The Climate Ahead: Global Changes and Local Impacts

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The Climate AheadGlobal Changes and Local
Impacts

• Anthony J. Broccoli
• Director, Center for Environmental
  PredictionDepartment of Environmental Sciences
• Rutgers University
• Rutgers University Environmental
  StewardsFebruary 2008

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Greenhouse gases are now higher than any time in
the past 650,000 years.
Source Brook, E., 2005 Tiny bubbles tell all,
Science, 310, 1285-1287.
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Northern Hemisphere Temperature Reconstructions
It can be said with a high level of confidence
that global mean surface temperature was higher
during the last few decades of the 20th century
than during any comparable period during the
preceding four centuries the committee finds
it plausible that the Northern Hemisphere was
warmer during the last few decades of the 20th
century than during any comparable period over
the preceding millennium. National Research
Council
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Temperature Indicators
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Record low Arctic sea ice cover in September 2007.
http//nsidc.org/news/press/2007_seaiceminimum/200
71001_pressrelease.html
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Source Polar Research Group, Univ. of Illinois
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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
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What Are Climate Models?
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Coupled Climate Model Schematic
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It is extremely unlikely that global climate
change of the past fifty years can be explained
without external forcing.
Blue Natural Pink Natural Human-induced
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Projecting Future Climate
Atmospheric chemistry and transport models
Global and regional climate models
Scenarios of emissions of greenhouse gases and
aerosol precursors
Scenarios of concentrations of greenhouse gases
and aerosols in the atmosphere
Projections of future climate
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Future Emissions Scenarios
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Projections of Future Climate
Variations among colored lines represents
uncertainty due to uncertainty in future
emissions.
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Simulating Future Climate Change
Source NOAA Geophysical Fluid Dynamics Laboratory
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Potential Climate Change Impacts
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Global Impacts of Climate Change
Report by IPCC Working Group II on Impacts,
Adaptation and Vulnerability was released on 6
April 2007. Some of the highlights from this
report

• There will be some winners, but more losers
• Densely populated coastal regions will face
  increased pressures from sea level rise and more
  extreme weather
• Poor communities and stressed ecosystems will
  suffer most, as they are already living on the
  edge
• 60 of worlds species are already responding to
  change

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Global Impacts of Climate Change
Report by IPCC Working Group II on Impacts,
Adaptation and Vulnerability was released on 6
April 2007. Some of the highlights from this
report

• There will be some winners, but more losers
• Densely populated coastal regions will face
  increasedpressures from sea level rise and more
  extreme weather
• Poor communities and stressed ecosystems will
  suffer most, as they are already living on the
  edge
• 60 of worlds species are already responding to
  change

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Global mean sea level changes
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Why Is Global Sea Level Rising?

• Thermal expansion
• Warmer water is less dense than colder water.
• Melting of glaciers and ice caps
• Water released by the melting of ice on land
  adds to the volume of the oceans.
• Melting and calving of Greenland and Antarctic
  ice sheets
• Depends on the ice sheet dynamics (how the ice
  flows).

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Why Is Global Sea Level Rising?

• Thermal expansion
• Warmer water is less dense than colder water.
• Melting of glaciers and ice caps
• Water released by the melting of ice on land
  adds to the volume of the oceans.
• Melting and calving of Greenland and Antarctic
  ice sheets
• Depends on the ice sheet dynamics (how the ice
  flows).

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Why Is Global Sea Level Rising?

• Thermal expansion
• Warmer water is less dense than colder water.
• Melting of glaciers and ice caps
• Water released by the melting of ice on land
  adds to the volume of the oceans.
• Melting and calving of Greenland and Antarctic
  ice sheets
• Depends on ice sheet dynamics (how the ice
  flows).

