SOAR 2007 Current Changes and Future Climates

Predicting the Future Climate Systems  Atmosphere – changes over hours  Oceans – surface changes over weeks – depths change over millennia  Biosphere – changes annually to centuries  Cryosphere – ice, glaciers permafrost, snow – various change scales  Geosphere – volcanos, continental drif – long time scales, large changes Climate Systems  Atmosphere – changes over hours  Oceans – surface changes over weeks – depths change over millennia  Biosphere – changes annually to centuries  Cryosphere – ice, glaciers permafrost, snow – various change scales  Geosphere – volcanos, continental drif – long time scales, large changes

Modeling the Climate Systems & Feedbacks Among  Radiation  insolation (incoming sunlight varies)  reflection, absorption, re-radiation by surface, air  Water cycle  evaporation, precipitation, runoff  Land surface  soil moisture, vegitation, topography, snow & ice  Ocean  surface currents, deep currents, chemistry (salinity)  Sea Ice  strongly affected by feedbacks Systems & Feedbacks Among  Radiation  insolation (incoming sunlight varies)  reflection, absorption, re-radiation by surface, air  Water cycle  evaporation, precipitation, runoff  Land surface  soil moisture, vegitation, topography, snow & ice  Ocean  surface currents, deep currents, chemistry (salinity)  Sea Ice  strongly affected by feedbacks

Feedbacks Positive  Any change leads to further change  eg. Ball on a hill Negative  System always returns to equilibrium  eg. Ball in a bowl Neutral  System stays in new state  eg. Ball on a plain Positive  Any change leads to further change  eg. Ball on a hill Negative  System always returns to equilibrium  eg. Ball in a bowl Neutral  System stays in new state  eg. Ball on a plain

Feedbacks Greenhouse Effect: Warming  Good … makes Earth inhabitable!!  Ground absorbs sunlight Ground heats (parking lots in summer) Ground radiates heat (Infrared, IR) Atmosphere absorbs (some) IR Atmosphere heats  Feedbaack Mechanisms  Evaporation  Plant growth  Ice-Albedo effect Greenhouse Effect: Warming  Good … makes Earth inhabitable!!  Ground absorbs sunlight Ground heats (parking lots in summer) Ground radiates heat (Infrared, IR) Atmosphere absorbs (some) IR Atmosphere heats  Feedbaack Mechanisms  Evaporation  Plant growth  Ice-Albedo effect

Feedbacks Feedback Mechanism: Evaporation  H 2 O vapor absorbs more IR  warming increases? Clouds shade surface, cool it, warming stops?  warming decreases? Feedback Mechanism: Plant Growth  More CO 2 increases plant growth  More plant growth is good!!  Plants absorb CO 2 (Keeling curve annual cycles  CO 2 is Reduced Feedback Mechanism: Evaporation  H 2 O vapor absorbs more IR  warming increases? Clouds shade surface, cool it, warming stops?  warming decreases? Feedback Mechanism: Plant Growth  More CO 2 increases plant growth  More plant growth is good!!  Plants absorb CO 2 (Keeling curve annual cycles  CO 2 is Reduced

Feedbacks Feedback Mechanism: Ice Albedo Effect  Warming melts glaciers, sea ice  Ground warms more than snow/ice Ground warms, radiates more IR Atmosphere warms More ice melts  warming increases  Cooling increasing glaciers More sunlight reflected Ground Cools  cooling increases Feedback Mechanism: Ice Albedo Effect  Warming melts glaciers, sea ice  Ground warms more than snow/ice Ground warms, radiates more IR Atmosphere warms More ice melts  warming increases  Cooling increasing glaciers More sunlight reflected Ground Cools  cooling increases

Feedbacks Feedback Mechanism: Ice Albedo Effect  Warming melts glaciers, sea ice  Ground warms more than snow/ice Ground warms, radiates more IR Atmosphere warms More ice melts  warming increases  Cooling increasing glaciers More sunlight reflected Ground Cools  cooling increases Feedback Mechanism: Ice Albedo Effect  Warming melts glaciers, sea ice  Ground warms more than snow/ice Ground warms, radiates more IR Atmosphere warms More ice melts  warming increases  Cooling increasing glaciers More sunlight reflected Ground Cools  cooling increases

IPCC Intergovernmental Panel on Climate Change  Established in 1988  World Meteorological Org. (WMO)  UN Environment Programme (UNEP)  Mandate Intergovernmental Panel on Climate Change  Established in 1988  World Meteorological Org. (WMO)  UN Environment Programme (UNEP)  Mandate “The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio- economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.”

