Table 7.1 Sources of four principal greenhouse gases a

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1 Table 7.1 Sources of four principal greenhouse gases a GAS Natural sources Human-derived sources Carbon dioxide Methane Nitrous oxide Terrestrial biosphere Oceans Natural wetlands Termites Oceans and freshwater lakes Oceans Tropical soils (wet forests, dry savannas) Temperate soils (forests, grassland) Fossil fuel combustion Cement production Land-use modification Fossil fuels (natural gas production, coal mines, petroleum industry, coal combustion) Enteric fermentation (e.g. cattle) Rice paddies Biomass burning Landfills Animal waste Domestic sewage Nitrogenous fertilizers Industrial sources Land-use modification (biomass burning, forest clearing) Cattle and feed lots Chlorofluorocarbons b Nil Rigid and flexible foam Aerosol propellants Teflon polymers Industrial solvents a Sources listed in order of decreasing magnitude of emission except where otherwise indicated. b Sources of chlorofluorocarbons not in order of decreasing magnitudes of emission.

2 Table 7.2 Radiative forcing relative to CO 2 per unit molecule change in the atmosphere. Source: Extracted from Houghton et al. (1990: 53, table 2.3). Reproduced with permission Gas Relative radiative forcing Residence time in atmosphere (years) CO CH 4 (methane) N 2 O (nitrous oxide) CFC-11 12, CFC-12 15,

3 Table 7.3 Sources and strengths of nitrous oxide and methane (a) Estimated sources and sinks of methane in millions of tonnes per year. Source: After Houghton (2009, table 3.2) Sources Natural Wetlands 150 Termites 20 Ocean 15 Other (including hydrates) 15 Human-generated Coal mining, natural gas, petroleum industry 100 Rice paddies 60 Enteric fermentation 90 Waste treatment 25 Landfills 40 Biomass burning 40 Sinks Atmospheric removal 545 Removal by soils 30 Atmospheric increase 22 Best estimate (b) Estimates of nitrous oxide (N 2 O) source strengths and sinks. Source: Data in UNEP (1991) Sources/sinks Range (10 6 t a 1 ) Sources Oceans Soils (tropical forests) Soils (temperate forests) Fossil fuel combustion Biomass burning Fertilizer (including groundwater) Sinks Removal by soils Unknown Photolysis in the stratosphere 7 13 Atmospheric increase 3 4.5

4 Table 7.4 Albedo values for different land-use types. Source: From miscellaneous data from Pereira (1973) collated by author Surface type Location Albedo (%) Tall rainforest Kenya 9 Lake Israel 11.3 Peat and moss England and Wales 12 Pine forest Israel 12.3 Heather moorland England and Wales 15 Evergreen scrub (maquis) Israel 15.9 Bamboo forest Kenya 16 Conifer plantation England and Wales 16 Citrus orchard Israel 16.8 Towns England and Wales 17 Open oak forest Israel 17.6 Deciduous woodland England and Wales 18 Tea bushes Kenya 20 Rough grass hillside Israel 20.3 Agricultural grassland England and Wales 24 Desert Israel 37.3

5 Table 7.5 Some recent studies of climatic effects of vegetation removal Source Location Subject Fuller and Ottka (2002) West Africa Albedo and desertification Fu (2003) East Asia Reduced atmospheric and soil moisture in East Asian monsoon region Chase et al. (2000) Global Effects on main circulation features Werth and Avissar (2002) Amazonia Reduction of local precipitation, evapotranspiration and cloudiness and also global effects Berbet and Costa (2003) Amazonia Precipitation variability Reale and Dirmeyer (2000) Mediterranean Basin Increased precipitation prior to deforestation in Roman times Taylor et al. (2002) Sahel Rainfall decrease Sampaio et al. (2007) Amazonia Rainfall decrease Doughty et al. (2012) South America Rainfall decrease

