Climate change

Climate Change, Global Warming & Ozone Layer

Depletion

Vivek Kumar,St. Vincent Pallotti

College of Engineering and

Technology, Nagpur

Climate Change:Fitting the pieces together

What is Climate?

• Climate is the pattern of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods.

• Climate can be contrasted to weather, which is the present condition of these variables over shorter periods.

What is Climate Change?

• Climate is the average weather at a given point and time of year, over a long period (typically 30 years).

• Climate change is the greatest threat facing our planet today.

• A warming planet alters weather patterns, water supplies, seasonal growth for plants and a sustainable way of life for us and the world’s wildlife.

• Climate change has already started, but it’s not too late to take action. There’s still time for us all to be part of the solution.

What Changes Climate?

• A continuous flow of energy from the sun heats the Earth. Naturally occurring gases in the atmosphere, known as greenhouse gases – this includes carbon dioxide (CO2) - , trap this heat like a blanket, keeping the Earth at an average of 15 degrees Celsius – warm enough to sustain life.

• The overuse of fossil fuels is increasing CO2 in the atmosphere, trapping more and more heat and warming the Earth.

• Changes in:– Sun’s output– Earth’s orbit– Drifting continents– Volcanic eruptions– Greenhouse gases

What Changes Climate?

“Greenhouse effect” Increasing greenhouse gases trap more heat

Other evidence of Climate Change

• Glacier retreat

1875 2004

Why should we care?

Sea-level rise projections : a few inches to a few feet

•2 ft: U.S. would lose 10,000 square miles•3 ft: Would inundate Miami•Affects erosion, loss of wetlands, freshwater supplies•Half of the world’s population lives along coasts•Big question: Ice sheets

Conclusions• Warming of the climate system is unequivocal• Very high confidence that global average net

effect of human activities since 1750 one of warming

• Human-caused warming over last 30 years has likely had a visible influence on many physical and biological systems

• Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century.”

•Produce more fuel-efficient vehicles•Reduce vehicle use•Improve energy-efficiency in buildings•Develop carbon capture and storage

processes•Triple nuclear power•Increase solar power•Decrease deforestation/plant forests•Improve soil carbon management

strategies

What WE can do?

Ozone Layer depletion

Ozone DepletionOzone Depletion

Significant concentrations of ozone (OSignificant concentrations of ozone (O33) exist in ) exist in the lower elevations of the stratosphere. the lower elevations of the stratosphere.

Ozone in the stratosphere Ozone in the stratosphere absorbs UV B radiation absorbs UV B radiation from sunlight.from sunlight.

UV B radiation UV B radiation damages DNA damages DNA molecules and can molecules and can cause genetic defects cause genetic defects on the outer surfaces on the outer surfaces of plants and animals, of plants and animals, including human skin including human skin (skin cancer)(skin cancer)

• Ozone depletion is the seasonal loss of a large swath of our stratospheric ozone above Antartica, as well as the general degradation of this protective layer around the globe.

• With less ozone in the atmosphere, more ultraviolet radiation strikes Earth, causing more skin cancer, eye damage, and possible harm to crops.

Ozone Layer Depletion

Ozone Layer: Function

• What does the ozone layer do for us?

• Ozone is the only major atmospheric constituent that absorbs significantly between 210 and 290 nm.

• Without it life would have remained underwater

• The ozone layer is a consequence of oxygen-only chemistry. It formed once photosynthetic marine organisms (cyanobacteria) began “polluting” the atmosphere with oxygen.

Ozone Depletion ResultsOzone Depletion Results

Each 1% loss of ozone leads to a 2% Each 1% loss of ozone leads to a 2% increase in UV radiation striking the increase in UV radiation striking the earth.earth.

A 2% increase in UV radiation results in a A 2% increase in UV radiation results in a 5% to 7% increase in skin cancer, 5% to 7% increase in skin cancer, including a 1% increase in deadly including a 1% increase in deadly malignant melanomamalignant melanoma

A 5% Ozone Depletion would A 5% Ozone Depletion would cause:cause:• An additional 940,000 cases annually of basal-cell and An additional 940,000 cases annually of basal-cell and

squamous-cell skin cancer (disfiguring, but not usually squamous-cell skin cancer (disfiguring, but not usually deadly)deadly)• An additional 30,000 cases annually of melanoma skin An additional 30,000 cases annually of melanoma skin cancer (often fatal). There are 9,000 American deaths cancer (often fatal). There are 9,000 American deaths per year from this now.per year from this now.• A sharp increase in eye cataracts and severe sunburn A sharp increase in eye cataracts and severe sunburn in people, cataracts in cattle.in people, cataracts in cattle.

