Green House Effect, Global Warming and

Climate Change

ENV 101: Introduction to Environmental Science

What is Greenhouse Effect

•The greenhouse effect is often referred to as the enhanced greenhouse effect which is an increase in the concentration of greenhouse gases in the atmosphere leading to an increase in the amount of infrared or thermal radiation near the surface.

•Most scientists agree that the enhanced greenhouse effect is leading to rising temperatures referred to as global warming, and other changes in the atmospheric environment, known as climate change (a term that in common usage also includes natural changes).

•The greenhouse effect is caused by 'green house gases', which are primarily made up of Argon, Carbon Dioxide, Neon, Helium, Methane, Hydrogen, Nitrous Oxide and Ozone.

Greenhouse Gases (GHGs) are the gasses that absorb infrared radiation and emit it in thermal range.CO2, CO, N2O, cH4, H2o and hydrocarbon groups are the main GHGs. UNFCCC recognized 6 gasses as direct GHGs

CO2 - Carbon dioxide

CH4 - Methane

N2O - Nitrous oxide

PFCs - PerfluorocarbonsHFCs - Hydrofluorocarbons

SF6 - Sulphur hexafluoride

Carbon dioxide comes mainly from fossil fuel burning and deforestation.Methane comes from rice, cattle.Nitrous oxide comes from fertilizers, crop residues, fossil fuel burning.CFCs come from refrigerators, ACs, aerosol propellants, foam blowing agents.

Source: UNFCCC

Source: UNEP GRID

What Causes the Greenhouse Effect? Life on earth depends on energy from the sun.

About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet’s surface and is reflected upward again as a type of slow-moving energy called infrared radiation.

As it rises, infrared radiation is absorbed by “greenhouse gases” such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.

Although greenhouse gases make up only about 1 percent of the Earth’s atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.

Global Warming and Climate Change Global Warming: A process through

which the atmosphere is warmed by an increase of greenhouse gases (GHG), caused by human actions.

Climate Change: The earth’s climate has been shaping and reshaping continuously. Generally, climate is the long-term characteristics of weather. Temperature, precipitation, humidity, sunshine hours and wind are the variables of the climate; whose long term fluctuations shape earth’s climate.

Climate change in manmade

Currently we are living in a post-ice age. The main concern of recent age is the drastic increase of temperature from industrial period. Since then greenhouse gas emission has increased beyond atmosphere’s carrying capacity for the sake of development that contributes to global temperature increase. Even though most greenhouse gases have both natural and anthropogenic sources, but in the Industrial era human activities have added greenhouse gases more abruptly than pre-industrial era, mainly through burning of fossil fuels and clearing of forests. Therefore, today’s climate change is Anthropogenic

Global warming is the main causes of climate change through changing precipitation and wind pattern, glaciers melt and resultant sea level rise.

IPCC 4th assessment report (2007) argued that increases in anthropogenic greenhouse gas concentrations are very likely to have caused most of the increases in global average temperatures since the mid-20th century.

Gas Level in 2005 Level in 1998 Increase since 1750 (comparing with 2005)

CO2 - Carbon dioxide 379 ± 0.65 μmol/mol 365μmol/mol 100 μmol/mol

CH4 - Methane 1,774 ± 1.8 nmol/mol 1,745nmol/mol

1056 nmol/mol

N2O - Nitrous oxide 319 ± 0.12 nmol/mol 314nmol/mol

49 nmol/mol

PFCs – Perfluorocarbons

Hexafluoroethane- (C2F6)

2.9 ± 0.025 pmol/mol3 pmol/mol

3 pmol/mol

Carbon tetrafluoride (CF4) 74 ± 1.6 pmol/mol 80 pmol/mol 34 pmol/mol

HFCs – Hydrofluorocarbons

HCFC-22 169 ± 1.0 pmol/mol 131 pmol/mol

HFC-134a (C2H2F4) 35 ± 0.73 pmol/mol 7.5pmol/mol

35

HFC-23(CHF3) 18 ± 0.12 pmol/mol 14pmol/mol

18

HFC-152a* (C2H4F2) 3.9 ± 0.11 pmol/mol 0.5pmol/mol

3.9

SF6 - Sulphur hexafluoride 5.6 ± 0.038 pmol/mol 4.2 pmol/mol 5.6 pmol/mol

Mole fractions: μmol/mol = ppm = parts per million (106); nmol/mol = ppb = parts per billion (109); pmol/mol = ppt = parts per trillion (1012)

Impacts of climate changeThe extreme weather events such as

floods, droughts, cyclones, sea level rise, salinity intrusion have been demonstrating the evidence of climate change. Even though those weather events are not new to human civilization, however the frequency and intensity have increased manifold in recent years, specially affecting global south due to their geographically vulnerable position and less capacity to withstand capacity.

