Greenhouse Effect & Global Warming

What is Greenhouse Effect?

Green House effect is a naturally occurring phenomenon that is responsible for heating of Earth’s Surface and atmosphere

What is Global Warming ?

Global warming is the result of greenhouse gases trapping heat and light from the sun in the earth's atmosphere, which increases the temperature, heating up the earth.

Greenhouse

This looks like a small glass house and is used for growing plants especially in winter season. In a greenhouse the glass panel lets the light in but does not allow heat to escape. Therefore the green house warms up.

Causes : Greenhouse Gases

The primary greenhouse gases include:Carbon dioxideMethaneNitrogen oxides, andFluorinated gases

Greenhouse gases reflect radiation from the Earth and stop it from being lost into space. This causes the Earth's temperature to be higher than its normal temperature.

A Flow Chart

Part of this heat is sent towards the ground, and it heats the earth’s surface and the lower atmosphere again.

The Green House Gases absorb this heat.

The land heated by the sunlight emit back the heat as infrared rays

The sunlight passes through the atmosphere and the earth's surface absorbs it.

Why is Greenhouse Effect Dangerous?

Global WarmingEndangered SpeciesClimate Change

Global Warming

The changes in the global temperature, brought about by the green house effect which is induced by enhanced greenhouse gases into the air.This can be termed as global warming.

Causes Of Global Warming

DeforestationClimate change is a severe outcome of excessive cutting down of trees. It results in an increase in the amount of carbon and other greenhouse gases in the environment.

Greenhouse GasesGreenhouse gases are the gases which trap the solar radiations and trigger a rise in Temperature levels on the planet.

LandfillLandfills also produce greenhouse gases, both by methane gas escaping, and by burning the waste to save space on landfills.

PollutionPollution is a serious threat to the environment and a culprit for global warming. It is one of the causes of the greenhouse effect, which traps in the suns heat and doesn't let it escape.

Consequences Of Global Warming

Climate changeChanges in wildlife adaptations and cyclesIncrease in sea levelOn Health

The Consequences of Global Warming On Weather Patterns

More Powerful and Dangerous HurricanesWarmer water in the oceans pumps more energy into tropical storms, making them stronger and potentially more destructive.

Drought and WildfireWarmer temperatures could increase the probability of drought. Greater evaporation, particularly during summer and fall, could exacerbate drought conditions and increase the risk of wildfires.

Intense RainstormsWarmer temperatures increase the energy of the climatic system and can lead to heavier rainfall in some areas. Scientists project that climate change will increase the frequency of heavy rainstorms, putting many communities at risk for devastation from floods

The Consequences of Global Warming On Wildlife

Ecosystem Shifts and Species Die-OffIncreasing global temperatures are expected to disrupt ecosystems, pushing to extinction those species that cannot adapt.

The U. S. Geological Survey has predicted that two-thirds of the world's polar bear sub-populations will be extinct by mid-century due to melting of the Arctic ice cap.

Approximately 20 to 30 percent of plant and animal species assessed so far are likely to be at increased risk of extinction if global average temperature increases by more than 2.7 to 4.5 degrees Fahrenheit.

The Consequences of Global Warming On Glaciers and Sea Levels

Melting Glaciers, Early Ice ThawRising global temperatures will speed the melting of glaciers and ice caps and cause early ice thaw on rivers and lakes.

According to NASA, the polar ice cap is now melting at the alarming rate of nine percent per decade. Arctic ice thickness has decreased 40 percent since the 1960s.

The Consequences of Global Warming On Health

Hotter weather enables deadly mosquitoes to travel greater distances; carbon dioxide in the air aggravates asthma and allergies.Deadly Heat WavesMore frequent and severe heat waves will result in a greater number of heat-related deaths.Bad Air, Allergy and AsthmaGlobal warming could increase smog pollution in some areas and intensify pollen allergies and asthma.Infectious Disease and Food and Waterborne Illness OutbreaksWarming temperatures, alternating periods of drought and deluges, and ecosystem disruption have contributed to more widespread outbreaks of infections like malaria, dengue fever, tick-borne encephalitis, and diarrheal illnesses.Dangerous Weather EventsA warmer atmosphere can hold -- and dump -- more moisture, contributing to more intense extreme weather events, which in turn put people's lives at risk.

More Consequences

Species becoming endangered or extinctHeavy draughtSpread of DiseaseRise in TidesChange in Weather patterns

El NinoEl Nino, an abnormal warming of surface ocean waters in the eastern tropical Pacific. El Nino happens when the surface pressure is high in the eastern tropical Pacific it is low in the western tropical Pacific, and vice-versa.What Causes El Niño? The warming of the Pacific occurs as a result of the weakening of trade winds that normally blow westward from South America toward Asia.The major impacts of El Niño are temperature anomalies, changes in precipitation variability, floods and droughts throughout the world. El Niño events happen irregularly and are hard to predict.