• Suppression of the human immune systemSuppression of the human immune system

• An increase in smog. The EPA estimates a 1% An increase in smog. The EPA estimates a 1% decrease in stratospheric ozone causes a 2% increase decrease in stratospheric ozone causes a 2% increase in ozone near the groundin ozone near the ground• Reduced yields from crops like corn, rice, beans, and Reduced yields from crops like corn, rice, beans, and wheatwheat• Reduction in ocean phytoplankton growthReduction in ocean phytoplankton growth

• Loss of $2 billion per year from materials degradationLoss of $2 billion per year from materials degradation

• Increased global warmingIncreased global warming

Causes of DepletionCauses of Depletion

• Chlorine and Bromine in the StratosphereChlorine and Bromine in the Stratosphere

• CFC-11 (chlorofluoromethane) and CFC-11 (chlorofluoromethane) and CFC-12 (dichlorofluoromethane) are CFC-12 (dichlorofluoromethane) are the most widely used as coolants for the most widely used as coolants for refrigerators and air conditionersrefrigerators and air conditioners

• CFC-11 (chlorofluoromethane) and CFC-12 CFC-11 (chlorofluoromethane) and CFC-12 (dichlorofluoromethane) are the most widely (dichlorofluoromethane) are the most widely used as coolants for refrigerators and air used as coolants for refrigerators and air conditionersconditioners

SourcesSources Chlorofluorocarbons (CFC’s)Chlorofluorocarbons (CFC’s)• Commonly called Freons (a Du Pont Commonly called Freons (a Du Pont

Chemical tradename)Chemical tradename)

• Also used as propellant in aerosol cans, industrial Also used as propellant in aerosol cans, industrial cleaner, hospital sterilant, fumigant, and to create cleaner, hospital sterilant, fumigant, and to create bubbles in polystyrene plastic foam used for bubbles in polystyrene plastic foam used for insulation and packaging.insulation and packaging.

HalonsHalons• Bromine containing compounds used in fire Bromine containing compounds used in fire

extinguishersextinguishers

Carbon TetrachlorideCarbon Tetrachloride• An industrial solventAn industrial solvent

United States accounts for largest part of world-wide United States accounts for largest part of world-wide consumption o CFC’sconsumption o CFC’s

29% of global consumption is from US29% of global consumption is from US

Americans use six times more CFC’s than Americans use six times more CFC’s than global averageglobal average

Vehicle air conditioners accounted for about Vehicle air conditioners accounted for about 75% of annual CFC emissions in the US in 75% of annual CFC emissions in the US in 19901990

Since 1978 the use of CFC’s in aerosol Since 1978 the use of CFC’s in aerosol cans has been banned in many countries; cans has been banned in many countries; however, worldwide, aerosol cans still however, worldwide, aerosol cans still account of 25% of CFC emissionsaccount of 25% of CFC emissions

What do these compounds do?What do these compounds do?

Spray cans, discarded and/or leaking refrigeration and air Spray cans, discarded and/or leaking refrigeration and air conditioning units, the production and burning of plastic foam conditioning units, the production and burning of plastic foam products, and the use of solvents result in the release of products, and the use of solvents result in the release of these compounds into the environment.these compounds into the environment.Most of these compounds are non-reactive and have lives Most of these compounds are non-reactive and have lives of 22 to 111 years in the atmosphereof 22 to 111 years in the atmosphere..

They circulate in the atmosphere until they reach the They circulate in the atmosphere until they reach the stratosphere.stratosphere.In the stratosphere they are broken down by UV radiation In the stratosphere they are broken down by UV radiation to release chlorine and bromine atomsto release chlorine and bromine atoms

Chemical reactions between chlorine or bromine and Chemical reactions between chlorine or bromine and ozone cause ozone to degrade to Oozone cause ozone to degrade to O22 and O. and O.

Over time a single chlorine atom can cause the Over time a single chlorine atom can cause the breakdown of as many as 100,000 molecules of ozone.breakdown of as many as 100,000 molecules of ozone.

The Ozone HoleThe Ozone Hole

In the 1980’s researchers discovered that up to 50% In the 1980’s researchers discovered that up to 50% of the ozone in the stratosphere over Antartica is of the ozone in the stratosphere over Antartica is destroyed between September and October (Arctic destroyed between September and October (Arctic Spring). An area larger than the USSpring). An area larger than the US

CauseCauseVortexing winds with ice crystals that have absorbed CFC’s Vortexing winds with ice crystals that have absorbed CFC’s on the surface that lift CFC’s into the stratosphere and on the surface that lift CFC’s into the stratosphere and destroy the ozone at a fast rate.destroy the ozone at a fast rate.

