Transcript lecture_2newx

The Greenhouse effect
•Without the greenhouse effect, the earth would be a frozen ball
http://www.gov.mb.ca/agriculture/soilwater/climate/images/indexfig1.jpg
Energy Balance and Planetary Temperatures
“All objects, including stars and planets, radiate energy to their surroundings. The wavelengths
of the emitted radiation depend on the temperature of the object.”
The hot sun emits mostly in the
UV and Visible. The cooler
earth emits mostly in the IR.
Greenhouse gases absorb IR
radiation which reduces
emission of some radiation.
The greenhouse effect keeps us
comfortable. Enhanced
greenhouse effect causes
increased temperatures.
Scales differ by 106
3
NASA, NOAA Analyses Reveal Record-Shattering Global Warm
Temperatures in 2015
Posted Jan. 20, 2016
2015 was the warmest year since modern record-keeping began in 1880, according
to a new analysis by NASA’s Goddard Institute for Space Studies.
The record-breaking year continues a long-term warming trend — 15 of the 16
warmest years on record have now occurred since 2001. (Credit:
NSA/GSFC/Scientific Visualization Studio)
The planet’s average surface temperature has risen about 1.8 degrees Fahrenheit
(1.0 degree Celsius) since the late-19th century, a change largely driven by increased
carbon dioxide and other human-made emissions into the atmosphere.
4
Source: NASA GISS Surface Temperature Analysis: http://data.giss.nasa.gov/gistemp/maps/
5
6
Total U.S. Greenhouse Gas Emissions by
Economic Sector in 2010
http://epa.gov/climatechange/ghgemissions/sources.html
Short History of Climate Change
1824 - Joseph Fourier discovered the greenhouse effect.
1859 - John Tyndall discovered that H2O and CO2 absorb infrared confirming
the Fourier greenhouse effect.
1896 - Svante Arrhenius proposed human CO2 emissions would prevent earth
from entering next ice age (challenged 1906).
1950’s Guy Callendar found H2O and CO2 did not overlap all spectra bands,
therefore warming from CO2 expected (countered the 1906 objections against
Arrhenius).
1955 - Hans Suess identified the isotopic signature of industrial based CO2
emissions.
1956 - Gilbert Plass calculated adding CO2 would significantly change radiation
balance.
1957 - Revelle/Suess suggested oceans would absorb less CO2 causing more
global warming than predicted.
1958/60’s - Charles David Keeling proved CO2 was increasing in the
atmosphere.
70’s/80’s Suke Manabe and James Hansen began modeling climate projections.
Current: NCAR, GISS, Hadley, CRU, RSS TLT, UAH, MSU, Glacier Melt, Sea Level
Rise, Latitudinal Shift all confirm models.
http://www.ossfoundation.us/projects/environment/global-warming/climate-science-history
The Intergovernmental Panel on Climate Change
(IPCC) History
• Established in 1988 by two United Nations
Organizations, the World Meteorological
Organization and the United Nations Environment
Programme to assess “the scientific, technical and
socioeconomic information relevant for the
understanding of the risk of human-induced climate
change.”
• Led to the United Nations Framework Convention on
Climate Change (UNFCCC)
• Produces Assessment Reports
The United Nations Framework Convention on
Climate Change (UNFCCC)
• Treaty established in 1992 to stabilize greenhouse gas concentrations in
the atmosphere.
• Adopted Kyoto Protocol in 1997
– Industrialized countries ("Annex I countries") commit themselves to a
reduction of four greenhouse gases (GHG)
– Never ratified by US since there are no requirements on
underdeveloped nations
– Top-ten emitters
1. China: 7,711 million tonnes (MT) or 25.4%
2. US: 5,425 MT or 17.8%
3. India: 1,602 MT or 5.3%
4. Russia: 1,572 MT or 5.2%
5. Japan: 1,098 MT or 3.6%
6. Germany: 766 MT 2.5%
7. Canada: 541 MT or 1.8%
8. South Korea: 528 MT or 1.7%
9. Iran: 527 MT or 1.7%
10. UK: 520 MT or 1.7%
http://www.guardian.co.uk/environment/2011/apr/21/countries-responsible-climate-change
Latest news on climate change agreements
OUTCOMES OF THE U.N. CLIMATE CHANGE CONFERENCE IN PARIS Nov 30 –Dec 12, 2015
• Reaffirm the goal of limiting global temperature increase well below 2 degrees Celsius,
while urging efforts to limit the increase to 1.5 degrees;
• Establish binding commitments by all parties to make “nationally determined
contributions” (NDCs), and to pursue domestic measures aimed at achieving them;
• Commit all countries to report regularly on their emissions and “progress made in
implementing and achieving” their NDCs, and to undergo international review;
• Commit all countries to submit new NDCs every five years, with the clear expectation that
they will “represent a progression” beyond previous ones;
• Reaffirm the binding obligations of developed countries under the UNFCCC to support the
efforts of developing countries, while for the first time encouraging voluntary contributions
by developing countries too;
• Extend the current goal of mobilizing $100 billion a year in support by 2020 through 2025,
with a new, higher goal to be set for the period after 2025;
• Extend a mechanism to address “loss and damage” resulting from climate change, which
explicitly will not “involve or provide a basis for any liability or compensation;”
• Require parties engaging in international emissions trading to avoid “double counting;”
• Call for a new mechanism, similar to the Clean Development Mechanism under the Kyoto
Protocol, enabling emission reductions in one country to be counted toward another
country’s NDC.
http://www.c2es.org/international/negotiations/cop21-paris/summary
What happened to the carbon dioxide
emissions?
Disposition of
Carbon Dioxide
1750-2011
GtC
Atmosphere
240
Oceans
155
Land
160
Atmosphere
Oceans
Land
12
http://www.pmel.noaa.gov/co2/gif/globcar.png
GTC: gigatons of carbon
Climate Models
•
Accounts for positive feedback
– Ice melts due to warming
– Ice reflects sunlight
– Less ice, les reflection, more warming
•Account for negative feedback
•Clouds form due to warming
•Clouds reflect sunlight, less
warming
•Models’ predictions under different
scenarios
–Models are extremely complex and
must account for scores of factors
–Base on AOGCM, Atmosphere-Ocean
General Circulation Model
–Climate Science is still evolving
http://www.epa.gov/climatechange/science/futur
etc.html
IPCC Special Report on Emissions Scenarios
(SRES)
• Over 40 scenerios
– A1F1:
• High global economic growth and continued heavy reliance
on fossil fuels,
• Close to Business as Usual (BAU)
– A2
• Used most often
• Middling scenario, with less even economic growth and
some adoption of alternative and renewable energy
sources
– B1
• Assumes a major move away from fossil fuels toward
alternative and renewable energy
Science Gap: Dems, GOP Still Disagree on Global
Warming
• While Democrats and Republicans generally agree on many
science issues – including food safety, space travel and
medicine – they sharply diverge when it comes to climate
change and energy policy
• More than 70 percent of Democrat-leaning voters, say
human activity is driving global warming – a fact
overwhelmingly supported by scientific study.
• Just 27 percent of Republican-leaning voters believe climate
change is being driven by human-generated carbon
emissions instead of natural forces.
http://www.usnews.com/news/blogs/data-mine/2015/07/06/democrats-republicans-disagree-on-energyglobal-warming