Global warming is long-term rise in the average temperature of the earth’s climate system. It is a major aspect of current climate change, and has been demonstrated by direct temperature measurements of various effects of the warming. The term commonly refers to the human caused increase in global surface temperatures. Although there prehistoric phases of global warming, but observed changes since the mid 20th century have been much greater than previous records covering decades to thousands of years.
2. GLOBAL WARMING AND
GREENHOUSE GASES
GLOBAL WARMING IS LONG-TERM RISE IN THE AVERAGE TEMPERATURE OF THE EARTH’S
CLIMATE SYSTEM. IT IS A MAJOR ASPECT OF CURRENT CLIMATE CHANGE, AND HAS BEEN
DEMONSTRATED BY DIRECT TEMPERATURE MEASUREMENTS OF VARIOUS EFFECTS OF THE
WARMING. THE TERM COMMONLY REFERS TO THE HUMAN CAUSED INCREASE IN GLOBAL
SURFACE TEMPERATURES. ALTHOUGH THERE PREHISTORIC PHASES OF GLOBAL
WARMING,BUT OBSERVED CHANGES SINCE THE MID 20TH CENTURY HAVE BEEN MUCH
GREATER THAN PREVIOUS RECORDS COVERING DECADES TO THOUSANDS OF YEARS.
3. CAUSES OF GLOBAL WARMING
The chief causes of global warming (or the physical drivers of climate
change) include:
A)Greenhouse Gases
B)Land Use Change
C)Aerosols and Soot.
D)Minor Forcings.
4. GREENHOUSE GASES AND
GREENHOUSE EFFECT.
A greenhouse gas is a gas that absorbs and emits the infrared radiation in
the wavelength range emitted by earth.The greenhouse gases trap the heat
radiating from the earth into space. This heat in the form of infrared
radiations, get absorbed and emitted by these gases in the atmosphere, thus
warming the earth’s surface .The major greenhouse gases are:
A)Water vapour causing 36-70% of the greenhouse effect.
B)Carbon Dioxide causing 9-26% percent of the greenhouse effect.
C)Methane: Causing about 4-9%
D)Ozone: Causes about 3-7%.
Human Activity since the Industrial Revolution increased the amount of
greenhouse gases in the atmosphere.
5. Earth receives energy from the Sun in the form of ultraviolet, visible,
and near-infrared radiation. About 26% of the incoming solar energy is
reflected to space by the atmosphere and clouds, and 19% is absorbed
by the atmosphere and clouds. Most of the remaining energy is
absorbed at the surface of Earth. Because the Earth's surface is
colder than the Sun, it radiates at wavelengths that are much
longer than the wavelengths that were absorbed. Most of this thermal
radiation is absorbed by the atmosphere and warms it. The atmosphere
also gains heat by sensible and latent heat fluxes from the surface. The
atmosphere radiates energy both upwards and downwards; the part
radiated downwards is absorbed by the surface of Earth. This leads to a
higher equilibrium temperature than if the atmosphere did not radiate.
6. Greenhouse Gases
Carbon dioxide
combustion of solid waste, fossil fuels (oil, natural gas, and coal), and wood and
wood products
Methane :
production and transport of coal, natural gas, and oil. Methane emissions also
result from the decomposition of organic wastes in municipal solid waste landfills,
and the raising of livestock.
Nitrous oxide
agricultural and industrial activities, as well as during combustion of solid waste
and fossil fuels.
hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur
hexafluoride
7. Other causes of Global Warming
Land use Change:
type of vegetation in a region by changing how much sunlight gets reflected
back into space called albedo, and how much heat is lost by evaporation.
For example, the change from a dark forest to grassland makes the surface
lighter, causing it to reflect more sunlight.
Aerosols and Soot.
Solid and liquid particles known as aerosols(from volcanoes, planktons, human-
made substances) reflect sunlight, thereby cooling the climate.
While aerosols limit global warming by reflecting sunlight, black carbon in soot that
falls on snow or ice can contribute to global warming. Limiting the black carbon
deposits in the Arctic regions could reduce global warming by 0.2 degress by 2050.
11. Many of the effects of global warming have been well-documented, and observations from real life are
consistent with earlier predictions.
The effects that can be predicted include:
•more drought and more flooding
•rising sea level
•less ice and snow
•more extreme weather incidents
12. More drought and more flooding:
In some regions of the world this will result in crop
failure and famine especially in areas where temperatures
are already high.
When the weather gets warmer, evaporation from both
land and sea increases. This can cause drought in areas of
the world.
Individual droughts have been linked to climate change,
such as the drought that hit central India in 2008 when the
north-south pattern of precipitation was disrupted by
unusual weather driven by abnormally high sea surface
temperatures due in part to global warming
Extra water vapour in the atmosphere falls again as extra
rain which can cause flooding in other places in the world.
