Enhanced Greenhouse Effect - Handout

Enhanced Greenhouse Effect

Jeremy Kim Alice Li

Processes Visible and UV waves (short wavelength) pass through atmosphere; Earth absorbs longer wavelength infrared heat rays; troposphere heated (keeps Earth habitable; few degrees cooler = ice age conditions) o Greenhouse gases [H2O (most abundant), CO2, CH4, N2O] trap longer wavelength radiation (H2O absorbs least; N2O absorbs the most)  reradiated towards earth - Increase of greenhouse gases from human activity  more infrared rays reradiated to earth  increasing average temp. of Earth = enhanced greenhouse effect - 0.004% of atmospheric gases = CO2 and fewer percentage = other greenhouse gases, but small amounts of greenhouse gases very potent - Since Industrial Revolution: CO2 ppm = +30%, NO2 = +15%, CH4 = +100%  average global temperature = +0.5Cº in past 100 years Causes

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Industrial processes (CO2 ppm increased ever since Industrial Revolution in 1800’s); developing nations, e.g. China, uses coal as dominant energy source to fuel expanding economies (natural gas, oil, etc. also create greenhouse gases) - Automobiles; release of CO2 - Increasing use of pesticides Certain material used in coolants (i.e. PVC), - Increased population; respiratory system as well as other products, release releases CO2 greenhouse gases - Deforestation; damages carbon cycle - Increased number of cattle (methane gas from flatulence) - Decomposition of organic material; on surface and newly revealed matter from melting permafrost (lower albedo  feedback loop) Feedback Loops (Causality: Enhanced greenhouse effect causes more greenhouse gases to exist in atmosphere and so on) Increasing temperature causes: o More Forest fires (releases smog and CO2 and damages carbon cycle; less CO2 intake/O2 outtake) o Increased evaporation (releases more water vapours, a natural greenhouse gas) o Melting permafrost (releases more CO2 or CH4 (methane 20x more potent than CO2), depending on humidity of area when permafrost melting; if dry = methane, if wet = CO2 b/c of oxidation; esp. Canadian North + Siberia = world’s largest peat bog) Melting polar ice caps and glaciers reduce albedo (ice reflects 90% of sunlight hitting it) causing faster heating and melting rates *Note: Volcanic eruptions temporarily cools atmosphere because of reflective solid particles, but increases overall existence of greenhouse gas particles in atmosphere (e.g. Mt. Pinatubo) **N.B.**: Moderate change (+ or -) could result in catastrophic climate change b/c climate change based on reaching thresholds (“gradual instant”) Physical Impacts

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Warmer oceans; cooler continents because of changing ocean currents (currents act as thermoregulators of surface temperatures) Desertification: cattle die (Ethiopia, 2006; ~80% cattle died), nationwide famines occur Increasing temperature of water o Molecular level: expands oceans because of less dense water (dominant cause of rising sea levels) o Melting polar ice caps and glaciers: rising sea level (to lesser extent) and increasing amount of fresh water in oceans (damages North Atlantic Drift; Europe, esp. UK becoming colder; 1700’s = mini ice age) Tree line slowly moving north; “drunken” tree effect from tilt as trees move Pine beetle infestation in coniferous forests of North America because more pine beetles able to survive warmer winters Earlier bird nesting; traditional food sources disturbed; more birds in danger of extinction Fish unable to cope in warmer waters; moving North to cooler waters (e.g. salmon in BC) Coral reefs greying and dying off (speculated to be completely gone within century) Polar bears and seals at risk because of warming north; seals dying because of warmer water  less food for polar bears; fewer cubs born

Enhanced Greenhouse Effect

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Jeremy Kim Alice Li

Decreasing biodiversity, because of warmer waters, atmosphere, and added destruction of ancient forests by forest fires Seasons imbalanced and stalled (no snow in conventional “winter months” but snow and hale during spring) Increased precipitation because of increased concentration of condensation nuclei in atmosphere as a result of greenhouse gases Increased frequency and severity of hurricanes and typhoons (see Katrina and hurricane season and recovery rate in south-eastern US) [doubled number of category 4, 5 hurricanes and 50%+ hurricane wind speed and duration since 1970’s] Northern hemisphere: Ice forms 1 week later; melts 1 week earlier

Human Impacts

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Air pollution; health hazards (respiratory illnesses, etc.) esp. on local scales such as large cities where there are many pollutants but few vegetation (imbalanced carbon cycle near large cities) Rising sea level; drowns settlements near rivers and esp. coasts; islands in danger of submerging (e.g. US Marshall Islands, Maldives, etc.) Melting alpine glaciers (water source imbalance: floods when ice melts too fast; droughts after floods because frozen water source depleted; more floods after because top soil too hard and dry) Changing climates to extremities and different crops thrive or die (e.g. Australia + SE Asia: wetter and more stormy; American prairies + Russian steppes: too dry for wheat, but in more northern latitudes, now can be grown; England: maize, oranges, peaches, vines can thrive) Longer growing seasons and more area able to be farmed for some areas (e.g. Canada); inability to farm in others (e.g. Sub-Saharan Africa) Increased erosion on coasts and river deltas  human settlements, multi-million dollar tourist resorts, and agricultural lands at risk Increased risk of landslides, etc. because of heavier rainfall

