sources
Anthropogenic –resulting
from human activity
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Sources of Greenhouse Gases: Carbon Dioxide (CO2)
Where does carbon dioxide come from naturally?
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Sources of Greenhouse Gases: Carbon Dioxide (CO2)
What are anthropogenic sources of CO2?
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Carbon Cycle Animation:
http://www.biology.ualberta.ca/facilities/multimedia/uploads/alberta/C
arbonCycle.html
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Source of Greenhouse Gases:
Carbon Dioxide (CO2)
Gigaton = 1 billion tons (1,000,000,000 tons)
Location
Gigatons of Carbon
Atmosphere
750
Plants / biomass
610
Soil
1,580
Oceans (includes
sediments & rocks)
39,000
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http://upload.wikimedia.org/wikipedia/commons/5/55/Carbon_cycle-cute_diagram.jpeg
Sources of Greenhouse Gases: Methane (CH4)
Natural Sources:
Anthropogenic Sources:
fuel production, especially coal
animal husbandry (ruminants)
rice cultivation
biomass burning
waste management
(decomposition of wastes in landfills)
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/images/atmosphere/structure_co
mposition/methane_naturalchart2_EPA.gif
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Sources of Greenhouse Gases: Nitrous Oxide (NO)
Anthropogenic Sources:
Natural Sources:
Breakdown of material
by microbes in soil and
in ocean
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Sources of Greenhouse Gases: Ozone (O3)
Anthropogenic Sources:
Natural Sources:
Stratosphere
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How is climate measured and described?
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How is climate measured and described?
•
•
•
•
•
•
Human Records
Tree rings
Glaciers
Sediments
Fossils
Rocks
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What causes climate change?
Position of Continents
Uplift of Land Surfaces
Rock Formation
Life
Long-term eruptions
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Examples
of past
extreme
climate
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What was Snowball Earth?
Precambrian (850-630Ma)
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What was Snowball Earth?
• Low greenhouse gas
concentrations due to
high rates of rock
weathering
• Dimmer Sun
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What was Snowball Earth? Evidence
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What was the Cretaceous Greenhouse?
Cretaceous Period (80 Ma)
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What caused the Cretaceous Greenhouse?
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What was the Pleistocene Ice Ages?
Pleistocene Epoch (~18 ka)
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What caused the Pleistocene Ice Ages?
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http://www.seed.slb.com/en/scictr/watch/climate_change/causes_co2.htm
Climate change right now
http://earthobservatory.nasa.gov/IOTD/view.php?id=5668
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Evidence for Climate Change: Temperature
Global mean surface temperature has
increased by 1.0-1.7°F since 1850
Increased by about 1°F since the 1970’s
Graph from NASA
Global mean surface temperature has
increased by 1.0-1.7°F since 1850
Increased by about 1°F since the 1970’s
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Evidence for Climate Change: Ocean Temperature
Graph from NASA
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Evidence for Climate Change: Ocean Temperature
The top 700 m (2,300 ft) of ocean
show warming of 0.3 °F since 1969
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Evidence for Climate Change: Precipitation
How much precipitation changed between
1991 and 2012 compared to the average
precipitation observed between 1901 and
1960
Graph from NASA
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http://www.climatecentral.org/
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Evidence for Climate Change: Loss of Ice
• Ice Sheets of Greenland
& Antarctic
• Loss of Arctic Sea Ice
• Glacial Retreat
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Evidence for Climate Change: General observations
Extreme Weather Events
Ocean Acidification
– 30% increase
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What is causing climate change now?
Greenhouse effect
Amount of sunlight reflected
Amount of solar energy received
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Anthropogenic Impact
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Anthropogenic Change
http://www.waterwise.com/images/waterwisdom/thinkbeforeyoudrinkpict.jpg
http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/ozone_hole_large
.jpg
http://lakelandschools.org/LCBMS/Teachers_Pages/JTOLEDANO/AcidRain/acidrainpict.jpg
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Is the increasing CO2 due to anthropogenic changes?
http://www.patdixon.org/images/co2sourcesink.jpg
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Is the increasing CO2 due to anthropogenic changes?
Sources
Amount
Sinks
Amount
Land Respiration
440 Photosynthesis
440
Volcanoes
0.3 Weathering
0.7
Ocean Release
260 OceanAbsorption
260
Industrial
26 Post-ind ↑ PS
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Post-industrial
Post-indust. Ocean
Ocean Release
70 Absorption
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Changing Land Use
6
790.7
802.3
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Atmospheric Changes in
Greenhouse Gases
• Carbon Dioxide (CO2)
– Increase from 280 ppm (pre-industrial times) to
382 ppm (2006); ~36% increase
• Methane (CH4)
– higher now than in past 650,000 years; ~148%
higher than in pre-industrial times
• Nitrous Oxide (N2O)
– Increase by ~18% since pre-industrial times
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What are the consequences of a changing climate?
http://climate.nasa.gov/effects/
http://www.cbc.ca/news/background/climatechange/gfx/graphic4b.jpg
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What are the consequences of a changing climate?
http://climate.nasa.gov/effects/
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What are the consequences of a changing climate?
http://climate.nasa.gov/effects/
Reduction of the West Antarctic and Greenland ice
sheets similar to past reductions would cause sea
level to rise 10+m. A sea-level rise of 10m would
flood about 25% of the U.S. population
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What are the consequences of a changing climate?
http://climate.nasa.gov/effects/
Wildfires
http://www.wildlandfire.com/pics/wall/wildfire.jpg
Desertification & Drought
Storm Intensity
http://library.thinkquest.org/J0113061/media/newlake.gif
http://www.putnam.k12.il.us/twin.jpg
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Why should you care about climate change?
http://www.pbs.org/wgbh/nova/earth/bowring-extinctions.html
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Why should you care about climate change?
Global problems
• Rising sea level
– Displace people
• Water changes
– Disrupt agriculture (shortages and price spikes)
• Changing weather
– Stress infrastructure: storm sewers, roads, bridges,
water storage
• Extreme Weather and Climate Change:
http://video.pbs.org/video/2107362228
– (4:27mins PBS 2011)
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Why should you care about climate change?
Water Resources
• Water Quality and Quantity
– Less ice cover, more evaporation
– Lower groundwater levels
• More flooding
– Heavy rainfall events stress
infrastructure
• Less winter snow
– Recreation
– Hibernation, food supplies, habitat
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Why should you care about climate change?
Minnesota
• Average temperature
increase, more heat
waves
• 20% increase in
precipitation in parts
of MN
• May be like Missouri
• Forested areas may
become grasslands
• North woods (pine and
aspen) switch to oak
and other trees
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Why should you care about climate change?
Minnesota
• Temperature & moisture will change
faster than biota can adapt
• Pests, disease, invasive species
extend range into MN
• Loss of cold weather species
– Trout
– Moose
• Extinction
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Are you worried?
How about some perspective?
Oldest homo specimen fossil
2.3 million years old
Oldest homo sapiens
160,000 years old
http://news.nationalgeographic.com/news/2001/02/0227_climate4.html
http://news.nationalgeographic.com/news/2001/02/0227_climate4.html
Predict the future…
A
B
C
60,000 years
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In 50 million years…
http://www.scotese.com/future.htm
Loss of Mediterranean, Australia collides
with SE Asia, California slides northward
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towards Alaska coast
In 250 million years…
Formation of Supercontinent: Pangea Ultima
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