1. Why is this happening? Bruce A. McCarl Distinguished Professor of Agricultural Economics Texas A&M University mccarl@tamu.edumccarl@tamu.edu http://agecon2.tamu.edu/people/faculty/mccarl-bruce/ Energy Climate Change Adaptation Climate Change Mitigation Climate Change Effects

2. IPCC (1995) “The balance of evidence suggests a discernible human influence on global climate.” IPCC (2001) “Most of the warming of the past 50 years is likely (>66%) to be attributable to human activities.” IPCC (2007) ”Most of the observed increase in global average temperatures since the mid-20th century is very likely (>90%) due to the observed increase in anthropogenic (human caused) greenhouse gas concentrations.” IPCC (2013) It is extremely likely (95–100% probability) that human activities caused more than half of the observed increase in global average surface temperature from 1951 to 2010. Why are we seeing climate change?

3. Source : U.S. National Assessment/ http://www.usgcrp.gov/usgcrp/Library/nationalassessment/images/Greenhouse-s.jpg./ Some gases, like carbon dioxide (CO), trap heat in the atmosphere by absorbing longwave radiation while letting the Sun's energy pass through. The transparent roof and walls of a greenhouse allow in the sunlight while keeping in the heat. Since these gases act similarly in the atmosphere, we call them greenhouse gases. Degree of climate change Why is this happening

4. Degree of climate change Why is this happening Cant be from the sun

5. Emissions Anthropogenic emissions Emissions of greenhouse gases, aerosols, and precursors of a greenhouse gas or aerosol caused by human activities. These activities include the burning of fossil fuels, deforestation, land use changes, livestock production, fertilization, waste management, and industrial processes.

6. Pre industrial - 275 1985 - 345 2014 average - 399 GHG Concentration http://co2now.org/ Why is this happening Counting Non CO 2 this increase exceeds 480ppm For the past ten years (2005 - 2014), the average annual rate of increase is 2.11 parts per million (ppm). This rate of increase is more than double the increase in the 1960s.

7. http://www.whrc.org/resources/online_publications/warming_earth/scientific_evidence.htm Degree of climate change - Why is this happening CO2 and temperature linked but does not lead

8. Pre industrial - 275Counting Non CO 2 1985 - 345this almost hits 480 2015 - 400 http://co2now.org/ Why are we seeing climate change?

9. 5016.7 10 7.14 microns http://geosci.uchicago.edu/~archer/cgimodels/radiation.html earth emission with today’s atmosphere; ground temperature adjusted to balance the radiation (no clouds) emitted high in the atmosphere from carbon dioxide Why is this happening - Radiation Escaping

10. GHGs

11. Greenhouse gas (GHG) Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the Earth’s surface, the atmosphere itself, and by clouds. This property causes the greenhouse effect. Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3) are the primary greenhouse gases in the Earth’s atmosphere. Moreover, there are a number of entirely human-made greenhouse gases in the atmosphere, such as the halocarbons and other chlorine- and bromine-containing substances, dealt with under the Montreal Protocol. Beside CO2, N2O and CH4, the Kyoto Protocol deals with the greenhouse gases sulphur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).

12. Pre industrial - 275Counting Non CO2 1985 - 345this almost doubles Jan 2015- 400 pre industrial Jan 2013: 395.6 Jan 2012: 393.1 Degree of climate change Why is this happening http://www.esrl.noaa.gov/gmd/ccgg/trends/ PPM CO2 Year Increase 1960 0.54 1965 1.02 1970 1.06 1975 1.13 1980 1.73 1985 1.25 1990 1.19 1991 0.99 1992 0.48 1993 1.40 1994 1.91 1995 1.99 1996 1.25 1997 1.91 1998 2.93 1999 0.93 2000 1.62 2001 1.58 2002 2.53 2003 2.29 2004 1.56 2005 2.52 2006 1.76 2007 2.22 2008 1.60 2009 1.92 2010 2.42 2011 1.83 2012 2.54

13. Degree of climate change Why is this happening http://www.epa.gov/climatechange/scie nce/indicators/ghg/ghg- concentrations.html

14. GWP Global Warming Potential (GWP) An index, based on radiative properties of greenhouse gases, measuring the radiative forcing following a pulse emission of a unit mass of a given greenhouse gas in the present-day atmosphere integrated over a chosen time horizon, relative to that of carbon dioxide. The GWP represents the combined effect of the differing times these gases remain in the atmosphere and their relative effectiveness in causing radiative forcing. The Kyoto Protocol is based on GWPs from pulse emissions over a 100-year time frame. As for the Kyoto Protocol, this report uses GWP values derived from the IPCC Second Assessment Report: 21 for methane (CH4), 310 for nitrous dioxide (N2O), 1,300-11,700 for hydrofluorocarbons (HFCs), 6500- 9200 for perfluorocarbons (PFCs), and 23,900 for sulphur hexafluoride (SF6).

