Alan Robock

1
Global Warmingand the Impact onCoastal
Communities
Alan Robock Department of Environmental
Sciences Rutgers University, New Brunswick, New
Jersey USA
robock_at_envsci.rutgers.edu
http//envsci.rutgers.edu/robock
2
http//data.giss.nasa.gov/gistemp/2005/2005cal_fig
1.gif
3
Global Warming Fundamental Questions
1. How will climate change in the future? 2.
How will climate change affect us? 3. What
should we do about it?
Intergovernmental Panel on Climate Change (IPCC)
Working Group I (WG I) IPCC WG II IPCC WG III
4
Intergovernmental Panel on Climate Change
(IPCC) Established in 1988 jointly by the World
Meteorological Organization and the UN
Environment Programme 3000 scientists from more
than 150 nations
First Assessment Report (FAR), 1990 Second
Assessment Report (SAR), 1996 Third Assessment
Report (TAR), 2001 Fourth Assessment Report
(4AR), 2007
5
Released in Paris, February 2, 2007
6
In this Summary for Policymakers, the following
terms have been used to indicate the assessed
likelihood, using expert judgment, of an outcome
or a result Virtually certain 99
probability of occurrence Extremely likely
95 Very likely 90 Likely 66 More likely
than not 50 Unlikely 10 Extremely unlikely 7
The unequivocal detection of the enhanced
greenhouse effectfrom observations is not likely
for a decade or more. Climate Change The IPCC
Scientific Assessment (1990)
The balance of evidence suggests a discernible
human influence on global climate. Climate
Change 1995 The Second Assessment of the
Intergovernmental Panel on Climate Change (IPCC)
Most of the observed warming over the last 50
years is likely to have been due to the increase
in greenhouse gas concentrations. Climate Change
2000 The Third Assessment Report of the IPCC
Most of the observed increase in globally
averaged temperaturessince the mid-20th century
is very likely due to theobserved increase in
anthropogenic greenhouse gas concentrations. Clim
ate Change 2007 The Fourth Assessment Report of
the IPCC
8
The unequivocal detection of the enhanced
greenhouse effectfrom observations is not likely
for a decade or more. Climate Change The IPCC
Scientific Assessment (1990)
The balance of evidence suggests a discernible
human influence on global climate. Climate
Change 1995 The Second Assessment of the
Intergovernmental Panel on Climate Change (IPCC)
Most of the observed warming over the last 50
years is likely to have been due to the increase
in greenhouse gas concentrations. Climate Change
2000 The Third Assessment Report of the IPCC
Most of the observed increase in globally
averaged temperaturessince the mid-20th century
is very likely due to theobserved increase in
anthropogenic greenhouse gas concentrations. Clim
ate Change 2007 The Fourth Assessment Report of
the IPCC
9
Issues addressed by IPCC Working Group
I Detection Was there an unusual climate
change? Attribution What was the cause of the
climate change? Projection How will future
human actions affect climate?
10
Warming of the climate system is unequivocal, as
is now evident from observations of increases
in global average air and ocean temperatures,
widespread melting of snow and ice, and rising
global mean sea level.(Detection) Discernible
human influences now extend to other aspects of
climate, including ocean warming,
continental-average temperatures, temperature
extremes and wind patterns.(Attribution) Climate
Change 2007 The Fourth Assessment Report of
the IPCC
11
(No Transcript)
12
Observations
As simulated with all forcings
As simulated with only natural forcings
13
Paleoclimate information supports the
interpretation that the warmth of the last half
century is unusual in at least the previous 1300
years. The last time the polar regions were
significantly warmer than present for an extended
period (about 125,000 years ago), reductions in
polar ice volume led to 4 to 6 metres of sea
level rise.
Mann et al. (1999)
14
The equilibrium climate sensitivity is a
measure of the climate system response to
sustained radiative forcing. It is not a
projection but is defined as the global average
surface warming following a doubling of carbon
dioxide concentrations. It is likely to be in the
range 2 to 4.5C with a best estimate of about
3C, and is very unlikely to be less than 1.5C.
15
The SRES scenarios do not include additional
climate initiatives, which means that no
scenarios are included that explicitly assume
implementation of the United Nations Framework
Convention on Climate Change or the emissions
targets of the Kyoto Protocol.
Emission Scenarios of the IPCCSpecial Report on
Emission Scenarios (SRES)
A1FI
A1B
A1B. Very rapid economic growth, rapid
introduction of new and more efficient
technologies, balance of fossil intensive and
non-fossil energy sources.
A1T
B1
B2. Continuously increasing global population,
intermediate levels of economic development, and
less rapid and more diverse technological change
than in the B1 and A1 storylines.
