CLIM 101: Global Warming: Weather, Climate and Society Carbon Footprint, Energy Use Lecture 17, 2 Nov 2010

Evidence for Human-induced Changes in GHGs (Overwhelmingly convincing!) ※ Rate of increase of GHG is largest in 10,000 years

Carbon Cycle

Fossil fuel burning also subduction, metamorphosis, and volcanism Carbon Cycle

Total known fossil fuel deposits: 4500 Gt

Are there changes in the efficiency of the land and/or ocean sinks for CO2 ? Fossil fuel burning Decay and burning of live biomass Photosynthesis Solution

Fraction of the CO2 emitted by human activities which remains in the atmosphere airborne fraction = atm / (fossil fuel + cement + land use emissions)

CO 2 in the Atmosphere CO2 ConcentrationRemained in the ATM.

What are the implications for global warming? Residence time of CO2 in the atmosphere is difficult to interpret. Roughly 10% of the carbon in the fossil fuel reservoir has been burned so far and at the current rate it will take us 500 years to burn the rest of it. Most of the carbon in the fossil fuel reservoir is in the form of coal. Burning all known coal deposits would add to the atmosphere-ocean reservoir a mass of carbon roughly equivalent to 5 x the carbon presently in the atmosphere and 8 x the pre-industrial level. The true size of the fossil fuel reservoir may be larger but it’s hard to say by how much because we don’t know how much oil shale and methane hydrates we will be able to utilize. Were it not for the biosphere, and especially the marine biosphere, most of the Earth’s carbon would be in the form of atmospheric CO2 as it is on Venus.

Global CO 2 Emissions In 2005, global emissions were 27 billion tons of CO 2 Per capita, emission (27/6.7 billions) = 4 tons/per capita/yr US emissions = 20 tons/per capita/yr

What is 4 tons of CO 2 per person per year? Drive 10,000 miles per year with a car that gives 30 miles per gallon. Fly 10,000 passenger miles per year. 300 KWH per month of electricity from coal fired plant. 600 KWH per month of electricity from natural gas fired plant. (my house: 580 KWH in Mar. 2008; 380 KWH in Mar. 2009)

The present concentration is 380 parts per million (ppm): fraction of molecules 380 CO 2 molecules for each million air molecules 0.38 CO 2 molecules for each thousand air molecules 0.038% of the air molecules are CO equivalent to 38 cents per $1000 Has increased from 315 ppm in 1958 to 380 ppm today Unit of measurement of Atmospheric CO 2 Concentration

Atmospheric Carbon Dioxide (CO 2 ) At Mauna Loa, Hawaii

Metric tons of carbon (1 metric ton = 2200 lb) note that we only count the mass of carbon atom in CO2 If M is molecular weight M(C) = 12 M(O) = 32 M(CO 2 ) = 44 M(C)/M(CO 2 ) = 12/44 = 0.27 CO 2 = 20 tons per capita/yr  C = 20X0.27 = 5.4 tons per capita/yr For reference, consumption of energy and products by the average American results in the emission of ~5.4 tons of carbon (tC) per year. US population is slightly more than 300 million. Hence, the US emissions are ~1600 MtC (megatons; millions of tons of carbon per year), or 1.6 about GtC (gigatons; billions of tons of carbon) The US accounts for 22% of the World current emissions, so the total global annual emission is roughly 1.6/0.22 = 7.2 GtC = 27 GtCO 2 Unit of measurement of Carbon Emission

To convert ppm to GtC, multiply 380 ppm by the mass of the atmosphere (5.12 x Gt) and by M(C)/M(air molecules) = 12/29 = (380 x ) x (5.12 x Gt) x = 806 GtC Hence each year carbon emissions due to human activities are equivalent to 7.2/806 or nearly 1% of the mass of carbon currently residing in the atmosphere. There is a small additional mass of carbon in the atmosphere in the form of methane. How does 7.2 GtC compare with the amount that’s already in the atmosphere?

Distribution of regional GHG emissions in 2004 per capita, over the population of different country groupings All Kyoto gases including those from land-use The percentages in the bars indicate a region’s share in global GHG emissions EIT Annex I: Eastern Europe Europe Annex II & M&T: Western Europe JANZ: Japan, Australia, New Zealand. Middle East Latin America & the Caribbean Non-Annex I East Asia South Asia North America: Canada, United States of America. Other non-Annex I: past Soviet Union Africa. 46%54% 5% of the world’s population (North America) emits 19.4%, while 30.3% (Non-Annex I South Asia) emits 13.1%.

Which countries are emitting the most greenhouse gases? Per capita emissions Total emissions

US Energy Consumption by Energy Source,

US Primary Energy Consumption by Source & Sector, 2007

US CO 2 Emissions by Fuel & Sector, 2006

How much do different activities contribute?

