What is Global Warming and how can it

What is Global Warming and how can it Change the Climate? 1

Questions? ? u 1. How do greenhouse gases keep heat in our lower atmosphere? u 2. What kind of radiation do they absorb? u 3. List 6 greenhouse gases. u 4. What evidence do we have that global warming is already taking place?

5. Can you think of any reasons to argue against global warming, that is, it is not happening and probably will not happen in the future?

What is Global Warming and how can it Change the Climate? i. Global warming is related to the green house effect i. It is similar to the temperature rise in a car when you have the windows rolled up on a sunny day i. This is illustrated on the following overhead 4

What causes the temperature rise? 1. Light from the sun comes to earth over a range of colors or frequencies which range from the ultra violet to the colors to the infrared. 2. When light strikes the earth's surface some of it is changed into infrared radiation. 3. Some molecules like CO 2 and H 2 O adsorbed infrared and “trap” it near the earth's surface. These gases are called green house gases. 5

CO 2 6

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Calculating the Temp. at the Earths surface w/o any green house effect u The total radiation, Es, in watts emitted by the sun at its surface R= radius of sun, T = Tempsurf s = 5. 67 x 10 -8 W m-2 K-4 Stefan Boltzmann constant (Intro Atmos Chem, , D. Jacob, Princeton Univ. Press p 123, 1999, ISBN 0 -691 -00185 -5 8

The Sun’s energy reaching the Earth’s surface, Fs, in W m-2 Rs= radius of sun = 7 x 105 km T = Tempsurf= 5800 K s = 5. 67 x 10 -8 W m-2 K-4 Stefan Boltzmann constant d = distance from sun to earth=1. 5 x 108 km So, Fs = 1370 W m-2 9

The actual energy reaching the Earth’s surface = light in – light reflected earth The total Sun’s energy striking the projected area of the earth per unit time is: pr 2 Fs (1 -A); where A = 0. 28 light reflected Sun’s energy striking/absorbed per m 2 per time by the surface area of the earth is: pr 2 Fs (1 -A)/4 pr 2= ` Fs (1 -A)/4 10

The actual energy absorbed by the Earth’s surface = heat flux reflected The heat flux reflected by a black body radiator is s T 4 where T = temp of Earth’ surface Fs (1 -A)/4 = s T 4 T = 255 K!!!!; ave. Temp 285 K Green house gases are causing this difference 11

Climate forcing often is related to the net changes in energy (in W m-2) Dr. James Hansen, Sci American, March 2004 12

Climate forcing often related to the net change in energy (in W m-2) The previous ice age was on average (20, 000 years ago) was on average 5 o. C cooler than now and the average forcing was ~6. 5 o. W m-2 less than today; this gives 0. 75 o. C per change in one W m-2 So now we can estimate the change in global temp. from different green house gases and particles 13

u Changes in the global temperature may have profound consequences for the natural environment and for societies. ŒOcean life and ocean currents 14

u Changes in the global temperature may have profound consequences for the natural environment and for societies. ŒOcean life and ocean currents sea level and weather patterns 15

u Changes in the global temperature may have profound consequences for the natural environment and for societies. ŒOcean life and ocean currents sea level and weather patterns Ž Availability of water 16

u Changes in the global temperature may have profound consequences for the natural environment and for societies. ŒOcean life and ocean currents sea level and weather patterns Ž Availability of water Agriculture 17

How fast are green house gases increasing? ? ? i. On the next slide you will see a time trace for the concentration of carbon dioxide from 1958 -1992 at Mt. Mauna lowa Hawaii i. Why does it oscillate up and down as it generally goes up? ? 18

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Ice core data can give CO 2 trend information!!!! 20

Ice core data 21

i. Ice core and direct temperature measurements show similar patterns and absolute amounts when they are both taken over the same period i. This gives us some confidence in the ice core data 22

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How fast is Global Warming Occurring? i. The rate of global warming over the next century may be more rapid than any temperature change that has occurred over the past 100, 000 years!!! i. This will cause major geographical shifts in forests, vegetation, and cause significant ecological disruption 24

