Transcript PowerPoint file - USRA`s Science and Technology Institute

1-1
The Earth’s Climate System
Forces
Acting
on
Climate
Climate
Respons
e
Impact
Climate Feedback
•
External Forcing - Incoming solar energy drives the climate system, volcanoes
modify the climate system.
•
Internal Forcing - Water vapor and other gases govern how the atmosphere
reacts to solar energy, producing the “greenhouse” effect that keeps the
Earth habitable.
Climate and Global Change Notes
1-2
The Earth’s Climate System
The Earth System
Solar Energy
Kump, L.R., J.F. Kasting and
R.G. Crane, 2004: The Earth
System (2nd edition), Pearson
Education, Inc., p. 3.
Atmosphere
Hydrosphere
Biota
Solid Earth
Heat Energy
Heat Energy
Climate and Global Change Notes
1-3
The Earth’s Climate System
Climate and Global Change Notes
1-4
The Earth’s Climate System
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
http://www.ucar.edu/communications/CCSM/overview.html
Climate and Global Change Notes
1-5
The Earth’s Climate System
Physical Climate Systems
Climate
Change
Stratospheric
Chemistry/Dynamics
Sun
Volcanoes
Ocean
Dynamics
Terrestrial
Energy/Moisture
Global Moisture
Marine/
Biogeochemistry
Soil
Terrestrial
Ecosystems
Tropospheric Chemistry
Biogeochemical Systems
Human
Activities
CO2
Human Forcing
External Forcing
Atmospheric Physics/Dynamics
Land
Use
CO2
Pollutants
Climate and Global Change Notes
1-6
Budgets and Cycles
The Energy Budget
•
The movement and transformation
of energy in its various forms within
the Earth system
•
The solar cycle
•
The radiation budget
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
http://www.cmdl.noaa.gov/infodata/faq_cat-1.html
Climate and Global Change Notes
1-7
Budgets and Cycles
The Hydrologic Cycle
•
“The ceaseless
flow of water
among terrestrial,
oceanic, and
atmospheric
reservoirs.”
(Moran & Morgan,
p. 498)
http://ga.water.usgs.gov/
edu/watercycle.html
Climate and Global Change Notes
1-8
Budgets and Cycles
The Carbon Cycle
•
The flow of carbon among
terrestrial, oceanic, and
atmospheric reservoirs.
(Moran & Morgan, p. 15)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
http://www.windows.ucar.edu/tour/link=/earth/
climate/images/carboncycle_jpg_image.html
Climate and Global Change Notes
1-9
Budgets and Cycles
The Nitrogen Cycle
•
The flow of
nitrogen among
terrestrial,
oceanic, and
atmospheric
reservoirs
http://www.igbp.kva.se//
uploads/NL_64.pdf
Climate and Global Change Notes
1-10
External Forcing
Solar Energy the Earth Receives
•
Sun’s energy is emitted in all directions
•
Intensity of the Sun’s energy decreases as the square of the distance from the
Sun increases, i.e., Intensity a 1 / (distance )2
Sun
Climate and Global Change Notes
1-11
External Forcing
Solar Energy the Earth Receives
•
The Earth intercepts only a small portion of the Sun’s energy; about
1.716 x 1014 kilowatts
Sun
150 x 106 km
Earth
Climate and Global Change Notes
1-12
External Forcing
Solar Radiation and the Earth’s Atmosphere
Total Albedo 30%
4% Reflected
from Surface
Incoming Solar
Radiation 100%
6% Scattered
by Air
20% Reflected
by Clouds
25% Direct
26% Diffuse
16% Absorbed 3% Absorbed
by Clouds
by Air
51% Absorbed at the
Earth's Surface
Climate and Global Change Notes
1-13
External Forcing
Radiation
•
Energy per unit time per unit area; cal / ( s - m2 ) or watts / m2
Climate and Global Change Notes
1-14
External Forcing
Volcanic Activity
•
Tree-ring width vs year of
eruption
-
•
Growth index for the
24 largest volcanoes
Temperature vs year of eruption
-
Composite global surface
temperature change
near the time of the
five volcanoes
producing the
greatest optical
depths since 1880:
Krakatau (1883),
Santa Maria (1902), Agung (1963),
El Chichon (1982) and Pinatubo (1991)
Climate and Global Change Notes
1-15
Changes
Temperature Change
Science Concepts
Observations
Number
Location
Climate and Global Change Notes
1-16
Changes - Temperature
What do we mean by global warming?
How do we measure the temperature of the globe?
Climate and Global Change Notes
1-17
Changes - Temperature
NASA's Goddard Institute for Space Studies Surface
Station Data
•
Anomalies from 1951-1980 average global temperature
•
Linear trend is 0.06°C per decade
-
Total change for the 120 years is about 0.7°C
Data from http://data.giss.nasa.gov/
gistemp/graphs/
Climate and Global Change Notes
1-18
Changes - Temperature
Global Climate Laboratory Temperature Stations in 1900
Peterson, T.C., and R.S. Vose, 1997: An overview of the Global Historical Climatology Network temperature
database, Bull. Amer. Meteor. Soc., 78, 2837-2849.
Climate and Global Change Notes
1-19
Changes - Temperature
Global Climate Laboratory Temperature Stations in 1997
Peterson, T.C., and R.S. Vose, 1997: An overview of the Global Historical Climatology Network temperature
database, Bull. Amer. Meteor. Soc., 78, 2837-2849.
