Global Climate Change

Ashok KumarAbhishek Bhat

University of ToledoSept. 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.

What is Climate?

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.

Climate Controls

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

Influence of Human Activities

Measures of Climate Change

Greenhouse Effect and Greenhouse Gases

Global Climate Change Models

Global Climate Change

Average Temperature

Precipitation

Wind

Glaciations

Frequency of Extreme Events

Measures of Climate Change

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

Temperature

Average Temperature Trend

Palmer Drought Severity Index (PDSI)

Index Severity-2 Moderate Drought-3 Sever Drought-4 Extreme Drought2 Moderate Rainfall3 Sever Rainfall

Changes in Ice Volume

Climate Change and Weather

Greenhouse Effect

Greenhouse Gases The greenhouse

effect◦ Continuous warming◦ O.5 – 0.7 0c warming

Greenhouse gases◦ Carbon Dioxide◦ Methane◦ Nitrous Oxide◦ CFC◦ Water Vapor

Sources and Estimated Lifetime for Selected Pollutants

Half Life of Contaminants

Contaminants Approximate Residence Time

CO2 15 yr

CH4 10 yr

N2O 150 yr

CO 65 daysCFC 11 65 yr

Changes in Greenhouse Gases and corresponding change in

Temperature

Carbon Cycle

Carbon Dioxide

CO2 Emissions Global CO2 Emissions

Methane

Global Methane Emissions Methane Measures

N2O

N2O Concentration N2O sources

Ozone Depletion

Ozone Depletion

CFC Sources

CFC Source Distribution CFC Source Distribution

CFC Concentration

CFC-11 Concentration CFC-12 Concentration

Water Vapor

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

Global Climate Models

Global Atmospheric Model

GCM

Model Projections Model Accuracy

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)

Climate Change Calculations

Surface temperature change:ΔTs = ΔF * λ

ΔTs: Surface temperature ΔF: Radiative forcing λ: Climate sensitivity factor (0.57 in 0C/W/m2)

Cont…

GCM Performance

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 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

References

Questions?