1) The document discusses the evidence and impacts of climate change, including rising global temperatures, extreme weather events, and effects on ecosystems and human health and society. 2) Key drivers of climate change identified are greenhouse gas emissions from burning fossil fuels and deforestation which increase atmospheric CO2 and global temperatures. 3) Impacts of climate change discussed include melting ice sheets and glaciers, rising sea levels, ocean warming and acidification, and threats to food production and biodiversity.

1. Module 13

2. Why Should You Care
About Climate Change?
For approx. 10,000 years climate fairly stable (maybe)
- Since 1980 temperatures rising
- Climate change
- 2,500 top scientists, 29,000 data sets
- Century of rapid climate change
- Likely due to burning of fossil
fuels/deforestation/cement production
- Climate change will affect other things
- Shifting water availability
- Heat waves
- Food production
- Extinctions

3. Figure 13.1 p350
Two possible consequences of projected climate change during this century
are (a) crop losses from excessive heat and lack of water in some areas and
(b) prolonged and heavy flooding in other regions such as this area of
Thailand that suffered heavy rains in 2011.

4. What Do You Need to Know?
Weather and Climate
Weather and climate
- Weather is short-term
- Easy to recognize
- Climate is average during seasons
- Requires long-term records
- Single hot summers or single cold winters do
not predict climate change

5. The Earth’s Major Climate Zones
Earth’s climate into zones
- Differences in average temperature and
precipitation
- Tropical
- Temperate
- Polar
- Heat/sunlight and moisture distributed unevenly
- Unevenness/Gradient causes movement
- Ocean currents/drifts
- Winds
- Hadley, Ferrel and Polar Rotations/Cells

6. Figure 13.2 p351
This map shows the earth’s major climate zones along with major warm and cold
ocean currents that distribute some of the earth’s moisture and heat.

7. Figure 13.3 p352
Three climate zones—tropical, temperate, and polar—are created by uneven solar heating
of the planet, the rotation of the earth on its axis, and the resulting prevailing winds and
ocean currents that distribute heat and moisture unevenly around the globe.

8. Atmospheric Warming and
Cooling
Life depends on natural Greenhouse Effect
- Heat trapped keeps earth warmer
- Greenhouse gases
- Water
- Carbon dioxide
- Methane
- Nitrous oxide
- Climate has changed in past (warmer and cooler)
- Current rate of change may be unprecedented

9. Environment, Fourth Edition by Peter H. Raven
and Linda Berg.
The Greenhouse Effect

10. Figure 13.5 p353
These maps show the changes in ice coverage in the Northern
Hemi-sphere during the past 18,000 years.

11. Figure 13.8 p355
Scientists study ice cores, such as this one (a) obtained by drilling a deep hole in an
Antarctic glacier. Thousands of such cores from around the world are stored at (b)
the U.S. National Ice Core Center in Denver, Colorado.

12. Figure 13.4 p353
This graph shows the estimated global average temperatures of the
atmosphere near the earth’s surface over 900,000 years.
Vostoc Ice Core Data

13. Past Temperatures and Key Greenhouse Gas Concentrations

14. Figure 13.9 p355
This graph shows the global average temperature of the
atmosphere at the earth’s surface between 1980 and 2011.

15. Carbon Dioxide and Climate
CO2 plays important climate role
- Increase in CO2, increases temperature
- Long-term impacts
- Effect recognized 100 years ago
- Svante Arrhenius, Swedish chemist (1894)
- postulated mankind was adding CO2 to
atmosphere faster than Carbon Cycle can “handle”
- Vostok Ice Core data is the key to the historic record

16. Carbon Cycle
(black numbers are reservoirs and purple numbers are fluxes)
Visionlearning.com

17. Figure 13.7 p353
These graphs compare changes in the estimated average atmospheric
temperatures and CO2 levels during the last 400,000 years

18. How Scientists Study Climate
Several ways to estimate previous climate
- Tree rings
- Ancient fossils
- Marine sediments
- Air bubbles in ice cores
- Climate measured daily since 1982
- Build/run Models to predict climate trends
- Compare model runs to Vostok/other data