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1979 perennial Ice coverage Nat. Geographic, Sept 2004) 27

2003 perennial Ice coverage 28

How does this effect the earth’s albedo? ? 29

How does this effect the earth’s albedo? ? With less polar ice there is evidence of more green plant growth They consume more CO 2 30

l. Since 1900 the average temperature of the earth’s surface has increased 0. 3 to 0. 6 0 C l. The ten hottest years ever recorded have occurred since 1980

l. Since 1900 the average temperature of the earth’s surface has increased 0. 3 to 0. 6 0 C l. The ten hottest years ever recorded have occurred since 1980. The 5 hottest years on record 1998, 2002, 2003, 2001, 1997…Extreme weather events have increased l. The average temp. is expected to increase 2 -4 o. C in the next century

El Nino i. Is the periodic warming every 2 - 7 years of the Pacific ocean off the coast of Peru. i. This causes a warming of the winds moving north and results in storms/floods off the coast of Calif. and possibly droughts in other parts of the world like Indonesia. 33

Ocean Currents i. Gulf stream, etc. moves warm water on the surface of the ocean north, where it then sinks and returns south. i. Model predictions using 750 ppm CO 2 by the year 2100 could actually shut the gulf stream down. Huge cooling in Europe would be predicted…In 1997 these types of models had not received a lot of credence… there are now a number of supporting studies. i. The model also predict that slower rates of 34 temp. increase would just slow down

Some raw satellite data has suggested: iaverage global temperatures may actually be decreasing i. It was observed, however that the orbits of the satellite was changing. i. After correcting for this, the satellite data showed an increase similar to that observed by other measurements 35

Doubling Emissions of CO 2 i. Often discussed are the effects of doubling CO 2 concentrations from pre-industrial times (2 xpre-Ind. CO 2=550 ppm) i. Some times predications are made with the assumption of CO 2 doubling or even quadrupling. i. On the next slide you will see world wide emissions using different assumptions. 36

Global Models i. Developing predictions of climate change requires the use of computer based models that characterize much as possible of our understanding of the Earth’s climatological processes i. These models are called global circulation models (GCMs) ired= +2. 5 o. C, yellow =+1 o. C, blue = -. 50 C 37

§ In the next slide the impact of doubling CO 2 emissions is explored with a GCM § In the second slide one can see the effects of a quadrupling.

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Including Particles in Global Models i. Fine particles, especially sulfate particles resulting from SO 2 emissions from coal, combustion can reflect light from the sun and actually cause a negative temp. effect i. The next 2 picture from a global circulation model (GCM by Bob Charleston, UW-Wash, USA), shows a cooling effect in the industrialized world. First without considering particles then with ired= +2 o. C, yellow =+3 o. C, blue = +10 C 41

red= +2 o. C, yellow =+3 o. C, blue = +10 C 42

red= +2 o. C, yellow =+3 o. C, blue = +10 C

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Partial verification of the Models came in 1991 u Mt. Pinatubo in the Philippines erupted in June 1991, and added a huge amount of SO 2 and particulate matter the stratosphere. After one year how much SO 2 was left? u. A lot of SO 2 was injected into the atmosphere u This SO 2 formed fine sulfate particles that reflect light back into the atmosphere and this cools the upper troposphere 45

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Other Feedback Processes i. As more water goes into the atmosphere global cloud coverage will increase. This may tend to reflect more light from the sun and cools the earth i. As cold regions warm they will release methane, which is strong green house gas i. Loss of stratospheric O 3 cools the stratosphere; lower O 3 absorbs less light 47

Other green house gases; Freons… i Cl F F C-C Cl i. Sulfur hexachloride is a green house gas which is used the electric utility industry (they purchase ~80% of all produced. 48

SF 6 i. Sulfur hexafluoride (SF 6) has a global warming potential which is 23, 900 times greater than CO 2 i. It has a half-life in the atmosphere of 32000 years and is the most potent green house gas known 49