The vortex breaks up in a couple of months and large masses of The vortex breaks up in a couple of months and large masses of ozone depleted air flow northward over parts of Australia, New ozone depleted air flow northward over parts of Australia, New Zealand and southern South America. During this time UV Zealand and southern South America. During this time UV levels increase by as much as 20% there.levels increase by as much as 20% there.

A similar phenomenon has recently been observed in the A similar phenomenon has recently been observed in the Arctic regionsArctic regions

Satellite photo of south pole. Purple shade shows the extent of the Satellite photo of south pole. Purple shade shows the extent of the ozone hole.ozone hole.

Protecting the Ozone LayerProtecting the Ozone Layer

Ban the use of CFC’sBan the use of CFC’s

Have to replace with somethingHave to replace with something

Current replacements are greenhouse Current replacements are greenhouse gases and do not eliminate ozone gases and do not eliminate ozone depletion, just slow it downdepletion, just slow it down

Air Quality StandardsAir Quality Standards

Emission StandardsEmission Standards

Limit amounts of pollutants that can be Limit amounts of pollutants that can be emitted by pollution sourcesemitted by pollution sources

Generally set by State Air Quality OfficesGenerally set by State Air Quality Offices

Ambient Air Quality Ambient Air Quality StandardsStandards• The Clean Air Act, which was last amended in 1990, The Clean Air Act, which was last amended in 1990,

requires EPA to set National Ambient Air Quality requires EPA to set National Ambient Air Quality Standards for pollutants considered harmful to public Standards for pollutants considered harmful to public health and the environment. The Clean Air Act health and the environment. The Clean Air Act established two types of national air quality standards. established two types of national air quality standards. Primary standards set limits to protect public health, Primary standards set limits to protect public health, including the health of "sensitive" populations such as including the health of "sensitive" populations such as asthmatics, children, and the elderly. Secondary asthmatics, children, and the elderly. Secondary standards set limits to protect public welfare, including standards set limits to protect public welfare, including protection against decreased visibility, damage to protection against decreased visibility, damage to animals, crops, vegetation, and buildings.animals, crops, vegetation, and buildings.

• The EPA Office of Air Quality Planning and Standards The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" for six principal pollutants, which are called "criteria" pollutants. They are listed below. Units of measure for the pollutants. They are listed below. Units of measure for the standards are parts per million (ppm) by volume, standards are parts per million (ppm) by volume, milligrams per cubic meter of air (mg/m3), and milligrams per cubic meter of air (mg/m3), and micrograms per cubic meter of air (µg/m3).micrograms per cubic meter of air (µg/m3).

Observations• Global surface temperatures have risen by about

0.6°C since 1900• It is likely that this warming is larger than for any

century since 200AD, and that the 1990s were the warmest decade in the last millennium.

• The warming differs in different parts of the world, but over the last 25 years, almost everywhere has warmed, and very few places have cooled.

• Other changes have occurred, e.g.:– Sea level has risen by about 20 cm,– Ocean heat content has increased,– Almost all mountain glaciers have retreated

• Coincident with this global warming, levels of CO2 (and other ‘greenhouse’ gases) have dramatically increased, to levels higher than those experienced for maybe millions of years.

The Ozone Hole – Explained!

Global Warming

Global Warming

• Global warming is a Global phenomenon.

• It refers to a gradual increase in the temperature of the Earth due to trapping of green house gases.

Green House gases

• Gases such as CO2, SO2, NO2,CH4, etc. Are the green house gases.

• Most of these are the polluting gases that are produced by the industries.

• These gases trap the heat from the sunrays that are reflected from the sun.

Why Global Warming Occurs?

It is the effect of the process of trapping of Heat due to CO2 which has been going on since times unknown.

• But due to rapid rise in population over the last few decades, the CO2 emission has increased whereas due to deforestation, the rate of CO2 absorption has gone down thus disturbing the balance of Nature.

Why Global Warming Occurs?• Also due to Globalization, various

industries started to grow.• This also led to the problems of

various types of pollutions including air pollution.

• Most of the gases that pollute the environment are Green house gases.

• This leads to Global warming.

What do climate scientists really think?

Effects of Global Warming

• It has been reported that the temperature of Earth is increasing each day by few degrees.

• As a result of this, the snow in various regions of Earth is rapidly melting.

• This may add more water to fresh water reserves like lakes and rivers in the beginning but when the “meltdown” is completed, there would be no fresh water reserves.

• Also it destroys the ecosystem in the Polar region.

Prevention Of Global Warming

• The various ways to control Global Warming are:-

1.Control of population. But, since it is not possible to control population, the best way to control Global warming is by planting trees.

2.Use of ecofriendly and biodegradable products.

3.Avoid using vehicles when not necessary.

SAVE EARTH…..SAVE LIFE……….

THANK YOU………………….