B1. Same global population as in A1, but rapid
change toward a service and information economy,
with reductions in material intensity and the
introduction of clean and resource efficient
technologies.
A2
A2. Rapid economic growth and continuously
increasing population. Technological change more
fragmented and slower than other storylines.
B2
16
A1FI
A1B
A1T
B1
A2
B2
The SRES scenarios do not include additional
climate initiatives, which means that no
scenarios are included that explicitly assume
implementation of the United Nations Framework
Convention on Climate Change or the emissions
targets of the Kyoto Protocol.
CO2 emissions
CH4 emissions
SO2 emissions
CO2 concentrations
CH4 concentrations
N2O concentrations
Radiative forcing
Global mean temperature
B1. Same global population as in A1, but rapid
change toward a service and information economy,
with reductions in material intensity and the
introduction of clean and resource efficient
technologies.
A1B. Very rapid economic growth, rapid
introduction of new and more efficient
technologies, balance of fossil intensive and
non-fossil energy sources.
A2. Rapid economic growth and continuously
increasing population. Technological change more
fragmented and slower than other storylines.
17
Better tools for projection The new
assessment of the likely ranges now relies on a
larger number of climate models of increasing
complexity and realism, as well as new
information regarding the nature of feedbacks
from the carbon cycle and constraints on climate
response from observations. Warming tends to
reduce land and ocean uptake of atmospheric
carbon dioxide, increasing the fraction
of anthropogenic emissions that remains in the
atmosphere.
18
NCAR PCM climate model
19
Climate forcings for the past 150 years GHGs
greenhouse gases (CO2, CH4, N2O, CFCs)
http//www.giss.nasa.gov/data/simodel/
20
NASA GISS climate model
21
CCSM Climate Forecasts
(C)
(C)
Produced by Gary Strand, NCAR
22
For the next two decades a warming of about
0.2C per decade is projected for a range of SRES
emission scenarios.
23
For the next two decades a warming of about
0.2C per decade is projected for a range of SRES
emission scenarios. Even if the concentrations
of all greenhouse gases and aerosols had been
kept constant at year 2000 levels, a further
warming of about 0.1C per decade would be
expected.
24
Increases in the amount of precipitation are
very likely in high-latitudes, while decreases
are likely in most subtropical land regions,
continuing observed patterns in recent trends.
25
Based on a range of models, it is likely that
future tropical cyclones (typhoons and
hurricanes) will become more intense, with larger
peak wind speeds and more heavy precipitation
associated with ongoing increases of tropical
SSTs.
Hurricane Katrina, August 29, 2005, 1445
GMT(1045 am, EDT)
26
It is very likely that hot extremes, heat
waves, and heavy precipitation events will
continue to become more frequent.
Changes in number of days with heat waves from
UCS Northeast Climate Impacts Assessment
27
(No Transcript)
28
Increasing atmospheric carbon dioxide
concentrations lead to increasing acidification
of the ocean. Projections based on SRES
scenarios give reductions in average global
surface ocean pH of between 0.14 and 0.35 units
over the 21st century, adding to the present
decrease of 0.1 units since pre-industrial times.
From a Royal Society report, Ocean Acidification
Due to Increasing Atmospheric Carbon Dioxide
(2005) - The oceans are already 30 more acid
that before fossil fuel burning started. -
Acidification will kill corals, and probably make
many other species (like squid) extinct. - The
overall effects are unknown - there has been no
period like this in the last 2,000,000 years.
29
From a Royal Society report, Ocean Acidification
Due to Increasing Atmospheric Carbon Dioxide
(2005) - The oceans are already 30 more acid
that before fossil fuel burning started. -
Acidification will kill corals, and probably make
many other species (like squid) extinct. - The
overall effects are unknown - there has been no
period like this in the last 2,000,000 years.
Increasing atmospheric carbon dioxide
concentrations lead to increasing acidification
of the ocean. Projections based on SRES
scenarios give reductions in average global
surface ocean pH of between 0.14 and 0.35 units
over the 21st century, adding to the present
decrease of 0.1 units since pre-industrial times.
30
Global mean sea level changes
31
Dynamical processes related to ice flow, not
included in current models but suggested by
recent observations, could increase the
vulnerability of the ice sheets to warming,
increasing future sea level rise.
Understanding of these processes is limited and
there is no consensus on their magnitude.
32
Titus, J. G. and C. Richman, 2001, Climate
Research.
33
Titus, J. G. and C. Richman, 2001, Climate
Research.
34
SC
NC
Titus, J. G. and C. Richman, 2001, Climate
Research.
