Ashok Kumar Abhishek Bhat University of Toledo Sept. 21, 2009

 Defined as the weather conditions averaged over some period of time, the seasonal distribution, and the extremes in weather for a place.  Climate: Normals, means, and extremes of different weather elements.  Extremes: coldest, warmest, driest, wettest, snowiest, or cloudiest month or year.

 Climatic controls include latitude, elevation, topography, presence of water bodies, and atmospheric circulation.  Climate norms are computed over a 30-year period since They are adjusted after every decade.  Air mass climatology is also used to describe climate.

 By altering the radiational properties of the earth’s surface (e.g.: albedo)  By releasing waste heat into the atmosphere  By changing the concentrations of certain key gaseous or aerosol components of the atmosphere

 Measures of Climate Change  Greenhouse Effect and Greenhouse Gases  Global Climate Change Models

 Average Temperature  Precipitation  Wind  Glaciations  Frequency of Extreme Events

 Determination of Past Global Temperatures ◦ Historical documentation ◦ Tree rings ◦ Changes in ice volume ◦ Changes in sea volume ◦ Fossil pollen analysis ◦ Geologic observation related to glacial movement

Palmer Drought Severity Index (PDSI) IndexSeverity -2Moderate Drought -3Sever Drought -4Extreme Drought 2Moderate Rainfall 3Sever Rainfall

Changes in Ice Volume

Greenhouse Gases  The greenhouse effect ◦ Continuous warming ◦ O.5 – c warming  Greenhouse gases ◦ Carbon Dioxide ◦ Methane ◦ Nitrous Oxide ◦ CFC ◦ Water Vapor

Sources and Estimated Lifetime for Selected Pollutants

ContaminantsApproximate Residence Time CO 2 15 yr CH 4 10 yr N2ON2O150 yr CO65 days CFC 1165 yr

CO 2 EmissionsGlobal CO 2 Emissions

Global Methane Emissions Methane Measures

N 2 O ConcentrationN 2 O sources

Ozone Depletion

CFC Source Distribution

CFC-11 ConcentrationCFC-12 Concentration

 General Circulation Models (GCMs) are a class of computer-driven models for weather forecasting, understanding climate and projecting climate change, where they are commonly called Global Climate Models.  Different Types of Models ◦ Simple General Circulation Model (SGCM) ◦ Atmospheric GCM ◦ Oceanic GCM ◦ Coupled Atmospheric-Oceanic GCM

Model ProjectionsModel Accuracy

 CO 2 Emission Calculation: CO 2 = (P i )*(Fo i )*C i  P: Amount of fuel  FO : Fraction oxidized  C : Average carbon content  i: Particular fuel type  Change in radiative forcing: For CO 2 ΔF CO2 = K 3 ln [(co 2 )/(co 2 ) 0 ]  K 3 : 6.3 (W/m 2 )

 Surface temperature change: ΔT s = ΔF * λ  ΔT s : Surface temperature  ΔF: Radiative forcing  λ: Climate sensitivity factor (0.57 in 0 C/W/m 2 )

Model Performance Global Warming Projection

 IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp.  IPCC, 2007: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 976pp.  IPCC, 2007: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA., XXX pp.  IPCC, 2007: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A.(eds.)]. IPCC, Geneva, Switzerland, 104 pp.  Climate Change, Retrieved November 24 th, Web site:  Global Warming, Retrieved November 24 th, Web site:  Greenhouse Effect, Retrieved November 24 th, Web site:  Atmospheric Cleansing and Current Air Pollution Issues, Retrieved November 24 th, Web site: