PowerPoint Presentation
GLOBALCLIMATE CHANGEWhat is it?
Global Climate ChangeIdentifiable change in the climate of Earth
as a whole that lasts for an extended period of time (decades or
longer) When due to natural processes, it is usually referred to as
global climate variabilityUsually refers to changes forced by human
activities that change the atmosphereWhat causes Earths climate to
change?Changes in the atmosphereNatural processesVolcanoes Tectonic
plate movementChanges in the sunHuman activities any activity that
releases greenhouse gases into the atmosphere
Greenhouse Effect & Global warming
What are greenhouse gases?carbon dioxidenitrous
oxidemethanewater vapor
GLOBAL WARMING IS CAUSED BY:
THE GREENHOUSE EFFECT!So what is a greenhouse? How does it work?
What has this got to do with global warming then??REMEMBER....The
greenhouse effect is NATURAL! It is supposed to happen! It would
happen even if there was not a human being on the planet! In fact
if there was no greenhouse effect then humans could not live here
as the planet would be 33c colder and would look like and be as
cold as Mars!
So it's us that turns the GREENHOUSE EFFECT intoGLOBAL
WARMING!!!But HOW!?!?!
GLOBAL WARMING
Think about the greenhouse as if it was the planet and this
is.So what is GLOBAL WARMING then?Unfortunately human activity is
adding more gas to the layer than there should be. It is therefore
getting thicker and thicker. It is still able to let the suns heat
through but even less heat is escaping back into the atmosphere.
This means that the earths temperature is rising.
Human activity is adding more gases to the naturally occurring
layer of greenhouse gases. This thickens it so it cannot let as
much heat return to space and so the temperature of the earth
gradually increases GLOBAL WARMING!What are greenhouse gases?
Name of gasContributionSource(s)Carbon dioxide(CO2) 50%From
burning coal and oil, and the removal of
vegetationChlorofluorocarbons(CFCs) 20%From air conditioners,
refrigerators and aerosolsMethane(CH4) 16%From rice growing, animal
waste, swamps and landfillsOzone(O3) 8%From air pollutionNitrous
oxide(N2O) 6%From fertilizers and burning of coal and oil
As you can see the main culprit isCARBON DIOXIDE
So where are these gases coming from?
Power stations release huge amounts of carbon dioxide as they
burn coal (a fossil fuel) in order to produce electricity.Just
think for a moment about how much electricity we all
use..!ELECTRICITY
But who are the main culprits.?
Its many LEDCsThey are currently experiencing their industrial
revolution and are becoming the greatest users and producers of
electricity and are burning huge quantities of fossil fuels to keep
their booming industries going. This is creating masses of
pollution and contributing greatly to global warming. China and
India are particular bad contributors to global warming.
ObservedChanges and EffectsWarming of ClimateWarming of the
climate is definitely occurring and can be observed by
the:Increases in global sea and air temperatures Widespread melting
of snow and iceRising global sea level
Temperature Change Data
1880-1884
1880-1884
1886-1890
1896-1900
1906-1910
1916-1920
1926-1930
1936-1940
1946-1950
1956-1960
1966-1970
1976-1980
1986-1990
1996-2000
2003-2007Other Observed Changes and Effects89% of current
changes in ecosystems are consistent with changes expected due to
global climate changeCarbon dioxide, methane, and nitrous oxide
levels in atmosphere have increased greatly due to human activities
since 1750 and now far exceed previous levelsCarbon dioxide has
increased by approximately 80% since 1970But what are the real
consequences of global warming for us all?
ICE CAPS MELTING AND SEA LEVEL RISEGlobal warming causes the
polar ice sheets melt. It increases the sea-level. It will possibly
rise 18 cm by 2030 and 58 cm by 2090. Flooding will probably occur
in lowlands. Many cities along the coast may be under sea
water.
The loss of polar ice will have a profound effect on nature in
particular animal habitats.
7 METRE RISE13 METRE RISE84 METRE RISESea level rise around the
world is going to leave many people homeless!Many of the worlds
islands are already disappearing beneath the sea.
The tiny island nation of the Maldives is in trouble. If global
warming continues, say scientists, the country could sink beneath
the ocean within 100 years. The average height of the islands above
sea level is 1.5 metres and the rate of sea level rise is currently
59cm per century.
Tuvalu is found in the ocean near Australia. Most of Tuvalu is
less than one metre above seal level.
Most of the observed increase in global average temperature
since the mid-20th century is very likely due to the observed
increase in human-caused greenhouse gas concentrations and human
influences have very likely contributed to sea level rise, too.
