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
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
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
15.
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
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
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