1. GLOBAL WARMING Just the facts.

2. Making Connections  We are discussing global warming for 2 reasons: 1. There is evidence that increasing [CO 2 ] is a factor in the apparently increase in global temperatures 2. Plants play an extremely important role in the drama called ‘global warming’ - (plants... photosynthesis... CO 2... get it?)

3. What is global warming?  The apparent increase in average temperature all over the world  about 0.8 oC since the late 1800s (agreed upon by 600-700 balloon stations, satellites, and surface measurements)  Where does this come from? THE GREENHOUSE EFFECT  Why do we care? Changes have been:  Unprecedented  Rapid  Irreversible

4. THE GREENHOUSE EFFECT

5. Greenhouse Gases (GHG’s) NATURAL GHG’s  CO 2 – carbon dioxide  H 2 O (g) – water vapor  CH 4 - Methane  N 2 O – Nitrous oxide  O 3 – Ozone ARTIFICIAL  CFC - chlorofluorocarbons  HCFC – hydrochloroflurocarbons  HFC - hydroflurocarbons

6. Effect of Greenhouse Gases (GHG’s) DIRECT:  Absorb reflected IR radiation, thus the energy (heat) it carries remains in the atmosphere INDIRECT:  Emit non-GHG such as CO, NO x, etc that react chemically to create O 3 or extend the lifetime of GHGs BOTH! CH 4 is a GHG but also affects the amount of other GHGs in the atmosphere (atmospheric chemistry)

7. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs 1. N 2 O – Nitrous oxide **levels have climbed from 275ppbv – 315ppbv Sources:  Nitrogen fertilizers on soils  Biomass/fossil fuel burning  Lightning  Natural Fires  Oceans Life span: 120 years! Sinks:  Photochemical destruction in the stratosphere by UV

8. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs 2. O 3 – Ozone (there are 2 types: stratospheric and tropospheric) * tropospheric levels have doubled from 10-15ppbv – 20-30ppbv **levels are as high as 100ppbv in polluted cities Sources:  Not directly released but produced from rxn’s of other hydrocarbons:  CH 4  NO x,  CO Life span: a few weeks! Sinks:  Chemical reactions in the atmosphere **Due to this short life span we COULD regain the full ability of the ozone layer in 50 years**

9. Effect of Greenhouse Gases (GHG’s) So what’s the real deal with the Ozone... The stratosphere is where ‘ozone hole’ is located: There is not a hole in the ozone layer, it’s just a thinning of the stratosphere in above the poles (especially Antarctica) This allows more UV-B rays to reach the earth’s surface Increased UV radiation can lead to: Increased incidences of skin cancer and cataracts weakened immune response decreased crop yield (UV-B affects cyanobacteria in roots)

10. Effect of Greenhouse Gases (GHG’s) What are the main causes for ozone layer depletion?  CFCs (and the family of HCFCs, HFCs, etc)  Contain chlorine and bromine which are able to break down O 3  This occurs more rapidly at colder temperatures  CO 2  Decreases temp of stratosphere, thus increasing affect of CFCs  CH 4  Oxidation of CH 4 in the stratosphere to form OH - which reacts with HCl to release harmful Cl - ions

11. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs... 3. CH 4 – Methane **levels have climbed from 0.700ppmv – 1.725ppmv (~150%)

12. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs... 2. CH 4 – Methane Sources:  Ruminant animals  Manure  rice paddies  landfills/sewage treatment  biomass burning  coal mine seepage  natural gas venting in oil operations Life span: 8 years! Sinks:  85% - Conversion by OH - to form CO 2 andH 2 0  15% - Absorbed by soils

13. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs... 4. CO 2 – Carbon Dioxide Sources:  Fossil fuel burning (7Gt) [Gt = gigatons = 10 9 ]  Deforestation (2Gt)  Decay of plant and animal matter,  respiration of plants and animals = 100 Gt/yr  but is almost perfectly balanced by photosynthesis (for now!!).  Also, gaseous outflows from oceans  but is almost perfectly balanced by gaseous inflow under constant climate

14. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs... 4. CO 2 – Carbon Dioxide Sinks:  60% is absorbed by oceans and land plants  for now, all but 10-20% of what we have emitted so far will eventually be absorbed by oceans  After several 1000 years, all but 5-10% will be absorbed by oceans (as CaCO 3 on the ocean floor will dissolve) *Life span: Depends, it may be within a matter of years or 100,000 years !

15. Effect of Greenhouse Gases (GHG’s) Lets break down the GHGs... 5. CFCs – Chlorofluorocarbons (& family) *ZERO natural concentration, a rapid increase in [x] after 1960 **[CFC] has started to decrease due to phase out of products, WHILE Sources:  Entirely human.  Used in refrigeration, air conditioning, and cleaning electrical equipment Sinks:  Photochemical destruction in the stratosphere,  Destruction of HCFCs/HFCs in troposphere by OH - *Life span: 50,000 years for CFCs, 1-10 years for HCFCs, 10-100 years for HFCs!