Locations of Enhanced Greenhouse Gas Emissions and Saliently Affected Areas MEDCs and developing nations produce most greenhouse gases Entire globe being severely affected, although arguably, there are benefits for some MEDCs such as longer growing seasons; overall the prospects are negative for virtually all nations and peoples with continuing climate change

Response to Hazard Higher sea defences for major cities (e.g. ) in some MEDCs International response: o Kyoto Protocol (goal = reduce emissions from industrialized nations by 5.2% below 1990 levels by 2008~2012; ineffective) o China and India (high rate of development and high populations) favouring international community response to enhanced greenhouse effect and global warming because they can gain sustainable developmental aid for more efficient plants and industries, and so offset costs to themselves (“footing the bill”) New energy-efficient technologies developed; only some used (e.g. cars) because upgrading expensive (e.g. industries, although largest industries forced by MEDC governments to upgrade) - Advocates of preparations for migration of populations and settlements away from hazardous areas in danger of flooding (James Lovelock) New energy sources or alternatives sought in different countries, esp. nuclear technology (significant pros and cons; see Iran, North Korea) - Populations alerted to realities of global warming; “hot” issue  population = voters and market  governments and businesses act o Banks (e.g. HSBC) invest in “green projects” o Major corporations (e.g. Wal-mart) installing wind turbines on stores + considering solar reflectors on parking lots o State and local lawmakers put forth laws to curb emissions o President Bush acknowledges climate change + boasting that he’s taking steps to fight it o **Problem: Most responses = voluntary; little to no federal actual response to reducing emissions in federal level in US Detection and Monitoring

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Jeremy Kim Alice Li

19/20 hottest years on record = 1980+; 2005 = hottest year on record Geological records from ice core samples show previous ice ages, concentrations of CO2 in the atmosphere then, stranded coral reefs, fossilized pollen, and ancient ocean sediments. (showed that when threshold temp. reached, glaciers in Greenland and the Artic melted rapidly with 10 feet rise in sea levels) Extensive measurements done in upper atmosphere, under the sea, on tundra, on deserts permafrost and glacial ice cores. Measurements done by satellites and weather balloons Climate models using a multitude of factors processed through super computers used to simulate likely changes of atmospheric composition and predict future and potential climate changes; climate model predictions compared with observations to determine extent of impact of enhanced greenhouse effect.  prediction = global average temperature will increase by 1.7~6.1 Cº by 2100

LEDC – Bangladesh Bangladesh emits a tiny fraction of total greenhouse gas emissions, but may be more severely affected than other MEDC’s 90% of area is flat Delta of River Ganges ideal for rice growing and therefore population settlements focused around delta (40 million) o Coastal inundation, saline groundwater intrusion, drainage congestion of farming systems  Loss of arable land o 2100 prediction: 1 m rise in sea level = 25% land submerged = 60% population directly affected  forced migration - Melting alpine glaciers of Himalayas  increase flooding in rivers and delta Deforestation of Himalayan area o Less vegetation to intercept rainfall; less vegetation cover to reduce throughflow  flooding o Less trees for carbon cycle, esp. on local scale Bay of Bengal: increased frequency and severity of tropical cyclones in autumn may result in storm surges and flooded deltas (Changes uncertain: frequency of tropical cyclones in northern Indian Ocean during last 30 years found to be inversely correlated with sea-surface temperature even though the energy source for the cyclones is the heat in the surface mixed layer) Change of climate pattern (monsoon climate) severely affects farming; crop and farming technology based on state of climate - Rice monoculture: Certain crops, including and esp. rice padi fields, cannot grow in new extreme climate changes, i.e. heavy rain leads to flooding, followed by drought o 90% population depends on rice as staple food o Country’s economy also dependant on agriculture

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Changing climates (increased monsoon rains and droughts)  infrastructure must evolve to accommodate change

MEDC – Canada

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Initiatives to reduce emissions: 2000 Action Plan with $500 million budget; signed Kyoto Protocol (pledged 6% reduction from 1990 levels, but poor record so far); One Tonne Challenge; Montreal Action Plan (to commence in 2006); Clean Development Mechanism and Joint Implementation Office; etc. Eighth largest emitter of CO2 from industrial processes (435,000 thousand metric tons – 2000) Impact of Greenhouse Emissions and Global Warming on Canada: o Damage to infrastructure in north because of melting permafrost o Salmon move to cooler waters north o Less snow in mountains; shorter ski season; damages tourism industry  Excess of water from alpine glacial melt followed by temporary water shortages (e.g. summer, 2005 in BC: “If its yellow let it mellow, if its brown, flush it down”) o Increased frequency of forest fires o Pine beetle infestation in Western forests damage forests; risk of pine beetle infestation spreading East and South o Prolonged droughts in central Canada; damage to crops o Polar bears thinning and less offspring procured; declining polar bear population o Frequent icebergs in Atlantic near Maritime Provinces from Artic ice break-off (hazard to ships) o Drop in water levels in Great Lakes; hydro power and shipping losses o Possibility of tropical storms in Eastern Canada as a result of warming ocean temperatures (theoretical)