Potential and realized consequences of climate change include: 1) Drought, melting ice, rising sea levels, and permafrost melt are already occurring as a result of climate change. 2) Additional potential consequences that some experts say may already be happening include altered ocean circulation patterns and more extreme weather events. 3) Further potential consequences include threats to biodiversity like coral bleaching and disrupted animal migration patterns, shifting agricultural production, and risks to human health from factors like heat waves.

1. Possible Effects of aPossible Effects of a
Warmer PlanetWarmer Planet
Ch. 19,
part 2
Gaby, I
need to
talk to you

2. What do I need to know about
climate change?
 What evidence do we have?
1. What are some of the potential and realized
consequences of a changing climate?
2. What are the challenges to addressing climate
change? (why is it so hard?)
3. What are some of the ways we can combat
climate change (i.e. halt it and/or reverse it)
4. What have we already done? Did it work?

3. Consequences
Realized
 Drought
 Melting ice
 Sea level rise
 7 consequences
 Permafrost melt
Potential?
 Altered thermohaline
circulation
 Extreme weather
 Extinctions
 Coral bleaching
 Altered migratory patterns
 More pests
 Shifting ag
 Threats to human health

5. Which first? The good news or
the bad news?

6. Why do we care about a few degrees?
 NOT weather
 Not just concern about the temp
 Concern about how quickly it is occurring
 Fast change means we need to quickly adjust to:
• Where we grow food
• New areas experiencing drought, new areas experiencing flooding
• Where people live
• Wildlife and biodiversity

7. What the experts are saying
Global warming and the resulting
climate change must be viewed
as a serious threat to global
stability and should be elevated to a U.S.
national security concern
Peter Schwartz,
Doug Randall, US
DOD

8. What the experts are saying
In my view, climate change is the most
severe problem we are facing today -
more serious even than the threat
of terrorism.
Sir David King, UK Chief
Science Advisor

9. What the experts are saying
The effects will be catastrophic -
on the level of nuclear war
International
Institute for
Strategic Studies
- works with
military on
security issues

10. What the experts are saying
A 2°C warming is inevitable -
we have waited too long to
prevent it and ignored the warnings
from prestigious committees
of climate scientists for more than
25 years

11. Realized Consequences
it‘s already happening…

12. The Tipping Point
 The point at which a
series of small
ineffective changes
acquires enough
pressure or
importance to cause
a larger, more
significant change

13. Bad News: Severe Drought is
Increasing
 Drought - evaporation from high
temps exceeds precipitation
 Less soil moisture
 Less surface water
 Less photosynthesis so less CO2
out of air
 More fires  more CO2
 Water tables drop
 1-3 billion people face water
shortages
 Decrease in biodiversity

14. Bad News: Ice and
Snow are Melting
 Ice reflects light back
 As ice melts - exposes more
dark soil
 Dark absorbs heat --> warmer -->
melts more ice
 Many people rely on snow melt
for freshwater
 Loss of mountain glaciers means
loss of freshwater
• Alps, Ganges River, Yangtze and
Yellow River in China, Glacier
National Park

16. Bad News: Sea Levels are
Rising
 IPCC - average sea
level very likely to rise
18-59 cm (.6 - 19 ft)
during this century
and to continue to rise
for centuries to come
 Expansion of water
 Melting ice

17. What effect: rising sea levels?
 Degrade or destroy ~1/3 of the world’s
coastal, estuary, coral reefs

18. What effect: rising sea levels?
 Disrupt
marine
fisheries
 Changes
where
fish are

19. What effect: rising sea levels?
 Flood and loss of low lying barrier islands

20. What effect: rising sea levels?
 Flooding of ag land where most of the rice
is grown

21. What effect: rising sea levels?
 Contamination of freshwater coastal
aquifers with saltwater & less
groundwater for irrigation, drinking,
cooling power plants

22. What effect: rising sea levels?
 Submergence of low lying islands - home
to 5% of the world’s people (350 million
people)

23. What effect: rising sea levels?
 Flooding of coastal areas including world’s largest
cities in China, India, Japan, Bangladesh, Vietnam,
Indonesia, Egypt, USA
 More than 100 million people affected

24. Bad News: Permafrost is
melting
 LOTS of carbon trapped in permafrost
 50-60X the amount of CO2 we put in the air
 When permafrost melts - lots more CO2 and
CH4 added to atm.
 Positive feedback
loop

25. Potential Consequences
Some experts say we
are already
experiencing these…
but scientists still
saying maybe

26. Bad News- Ocean Currents are
Changing…
 Threat Unknown
 Less O2 delivered to ocean bottom
 Changing climates worldwide

27. Bad News: Extreme Weather
will Increase in some areas
 Heat waves and droughts in
some areas
 Prolonged rains and flooding
in other areas
 More extreme storms
 Hurricanes Katrina and Rita,
Super Storm Sandy

28. Bad News: Global Warming is a
Major Threat to Biodiversity :’(
 Most susceptible ecosystems
 Coral reefs
 Polar seas
 Coastal wetland
 High-elevation mountaintops
 Alpine and arctic tundra

29. Bad News: Coral Bleaching
Warmer water kills coral

30. Bad News: Migration timing
gets thrown off
 Migratory animals - 1000s of
years of biological clock timing
 Mismatch between when
animals arrive and when food is
available

31. Exploding Populations of Mountain Pine
Beetles in British Columbia, Canada
Bad News: Climate change favors pest
organisms (like disease causing insects,
molds, fungi, mosquitos)

32. Bad News: Climate Change will Shift
Areas where crops can be grown
 Farming depends on a stable
climate
 Regions of farming may shift
 Decrease in tropical and
subtropical areas - poor areas
already
 Increase in northern latitudes
• Less productivity; soil not as fertile
 For awhile, food productivity will
increase due to longer growing
season
 Genetically engineered crops

33. Bad News: Climate Change will
threaten human health
 Deaths from heat waves will
increase
 2003 - 52,000 people died from
heat wave in Europe
 Deaths from cold weather will
decrease
 Higher temperatures can cause
 Increased flooding
 Increase in some forms of air
pollution, more O3
 More insects, microbes, toxic
molds, pollen, and fungi