16. So what’s the deal with CO 2 ?  Water vapour – H 2 O(g) – is actually the most prevalent GHG  But, CO 2 is much more potent in increasing the greenhouse effect

17. Effects of CO 2

18. Mid-latitude Tornadoes - May become more destructive as climate warms (but very uncertain). - Most likely they will become regionally depending on the ocean temperature and wind shear. Tsunamis When the ice is lost, the earth's crust bounces back up again and that triggers earthquakes, which trigger submarine landslides, which cause tsunamis

19. Effects of CO 2 (positive feedback) Increasing CO 2 --> warmer climate -->  partial drying of saturated Arctic soils --> respiration of peat --> more CO 2 to atm  forests can't adapt and die back --> further increase CO 2 to atm  thawing of land and continental shelf permafrost in arctic --> further warming of climate  ice and snow melt back --> less albedo --> more solar energy absorbed (less reflected back out) --> further warming  more sluggish ocean circulation (less wind) --> reduced marine activity due to less upswelling of nutrients --> higher CO 2 to atm

20. Direct CO 2 effect on agriculture 1)Increased water use efficiency by plants CO 2 enters plant through stomata on bottom of leaves and depends on: a) number and size of stomata openings and b) difference in [CO 2 ] inside and outside leaf Increasing CO 2 outside of leaf will increase the concentration gradient and cause the openings to not open as much to take in as much CO 2 for photosynthesis. Narrower stomata inhibit the loss of water and thus an increase in water use efficiency 2) Increases photosynthetic rate C3 plants depend on the balance between gross photosynthesis and photorespiration both processes use the enzyme Rubisco If more CO 2 is present than O 2, then CO 2 will outcompete O 2 for binding sites and photosynthesis is favoured (this will occur even if light is a limiting factor) 3) Ecological Considerations Earlier flowering may occur, thus insect pollinators could be important (migration rates) Decrease in litter quality, which reduces rates of decomposition Decrease of forage quality, thus herbivores will have to eat more to get the same amount of nutrients

21. Indirect CO 2 effect on agriculture 1)Temp increase will be beneficial for agriculture in regions near cold-limits but will be detrimental for: A)crops that already suffer heat stress B)grain crops where a decrease in the length of time to maturation yields less grain products C)poor developing countries D)tropics, as corn yields fall with any amount of warming, E)rice yields rise for a 1 o warming (but drop after that) 2) Precipitation – increase in average rainfall will affect: A) Individual events: if occur as fewer but more intense downpours, more of the rain will be lost as runoff and average soil moisture will decrease. B) Seasonal distribution: an increase in rainfall in a dry region all occurring at the beginning of the growing season, or when grain should be ripening, isn't much good 3) Evaporation and Soil Moisture A warming climate will increase evaporation, thus precipitation must increase simply to maintain present soil moisture if precipitation doesn't increase enough, soil moisture will decrease

22. DEFORESTATION Simply put... Plants (or trees) are a HUGE sink for CO 2 By clear cutting forests, we are losing these CO 2 sinks, thus increasing CO 2 in the atmosphere Sadly, underdeveloped countries cannot protect their forests so underground logging operations are clear cutting everything they can

23. How can we overcome deforestation? 1. End Deforestation -requires making more efficient use of forest products (more efficient wood burning stoves) -using agricultural land more efficiently so that less land is needed for food production 2. Reforestation -net carbon removal only occurs while trees are growing. -once the forest has reached its maturity, it must be maintained or the carbon will go back to the atmosphere - leaving no net benefit -reforesting land that is not suitable for agriculture could absorb 1-2Gt C/year for several decades -*combined with deforestation this could surely stabilize atmospheric CO2 while we work on fossil fuel emissions *REFORESTATION COSTS MONEY!!! (what is the country going to get out of it?)

24. How can we overcome deforestation? 3. Biomass Energy (wood, straw, biological waste products such as manure) -used as an energy source to displace coal and other fossil fuels. -The net carbon benefit of using land for biomass energy is greater than using the same land for permanent carbon storage 4. Enhanced growth of existing forests -using forests as a sink to partially offset CO2 emissions requires 1) that those emissions themselves are falling so that the degree and rate of climatic change are kept as small as possible 2) that other stress on forests (acid rain and ozone) are diminished as quickly as possible, which also implies reduced use of fossil fuel

25. SEA LEVEL RISE (SLR)! So far: 1.8mm per year for the last century (1.8mm x 100 = 180mm = 18cm) *Studies suggest that 2.8mm – 3.1mm per year in the last decades Predictions: typically range from 90 to 880 mm over next 100 years Regional Impacts of SLR Coastal wetlands coral reefs estuaries Physical Impacts of SLR flooding of coastal regions, impacts on islands, coastal erosion, salt water intrusion, interactions with rivers flooding of waste facilities change in storm frequency