The number of natural hazards has been increasing in recent years and 2010 was the most hazardous year since nineteenth century

. In 2010, heavy rainfall in Colombia, Peru, Pakistan, Western Africa, Egypt, Israel, France, and Australia triggered extreme floods.

On the other hand, many Caribbean countries, Brazil, Guam experienced drought.

In case of cyclone occurrence, 2010 breaks previous records with 39 cyclones hit different parts of the world.

Arctic and Atlantic experienced lowest sea extent since 1900. Similarly, Finland experienced warmest decade (2001-2010) since 1840s, Alaska had 3rd driest year since 1918, Mexico since 1948, Canada since 1948 respectively.

On the contrary, US and Ireland had the coolest winter after 1962-1963.

Climate science and Policy IPCC WMO and UN established

the Intergovernmental Panel on Climate Change (IPCC) in 1988 to address the challenges of global warming.

IPCC involves the collaboration of hundreds of specialists, and produces ‘assessment reports’ on climate change, adaptation and mitigation

UNFCCCUnited Nations

Framework Convention on Climate Change (UNFCCC) is the base of the global attempt to combat climate change. It entered into force 1 March,1994.

The Supreme Body of the Convention is the Conference Of the Parties(COP). The First meeting of the COP held in 1995 in Berlin.

Meeting Year Location Key Decisions

COP 1 1995 Berlin, Germany *Adopted Berlin Mandate*A new subsidiary body named Ad hoc Group established

COP 2 1996 Geneva, Switzerland *Accepted the Intergovernmental Panel on Climate Change (IPCC) in its second assessment

COP 3 1997 Kyoto, Japan *Kyoto Protocol, the greenhouse gas emissions reduction commitment adopted

COP 4 1998 Buenos Aires, Argentina *Two years Plan of Action adopted to tie up Kyoto Protocol

COP 5 1999 Bonn, Germany *Set the time table for Kyoto Protocol

COP 6 2000 The Hague, Netherlands * Flexible Mechanisms- 1. Emission Target 2. Joint Implementation 3. Clean Development Mechanism* Financing: 3 new fund established to support the climate change- 1. Fund for climate change 2. LDC fund to support adaptation program of action 3. Kyoto Protocol adaptation fund supported by a CDM levy and voluntary contributions

COP 7 2001 Marrakech, Morocco *Marrakech Accord recognized

COP 8 2002 New Delhi, India *Discus about technology transfer to minimize climate change impact

COP 9 2003 Milan, Italy *Parties agreed to use Adaptation Fund established in COP 7

COP 10 2004 Buenos Aires, Argentina *Buenos Aires Plan of Action was adopted

COP 11 2005 Montreal, Canada *Kyoto Protocol inter into force*Montreal Action Plan introduced to extend the life of the Kyoto Protocol and deeper cuts in greenhouse-gas emissions.

COP 12 2006 Nairobi, Kenya *Agreed to modify the Adaptation Fund and five year adaptation plan for developing countries

COP 13 2007 Bali, Indonesia *Bali Action Plan adopted*AWG-LCA established for implementation of the convention beyond 2012*REDD+ proposed

COP 14 2008 Poznan, Poland *Delegates agreed to financing for developing countries

COP 15 2009 Copenhagen, Denmark *Copenhagen Accord proposed and the decision to implement REDD+ during 2012 is taken

COP 16 2010 Cancun, Mexico *Cancun agreement recognized

COP17 2011 Durban, South Africa Durban Platform

Kyoto ProtocolThe Kyoto Protocol was adopted in Kyoto, Japan, on

11 December 1997 and entered into force on 16 February 2005. The detailed rules for the implementation of the Protocol were adopted at COP 7 in Marrakesh in 2001, and are called the “Marrakesh Accords.”

Kyoto Protocol is the first protocol which set binding target for 37 industrialized countries to reducing 6 greenhouse gasses( Carbon Dioxide, Methan, Nitrous Oxide, Hydroflurocarbons, Perflurocarbons, Sulpher hexafluoride) emission. Objective of the treaty is to reduce Greenhouse Gas emissions in developed countries 5.2% relative to 1990 levels by 2008-2012(Phase I). The Kyoto Protocol sets three flexible mechanism which known as Kyoto mechanism.