Climate and Global Change Notes
1-20
Changes - Temperature
NASA's Goddard Institute for Space Studies Surface
Station Data
•
Anomalies from 1951-1980 base period
http://data.giss.nasa.gov/gistemp/
graphs/Fig.A2.pdf
2005 Anomalies (°C)
http://data.giss.nasa.gov/gistemp/2005/
http://data.giss.nasa.gov/gistemp/
graphs/Fig.A3.pdf
Climate and Global Change Notes
1-21
Changes - Temperature
•
Surface
data
Trend
=
0.168°C
per
decade
•
Satellite
loweratmosphere
data
Trend
=
0.132°C
per
decade
Climate and Global Change Notes
1-22
Changes - Temperature
Temperature Anomalies
•
Satellite measured lower-atmosphere temperature anomalies
El Nino
La Nina
Pinatubo
Climate and Global Change Notes
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Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
Human activities are increasingly altering the Earth's climate. These effects add to
natural influences that have been present over Earth's history. Scientific evidence
strongly indicates that natural influences cannot explain the rapid increase in
global near-surface temperatures observed during the second half of the 20th
century.
Human impacts on the climate system include increasing concentrations of
atmospheric greenhouse gases (e.g., carbon dioxide, chlorofluorocarbons and
their substitutes, methane, nitrous oxide, etc.), air pollution, increasing
concentrations of airborne particles, and land alteration. A particular concern is
that atmospheric levels of carbon dioxide may be rising faster than at any time in
Earth's history, except possibly following rare events like impacts from large
extraterrestrial objects.
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Climate and Global Change Notes
1-24
Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
(Con’t)
Atmospheric carbon dioxide concentrations have increased since the mid-1700s
through fossil fuel burning and changes in land use, with more than 80% of this
increase occurring since 1900. Moreover, research indicates that increased levels
of carbon dioxide will remain in the atmosphere for hundreds to thousands of years.
It is virtually certain that increasing atmospheric concentrations of carbon dioxide
and other greenhouse gases will cause global surface climate to be warmer.
The complexity of the climate system makes it difficult to predict some aspects of
human-induced climate change: exactly how fast it will occur, exactly how much it
will change, and exactly where those changes will take place. In contrast, scientists
are confident in other predictions. Mid-continent warming will be greater than over
the oceans, and there will be greater warming at higher latitudes. Some polar and
glacial ice will melt, and the oceans will warm; both effects will contribute to higher
sea levels. The hydrologic cycle will change and intensify, leading to changes in
water supply as well as flood and drought patterns. There will be considerable
regional variations in the resulting impacts.
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Climate and Global Change Notes
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Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
(Con’t)
Scientists' understanding of the fundamental processes responsible for global
climate change has greatly improved during the last decade, including better
representation of carbon, water, and other biogeochemical cycles in climate
models. Yet, model projections of future global warming vary, because of differing
estimates of population growth, economic activity, greenhouse gas emission rates,
changes in atmospheric particulate concentrations and their effects, and also
because of uncertainties in climate models. Actions that decrease emissions of
some air pollutants will reduce their climate effects in the short term. Even so, the
impacts of increasing greenhouse gas concentrations would remain.
Climate and Global Change Notes
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Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
(Con’t)
The 1992 United Nations Framework Convention on Climate Change states as an
objective the "...stabilization of greenhouse gas concentrations in the atmosphere
at a level that would prevent dangerous anthropogenic interference with the
climate system." AGU believes that no single threshold level of greenhouse gas
concentrations in the atmosphere exists at which the beginning of dangerous
anthropogenic interference with the climate system can be defined. Some impacts
have already occurred, and for increasing concentrations there will be increasing
impacts. The unprecedented increases in greenhouse gas concentrations,
together with other human influences on climate over the past century and those
anticipated for the future, constitute a real basis for concern.
Climate and Global Change Notes
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Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
(Con’t)
Enhanced national and international research and other efforts are needed to
support climate related policy decisions. These include fundamental climate
research, improved observations and modeling, increased computational
capability, and very importantly, education of the next generation of climate
scientists. AGU encourages scientists worldwide to participate in climate
research, education, scientific assessments, and policy discussions. AGU also
urges that the scientific basis for policy discussions and decision-making be
based upon objective assessment of peer-reviewed research results.
Science provides society with information useful in dealing with natural hazards
such as earthquakes, hurricanes, and drought, which improves our ability to
predict and prepare for their adverse effects. While human-induced climate
change is unique in its global scale and long lifetime, AGU believes that science
should play the same role in dealing with climate change. AGU is committed to
improving the communication of scientific information to governments and private
organizations so that their decisions on climate issues will be based on the best
Climate and Global Change Notes
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Human Impacts on Climate
Adopted by American Geophysical Union Council 12/03
(Con’t)
The global climate is changing and human activities are contributing to that
change. Scientific research is required to improve our ability to predict climate
change and its impacts on countries and regions around the globe. Scientific
research provides a basis for mitigating the harmful effects of global climate
change through decreased human influences (e.g., slowing greenhouse gas
emissions, improving land management practices), technological advancement
(e.g., removing carbon from the atmosphere), and finding ways for communities to
adapt and become resilient to extreme events.
Climate and Global Change Notes