SF 6 i. Prices have increased recently and commercial equipment exists to recapture it during electrical switch gear maintenance i. Incentive to reduce because a little goes a long way i. Used in the production of Mg; There is pressure to look for another type of process 50

Other Green House Gases i. Methane (CH 4) i. Nitrous oxide (N 2 O) i. Chlorofluoro carbons (CFCs) i. Hydro-CFCs i. SF 6 51

Who is emitting all of this CO 2 i. On the next picture you will per capita emissions of CO 2 i. For the US i. Developing countries i. Former Soviet Union/Eastern Europe (FSU/E. Eu. R) i. Other European Countries (OCED) 52

On a person or percapita basis, the US emits more CO 2 than any other country 53

Per Capita CO 2 Emissions Metric Tonnes per year 6 5 4 3 2 1 0 US Canada Germany World-avg India Australia Russia Japan China

http: //www. theglobaleducationproject. org/earth/energysupply. php 55

Let’s calculate CO 2 emissions from cars and motor cycles u Assume that gasoline can be approximated by the compound hexane which has 6 carbons and 14 H= 86 g/mol u C 6 H 14 + 9. 5 O 2 -> heat + 6 CO 2 + 7 H 2 O u if we burn hexane ---> CO 2; CO 2 has a Mw of 44, but we make 6 x. CO 2 for each hexane; 6 x 44 = 264 g CO 2/mol hexane u we make 3 times the mass of CO 2 per unit mass of hexane burned u hexane has a density of ~0. 8; 1 liter = ~0. 8 kg 56

Let’s calculate CO 2 emissions from cars and motor cycles u. A student at CMU in Thailand will burn about 200 Liters/ year = ~160 kg/year of gasoline uabout 3 times the mass of CO 2 is produced for each unit mass of gasoline burned u. CO 2 = 160 x 3 = ~500 Kg/year= ~0. 5 metric tonnes uif you use a car for more than 2 hours/day = ~ 2 -5 metric tonnes of CO 2/year/person 57

Now let’s go back and see how much a CMU student and a car driver in Thailand emits compared to the rest of the world 58

Per Capita CO 2 Emissions Metric Tonnes per year 6 5 4 3 2 1 0 US Canada Germany World-avg India Australia Russia Japan China

Let’s see how world emissions by country will change in the future; 1 st 1995 and then 2 nd , 2030 60

% CO 2 emissions: 1995 O. Asia (6%) China (11%) USA (22%) Lat. A (4%) Africa (3%) Mid E. (3%) D. Asia (7%) W Eup (17%) FSU (27%)

Between 1995 and 2035, world wide emissions of CO 2 are expected to increase from 6. 5 billion tons to 11. 7 billion tons 62

Between 1993 and 2050, the population of the world was forcasted to increase from 5. 5 billion to ~10 billion people! There are ~ 6 billion people now 63

%CO 2 Emissions in 2035 O. Asia (14%) USA (15%) W Eup (12%) China (17%) Lat. A (6%) Africa (8%) Mid E. (5%) FSU (19%) D. Asia (4%)

CO 2 Emissions, 1995 & 2035 30 25 percent 20 15 10 5 0 USA FSU Mid E. Lat. A O. Asia W Eup D. Asia Africa China 1995 2035

Increasing Global temperatures has the tendency to dry out soils. light green = yellow = brown-red = 10% drying 20 -30% 40% 60%

Loss of soil moisture X 4 CO 2 light green = 10% yellow = 20 -30% brown-red= 40% red = 60% 67

l. Doubling CO 2 would alter world wide grain yields. l. Some places would increase and others decrease, but generally a decrease is predicted.

