Global Warming

Global Warming:

Global Warming Group Members NS Jawad Ijaz NS Muhammad Afnan NS Muhammad Umer NS Waqar Ahmed NS Ali Moaaz NS Muhammad Salman Zubair

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INTRODUCTION

Our Focus :

Our Focus Global warming – Overview Causes of global warming Evidences of global warming Effects of global warming Control global warming

What is global warming? Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth OR Global warming in when the earth heats up i-e The temperature rises. :

What is global warming ? Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth OR Global warming in when the earth heats up i -e The temperature rises.

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BRIEF HISTORY OF GLOBAL WARMING The hypothesis of global warming has existed since the 1880,s.  It was not until 1960 when scientists started to realize the long term hazards of global warming in terms of threat to the world supply of food and the increased level of oceans.As there were a lot of complexities associated with it. However, the dawn of 21st century evolved the fact that the climate changes would be harmful for the globe especially for certain regions.

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The sun’s heat can get into the car through the windows but is then trapped. and the heat builds up, just like it does in the earth’s atmosphere. EXAMPLE

How Global Warming Works:

How Global Warming Works Fossil fuels (coal, oil, natural gas) Carbon Dioxide (CO 2 )

WHAT IS GREEN HOUSE EFFECT?:

WHAT IS GREEN HOUSE EFFECT? The phenomenon whereby the earth's atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through but absorb heat radiated back from the earth's surface.

ORIGIN OF GREEN HOUSE EFFECT:

ORIGIN OF GREEN HOUSE EFFECT . It was proposed by Joseph Fourier in 1824 and was first investigated quantitatively by Svante Arrhenius in 1896. Arrhenius suggested a doubling of the CO 2 concentration would lead to a 5 o C temperature rise . In the 1990's scientists started to question the greenhouse effect theory From 1998 onwards the terminology on the greenhouse effect started to change as a result of media influences

Greenhouse gases :

Greenhouse gases Greenhouse gasses are gasses are in the earth’s atmosphere that collect heat and light from the sun.  With too many greenhouse gasses in the air, the earth’s atmosphere will trap too much heat and the earth will get too hot. It includes Carbon Dioxide (CO2) Methane (CH4) Nitrous Oxide (N2O) Fluorinated Gases

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By their percentage contribution to the greenhouse effect on Earth the four major gases are: water vapor , 36–70% carbon dioxide , 9–26% methane , 4–9% ozone , 3–7%

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The image below describes the Greenhouse effect and the role of greenhouse gases

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POSITIVE ASPECT OF GREEN HOUSE: Sometimes the temperature can change in a way that helps us.  The greenhouse effect makes the earth appropriate for people to live on.  Without it, the earth would be freezing, or on the other hand it would be burning hot.  It would be freezing at night because the sun would be down.  We would not get the sun’s heat and light to make the night somewhat warm.  During the day, especially during the summer, it would be burning because the sun would be up with no atmosphere to filter it, so people, plants, and animals would be exposed to all the light and heat d

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INTERESTING FACT ABOUT GREENHOUSE EFFECT: The greenhouse warming of the Earth's surface is believed by some people to be physically impossible. They claim it would violate the 2nd Law of Thermodynamics, which basically states that energy must flow from where there is more to where there is less . REASON The greenhouse effect is kind of like adding a lid to cover a pot of water on the stove...even though the lid is colder than the water, its presence actually makes the water warmer.

Causes of Global Warming:

Causes of Global Warming Green house gases are responsible for Global Warming. Question is what are green house gases

Green House Gases:

Green House Gases Definition Naturally occurring green house gases Green house gases caused by humans

The image below describes the Greenhouse effect and the role of greenhouse gases :

The image below describes the Greenhouse effect and the role of greenhouse gases

Carbon Dioxide (CO2):

Carbon Dioxide (CO 2 ) Principle GHG Causes of its emission Role of some other Green house gases

Green House Gases:

Green House Gases Human beings and nature also contribute towards global warming

Human made Causes:

Human made Causes Directly & indirectly caused global warming Industrialization Fossil Fuels and Organic matter Automobile Fertilizers Deforestation

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Burning of Fossil Fuels Pollution from coal, natural gas, and oil

Natural Causes:

Natural Causes Oceans, Rainforest Climatic Changes

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Explanation of the causes of global warming

EVIDENCE OF GLOBAL WARMING :

EVIDENCE OF GLOBAL WARMING

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SOME EVIDENCES FROM NATURE

MELTING OF ICE:

MELTING OF ICE Argentina's Upsala Glacier Disappearing at a rate of 200 metres per year.

GLACIAL CHANGE:

GLACIAL CHANGE The Rhone glacier in Switzerland. The glacier had shrunk by some 2.5km . 'snout' had shifted about 450 metres higher up .

RISING TIDES + EROSSION:

RISING TIDES + EROSSION Cape Hatteras in North Carolina in the USA, pictured in 1999 and 2004. Entire coastal village in some is being forced to move to higher ground, due to tides. Rising tides levels has speed up coastal erosion.