Kyoto Mechanism Kyoto Mechanism

IPCC’s Fourth Assessment Report (2007)Mean temperature and sea level are

projected to rise under all IPCC scenarios.

Global temperatures could rise by between 1.1°C and 6.4°C during the 21st century.

Sea levels could probably rise by 18 to 59 cm by 2100.

Warming in the last 100 years has caused temperature increase by about 0.74°C.

Global Impacts

Freshwater ResourcesAnnual mean river runoff and water supply to

increase by 10 to 40%.Drought affected areas and heavy rainfalls will

increase.By 2100, water supplies in glaciers are projected

to decline.

EcosystemsResilience of many ecosystems will be exceeded.

InfrastructurePoor communities will be most vulnerable.

HealthIncrease in malnutrition, heat strokes, diarrheal

diseases, vector-borne diseases.

Mitigation“Mitigation refers

the actions taken to reduce the GHGs emission to reduce the effect of climate change”

AdaptationAdaptation is an

adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities.

Adaptation are of two types-Autonomous or spontaneous and planned

Climate Change and Bangladesh

Bangladesh has contributed zero in the previous event of climate change but experiencing the largest collision of climate change.

Bangladesh became the most vulnerable country to climate change because of it geographical position, hydrological factor and some socio-economic factors.

From the IPCC fourth assessment report it shows that the Bangladesh has experiencing change in precipitation pattern, temperature increase and also sea level rise. Water crisis , flood , drought, frequency of cyclone increase tremendously.

IPCC predict if 40cm sea level will rise then coastal area and a large part of the Sundarban will be inundate. Environmentally induced migration will be a big problem to manage.

General Circulation Model(GCM) projection by US Climate Change Study team (NAPA,2005) for Bangladesh projected that

Temperature will increase 1.30C to 2.60C for the years 2030-2070.

1.40C change in winter and .70C in the monsoon for 20302.10C change in winter and 1.70C in the monsoon for 2070Precipitation will increase 12%-27% for the 2030-2070Temperature and precipitation change have direct impact

in agriculture all over Bangladesh. And the drought and flood frequency change is just a sight of impact of climate change. Most vulnerable sector by climate change are food security, agriculture, health, infrastructure, trade, Industry, disaster. All sectors are directly or indirectly interconnected and have final impact in likelihood. In different areas of Impact of climate change are different in region to region and also the severity varies.

AgricultureCrop cultivation and harvesting is largely

influenced by climatic condition. Any change in the climatic condition can

drastically modify the agricultural production.

Food production may increase with temperature rise by 1 to 3°C, but will decrease above that.

Increase in droughts and floods to affect local production negatively.

It is the less developed countries who will suffer from the climate change.

Forests Warmer temperature will force some tree species to migrate to

more cooler regions in the north and some will definitely disappear. If the earth warms at a rate of 20 C in 100 hundred years, then the tree species will have to migrate about 2 miles every year.

There can be one positive effect of global warming- increased carbon dioxide can be beneficial fertilization effect on plants. This will enable plants to use water more efficiently and thereby increase the withstanding capacity of plants to adverse climatic situation.

On the other hand, forest fire may increase. Changes of pest population will increase the stress on the forests.

The potential impacts of climate change will also be evident on forest wildlife. If their habitats shift to north , many forms of wildlife would be able to adapt themselves with changed climate. But the development of roads, human settlements and other modification of natural environment may block the migration routes.

FisheriesGlobal warming may have diverse effects on the fish

population and other aquatic life forms. It may change the chemical composition of the water

bodies. Loss of wet lands may alter the food supply for certain

species. Scientists have examined the implications of climate change

on three types of marine environment which are discussed below.

Inland Fisheries: Higher temperatures may have the most important implications for inland fisheries. Like plants and birds- most species of fish will require a wide difference between winter and summer season which may not be found in changed climatic condition.

Coastal Fisheries: Wetland loss, salinity changes, and higher temperatures are all likely to affect finfish and shell fish in the coastal zone. The most vulnerable species are those that either reproduce in coastal wetlands , spend their life times in the estuary or both.

Ocean Fisheries: Fish population living in the deep seas will be less affected by global warming.