Global WarmingGlobal Warmingand Climate Changeand Climate Change

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TruthTruthThe globe is warming.The globe is warming.

ConsequencesConsequences

So what are the possible So what are the possible consequences (to the climate and consequences (to the climate and the Earth’s ecosystems) of global the Earth’s ecosystems) of global warming?warming?

Extreme Weather: Heat Extreme Weather: Heat WavesWavesA A heat waveheat wave is a prolonged period of is a prolonged period of

excessively hot weather, which may result excessively hot weather, which may result in crop failures and deaths from in crop failures and deaths from hyperthermiahyperthermia (heat stroke). (heat stroke).

The 2003 European heat wave killed an estimated 35,000 people.

Extreme Weather: DroughtExtreme Weather: Drought

Areas near deserts (e.g. much of Areas near deserts (e.g. much of Australia) are particularly vulnerable Australia) are particularly vulnerable to to droughtdrought..

Extreme Weather: WildfiresExtreme Weather: Wildfires

Heat waves and drought conditions Heat waves and drought conditions also contribute to also contribute to wildfireswildfires..

2009 wildfires in Kelowna, British Columbia forced the evacuation of 17,000 people.

Positive Feedback LoopsPositive Feedback Loops

This can accelerate global warming in a This can accelerate global warming in a positive feedback looppositive feedback loop: :

wildfires add greenhouse gases to the wildfires add greenhouse gases to the atmosphere and remove COatmosphere and remove CO22-absorbing -absorbing trees.trees.

Positive Feedback LoopsPositive Feedback LoopsThe thawing of The thawing of permafrostpermafrost, releasing , releasing

methane, is another example of a positive methane, is another example of a positive feedback loop.feedback loop.

Extreme Weather: StormsExtreme Weather: Storms

Global warming can also lead to Global warming can also lead to increased evaporation and more increased evaporation and more intense storms.intense storms.

Hurricane Katrina strikes New Orleans, Aug 2005

Extreme Weather: FloodingExtreme Weather: Flooding

These storms can result in flooding, These storms can result in flooding, particularly in areas that have particularly in areas that have developed wetlands.developed wetlands.

July 2010 flash flooding in Montreal

Loss of Glacial RunoffLoss of Glacial RunoffMelting of Melting of glaciersglaciers has been a problem has been a problem

for many people around the world who for many people around the world who depend on runoff for their water depend on runoff for their water supply (and hydroelectric power).supply (and hydroelectric power).

Mount Kilimanjaro ice cover

Loss of Glacial RunoffLoss of Glacial RunoffMelting of Melting of glaciersglaciers has been a problem has been a problem

for many people around the world who for many people around the world who depend on runoff for their water depend on runoff for their water supply (and hydroelectric power).supply (and hydroelectric power).

Mount Kilimanjaro ice cover

Loss of Glacial RunoffLoss of Glacial RunoffThis is a particular problem in the This is a particular problem in the

Himalayas, since Himalayas, since 40% of the world’s 40% of the world’s populationpopulation is dependent on the rivers that is dependent on the rivers that drain the Himalayas.drain the Himalayas.

Global Sea Level RiseGlobal Sea Level RiseSome areas like Some areas like

Bangladesh, however, Bangladesh, however, are at greater risk from are at greater risk from rising sea levelsrising sea levels, , which are caused by which are caused by melting of the ice caps, melting of the ice caps, e.g. over Greenland.e.g. over Greenland.

Global Sea Level RiseGlobal Sea Level Rise

Slow Ocean CurrentsSlow Ocean CurrentsMelting freshwater also affects ocean Melting freshwater also affects ocean

currents; currents;

it is predicted that ocean currents it is predicted that ocean currents (including the Gulf Stream that warms (including the Gulf Stream that warms the East Coast) will slow down or even the East Coast) will slow down or even stop.stop.

Ocean Ocean WarmingWarming

Ocean warming is a Ocean warming is a problem not only problem not only because it because it produces more produces more intense hurricanes intense hurricanes and because the and because the expanded water expanded water causes further causes further rises in sea levels rises in sea levels but also because but also because warmer water warmer water absorbs less COabsorbs less CO22 – – another positive another positive feedback loop.feedback loop.

Ocean WarmingOcean Warming

Warmer water is Warmer water is also not ideal for also not ideal for photosynthesiziphotosynthesizing algae – the ng algae – the producers of producers of aquatic food aquatic food webs.webs.

Threatened SpeciesThreatened SpeciesAbout 40-70% of all species are at risk of About 40-70% of all species are at risk of

extinction if the global temperature extinction if the global temperature increases by only 3.3increases by only 3.3ooC.C.

Not-So-Threatened SpeciesNot-So-Threatened SpeciesThough some species seem to be increasing Though some species seem to be increasing

their populations and expanding their their populations and expanding their ranges, such as jellyfish and malaria-ranges, such as jellyfish and malaria-carrying mosquitoes.carrying mosquitoes.