IPCC Intergovernmental Panel on Climate Change “The IPCC does not carry out research nor does it monitor climate related data or other relevant parameters. It bases its assessment mainly on peer reviewed and published scientific/technical literature. Its role, organisation, participation and general procedures are laid down in the ‘Principles Governing IPCC Work’“

IPCC Working Groups  I: Science  knowns, unknowns & projections  II: Impact and Adaption  vulnerability: natural and human  consequences: + and –  III: Mitigation  options for changing human behavior and impact  Task Force on National Greenhouse Gas Inventories Working Groups  I: Science  knowns, unknowns & projections  II: Impact and Adaption  vulnerability: natural and human  consequences: + and –  III: Mitigation  options for changing human behavior and impact  Task Force on National Greenhouse Gas Inventories

IPCC Intergovenmental Panel on Climate Change  View of the bulk of the scientific community  Computer models estimate feedbacks  Reports every 5 years  2007 report available in print & electronic  3 rd Assessment report gave “Hockey Stick” Intergovenmental Panel on Climate Change  View of the bulk of the scientific community  Computer models estimate feedbacks  Reports every 5 years  2007 report available in print & electronic  3 rd Assessment report gave “Hockey Stick”

IPCC 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press

IPCC 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press

Assessment Report Four (ARF) Findings of Working Group I  Summary for Policymakers (18 pages)  Human & Natural Drivers of Climate Change  Direct Observations of Recent Climate Change  A Paleoclimatic Perspective  Understanding and Attributing Climate Change  Projections of Future Changes in Climate Findings of Working Group I  Summary for Policymakers (18 pages)  Human & Natural Drivers of Climate Change  Direct Observations of Recent Climate Change  A Paleoclimatic Perspective  Understanding and Attributing Climate Change  Projections of Future Changes in Climate

Assessment Report Four (ARF) Findings of Working Group I  Technical Summary (66 pages)  Chamges in Human & Natural Drivers of Climate  Observations of Changes in Climate  Understanding and Attributing Climate Change  Projections of Future Changes in Climate  Robust Findings and Key Uncertainties Findings of Working Group I  Technical Summary (66 pages)  Chamges in Human & Natural Drivers of Climate  Observations of Changes in Climate  Understanding and Attributing Climate Change  Projections of Future Changes in Climate  Robust Findings and Key Uncertainties

Union of Concerned Scientitsts Confronting Climate Change in the U.S. Northeast: Science, Impacts and Solutions

IPCC ARF WGI Radiative Forcing  “The change in net (down minus up) irradiance (solar plus longwave; in W/m2) at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values” Radiative Forcing  “The change in net (down minus up) irradiance (solar plus longwave; in W/m2) at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values” RF = net flux imbalance at tropopause

Atmospheric Structure Layers (from surface)  Troposphere – sphere of weather  Stratosphere – sphere of ozone (O 3 )  Mesosphere  Ionosphere – sphere of ions Layers (from surface)  Troposphere – sphere of weather  Stratosphere – sphere of ozone (O 3 )  Mesosphere  Ionosphere – sphere of ions RF = net flux imbalance at tropopause

IPCC ARF WGI Components of Climate Change Accounts for natural processes eg. Changes in evaporation eg. Melting permafrost releasing methane

IPCC ARF WGI Radiative Forcing Carbon Dioxide “Ozone Layer” absorbs UV, reduces RF at tropopause Methane Buildings increase surface albedo relative to forests Aerosols (particles) reflect sunlight AND increase cloud cover (eg. Contrails) Solar radiation has increased since 1750 (Little Ice Age end)

IPCC Climate Drivers Greenhouse Gases: CO 2, CH 4, H 2 O, NO x Grey Bars = Natural Variability Com- bined rate of change

IPCC Climate Drivers Greenhouse Gases: CO 2, CH 4, H 2 O, NO x Grey Bars = Natural Variability Com- bined rate of change

IPCC Changes Since 1850 Global Average Temperature Global Average Sea Level  mostly thermal expansion Northern Hemisphere Snow Cover Global Average Temperature Global Average Sea Level  mostly thermal expansion Northern Hemisphere Snow Cover

UCC Northeast US Climate of New York State

UCC Northeast US 100-yr Flood becoming 10-yr Flood

UCC Northeast US Snow cover decreasing Com- bined rate of change

IPCC ARF Continued Warming What we’re committed to by past behavior!

IPCC ARF Effects of Changing Mean Does not mean it never gets cold!

IPCC ARF Location of Changes Uncertainties

IPCC ARF Location of Changes

The Skeptics Important voices!  Skeptics keep science honest Agreements  CO 2 in atmosphere is increasing  CO 2 levels correlate with temperature Arguments  Climate is driven exclusively by insolation  Milankovitch Cycles  Sunspot Cycles  Too expensive to reduce CO 2 : Adapt  Global warming is good! Important voices!  Skeptics keep science honest Agreements  CO 2 in atmosphere is increasing  CO 2 levels correlate with temperature Arguments  Climate is driven exclusively by insolation  Milankovitch Cycles  Sunspot Cycles  Too expensive to reduce CO 2 : Adapt  Global warming is good!

The Skeptics Journal of American Physicians & Surgeons 2007  Mailed to all SLU Physics Professors Tuesday!! Journal of American Physicians & Surgeons 2007  Mailed to all SLU Physics Professors Tuesday!!

The Skeptics Claims all warming due to solar activity Scale minimizes hydrocarbon use, leaves out first century.

The Skeptics Claims all warming due to solar activity Scale minimizes hydrocarbon use, leaves out first century.

What to Do? Complex system hard to model Experts don’t agree Could be global disaster Complex system hard to model Experts don’t agree Could be global disaster Ignore it? Mitigate it? Kyoto + ? Adapt?