Download Climate and Weather - AHS * Humanities 11

Lauren Heerschap, Fort Lewis College, Spring 2016
• Do you think Earth is cooler or warmer now,
compared to past climates?
• What are some factors that cause Earth’s
climate to change?
• How do current changes compare to past
changes?
http://www.globalwarmingart.com/wiki/File:Phanerozoic_Climate_Change_Rev_png
http://www.globalwarmingart.com/wiki/Temperature_Gallery
http://www.globalwarmingart.com/wiki/Temperature_Gallery
• Paleoclimatology!
– Direct Measurements or Records:
• Instrumental Record – temperature since about 1860
• Historical Records – written records and archeology, ex: Little Ice Age,
Medieval Warm Period
– Proxy Data:
• Sedimentary Rock Record – rock types and fossils indicate past
environments
• Tectonic History – distribution of landmasses, mountains, oceans all
can affect global climate
• Isotopes – oxygen (O-16 vs. O-18) derived from corals and sediments
indicates “weight” of seawater and general temperature
• Evidence of Glaciation – erosion and deposition by ice leaves record
• Ice Cores – trapped gas bubbles show past CO2 and CH4, and also
contain ash, pollen, dust that help illustrate climate
• Tree Rings – dendrochronology, shows drought vs. wet seasons, fire
• Pollen – palynology, tells what plant species were nearby
• Tectonics – arrangement of continental masses and areas of
high elevation, mountain building
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Ocean currents – circulation of cold and warm currents
Volcanic activity – release of aerosols, GHGs
Atmosphere – amount of GHGs present, methane releases
Carbon sequestration or release – times of higher %
vegetation, coal formation, limestone formation, weathering
• Milankovitch cycles – variations in Earth’s orbit, tilt, and
axis wobble
• Solar cycles/forcing – variation in Sun’s energy (minor)
• Albedo – reflectance of surface leads to feedback loops
• Anthropogenic forcing – people!
Post-Industrial Revolution
increases in greenhouse gases, deforestation, agriculture
Ocean currents distribute warm and cold waters throughout the globe
Milankovitch Cycles are variations
in Earth-Sun geometry that cause
glacial fluctuations
Albedo is a measure of surface reflectance –
ocean water absorbs a lot of solar energy, while glaciated areas reflect
http://earthobservatory.nasa.gov/IOTD/view.php?id=5484
Composition of Earth’s Current Atmosphere
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Water vapor
Carbon dioxide
Methane
Nitrous oxide
Ozone
CFC’s
Sulfur hexaflouride
Earth would be -18 °C
on average without
these gases!
(It’s about 14 °C now…)
• These gases trap the Earth’s heat, reduce its heat loss,
maintain its temperature – like a greenhouse!
That’s 100 ppm higher than past 400,000 years!
March 2016
405
http://globalclimatechange.jpl.nasa.gov/
http://globalclimatechange.jpl.nasa.gov/evidence/
Where does this data come from?
From www.epa.gov
http://www.esrl.noaa.gov/gmd/ccgg/trends/
http://www.esrl.noaa.gov/gmd/ccgg/trends/
http://www.scar.org/images/news/Global_Temp_2007.png
http://www.noaanews.noaa.gov/stories2008/20081118_octobertemps.html
http://www.ncdc.noaa.gov/sotc/global/2014/13/supplemental/page-4
RANK
1=
WARMEST
PERIOD OF
RECORD:
1880–2015
YEAR
ANOMALY
°C
ANOMALY
°F
1
2015
0.90
1.62
2
2014
0.74
1.33
3
2010
0.70
1.26
4
2013
0.66
1.19
5
2005
0.65
1.17
6 (tie)
1998
0.63
1.13
6 (tie)
2009
0.63
1.13
8
2012
0.62
1.12
9 (tie)
2003 & 2006 0.61
1.10
9 (tie)
2007
1.10
0.61
https://www.ncdc.noaa.gov/sotc/global/201513
http://www.nasa.gov/press-release/nasa-noaa-analyses-revealrecord-shattering-global-warm-temperatures-in-2015
1880s
1980s
These maps show temperatures across the world in the 1880s (left) and the
1980s (right), as compared to average temperatures from 1951 to 1980. This
difference from average is called an anomaly. The map on the left shows that it
was colder in the 1880's in most places. The map on the right shows it was
warmer in the 1980s in most places. Earth's average surface temperature has
increased almost 1.5°F during the 20th century. Two-thirds of the warming has
occurred since 1975, at a rate of roughly 0.3°F-0.4°F per decade.
