Possible Effects of a Possible Effects of a Warmer Planet Warmer Planet Ch. 19, part 2 Gaby, I need to talk to you
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Possible Effects of a Possible Effects of a Warmer PlanetWarmer Planet
Ch. 19, part 2
Gaby, I need to talk to you
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?
ConsequencesRealized 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
Which first? The good news or the bad news?
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
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
What the experts are saying
In my view, climate change is the most severe problem we are facing today -
more serious even than the threatof terrorism.
Sir David King, UK Chief Science Advisor
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
What the experts are sayingA 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 than25 years
Realized Consequencesit‘s already happening…
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
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
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
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
What effect: rising sea levels? Degrade or destroy ~1/3 of the world’s
coastal, estuary, coral reefs
What effect: rising sea levels? Disrupt
marine fisheries
Changes where fish are
What effect: rising sea levels? Flood and loss of low lying barrier islands
What effect: rising sea levels? Flooding of ag land where most of the rice
is grown
What effect: rising sea levels? Contamination of freshwater coastal
aquifers with saltwater & less groundwater for irrigation, drinking, cooling power plants
What effect: rising sea levels? Submergence of low lying islands - home
to 5% of the world’s people (350 million people)
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
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 feedbackloop
Potential Consequences
Some experts say we are already experiencing these…but scientists still saying maybe
Bad News- Ocean Currents are Changing…
Threat Unknown Less O2 delivered to ocean bottom Changing climates worldwide
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
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
Bad News: Coral BleachingWarmer water kills coral
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
Exploding Populations of Mountain Pine Beetles in British Columbia, Canada
Bad News: Climate change favors pest organisms (like disease causing insects, molds, fungi, mosquitos)
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 more tolerant to drought
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
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