15. GWP, GTP and Climate Change GWP is used to make comparisons of relative contributions among GHGs to global warming by comparing the ability of each gas to trap radiation in the atmosphere over a chosen time horizon. Global Temperature change Potential (GTP), which is change in GMST at a chosen point in time relative to CO2 IPCC uses CO 2 as a reference gas with a GWP or GTP of 1 CO2 lifetime is complicated by multiple physical and biogeochemical processes in the ocean and the land. For a pulse of about 1000 PgC, about half is removed within a few decades, but the remaining fraction stays in the atmosphere for much longer. About 15 to 40% of the CO2 pulse is still in the atmosphere after 1000 years. Source: Climate Change 2014: The Scientific Basis, Table 8.7

16. Degree of climate change Why is this happening Greenhouse gas radiation reflection Increase in CO2 concentration Plus CH4 N2O Energy related emissions Energy – development relationship Growth of BRIC economies Data 1700-2013 http://www.esrl.noaa.gov/gmd/aggi/aggi.html http://www.epa.gov/climatechange/science/indicators/ghg/ global-ghg-emissions.html

17. Degree of climate change - Why is this happening The concentration of all GHGs, reached a value of 465 ppm CO 2 equivalents in 2009 and 481 in 2014. GAS Pre-1750 tropospheric concentration 1 Recent tropospheric concentration 2 GWP 3 (100-yr time horizon) Atmospheric lifetime 4 (years) Increased radiative forcing 5 (W/m 2 ) Concentrations in parts per million (ppm) Carbon dioxide (CO 2 )280 6 395.4 7 1~ 100-300 4 1.88 Concentrations in parts per billion (ppb) Methane (CH 4 )722 8 1893 9 /1762 9 2812 4 0.49 Nitrous oxide (N 2 O)270 10 326 9 /324 9 265121 4 0.17 Tropospheric ozone (O 3 )237 1 337 2 n.a. 3 hours-days0.40 Concentrations in parts per trillion (ppt) CFC-11 (trichlorofluoromethane)zero236 9 /234 9 4,660450.061 CFC-12 (CCl 2 F 2 )zero527 9 /527 9 10,2001000.169 CF-113(CCl 2 CClF 2 )zero74 9 /74 9 5,820850.022 HCFC-22(CHClF 2 )zero231 9 /210 9 1,76011.90.046 HCFC-141b(CH 3 CCl 2 F)zero24 9 /21 9 7829.20.0036 HCFC-142b(CH 3 CClF 2 )zero23 9 /21 9 1,98017.20.0042 Halon 1211 (CBrCIF 2 )zero4.1 9 /4.0 9 1,750160.0012 Halon 1301 (CBrCIF 3 )zero3.3 9 /3.3 9 6,290650.0010 HFC-134a(CH 2 FCF 3 )zero75 9 /64 9 1,30013.40.0108 Carbon tetrachloride (CCl 4 )zero85 9 /83 9 1,730260.0143 Sulfur hexafluoride (SF 6 )zero7.79 9,11 /7.39 9,11 23,50032000.0043 Other Halocarbonszero Varies by substance collectively <0.02 http://cdiac.ornl.gov/pns/current_ghg.html

18. Sources of Emissions

20. Figure SPM.3. (a) Global annual emissions of anthropogenic GHGs from 1970 to 2004.5 (b) Share of different anthropogenic GHGs in total emissions in 2004 in terms of carbon dioxide equivalents (CO2-eq). (c) Share of different sectors in total anthropogenic GHG emissions in 2004 in terms of CO2-eq. (Forestry includes deforestation.) {Figure 2.1} Global Emissions Share

21. Why is this Happening - Emissions growing Figure TS.2. Historical anthropogenic CO2 emissions from fossil fuel combustion, flaring, cement, Forestry and Other Land Use (FOLU) in five major world regions: OECD1990 (blue); Economies in Transition (yellow); Asia (green); Latin America (red); Middle East and Africa (brown). Panels show regional CO2 emission trends 1750- 6 2010 from: (a) all sources (c+e); (c) fossil fuel combustion, flaring and cement; (e) FOLU.

