global warming its causes and effects
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Global Warming
Submitted by:Muhammad khuzaima (14041561-011)
Global Warming
A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants.
Global warming
How global warming work?
Earth transforms sunlight's visible light energy into infrared light energy, which leaves Earth slowly because it is absorbed by greenhouse gases. When people produce greenhouse gases, energy leaves Earth even more slowly – raising Earth's temperature.
How Global Warming Works
Fossil fuels (coal, oil, natural gas)
Carbon Dioxide (CO2)
Causes of Global warming
Greenhouse gasesAerosols and sootSolar activityVariations in Earth's orbitClimate models
Greenhouse
The trapping of the sun's warmth in a planet's lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.
Greenhouse Effect
How does the greenhouse effect work?
Gases in the atmosphere such as carbon dioxide do what the roof of a greenhouse does. During the day, the Sun shines through the atmosphere. Earth's surface warms up in the sunlight. At night, Earth's surface cools, releasing the heat back into the air
What are the Greenhouse Gases?
Many chemical compounds found in the Earth’s atmosphere act as “greenhouse gases.” These gases allow sunlight to enter the atmosphere freely. When sunlight strikes the Earth’s surface, some of it is reflected back towards space as infrared radiation (heat). Greenhouse gases absorb this infrared radiation and trap the heat in the atmosphere.
There are many gases which exist that either directly or indirectly act as greenhouse gases. Furthermore, some gases have more dramatic effects then others.
Direct Greenhouse GasesCarbon Dioxide (CO2)
Carbon dioxide is without doubt the most well known greenhouse gas. It is also the greenhouse gas man contributes to most, primarily through burning fossil fuels. Since the industrial revolution concentrations of carbon dioxide in our atmosphere have increased at an even faster rate.
So how quickly are CO2 levels rising?
Main Sources of CO2
1) Stationary energy consumption (eg. power stations)
- coal fuelled power generation is the worst culprit for carbon dioxide emissions
- Oil and gas fuelled energy generation tends to have a lower carbon dioxide emission but due to its high use, still accounts for about half of all human caused C02 emissions.
- Even those energy generation strategies without apparent use of fossil fuels generally have some associated carbon dioxide emissions. Nuclear power, for instance, relies on large amounts of electricity for fuel processing and so indirectly results in carbon dioxide emissions.
Main Sources of Co2
2) Transportation
- Globally, transport related emissions of carbon dioxide are growing rapidly. The use of petroleum as a fossil fuel for transportation dominates carbon dioxide emissions from this source.
- Despite the rising costs of fuel, fuel consumption levels continue to rise. The large consumption of gas through vehicles is impacted by many factors including the following; number of vehicles on the road, types of vehicles on the road (SUV’s, smart cars, transport trucks, etc), traffic conditions, urban sprawl (distance vehicles have to travel), and maintenance of vehicles (emissions tests, oil changes).
- Energy use (stationary and transportation) are the main contributors to human made CO2.
Direct Greenhouse GasesMethane (CH4)Sources: Natural - Wetlands,
Termites, the OceansHuman Made - Ruminants
(livestock), Waste Treatment, Rice Agriculture, Biomass Burning
Direct Greenhouse GasesNitrous Oxide (N2O) Sources: Natural – The
Oceans, the Atmosphere, SoilsHuman Made – Agricultural soils, Biomass burning, Livestock, Transportation
Other Direct Greenhouse Gases
Tropospheric OzoneWater Vapor (in the stratosphere)CFC’s ChlorofluorocarbonsHFC’s Hydrofluorocarbons Perfluorocarbons (PFCs) and sulphur
hexafluoride (SF6) with atmospheric lifetimes of more than 1000 years.
Indirect Greenhouse Gases
Nitrogen oxides (NOx) act as indirect greenhouse gases by producing the tropospheric greenhouse gas 'ozone' during their breakdown in the atmosphere.
Carbon monoxide (CO) - can lead to the formation of the tropospheric greenhouse gas 'ozone'.
Hydrogen (H2) - hydrogen increases the lifetime of some direct greenhouse gases, such as methane.
Volatile organic compounds or VOCs - encompasses many compounds including hydrocarbons, alcohols, and organic acids. Man-made emissions tend to be concentrated in highly populated areas such as cities
What Might Happen?Cause and Effects
1) Global temperatures will rise!!!
Is the climate warming? YES!
Global surface temperatures have increased about 0.6°C since the late-19th century, and about 0.2 to 0.3°C over the past 25 years
How about each year, how hot is it really getting? Lets take a look at the average temperatures since the 1880’s and see the projections of where we are going.
Then we can look at the top 20 hottest ever recorded yearly temperatures!
The 20 Hottest Years on Record
3) Drought
An increase in the occurrence of drought – Areas that lack precipitation over a long period of time.
As fast as global warming is transforming the oceans and the ice caps, it's having an even more immediate effect on land.
4) Extreme Weather
As the world warms, some extreme climate events, like the frequency of heat waves and very heavy precipitation, are expected to increase.
Blizzards and snow storms may actually increase in intensity and frequency in some colder locations
As climate change gathers pace, devastation caused by extreme weather is becoming more common.
Bushfires are becoming more and more common due to intense heat and long periods without precipitation. Bushfire numbers are especially on the rises in countries like the US and Australia
Tornadoes are increasing in number and in severity, perhaps an effect of global warming
Hurricanes are increasing in numbers and in severity, Hurricanes require warm ocean temperatures in order to form.
Effects of Global WarmingIncreased Temperature
Habitat Damage and Species Affected
Changes in Water Supply
Rising Sea Level
What’s the proof that global warming is taking place?
Portage GlacierAlaska
1914 2004
Colorado RiverArizona
June 2002 Dec 2003
So how can each of us slow global warming now?
Replace a regular incandescent light bulb with a compact fluorescent light bulb
Don’t let heat escape from your house over a long period
Cover your pots while cookingUse the washing machine or dishwasher
only when they are full
So how can each of us slow global warming now?
Take a shower instead of a bathUse less hot waterRecycle your organic wasteReuse your shopping bagPlant a treeSwitch to green power