Remedies For Global Warming

Afforestation Planting more trees and reducing timber cuts worldwide will help restore the imbalance.Follow the 3 R’sWe must follow on environmental policy of ‘reduce, reuse, recycle’, i.e. promoting the reuse of anything. Use of fuel-efficient vehiclesFuel-efficient vehicles should be promoted as these vehicles have lower emissions of harmful gases.Eco- friendly technologies Public awareness campaignReduce the emission of green house gases

OzoneOzone is a gas that is present in the ozone layer in the stratosphere of the Earth. There, it will absorb almost all ultraviolet light which is harmful to many organisms.

The ”ozone hole”The ”ozone hole” is an extraordinary low ozone concentration caused by the ozone layer depletion at the South Pole during the arctic winter and spring period. The ”ozone hole” on satellite pictures it looks like a big hole. The ozone layer thickness in the ”ozone hole” region is 100 – 150 DU (the standard ozone layer thickness is 300 DU).[The Dobson unit (DU) is a unit of measurement of atmospheric ozone columnar density, which is dominated by ozone in the stratospheric ozone layer.]

Ozone Destruction Caused by Man-made Compounds (e.g. CFCs)

The 2011 Ozone Hole reached it's largest size of 26 million square

kilometers on September 12,2011

Impacts Of Ozone Depletion

Impact on the BiosphereA. Microscopic algae called phytoplankton form the foundation

of the undersea food chain. Less phytoplankton means less food for these animals to eat. It is estimated that a 16 % ozone depletion could result in further losses in Phytoplankton, which would lead to a loss of about 7 million tons of fish per year.

B. Damage to Crops

Impact on HumansA. UV-B damages DNA and Mutation may occur. It causes

aging of skin, damage to skin cells and various types of skin cancers

B. Cataracts In human eye, cornea absorbs UV-B radiation. "Snow

blindness" is the result of overexposure to UVB and causes the inflammation of cornea.

A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope

C. Immune System Recent studies shows that some viruses can be activated by

increased exposure to UV. This affects our Immune system.

How can we reduce Ozone Depletion?

Montrel Protocol

An International treaty that was signed at Montrel (Canada) in 1987 to control the emission of ozone depleting substances

Reduce the emission of CFC’s .

Degradation By Improper Resource Utilisation And MaintenanceSoil erosion It is a naturally occurring process on all land. The agents of soil erosion are water and wind, each contributing a significant amount of soil loss each year.Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing serious loss of topsoil. DesertificationDesertification is the persistent degradation of dryland ecosystems by variations in climate and human activities. It can be due to overgrazing, deforestation, agricultural activities, over exploitation of fuel wood and biochemical activities.

Water logging and Soil Salinity

Irrigation without proper drainage leads to water logging in the soil.Water logging draws salt to the surface of the soil.The salt is then deposited as a thin crust on the land surface. This increased salt content damages agriculture.

Both water logging and salinization could be reduced if the efficiency of irrigation systems could be improved.

DeforestationDeforestation is the removal of a forest or stand of trees where the land is thereafter converted to a non forested use.E.g. : conversion of forestland to farms, ranches, or urban use.It is done for timber, firewood, cattle ranching and for several purposes.Slash and Burn agricultureIt is also called Jhum cultivation. The farmers cut down the trees of the forest and burn the plant remains.The ash is used as fertilizer and is used for agriculture and farming purposes.After cultivation the area is left for several years for recovery.But when the land was not given enough time for recovery, it lead to deforestation.

Consequences Enhanced CO2 concentration.Loss of biodiversityCauses soil erosionCauses desertificationDisturbs hydrologic cycle

Reforestation

It is the process of restoring a forest that once existed but was removed at some point of time in the past. It can occur naturally.By Afforestation ( planting trees)

Case Study of People’s Participation in Conservation of Forests

Amrita Devi Bishnoi She died by trying to protect a tree from the king’s soldiers.Amrita Devi Bishnoi Wildlife Protection AwardFor those who dedicate their life for protecting wildlife.

Chipko Movement (1974) A local women protected trees from axe contractors.

Joint Forest Management (JFM) – 1980sGovt. of India introduced For working closely with local communities for protecting and managing forests. In return for the services the communities get many benefit of various forest products. ( fruits , gum, rubber, medicine etc.)

The End