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l. There may be decreases in food supplies to vulnerable populations l. Next are the forecasts of 3 different models

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l. A general reduction the water table is also predicted.

l. There may be an increase human heat stress.

l. Global warming would also increase the height of the oceans due to glacial melting l. It is expected to rise between 0. 15 and 1 meter over the next 100 years l. Below are some worst case predictions

Red means under water from a 1 meter rise in sea level

What is the world doing? ? u. International Meeting in Kyoto Japan, December 1997. The issues were: Œ How much should the western countries reduce CO 2 emissions? 79

What is the world doing? ? u. International Meeting in Kyoto Japan, December 1997. The issues were: Œ How much should the western countries reduce CO 2 emissions? Should just the industrialized countries reduce in the near future or all countries? 80

What is the world doing? ? u. International Meeting in Kyoto Japan, December 1997. The issues were: Œ How much should the western countries reduce CO 2 emissions? Should just the industrialized countries reduce in the near future or all countries? Ž Emissions Trading? 81

What was decided ? ? u. Six gases would be controlled w CO 2, Methane w nitrous oxide w perflurocarbons and HFCs w SF 6 82

Who would be controlled ? ? u. By the year 2012, collectively the industrialized countries must drop their emissions to 5. 2% below 1990 levels for CO 2, N 2 O and CH 4; The other 3 gases would be reduced by 5. 2% at some later date and baseline u. Impose binding limits on 39 industrialized countries and leave 121 less-developed for voluntary control 83

Who would be controlled ? ? u. The European Union would reduce its emissions to 8% below 1990 emissions u. Japan: -6%, USA: -7% below 1990 levels u. Russia, Ukraine, New Zealand: return to 1990 levels 84

Bubbles and Emission Trading u. The treaty divides the industrialized countries into two “Bubbles” i. Nations that achieve more than their required green house gas reductions in a given bubble, can trade them to those who exceed their limit 85

Bubbles and Emission Trading i. Emission credits forests or planting new ones are allowed, but must increase emission reductions if they have deforested since 1990 86

Other Issues u The USA claims that by 2035 it will only emit a small fraction of the total CO 2 emission (This is one of the rationales from the Bush administration). u The less developed countries say this is absurd, the industrialized countries to date have contributed ~ 70% of the CO 2 to the atmosphere!! 87

In the 1990’s US, President Clinton had some trouble with getting Congress to agree with global warming policies u. Since nobody is really doing anything right now, US emissions will increase by 28% by 2010 u. This means an actual reduction of 550 million metric tonnes is needed!!!! 88

IN the US, President Clinton could have done the following: u more fuel efficient cars and trucks 50 -60 million metric tonnes (we now have SUVs that use a lot of energy and pollute 4 xs as much as modern cars) u Increased house hold energy efficiency of major appliances 30 -50 million tonnes (some of this was started) u Install standby mode circuitry on TVs, VCRs, etc - 8 -10 mil. Tonnes (some started) 89

President Clinton began some of the following u. Re-route heat from elect. utilities into nearby factories - 20 -30 mil. tonnes u. Replace 3 -5% of the fuel in coalburning power plants with paper and crop waste - 15 -25 mil. tonnes uother msic. - ~25 u. Total ~200 mil. tonnes uneeded 550 mil. tonnes 90

President Bush’s Energy Policy, May 8, 2001 in order of importance 1. Oil and gas: Ease restrictions of oil and gas development in public lands; as an example open 8% of the National Wild life Reserve in Alaska 2. Coal: Provide tax incentives for developing new coal technologies and ease clean air regulations 3. Nuclear: speed up licensing of new and old reactors; speed up process to ensure national waste disposal; tax breaks for purchasing of nuclear plants; reauthorize law limiting industry's liability from nuclear accidents 91

President Bush’s Energy Policy, May 8, 2001 Renewable Energy: Tax credits to encourage development of energy plants that use organic waste, biomass and wind 15% tax credit for home owners who use solar panels u Conservation: Tax credit for the purchase of high -mileage gas/electric vehicles; regulatory relief for co-generation of plans producing heat and electricity u Other: look at economic sanctions against Iran to foster energy development and diplomatic efforts to expand oil production in Latin America, Asia and the Caspian Sea u 92

Real options? ? u Use of more gas instead of coal; it produces 1/2 the CO 2 until we figure out clean coal technology u Advanced turbine systems u Modern wind turbines u More efficient cars l fuel cell technology? ? l hybrids l electric vehicles u Serious conservation efforts (This actually worked during the Carter administration) u Biomass fuels? u More Research; more research!!! 93