26. SEA LEVEL RISE! Coral Reef Issues Bleaching (coral needs to be at specific depth below water level so that bacteria can use sunlight) Decreased Carbonate saturation increased attacks by disease organisms Marine Biological Productivity Reduced nutrient upwelling from ocean depths heat stress, reduced carbonate supersaturation, increased acidity of water (carbonic acid)

27. 5 Ways to Reduce CO2 1)Improve the efficiency in converting from 1 o to 2 o energy by: a) generating electricity more efficiently from fossil fuels than at present and b) reducing the energy losses in the production of refined gas productions from oil 2)Improve the efficiency in converting from 2 o to 3 o energy by more efficient: a) use of electricity (in motors, appliances, and lighting) and b) automobiles and aircrafts 3)Reducing the demand for end use (3 o ) energy: a) design cities that have shorter travelling distances and that have transit systems that promote walking, biking, or public transit; b) increase recycling of energy-intensive materials (steel and aluminum); c) design building that less heat is lost in winter (less cooling in summer); d) modify people's behaviour to be more climate conscious

28. 5 Ways to Reduce CO2 4) Switching the mix of energy sources used: a) switching from coal to oil to natural gas within the fossil fuel portion of the energy supply mix; b) switch from electricity to direct use of natural gas for space and water heating (especially when coal is used); c) switching from fossil fuels to renewable forms of energy wherever possible (such as solar, wind, biomass, and geothermal energy) 5) Capturing CO2 produced from the combustion of fossil fuels: - before it is released to the atmosphere, and permanently disposing of it in deep geological strata or in the deep ocean

29. Alternative Energy Wind: fastest growing source of energy of electricity generation in the world in the last 20 years, but is still a small fraction of electrical generation Wind turbines typically convert 25% of the kinetic energy of the wind that crosses the rotor to electricity Worldwide installed capacity by the end of 2006 was almost 75GW (compared to the 3300GW used world wide) North Dakota alone could generate electricity to total US consumption BUT problems: a)some of the best wind resources are not close to major demand centres b)the wind does not blow all the time, a minimum wind speed of 3-4m/s is needed before the turbine will produce any electricity at all

30. Alternative Energy Solar: 0.6% of the world's deserts surface is an area of 66,000km 2, whereas the cumulative worldwide production of PV modules only covers 25km 2 PROBLEMS: a)most of the electricity demand is not close to sunny deserts b) the sun doesn't always shine

31. Alternative Energy Hydro-electric: 0.2 TW worldwide with potential of 1.1TW. Most have to be left undeveloped to protect biological heritage regions and to respect native land rights Does not need to be a big operation, a lot can be obtained from many small-scale river plants that would have much less environmental and social impact Geothermal: Water is pumped down holes drilled into deep rock, is heat, then rises through other holes and is used to generate electricity. Worldwide capacity is 10GW Nuclear: hard to justify until determine where waste can go for 10,000yrs or more. More expensive which would worsen the greenhouse problem by taking away funds from more worthwhile investments

32. Alternative Energy Hydrogen 1. Usable in all the end-use applications where Fossil Fuels are currently used 2. Non-polluting 3. Storable (this is a problem limits electricity produced from renewable but intermittent energy sources such as solar, wind, tidal, or hydro-electric) 4. Portable (especially important for transportation energy use) 5. Safe 6. Efficient 7. Affordable 8. Capable of stimulating development of new technologies

33. FINALLY, WHAT YOU CAN DO! Windows of Opportunity The biggest opportunity to reduce energy use and incorporate renewable energy involves new buildings. Once they are built it becomes more difficult and costly to increase efficiency 1) compact flurorecent light bulbs (CFLs) now cost about $3-4 each and can replace just about any use of incandescent light bulbs. They use 4-5x less energy 2) The best front-loading clothes washer uses about 5x less energy than the typical top-loading machine. They also save energy because less detergent is needed. Also, the clothes come out with half the water on them thus less need for a increased drying time 3) The latest fridges use about 1/4 the electricity vs. older models,

34. FINALLY, WHAT YOU CAN DO! Windows of Opportunity 1)To design building with -High degrees of insulation -quality construction that eliminates air leakage, -high-performance windows (triple-glazed windows have 1/3 heat loss of a conventional double-glazed window!) -adjustable external shading devices -It has been consistently shown that space-heating requirements can be reduced by a factor of 4-10 2) To satisfy as much of the remaining energy demand through passive solar energy features as possible: -Lighting during daylight hours can be largely met with natural light, -Buildings can be designed such that most of the ventilation requirements can take advantage of winds and natural temp differences that drive ventilation flow. -Wear a friggin’ sweater!

35. FINALLY, WHAT YOU CAN DO! Windows of Opportunity 3) Use the most efficient equipment and systems available to meet the remaining cooling, lighting and ventilation requirements. - incremental improvements to individual energy-using devices. Ex. Using more efficient pumps, fans, & air conditioners 4) Use active solar energy features to supply as much of the remaining energy demand as possible: - solar thermal collectors (water pipes attached to an absorbing surface, used to make hot water) - PV (photovoltaic) panels to generate electricity.