19. What Are the Problems?
Rapid Atmospheric Warming
Mounting scientific evidence of rapid warming
- IPCC (Inter-governmental Panel on Climate Change)
- Four reports 1990, 1995, 2001, 2007
- Three basic conclusions
- Since 1980 lower atmosphere has warmed
- Computer models indicate due to human
activities
- Climate currently changing, will continue

20. Figure 13.10 p356
This graph represents the measurements of CO2 levels in the atmosphere at
Hawaii’s Mauna Loa Observatory, 1958 – 2011. (The Mauna Loa Record)

21. Figure 13.11 p356
This diagram is a simplified summary of some of the factors built into models of
the earth’s climate system. Red arrows show processes that warm the
atmosphere and blue arrows show those that cool the atmosphere.

22. Figure 13.12 p357
These graphs show climate model projections of global average atmospheric
temperature changes relative to the actual measured temperature changes
between 1901 and 1997. The models were used to make projections using (a)
only natural factors and (b) the combination of natural and human factors.

23. Human Activities and Climate
Change
CO2 major man-caused greenhouse gas
- 1850, 285 ppm CO2
- 2011, 393 ppm CO2
- Likely to rise much more
- Potential for a "tipping point“ (450 ppm?)
Soot (black carbon) also contributes
- Absorbs sunlight
- Settles out quickly
- Constant input has impact
Most think that Fossil fuels and deforestation responsible
for the increase in global temperatures since 1980.

24. Figure 13.14 p360
By (a) burning coal in power and industrial plants and (b)
burning gasoline and diesel fuel in motor vehicles, we emit
large quantities of CO2 into the atmosphere.

25. Figure 13.15 p361
In Brazil’s Amazon basin, large areas of tropical forest are burned every year
to clear land for plantation crops and livestock grazing. These fires emit huge
quantities of CO2 into the atmosphere.

26. Melting Ice
Warming has major effect in polar regions
- Increase 5-7 deg. F
- Twice as fast as world average
- Oceans transfer heat toward poles
- Sea ice melting
- Greenland ice sheet melting
- Increase in sea level by 23 feet if it all
melted
- 1850, Glacier National Park had 150 named
glaciers, now it has 25.

27. Figure 13.20 p364
Much of the Muir Glacier in Alaska’s Glacier Bay National Park
and Preserve melted between 1948 and 2004, and it continues
to melt today.

28. Figure 13.18 p363
Partial melting at the edges of the land-based ice sheet in Greenland increased
dramatically between 1982 and 2007.

29. Melting Permafrost
Permafrost (frozen soils) has large amounts of
methane (CH4) trapped
- Melting can release it
- Been frozen for thousands of years
- Much more potent greenhouse gas than CO2
- Although is shorter lived in atmosphere

30. Figure 13.21 p364
Ice forms in underground layers of frozen soil called permafrost
(a), in polar regions such as this area of Arctic tundra (b). These
areas have held stores (Peat) of methane and carbon dioxide
for thousands of years.

31. Rising Sea Levels
Glaciers melting, sea levels must rise
- Thermal Expansion; warming water expands,
occupies larger volume
- Sea level may rise 3-6.5 feet this century
- Keep rising for additional time
- Coastal ecosystems flood
- Many people live in threatened areas

32. Figure 13.22 p365
Projected climate change could submerge Male, the capital city of the
Maldives, along with the 1,200 other small islands that make up this
nation in the Indian Ocean.

33. Figure 13.23 p366
Areas of Florida, shown here in red, will likely be flooded if the
average sea level rises by 3 feet.