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Sea Level Trends in New Jersey
Atlantic City, NJ
Source National Oceanic and Atmospheric
Administration
NJ sea level rise global sea level rise
other effects 0.4 m/century 0.16
m/century 0.24 m/century
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Effects of Sea Level Rise on the Coastal
Environment
Land area susceptible to inundation
Land area susceptible to coastal flooding (30-yr
flood)
Source M. D. Beevers, U.S. Climate Change
Science Program Workshop, Nov. 2005
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Ash Wednesday Storm
Harvey Cedars, March 1962
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3 of 7 largest floodssince 2004
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Simulated Changes in Precipitation
Relative changes in precipitation () for the
period 20902099, relative to 19801999.
Stippled areas are where more than 90 of the
models agree in the sign of the change.
Increased frequency of heavy precipitation events
over most areas Very likely
More areas affected by drought Likely
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Warmer? MorePrecipitation
Warmer? MoreEvaporation
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there is an increased chance of intense
precipitation and flooding due to the greater
water-holding capacity of a warmer atmosphere.
This has already been observed and is projected
to continue because in a warmer world,
precipitation is concentrated into more intense
events IPCC Fourth Assessment, 2007
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IPCC 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
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• Changes in Heat Index
• The heat index combines the effects of
  temperature and humidity to estimate human
  comfort.
• Results are from simulations with three global
  climate models with two emissions scenarios,
  representing the low and high ends of the IPCC
  range.
• Under the high emissions scenario, Tri-State
  summers at the end of the 21st century are
  projected to be similar to those in Savannah,
  Georgia today.

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Future Emissions Scenarios
Some scenarios showdecreased emissionsin latter
half of 21stcentury
Even with aggressivereductions in emissions,CO2
would rise to 2xpreindustrial levels
All scenarios showincreasing emissionsduring
next severaldecades
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More Warming in the Pipeline
Future emissions
Additional zero-emission warming (aka
commitment)
Warming to date
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Evidence That Earth Is Warming?
Source Pew Research Center for the People and
the Press, June 2006
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Global Warming Not A Top Priority
Despite widespread agreement among survey
respondents that there is solid evidence that
global warming is happening, and in a broad sense
that its effects can be mitigated, dealing with
global warming remains a relatively low priority
for the American public. Asked to rate the
importance of various issues, 44 rate global
warming as very important. This is among the
lowest of 19 issues tested, including top-ranked
education (82 very important), the economy (80)
and health care (79).
Source Pew Research Center for the People and
the Press, June 2006
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Psychological Barriers?

• Climate change is not the result of malevolence.
• Climate change does not violate our moral
  sensibilities (i.e., cultural taboos).
• Climate change is perceived as a future rather
  than an immediate threat.
• Climate change proceeds gradually.

Source Daniel Gilbert, Harvard University, Los
Angeles Times, July 2006
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Controversy and Politics?

• Time/ABC News/Stanford Univ. poll (March 2006)
  found that 64 of those surveyed think that
  scientists disagree about global warming.

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Current/Future Activities at Rutgers
Research How will the climate change? What
alternative energy sources are available? How do
political systems respond to slowly evolving
problems?
Education Courses and programs in climate
change-related disciplines. Interdisciplinary
courses and programs related to climate and
environmental change. Graduate fellowships for
talented students interested in climate
change-related topics.
Outreach Public talks on climate change. Advice
to policymakers, particularly those in state and
local government. Extension specialist in climate
change (marine, agriculture, water and electric
utilities).
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The Global Warming Dilemma(J. Mahlman, In
Solutions for an Environment in Peril,
2002) There are no quick policy fixes,
nationally or globally. If we don't begin to
chip away at the problem soon, it is very likely
that serious consequences will be wired in for
the world of our great-grandchildren and for
their great-grandchildren.... The long time
scales and robustness of the problem almost
guarantees that our descendants in the 22nd
century will, with historical perspective, see
that we were actually confronted with a major
planet-scale stewardship/ management
problem. They will most assuredly note how we
responded, or how we did not respond to the
problem.
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The climate is changing