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Global Climate Change. Ashok Kumar Abhishek Bhat University of Toledo Sept. 21, 2009 . What is Climate?. Defined as the weather conditions averaged over some period of time, the seasonal distribution, and the extremes in weather for a place.
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Global Climate Change Ashok Kumar Abhishek Bhat University of Toledo Sept. 21, 2009
What is Climate? • 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.
Climate Controls • Climatic controls include latitude, elevation, topography, presence of water bodies, and atmospheric circulation. • Climate norms are computed over a 30-year period since 1933. They are adjusted after every decade. • Air mass climatology is also used to describe climate.
Influence of Human Activities • 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
Global Climate Change • Measures of Climate Change • Greenhouse Effect and Greenhouse Gases • Global Climate Change Models
Measures of Climate Change • Average Temperature • Precipitation • Wind • Glaciations • Frequency of Extreme Events
Temperature • 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
Greenhouse Gases • The greenhouse effect • Continuous warming • O.5 – 0.7 0c warming • Greenhouse gases • Carbon Dioxide • Methane • Nitrous Oxide • CFC • Water Vapor
Changes in Greenhouse Gases and corresponding change in Temperature
Carbon Dioxide CO2 Emissions Global CO2 Emissions
Methane Global Methane Emissions Methane Measures
N2O N2O Concentration N2O sources
CFC Sources CFC Source Distribution CFC Source Distribution
CFC Concentration CFC-11 Concentration CFC-12 Concentration
Global Climate Models • 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
GCM Model Projections Model Accuracy
Climate Change Calculations • CO2 Emission Calculation: CO2 = (Pi)*(Foi)*Ci • P: Amount of fuel • FO : Fraction oxidized • C : Average carbon content • i: Particular fuel type • Change in radiative forcing: For CO2 ΔFCO2 = K3 ln [(co2)/(co2)0] • K3 : 6.3 (W/m2)
Cont… • Surface temperature change: ΔTs = ΔF * λ • ΔTs: Surface temperature • ΔF: Radiative forcing • λ: Climate sensitivity factor (0.57 in 0C/W/m2)
GCM Performance Model Performance Global Warming Projection
References • 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 24th, 2008. Web site: http://www.wikipedia.com • Global Warming , Retrieved November 24th, 2008. Web site: http://www.wikipedia.com • Greenhouse Effect , Retrieved November 24th, 2008. Web site: http://www.wikipedia.com • Atmospheric Cleansing and Current Air Pollution Issues, Retrieved November 24th, 2008. Web site: http://www.eng.utoledo.edu/~akumar/IAP1/mainpage.htm