Transcript Climate is the average meteorological conditions—temperature

_________________ is the average
meteorological conditions—
temperature, precipitation, wind,
etc.—that prevail in a region.
Climate ____________
may refer to any change in
climate over time whether
due to natural variability or
human activity.
Three major sources of natural variability affect
climate:
1. Changes in Earth's orbit,
2. Changes in ocean currents due to shifting
continents or large-scale melting of continental ice, and
3. Changes in the composition of the global
atmosphere—especially water vapor and
"greenhouse" gases such as carbon dioxide (CO2),
methane (CH4), and nitrous oxide (N2O)—due to
volcanic or other tectonic activities.
“_______________________"
The term refers to the ability of these
gases to absorb energy radiated from
Earth to space and to thus warm the
atmosphere.
http://members.optushome.com.au/wingchan1/ian/globwarm/what.htm
Human activity may also influence the
composition of the global atmosphere.
• Major sources include
• combustion of fossil fuel,
• _______________________,
• production of some agricultural
commodities such as rice and
livestock.
Intergovernmental Panel on Climate
Change (IPCC),
1. organizes, summarizes, and reports
the work of several hundred
scientists.
2. does not make policy decisions.
3. is not in charge of global climate
control regulations.
Declines in crop production would likely be offset somewhat by
increases in livestock production.
Increase in atmospheric carbon dioxide (CO2) indicates that
its direct growth-promoting effects on crops would likely
boost world and U.S. agricultural production.
• The major greenhouse gases (GHG's)
associated with U.S. crop and
livestock production are
• carbon dioxide (CO2),
• methane (CH4),
• nitrous oxide (N2O).
• Agriculture contributes greatly to both
methane and nitrous oxide emissions.
Agriculture accounts for
• about a third of national methane emissions—mostly from the
digestive process in ruminant animals and manure
management
• nearly three-quarters of nitrous oxide emissions, mainly from
the use of nitrogen ____________________.
• Rice cultivation and crop residue burning also contribute to
GHG emissions.
• Farm production emits carbon dioxide mostly through
• the use of _______________________________ in farm operations,
• the manufacture and distribution of nitrogen fertilizers and other farm
chemicals, and
• the generation of electricity used on farms.
http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/RAMR5WNMKC/$File/04agriculture.pdf
Per capita GHG emissions by country
2000
http://upload.wikimedia.org/wikipedia/commons/e/ea/GHG_per_capita_2000.svg
Greenhouse Gas Emissions per Capita - 2003
http://globalis.gvu.unu.edu/indicator.cfm?IndicatorID=199
Agriculture is not the only source of
greenhouse gas emissions.
The international community is addressing the
challenges posed by global climate change through
the United Nations Framework Convention on
Climate Change (UNFCCC).
• The Convention seeks to stabilize atmospheric
concentrations of greenhouse gases (GHG's) at
safe levels. Covered gases include
•
•
•
•
•
•
carbon dioxide (CO2),
methane (CH4),
nitrous oxide (N2O),
hydrofluorocarbons,
perfluorocarbons,
sulfur hexafluoride.
The _________________________to the
UNFCCC
• Signed by over 80 counties in November 1998
• Formalizes this commitment by setting specific
emissions reduction targets for developed
countries, Eastern Europe, and the former
Soviet Union
• Across countries, the reductions in national
GHG emissions average about 5 percent below
1990 levels over the first commitment period
(2008-2012).