22. Why is this happening - Energy emissions growing IPCC 2014 WGIII Figure 7.3. Energy supply sector GHG emissions by Subsectors. Table shows average annual growth rates of emissions over decades and the shares Plus drivers (POP – population, FEC- final energy consumption)

23. Who Emits

24. Why is this happening - Emissions growing Emissions growing http://petrolog.typepad.com/climate_change/2010/01/cumulative-emissions-of-co2.html

25. Why is this happening - Emissions shares http://cdiac.ornl.gov/GCP/carbon budget/2014/

26. Global Greenhouse Gas Data http://cdiac.ornl.gov/trends/emis/overview_2009.html Most of the growth is in areas that are not todays biggest emitters Challenge there is better life but without emissions increase

27. Who Emits

28. Degree of climate change – Texas and GHGs US EIA, http://www.eia.doe.gov/environment.html 2003 State by State Energy related CO2 emissions -- Texas wins US EPA, http://www.eia.doe.gov/environment.html Emissions growing Most emissions from energy

29. Size of Potential Emissions Coal 5,000 to 8,000 PgC Biomass ~500 PgC Soils ~1,500 PgC Atmosphere 800 PgC (2004) Oil ~270 PgC N. Gas ~260 PgC Unconventional Fossil Fuels 15,000 to 40,000 PgC Source Jae Edmonds, Joint Global Change Research Institute at the University of Maryland

30. http://www.climatechangeconnection.org/emissions/GlobalchangesinGHG.htm World GHG emissions - by country

31. Figure TS.4a: Distribution of regional per capita GHG emissions (all Kyoto gases including those from land-use) over the population of different country groupings in 2004. The percentages in the bars indicate a region’s share in global GHG emissions [Figure 1.4a]. http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-ts.pdf

32. Source: IEA WEO 2007 and Socolow presentation at Americas Climate Choices Per-capita fossil-fuel CO2 emissions, 2005 1- World emissions: 27 billion tons CO 2 STABILIZATION AVERAGE TODAY

33. Emissions concentrations and forcing Source : IPCC 2013 ar5 wg I Science of Climate Change Figure SPM.5 | Radiative forcing estimates in 2011 relative to 1750 and aggregated uncertainties for the main drivers of climate change. Values are global average radiative forcing (RF14), partitioned according to the emitted compounds or processes that result in a combination of drivers. The best estimates of the net radiative forcing are shown as black diamonds with corresponding uncertainty intervals; the numerical values are provided on the right of the figure, together with the confidence level in the net forcing (VH – very high, H – high, M – medium, L – low, VL – very low). Albedo forcing due to black carbon on snow and ice is included in the black carbon aerosol bar. Small forcings due to contrails (0.05 W m–2, including contrail induced cirrus), and HFCs, PFCs and SF6 (total 0.03 W m–2) are not shown.

34. Future emissions are mostly projected to increase Figure 2-9: CO 2 Emissions in Global Futures Scenarios (narrative scenarios). Acronyms: OCF, the “Our Common Future” scenario from Duchin et al., 1994; GS, the “Global Shift”; ER, the “European Renaissance”; GC, the “Global Crisis”; and BG the “Balanced Growth” scenarios from the Central Planning Bureau of the Netherlands (CPB, 1992); A1, A2, A3, B, C1 and C2, scenarios from Nakicenovic et al., 1998; CW-R, “Conventional Worlds – Reference”; and CW-PR, “Conventional Worlds – Policy Reform” from Gallopin et al., 1997 and Raskin et al., 1998. Source IPPC 2001:Mitigation

35. Future emissions are mostly projected to increase YearA1BA1TA1FIA2B1B2 2000 356 2010 378393381385384391 2020 416442417407416432 2030 473493467449 470 2040 546561552507481511 2050 605622686575515555 2060 681673852670550599 2070 7467041033786578647 2080 7957231215920597697 2090 83172413851072607751 2100 86171715351256608808 Data from http://www.eea.europa.eu/data-and-maps/figures/observed-and-projected-changed-in-the-overall-kyoto-gasses-fig-1a-and-all-greenhouse-gasses-expressed-in-co2- equivalents-ipcc-2007a-partly-based-on-ipcc-2001-2