Source: NASA
http://www.global-greenhousewarming.com/sea-temperature.html
http://www.columbia.edu/~mhs119/SeaLevel/
http://www.carbonbrief.org/five-reasons-why-the-speed-of-arctic-sea-ice-loss-matters
http://www.globalwarmingart.com/images/f/f0/2007_Arctic_Sea_Ice.jpg
http://www.ncdc.noaa.gov/sotc/global/2013/13
http://www.ncdc.noaa.gov/sotc/service/global/extremes/201313.gif
• 2007 report by Intergovernmental Panel on Climate
Change, a group of 1200 scientists from 120
countries, concluded that there is 90% probability
that observed changes in climate are anthropogenic
• Milankovitch cycles are modeled to be on cooling
trend, not warming trend right now.
• Solar output is lower now than it has been in
decades.
http://www.epa.gov/climatechange/science/causes.html
http://www.global-warming-and-the-climate.com/images/Manns-hockey-stick.gif
• Pre-Industrial CO2 =
280 ppm
• Spring 2016 reached
405 ppm
• Already seeing over
1C temperature rise
• Models suggest 4-8C
further rise if CO2
continues to rise
http://www.epa.gov/climatechange/science/future.html
http://www.epa.gov/climatechange/science/future.html
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Shift in world’s climate zones
Extinctions, Loss of Biodiversity
Melting Ice: Sea Level Rise, Water Resources
Displaced coastal/island communities
Droughts, Famines
Increased storms, hurricanes, floods, landslides
Wildfires
Ocean Acidification
Feedback Loops
• IPCC conclusions:
– If temperatures
rise 2°C above preindustrial levels,
20-30% of plants
and animals may
be subject to
extinction
– If temperatures
rise 4°C, 40-70% of
species will be at
risk
Only melting land
ice contributes to
sea level rise, not
melting sea ice.
http://www.globalwarmingart.com/wiki/Special:SeaLevel
http://earthandindustry.com/2012/08/energy-and-environment-news-roundup-%E2%80%93-8-7-12/sea-level-rise/
http://www.buzzardsbay.org/images
/hurricane-frequency-us.gif
http://static.icr.org/i/articles/imp/imp406-Hurricane-frequency.jpg
Wildfires >250 acres, 1980-2003
http://www.nasa.gov/centers/godda
rd/news/topstory/2006/wildfire_thr
eat.html
• Positive (enhance changes): • Negative (dampen changes):
– Water vapor
– Natural GHGs
– Albedo & Melting Ice
– Methane hydrates
– CFCs & ozone layer
– Aerosols
– Black carbon
– Cloud cover
– Vegetation/Algal
Blooms
– Cold freshwater influx
into oceans
Stabilization
• Global:
– Intergovernmental Panel on Climate Change (IPCC) provides information to
guide policies – first report in 1990
– United Nations Framework Convention on Climate Change (UNFCCC) began in
1992 at Earth Summit in Rio de Janeiro
– Kyoto Protocol (1997): GHG emission target limits aiming for below 1990 levels
(US did not ratify)
– 2014 Agreement with China: https://www.whitehouse.gov/the-pressoffice/2014/11/11/fact-sheet-us-china-joint-announcement-climate-changeand-clean-energy-c
– Carbon Cap and Trade, Carbon Offsets, Carbon Tax
• National: US is not unified in efforts, many organizations are involved
• State: California target of reaching pre-1990 GHG levels by 2020 through
renewable electricity sources, carbon trading, strict vehicle emissions
standards
• Local: grassroots efforts aplenty!
• Individual????
The Ozone Hole
• “Discovered” in
1985
• Linked to CFC
release into
atmosphere
• 1987 Montreal
Protocol banned
these substances
• Steady “healing” of
the layer
http://www.theozonehole.com/cfc.htm
http://maps.grida.no/library/files/archivetv07_l.gif
• What facts support the idea of anthropogenic causes for
global warming?
• Climate skeptics use what counter-arguments against
anthropogenic causes?
• How can people look at the same facts but have differing
interpretations?
• In your opinion, what is the ‘scariest’ consequence of future
global warming?
• Are there any positive aspects of global warming?
• What is the most important thing humans should do NOW to
counteract global warming?
• Are the environment and the economy inherently at odds
with each other?
• EPA: http://www.epa.gov/climatechange/ and
http://www.epa.gov/climatechange/science/causes.html
• NOAA: http://www.ncdc.noaa.gov/climate-information
• IPCC: http://www.ipcc.ch/
• NASA: http://climate.nasa.gov/