6 Table 7.6 Some urban climate characteristics (from Griffiths 1976, reproduced with permission) (a) Average changes in climatic elements caused by cities Element Parameter Urban compared with rural (, less; +, more) Radiation On horizontal surface 15% Ultraviolet 30% (winter); 5% (summer) Temperature Annual mean +0.7 C Winter maximum +1.5 C Length of freezefree +2 to 3 weeks (possible) season Wind speed Annual mean 20% to 30% Extreme gusts 10% to 20% Frequency of calms +5% to 20% Relative Annual mean 6% humidity Seasonal mean 2% (winter); 8% (summer) Cloudiness Cloud frequency +5% to 10% + amount Fogs +100% (winter); 30% (summer) Precipitation Amounts +5% to 10% Days +10% Snow days 14% (b) Effect of city surfaces. Source: H. Landsberg in Griffiths (1976: 108) Phenomenon Consequence Heat production (the heat island) Rainfall + Temperature + Retention of reflected radiation by high walls Temperature + and dark-coloured roofs Surface roughness increase Wind Eddying + Dust increase (the dust dome) Fog + Rainfall + (?)

7 Table 7.7 Annual mean urban-rural temperature differences of cities. Source: Data from Detwyler (1971) and Wilby (2003). Reproduced with permission City Temperature differences ( C) Chicago, USA 0.6 Washington, DC, USA 0.6 Los Angeles, USA 0.7 Paris, France 0.7 Moscow, Russia 0.7 Philadelphia, USA 0.8 Berlin, Germany 1.0 New York, USA 1.1 London, UK 1.8

8 Table 7.8 Areas of maximum increases (urban-rural difference) in summer rainfall and severe weather events for eight American cities (from Changnon, 2003) City Rainfall Thunderstorms Hailstorms % Location a % Location a % Location a St Louis +15 B +25 B +276 C Chicago +17 C +38 A, B, C +246 C Cleveland +27 C +42 A, B +90 C Indianapolis Washington, DC +9 C +36 A +67 B Houston +9 A +10 A, B +430 B New Orleans +10 A +27 A +350 A, B Tulsa a A = within city perimeter, B = 8 24 km downwind, C = km downwind.

9 Table 7.9 Major urban pollutants Type Suspended particulate matter (characteristically μm in diameter) Sulfur dioxide (SO 2 ) Photochemical oxidants: ozone and peroxyacetyl nitrate (PAN) Oxides of nitrogen (NO x ) Carbon monoxide (CO) Toxic metals: lead Toxic chemicals: dioxins and so on Some consequences Fog, respiratory problems, carcinogens, soiling of buildings Respiratory problems, can cause asthma attacks. Damage to plants and lichens, corrosion of buildings and materials, production of haze and acid rain Headaches, eye irritation, coughs, chest discomfort, damage to materials (e.g. rubber), damage to crops and natural vegetation, smog Photochemical reactions, accelerated weathering of buildings, respiratory problems, production of acid rain and haze Heart problems, headaches, fatigue, and so on Poisoning, reduced educational attainments and increased behavioural difficulties in children Poisoning, cancers and so on

10 Table 7.10 UK emissions of selected heavy metals (in tonnes per year) from 1970 to 2000 (from data provided by National Atmospheric Emissions Inventory) Decrease (x) Cadmium Lead Mercury

11 Table 7.11 Nitrogen oxide and sulfur dioxide emissions. Source: Smith et al. (2001b). Reproduced with permission from Cambridge University Press (a) Emissions of sulfur and nitrogen oxides (as NO 2 ) in 1000 tonnes a year for selected European countries in 1980 and 1993 Country Sulfur Nitrogen oxides as % of as % of 1980 Czech Republic Denmark Finland France Germany Ireland Italy Netherlands Norway Poland Spain Sweden UK (b) Percentage contributions for four regions to global sulfur dioxide emissions. Source: Smith et al. (2001b). Reproduced with permission from Cambridge University Press Sulfur dioxide emissions by geographic region (%) US/Canada Europe Asia Rest of world