VANISHING ISLANDS:

VANISHING ISLANDS Tuvalu in the Pacific. The effects of a higher than usual tide.

LOW SNOWFALL:

LOW SNOWFALL Mount Hood in Oregon at the same time in late summer in 1985 and 2002.

GLOBAL TEMPERATURE RISE:

GLOBAL TEMPERATURE RISE Earth has warmed since 1880. 10 of the warmest years occurring in the past 12 years. Even though the 2000s witnessed a solar output decline but surface temperatures continue to increase.

OCEAN WARMING :

OCEAN WARMING The top 700 meters of ocean showing warming of 0.302 degrees Fahrenheit since 1969.8

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GRAPHS

TEMPERATURE RISING:

T EMPERATURE RISING Measurements recorded directly using thermometers suggests a clear warming trend . Average global temperatures have risen by 0.74 o C during the last 100 years and by 0.5 o C since 1950.

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Carbon dioxide concentration in the atmosphere measured by David Keeling and colleagues at Mauna Loa, Hawai'i and from polar ice cores, with average global surface temperature of earth. Image from Woods Hole Research Center, presentation by Director John P. Holdren, The Scientific Evidence.

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INDICATORS FOR GLOBAL WARMING

INDICATORS:

INDICATORS Land surface air temperature Sea surface temperature Air temperature over the oceans Lower troposphere temperature Ocean heat content Sea level Specific humidity Northern Hemisphere snow cover sea ice

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Where do we get our information?

LAND WEATHER STATIONS:

LAND WEATHER STATIONS Map of land stations in the Global Historical Climatology Network where air temperature was measured on land and islands. From: NOAA National Climate Data Center. On land, temperature is measured a hundreds of weather stations, somewhat unevenly distributed around the world, and on some oceanic islands

marine weather reports:

marine weather reports Number of reports of marine weather reports each year included in the International Comprehensive Ocean-Atmosphere Data Set (From NOAA Climate Diagnostics Center).

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Evidence from the past 1,000 to 400,000 years

Ice core :

Ice core When snow falls year on year it builds up a record. Water molecules and trapped air atmospheric gas concentrations at the time the snow originally fell.

LAYER OF ICE :

LAYER OF ICE The layers give the age of the ice. For the latest ten thousand years of longer, counting the layers gives age. The curve shows the variations in light intensity measured by a line scanner showing the light intensity scattered from the ice.

Other methods:

Other methods Dendrochronology uses measurements of the width of tree rings. Analysis of pollen deposited in layered sediments.

Global Warming - Effects:

Global Warming - Effects Geographical effects Climate change Wildlife humans

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Increase in sea levels. Increase in the intensity of extreme weather events Modifications of trade routes Glacier retreat Mass species extinctions Increases in the ranges of disease vectors Effects Of Global Warming

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Other fallouts include Spread of disease Warmer waters and more hurricanes Increased probability and intensity of droughts and heat waves Economic consequences Loss of Biodiversity Destruction of Ecosystems

How Much Temperature Increase?:

How Much Temperature Increase? Some models propose up to 9 ° C increase this century Two studies put the minimum at 1.5 ° C and maximum at 4.5 °C or 6.2°C

Rise in Sea Levels?:

Rise in Sea Levels? Present rate is 1.8 ± 0.3 mm/yr (7.4 in/century) Accelerating at a rate of 0.013 ± 0.006 mm/yr 2 If acceleration continues, could result in 12 in/century sea level rise

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Impacts on Coastal Areas Erosion Inundation of coastal lands Additional costs to protect coastal communities IPCC 2001 Hadley Centre

Climate Change:

Climate Change Important factor affected as a result of global warming Climate change happens when there is a change in Sun’s output Earth’s orbit Drifting continents Volcanic eruptions Greenhouse gases

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As the temperature of oceans rise, so will the probability of more frequent and stronger hurricanes . Warmer waters and more hurricanes

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Increased probability and intensity of droughts and heat waves

Wildlife effects:

Wildlife effects

Wildlife effects:

Wildlife effects Effects of global warming on animals is one of serious threat to Biodiversity Extinction Some species migrates from one place to other for survival

Wildlife Effects:

Wildlife Effects Polar Bears Require pack ice to live Might eventually go extinct in the wild Other species may go extinct as their natural habitat throughout the world is destroyed.

Effects on human beings:

Effects on human beings

Global warming and Humans:

Global warming and Humans Global warming will affect humans in a number of different ways The spread of infectious diseases will be affected Agriculture will be affected Weather patterns will be affected The supply of freshwater available to humans will be affected

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IPCC 2001 Hadley Centre d Present Danger of Global Warming

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One third of the world’s population is now subject to water scarcity. Population facing water scarcity will more than double over the next 30 years Climate change is projected to decrease water availability in many arid- and semi-arid regions IPCC 2001 Hadley Centre

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Questions & Answers