1. Climate Change
Climate Change

2. Questions Are global warming and climate change the same thing?
What is the difference between climate and weather?
What is the greenhouse effect?
What is the most abundant greenhouse gas?
Is climate change real?
What evidence is there for climate change?
Does the hole in the ozone layer cause climate change?

3. What’s the Difference? Global Climate Change
Any significant change in measures of climate (temperature, precipitation, or wind) lasting for an extended period (decades or longer)
Global Warming
Average increase in the temperature of the atmosphere, which can contribute to changes in global climate patterns.

4. Weather vs. Climate Weather Climate Short-term (minutes to months)
changes in the atmosphere
Climate
Long-term average pattern of weather in a particular area
Typically use 30 years of data

5. Greenhouse Effect
Earth’s average temperature would be 0°F without the greenhouse effect compared to the average temperature of 60°F that we experience.

6. Greenhouse Gases Water Vapor: 0-4% Carbon Dioxide (CO2): 0.036%
Methane (CH4): %
Nitrous Oxide (N2O): %
CFCs, HFCs, SF6

7. Global Greenhouse Gases

8. Evidence

9. Carbon Dioxide Levels in Relation to Global Temperature

10. Key Indicators Sea level Land Ice Carbon Dioxide Concentration
Timing of the seasons
Global Surface Temperature
Allergy season
Snowfall/Snowpack
Arctic Sea Ice

11. Ragweed Pollen Season
These trends are strongly related to changes in the length of the frost-free season and the timing of the first fall frost.

12. Cherry Tree blossom
Peak bloom date from main cherry trees in the Tidal Basin in Washington, D.C. Peak bloom date occurs when 70% of blossoms are in full bloom. Since 1921, peak bloom dates have shifted earlier by 5 days.

13. First Freeze
Freeze dates have shifted later by a rate of half a day to one day per decade.

14. Bird Migration
Trends of northern movement are closely related to increasing winter temperature

15. Radiative Forcing
Greenhouse gases produced by humans have caused overall warming influence on Earth’s climate since Carbon dioxide is by far the biggest contributor.

16. Evidence Sea Level Rise Global Temperature Rise
Global sea level rose 17 cm (6.7 in) in the last century
Rate in the last decade nearly double that of the last century
Global Temperature Rise
Earth has warmed since 1880 with most of warming occurring since the 1970s
20 warmest years occurred since 1981
10 warmest years occurred in the past 12 years

17. Evidence Warming Oceans Shrinking Ice Sheets
Top 700 m (2,300 ft) of ocean showing warming of 0.302°F since 1969
Shrinking Ice Sheets
Greenland: lost km3 (36-60 cubic miles) of ice per year between 2002 and 2006
Antarctica: lost 152 km3 (36 cubic miles) of ice between 2002 and 2005

18. Evidence Declining Arctic sea ice Glacial retreat
Extent and thickness of Arctic sea ice has declined rapidly over last several decades
Glacial retreat
Retreating almost everywhere around the world including Alps, Himalayas, Andes, Rockies, Alaska, and Africa

19. Evidence Extreme Events Ocean Acidification
Number of record high temps increasing since 1950
Number of record low temps decreasing since 1950
Increasing numbers of intense rainfall events
Ocean Acidification
CO2 content of oceans increasing since 1750
Currently increasing 2 billion tons per year
Increased ocean acidity by about 30%

20. IPCC Intergovernmental Panel on Climate Change
Group of scientists from around the world that review and assess information on climate change
Climate models
and projections

21. Projections for North America
Decreasing snowpack
in the western mountains
5-20% increase in yields
of rain-fed agriculture in
some regions
Increased frequency, intensity and duration of heat waves

22. Projections for Latin America
Gradual replacement of tropical forest by savannah in eastern Amazon
Risk of significant biodiversity loss through species extinction in many tropical areas
Significant changes in water availability for human consumption, agriculture, and energy generation

23. Projections for Europe
Increased risk of inland
flash floods
More frequent coastal
flooding and erosion
Glacial retreat in
mountainous areas
Reduced snow cover
and winter tourism
Extensive species losses
Reductions of crop
productivity in South Europe

24. Projections for Africa
By 2020, million
people are projected to be
exposed to increased
water stress
Yields from rain-fed
agriculture could be reduced
by up to 50% in some regions
by 2020
Agricultural production,
including access to food,
may be severely compromised

25. Projections for Asia
Freshwater availability projected to decrease by 2050
Coastal areas at risk for increased flooding
Death rate from disease associated with floods and droughts expected to rise

26. Wisconsin’s Climate 1950-2006 Average temperature increased 1.5°F
Greatest amount of warming in winter and spring, especially NW Wisconsin
Nighttime lows warming faster than daytime highs, especially in summer
Decline in extremely cold winter nights, especially in NW Wisconsin
Date of last spring freeze occurring 6-20 days earlier
Date of first fall freeze occurring 3-8 days later
Growing season increased up to 4 weeks
Annual average precipitation increased 15% although parts of the North became drier

27. Wisconsin’s Future Climate Projections
4-9°F increase by mid-21st Century
Warming most pronounced in winter
Fewer extremely cold winter nights and more hot summer days
Probability of greater than 3 in. rainstorms will increase during spring and fall

28. Projected change in the frequency of 2 inch precipitation events (days/decade) from 1980 to 2055
Projected change in the frequency of 90°F days per year from 1980 to 2055

29. Projected change in average winter temperature from 1980 to 2055
Projected change in annual temperature from 1980 to 2055

30. Madison Lakes Ice cover

31. Temperature Change

32. Shipping on the Great Lakes