34. Ocean Warming and
Acidification
Atmosphere temp increase raises ocean temperature
- Bleaching of coral
- Changes in habitats
CO2 dissolves in water forms carbonic acid
- Much CO2 emissions dissolve in ocean water
- Ocean acidification
- corals/mollusks can’t form shell
Healthy coral reefs serve as
habitats and food sources for an
amazing variety of marine species.
Figure 13.24 p366

35. Extreme Weather Events
and Worsening Drought
Climate change may cause extreme weather events
- Intense and longer heat waves
- Damaging storms
- Extreme cold and blizzard conditions
- More flooding
Some areas drier
- Warmer atmosphere can hold more water
- 45% earth may experience droughts
- More forest fires

36. Changes to Food Production
Some Areas Could Improve
- Canada, Russia, Ukraine
- Agriculture may decline around the world
- More serious pests
- Higher food prices
- Increase in food production in cooler areas
- Decline in tropical/temperate areas
- Possible international conflicts over resources

37. Threats to Human Health
Potential effects on human health
- Few deaths due to extreme cold
- Intense heat waves
- Higher CO2 favors insects, disease vectors
- Diseases more frequent
- Tropical diseases may spread
- Hunger/malnutrition
- Photochemical smog

38. Declining Biodiversity
Major environmental problems
- Loss/shift of habitats
- More extinctions
- Shifts in plant and animal ranges
- many tropical species or moving towards
poles and greatly expanding range
- Increased diseases
- Impacts of fires
- IPCC, 1 out of three species will go extinct if
global temps increase by 2.7-4.5 deg. F

39. Figure 13.25 p368
Because of warmer winters, populations of mountain pine beetles
have exploded and munched their way through large areas of (a)
whitebark pine forests (orange-colored trees that are dead or dying)
in Yellowstone National Park in the United States, and (b) lodgepole
pine forests in the Canadian province of British Columbia.
.

40. The Range of Projected Effects
Several climate-model projections
- Some degree of change now unavoidable
- How much caused by humans is debated
- Urgent problem currently
- Range of effects depends may depend on
changes mankind makes now and in future

41. Figure 13.26 p369
These are some of the projected impacts of climate change based on
average global CO2 levels and atmospheric temperatures.

42. What Can Be Done
Two General Strategies
Best to reduce greenhouse gas emissions quickly
- Current practices are leading to climate change
- Reduction by at least 40%
- Reductions would decrease severity later
- Change would continue for some time
- Reduction of energy waste is key
- Shift to low carbon sources of energy
Mitigate effects of climate change
- Move plant species to more suitable areas
- Redistribute Agriculture

43. What Can Be Done
Two General Strategies
Mitigate effects of climate change (continued)
- Earth’s climate may also be engineered
- Carbon sequestration strategies
- Millions of trees/wetlands
- Caves/caverns filled with Carbon
- Ocean fertilization/iron-ization
- Phytoplankton explosion
- Global dimming strategies
- Mirrors
- Sulfate particles in upper atmosphere

44. Figure 13.28 p373
Various geoengineering schemes have been proposed in hopes
of warding off climate change or offsetting its harmful impacts.

45. Enacting an International
Agreement and Sharing Technology
Countries working together to slow climate change
- 2007 Kyoto Protocol
- 191/194 countries signed
- Requires emissions to be sharply cut
- No requirement for China (#1) and India
- Negotiations failed in 2011
- U.S. failed to participate
Taxing CO2 emissions
Market-based approaches
Key is slowing population growth

46. Figure 13-29 p376

47. Figure 13.30 p376
Weighing the pros and cons of cap-and-trade.

48. Some Encouraging Progress
Dealing with climate change has been difficult
- Do not want to change way of life
- Waiting for technological fix
- Skepticism
- Changes appear to be coming
- U.S. cities and states planning for climate
change

49. Figure 13.31 p377
The Environmental Living and Learning Center at Northland College in Ashland,
Wisconsin, makes use of renewable energy sources.

50. Harmful and long-lasting effects
- Time to act is now
- Need to reduce emissions by 40% to start
- 80% would be better
- Climate assumptions may not be correct
- What happens if it is worse?
A Look to The Future: A Narrow and
Closing Window of Opportunity

51. What Would You Do?
At home
• insulate home,
seal air leaks
• energy efficient
windows
• energy efficient
appliances, bulbs
• efficient hot
water heating
Transportation
• walking, biking,
and taking public
transportation
• carpools
• energy-efficient
vehicles
Purchases
• eat less meat or
no meat
• buy reusable or
recyclable
products
• minimize
packaging
• patronize
companies that
minimize effects