Global warming

SAVE OUR EARTH

Prem Deshmane

Earth formed ~4.6 billion years ago

Originally very hot

Sun’s energy output only 70% of present

Liquid water present ~4.3 billion years

History of Earth’s Climate

Life appeared ~3.8 billion years ago

Photosynthesis began 3.5-2.5 billion years ago Produced oxygen and removed carbon dioxide and

methane (greenhouse gases)

Earth went through periods of cooling (“Snowball Earth”) and warming

Earth began cycles of glacial and interglacial periods ~3 million years ago

History of Earth’s Climate

Global Warming is the increase of Earth's averagesurface temperature due to effect of greenhouse gases,such as carbon dioxide emissions from burning fossilfuels or from deforestation, which trap heat that wouldotherwise escape from Earth. This is a type ofgreenhouse effect.

Do you know what is GLOBAL

WARMING ?

Greenhouse gas: Greenhouse gas emissions, such as

carbon dioxide (CO2), nitrous oxide and methane from

automobile exhausts and industries, trap heat in the

atmosphere.

Deforestation: Extensive logging is removing trees and

plants that would otherwise absorb CO2.

Reasons for GLOBAL WARMING

Oceans' absorption of CO2: Oceans help maintain a

delicate equilibrium by absorbing CO2 from the

atmosphere and reflecting heat from the sun. But this

balance is difficult to match with global CO2 emission

levels.

Loss of sea ice: Glaciers help maintain the temperature

of oceans, but with ice melting, there is less heat that is

reflected back and more water to absorb it.

The Earth's average surface temperature rose by

0.74=0.18 °C over the period 1906–2005. The rate of

warming over the last half of that period was almost

double that for the period as a whole (0.13±0.03 °C per

decade, versus 0.07±0.02 °C per decade). The urban heat

island effect is very small, estimated to account for less

than 0.002 °C of warming per decade since 1900

TEMPERATURE RISING !!

The greenhouse effect is the process by which absorption andemission of infrared radiation by gases in the atmosphere arepurported to warm a planet's lower atmosphere and surface.

Naturally occurring greenhouse gases have a mean warmingeffect of about 33 °C (59 °F).

The major greenhouse gases are water vapor, which causesabout 36–70 percent of the greenhouse effect; carbon dioxide(CO2), which causes 9–26 percent; methane (CH4), whichcauses 4–9 percent; and ozone (O3), which causes 3–7percent. Clouds also affect the radiation balance, but they arecomposed of liquid water or ice and so have different effectson radiation from water vapour.

GREEN HOUSE EFFECT

Annual world greenhouse gas emissions, in 2012, by sector.

Natural causes are causes that are created by nature. One

natural cause is a release of methane gas from arctic tundra

and wetlands. Methane is a greenhouse gas and a very

dangerous gas to our environment. A greenhouse gas is a

gas that traps heat in the earth's atmosphere. Another

natural cause is that the earth goes through a cycle of

climate change. This climate change usually lasts about

40,000 years.

NATURAL CAUSES

Man-made causes probably do the most damage to ourplanet. There are many man-made causes of globalwarming. Pollution is one of the biggest man-madeproblems. Pollution comes in many shapes and sizes.Burning fossil fuels is one thing that causes pollution.Fossil fuels are fuels made of organic matter such ascoal, or oil. When fossil fuels are burned they give off agreen house gas called CO2. When you dig up the fossilfuels you dig up the methane as well letting it escapeinto the atmosphere.

MAN-MADE CAUSES

The effects of Global Warming can already be seen

The IPCC's Third Assessment Report finds that in the last 40

years, the global average sea level has risen, ocean heat

content has increased, and snow cover and ice extent have

decreased, which threatens to inundate low-lying island

nations and coastal regions throughout the world.

Effects of global warming already being felt on plants and

animals worldwide

Global Warming Effects that will happen in the future:

EFFECTS OF GLOBAL WARMING

Global warming will affect agriculture. New crops will

be able to be grown in areas that are currently too cold to

support them. However, more pests and diseases may

offset any benefits higher temperatures may have. Water

resources will also be affected.

Global warming will have serious impacts on the

environment and on society. Higher temperatures will

cause a melting of ice in Greenland and Antarctica. This

will accelerate the rise of sea level. The speed at which

global warming is expected to occur in the 21st century

is faster than most plant and animal species will be able

to cope with. Some will adapt but others will suffer and

Effects of Global Warming on Earth in

Future

The ozone layer protects the Earth from the ultraviolet rays

sent down by the sun. If the ozone layer is depleted by

human action, the effects on the planet could be catastrophic.

Ozone is a bluish gas that is formed by three atoms of

oxygen. The form of oxygen that humans breathe in consists

of two oxygen atoms, O2. When found on the surface of the

planet, ozone is considered a dangerous pollutant and is one

substance responsible for producing the greenhouse effect.

OZONE LAYER DEPLETION

Useless usage of AC's and Refrigerators should be stopped

because from them harmful rays cfc's are emitted which

results in depletion of ozone layer and from that hole UV

rays of Sun comes to the earth and cause many diseases to

both animals and plants i.e. Skin cancer etc. , CNG and

hydrogen operated vehicles should be used, more no. of

trees should be planted, Chimneys in the Industries should

be upgraded so that most of the effluents should get

filtered down there.

PRECAUTION TO PREVENT

GLOBAL WARMING

Because greenhouse gas emissions are tied very closely to

our energy consumption, using less fossil fuel based

energy puts fewer greenhouse gases into the atmosphere.

This will help slow global warming.

Reduce our consumption of fossil fuels