35
Charleston, SC
Titus, J. G. and C. Richman, 2001, Climate
Research.
36
Rahmstorf, Stefan, et al., 2007 Recent climate
observations compared to projections.
Science.Published online 2 February 2007,
10.1126/science.1136843 Dashed lines and gray
shading are 2001 TAR projections. Colored lines
are observations. While CO2 is increasing as
projected, temperature is increasing a little
more than all the scenarios. Sea level closely
follows the upper gray dashed line, the upper
limit referred to by IPCC as including land-ice
uncertainty. Note that the rate of rise for the
last 20 years of the reconstructed sea level is
25 faster than the rate of rise in any 20 year
period in the preceding 115 years.
37
Detection Attribution
Projection
38
Areas of Human Endeavor That Could Be Affected by
Global Warming Agriculture Electricity
Demand Water Resources Wind Energy
Generation Fisheries Solar Energy Generation Air
Pollution Hydroelectricity Generation Human
Health Ocean Transportation Recreation Air
Transportation Insurance Land Transportation Wetl
ands Political Systems Forestry
39
(No Transcript)
40
Global Warming Fundamental Questions
1. How will climate change in the future? 2. How
will climate change affect us? 3. What should we
do about it?
Considerable warming, glacier retreat, more
precipitation and extremes, extinctions, stronger
hurricanes, and sea level rise Winners and
losers, but more losers, including water and
agriculture Mitigation now (reduce emissions,
efficiency), study impacts, and adapt
41
The United NationsFramework Convention On
Climate Change 1992 Signed by 194 countries and
ratified by 188(as of February 26, 2004) Signed
and ratified in 1992 by the United States The
ultimate objective of this Convention ... is to
achieve ... stabilization of greenhouse gas
concentrations in the atmosphere at a level that
would prevent dangerous anthropogenic
interference with the climate system.
42
Metrics for Dangerous Change Extermination of
Animal Plant Species 1. Extinction of Polar and
Alpine Species 2. Unsustainable Migration
Rates Ice Sheet Disintegration Global Sea Level
Rise Regional Climate Change 1. More Strong
Hurricanes 2. Droughts/Floods 3. Threats to Water
and Food Supply
Partly from Jim Hansen, 11/21/06
43
Science Implications 1. Warming 1C Risks
Different Planet - Maximum CO2 450 ppm -
Slightly larger if non-CO2 forcings ? 2. Quarter
of CO2 Stays in Air Forever - Future power
plants must be zero-CO2 - Vehicles eventually
must be zero-CO2 3. Gas and Oil Use Most of 450
ppm Limit - Gas and oil must be stretched via
efficiency - Coal and unconventional fossil fuels
must be phased out or capture CO2
From Jim Hansen, 11/21/06
44
Kyoto Protocol Adopted at the third session of
the Conference of the Parties to the UNFCCC in
Kyoto, Japan, on 11 December 1997. It has been
signed, but not ratified, by the US. Agrees to
limit US greenhouse gas emissions to 93 of the
level of 1990 by 2008-2012. To come into force,
the Kyoto Protocol had to be ratified by at least
55 countries, including Annex I countries
accounting for at least 55 of this
industrialized groups emissions in 1990. The
Kyoto Protocol entered into force on February 16,
2005, after Russia ratified it. As of 16
September 2005, 156 states and regional economic
integration organizations have deposited
instruments of ratifications, accessions,
approvals or acceptances. The total percentage
of Annex I Parties emissions is 61.6.
45
From Jim Hansen, 11/21/06
46
(No Transcript)
47
Nuclear power is NOT the answer, for any one of
the following reasons 1. Unsafe operation (poor
NRC oversight, for profit culture, planned and
unplanned releases, fire protection, evacuation
plans) 2. Possibility of catastrophic
accident 3. Possibility of terrorist attack and
radioactive release 4. Not economically
viable 5. Waste disposal problem not solvable in
near future 6. Nuclear weapons proliferation
(fuel processing plant could produce 10-30 U
weapons/yr, waste reprocessing could produce 30
Pu weapons/yr)
48
The answers are Efficiency hybrid autos,
trucks, and trains, solid state lighting, more
efficient furnaces and appliances Conservation
better insulation, public transportation,
bicycles Carbon Sequestration especially for
fixed coal-burning plants in the U.S., India, and
China Renewable Energy solar, wind, geothermal,
biomass (e.g., ethanol, biodiesel, wood)
49
(No Transcript)
50
(No Transcript)
51
(No Transcript)
52
The words of the prophets are written on the
subway walls Sounds of Silence (Simon and
Garfunkel, 1966)
Very Likely
Photograph by Warren Washington