Greenhouse Gas Mitigation: Greenhouse Gas Mitigation: A Brief OverviewA Brief Overview

The ProblemThe Problem Increasing Greenhouse Gas (GHG) Increasing Greenhouse Gas (GHG)

emissions may cause considerable global emissions may cause considerable global and regional climate change.and regional climate change.

Global Warming Potentials (over 100 y):Global Warming Potentials (over 100 y): COCO22 11 CHCH44 2323 NN22OO 296296

World GHG Emissions by SectorWorld GHG Emissions by Sector§§SectorSector COCO22 Emissions (GtC) Emissions (GtC) ShareShare growth rate†growth rate† rate rate

trendtrendBuildingsBuildings 1.731.73 31%31% +1.8%+1.8% deceleratingdeceleratingTransportTransport 1.221.22 22%22% +2.5%+2.5% steady steady IndustryIndustry 2.342.34 43%43% +1.5%+1.5% decelerating decelerating AgricultureAgriculture 0.220.22 4%‡4%‡ +3.1%+3.1% deceleratingdecelerating

Total EmissionsTotal Emissions 5.55.5 100%100% +1.8%+1.8% deceleratingdecelerating

(Total energy emissions accounted for 5.5 GtC emissions in 1995).(Total energy emissions accounted for 5.5 GtC emissions in 1995).

Mitigation of Greenhouse Gases Mitigation of Greenhouse Gases Energy EfficiencyEnergy Efficiency Low or no carbon energy productionLow or no carbon energy production SequestrationSequestration

Best StrategiesBest Strategies The most cost effective short-term (2-20 y) strategies for avoiding emissions The most cost effective short-term (2-20 y) strategies for avoiding emissions

due to electricity production are: due to electricity production are: Substitute natural gas for coalSubstitute natural gas for coal Substitute nuclear for coalSubstitute nuclear for coal Substitute wind for coalSubstitute wind for coal Substitute hydro for coalSubstitute hydro for coal

For the longer term (20-100 y), the following methods of electricity For the longer term (20-100 y), the following methods of electricity production production maymay become cost effective as fossil fuel costs increase: become cost effective as fossil fuel costs increase:

More wind, nuclear, and hydroMore wind, nuclear, and hydro Biomass and energy croppingBiomass and energy cropping Coal fired electricity, hydrogen production with sequestrationCoal fired electricity, hydrogen production with sequestration Solar Solar

Technology wildcards that probably aren’t likely, but could radically alter the Technology wildcards that probably aren’t likely, but could radically alter the mix:mix:

Artificial photosynthesisArtificial photosynthesis Nuclear fusionNuclear fusion Other?Other?