Natural GasPetroleum Coal/ CokeElectricityTotal Residential ,197.9 Commercial ,043.0 Industrial ,652.4 Transportation 33.21, ,013.4 Total , ,364.15,906.7 US 2006 Carbon Dioxide Emission Sources by use Sector US 2006 Carbon Dioxide Emission Sources by use Sector (Millions of Metric Tons)

( ) ( ) US GHGs Emissions, 2006

World list: All countries >1,000 MMT CO 2 or All regions >2,000 MMT CO 2 by 2006 Source: US DOE Energy Information Administration (EIA) World CO 2 Emissions

Primary Energy Consumption 2006 (US)

RenewableEnergy Solar Wind Water Biomass Geothermal Hydrogen & Fuel Cells

Wind Power

Recent US Trends: Encouraging 9% drop in US emissions in past 2 years (Recession; High gasoline price; Efficiency; Non-carbon energy) Wind farms, Solar power plants rapidly increasing Corporations concerned about risk, public opinion EPA ready to regulate Carbon under the Clean Air Act (Supreme court, 2007); ”A glorious mess”

Center of Ocean-Land- Atmosphere studies

Greenhouse Gas Emission Targets IPCC: 25% below the 1990 level by 2020 IPCC: 80% below the 1990 level by 2050 New York: 10% below the 1990 level by 2020 Vermont: 25% below the 1990 level by 2012 Virginia: 0% below the 2000 level by 2025 Waxman-Markey:17% below the 2005 level by 2020 Boxer-Kerry: 20% below the 2005 level by 2020

Greenhouse Gas (GHG) Emissions (India) Sharma et. al (2008); PM Council (2008) GHG (1994) = CO 2 (63%) + CH 4 (33%) + N 2 O (4%) = CO 2 E q GHG = CO 2 E q unit: Million Metric Tons (Mt) Rate of Increase (GHG): 4.2% per year Year GHG

Greenhouse Gas (GHG) Emissions (India) Sharma et. al (2008); PM Council (2008) 2004: CO 2 : 1.02 tons/person; Pop = million; Total CO 2 = Mt; GHG = (CO 2 /.63) = 1748 Mt 2004 GHG emissions = 1.62 tons per person 1994: Pop: 914 million; Total CO 2 = Mt; GHG 1228 Mt (3% of global) 1993 GHG emissions = 1.34 tons/person : CO 2 increase: 3.34% per year; GHG: 1.34 to 1.62 tons per capita

Global Carbon Dioxide () Emissions (2004) Global Carbon Dioxide ( CO 2 ) Emissions (2004) CO 2 (Gt) Population (millions) Tons per person World USA India China Unit: Billion Metric Tons (Gt) (PM Council, 2008)

2020: Projections for Emissions (India, USA) 2020: Projections for CO 2 Emissions (India, USA) USA: 20% below 2004; 4.7Gt; (4.7/338.4M) ~ 14 tons/person India: 72% above 2004; 3Gt; (3/1332M) ~ 2.3 tons/person USA: 50% below 2004: 2.9Gt; (2.9/404M) ~7.2 tons/person India: 2% increase ; 5.4Gt; (5.4/1620M) ~ 3.3 tons/person 3% increase ; 7.3Gt; (7.3/1620M) ~ 4.5 tons/person 2050: Projections for CO 2 Emissions (India, USA)

“Polluter must pay” (We (US) are the biggest polluters but we also have the biggest guns.) Those who have contributed the least to global warming will suffer the most and the earliest. Poor countries would like to improve the quality of life of their people (consume more energy). Sustainable developement in a changing climate is challenged by population growth and exetreme poverty. Ethics of Global Warming

Impacts Hit the Poor Hardest 30 to 200 million people at risk of hunger with temperature rises of 2 to 3°C. 0.7 to 4.4 billion people will experience growing water shortages with a rise of 2°C. Yields across Africa and Western Asia may fall by 15% to 35%

THANK YOU! ANY QUESTIONS?

Residence times

Global anthropogenic greenhouse gas emissions ( ) Global Anthropogenic Greenhouse Gas Emissions in 2004

GHG emissions by each sector (1990, 2004) GHG Emissions in 2004

Vehicle Ownership & Income per Capita Data are for 1900–2002, but the years plotted vary by country, depending on data availability Vehicle Ownership / 1000 persons Indi a US A UK

Center of Ocean-Land- Atmosphere studies USA 27.8% Cumulative Emissions to 2005 Cumulative CO2 Emissions, Country % of World (Rank) United States 29.3 (1) EU (2) Russia 8.1 (3) China 7.6 (5) Germany 7.3 (5) United Kingdom 6.3 (6) Japan 4.1 (7) France 2.9 (8) India 2.2 (9) Developed 76 Developing 24

World Per Capita Total Primary Energy Consumption USA EIA (Energy Information Administration)

Total emissions Main Threat to a Sustainable Earth US China

US China Sustainability Issues Per Capita Emissions

US Energy Production & CO 2 Emissions

How much do different activities contribute?

Now China emits more GHGs than US

Provide food (and good life) to 9 billion people. Reduce odds of catastrophic impacts. No magic bullet (push on all fronts). Must reduce demand of CO 2 (put a price). Cost in GDP ‘small’ but how to distribute? US must lead. Roles of Govts, Industry, Civil society Challenges and Opportunities