13. •Rising sea level:
Sea level rises because of melting ice and snow and because of the thermal
expansion of the sea (water expands when warmed). Areas that are just above
sea level now, may become submerged.
For example, some Pacific Island nations are expected to be partially or
completely submerged by the end of the century. Coastal and shallow marine
plants and animals will be affected, for example mangroves and coral reefs.
In countries with large areas of coastal lowland there will be a dual risk of
river floods and coastal flooding, which will reduce the area for living and
working. Coastal defences will need to be strengthened, and river levees will
need to be developed.
•The most recent meetings of scientists (2009 Climate Change Summit,
Copenhagen (COP15) suggest that the consequences of increase in temperature
caused by the greenhouse effect may be more severe than were previously
thought.
14. Less ice and snow:
Worldwide, glaciers are shrinking rapidly at present. Ice appears
to be melting faster than previously estimated. In areas that are
dependent on meltwater from mountain areas, this can cause
drought and lack of domestic water supply.
According to the IPCC, up to a sixth of the world's population
lives in areas that will be affected by meltwater reduction.
Polar bear extinction
Towns and villages that are dependent on meltwater from
mountain areas may suffer drought and lack of domestic water
supply.
15. Vienna Conference (1985)
The Vienna Conference was the first international conference on ozone layer depletion.
It was held in Vienna, Austria in 1985 when a hole in the stratospheric ozone layer was
observed in the South Pole marked by increased UV-B infiltration over Antarctica.
A 'hole', marked by significant drop in ozone molecules in the layer, as large as that of
United States, was discovered by a British team.
The Vienna Convention for the Protection of the Ozone Layer was agreed at the
conference and it entered into force in 1987.
16. Montreal Protocol 1987
The Montreal Protocol on Substances that Deplete the Ozone Layer is an
international treaty designed to protect the ozone layer by phasing out the
production of numerous substances that are responsible for ozone depletion.
The treaty was structured around several groups of halogenated hydrocarbons
that have been shown to play a role in ozone depletion. All of these ozone
depleting substances contain either chlorine or bromine (substances containing
only fluorine do not harm the ozone layer).
For each group, the treaty provides a timetable on which the production of those
substances must be phased out and eventually eliminated.
As a result of the international agreement, the ozone hole in Antarctica is slowly
recovering. Climate projections indicate that the ozone layer will return to 1980
levels between 2050 and 2070
17. Kyoto protocol 1992
THE KYOTO PROTOCOL IS A PROTOCOL TO THE UNITED NATIONS
FRAMEWORK CONVENTION ON CLIMATE CHANGE (UNFCCC), AIMED AT
THE FIGHTING GLOBAL WARMING.
THE UNFCCC IS AN INTERNATIONAL ENVIRONMENTAL TREATY WITH THE
GOAL OF ACHIEVING THE "STABILIZATION OF GREENHOUSE GAS
CONCENTRATIONS IN THE ATMOSPHERE AT A LEVEL THAT WOULD
PREVENT DANGEROUS ANTHROPOGENIC INTERFERENCE WITH THE
CLIMATE SYSTEM”.
THE PROTOCOL WAS INITIALLY ADOPTED ON 11 DECEMBER 1997 IN
KYOTO, JAPAN, AND ENTERED INTO FORCE ON 16 FEBRUARY 2005.
AS OF SEPTEMBER 2011, 191 STATES HAVE SIGNED AND RATIFIED THE
PROTOCOL.
EACH COUNTRY HAS A PRESCRIBED NUMBER OF 'EMISSION UNITS' WHICH
MAKE UP THE TARGET EMISSION. THE KYOTO PROTOCOL PROVIDES
MECHANISMS FOR COUNTRIES TO MEET THEIR EMISSION TARGETS.
18. Under the Protocol, 37 countries ("Annex I countries") commit themselves to a reduction
of four greenhouse gases (GHG) (carbon dioxide, methane, nitrous oxide, Sulphur
hexafluoride) and two groups of gases (hydro fluorocarbons and per fluorocarbons)
produced by them, and all member countries give general commitments
At negotiations, Annex I countries collectively agreed to reduce their greenhouse gas
emissions by 5.2% on average for the period 2008-2012.
Since the US has not ratified the treaty
19. Paris Agreement 2015
The Paris Agreement is an agreement within the United Nations Framework
Convention on Climate Change (UNFCCC) dealing with greenhouse gases
emissions mitigation, adaptation and finance starting in the year 2020 and has
been ratified by 61 countries till now.
Aims
To achieve a legally binding agreement, with universal participation among all nations.
To keep global warming below what most scientists say is the critical threshold of 2 degrees
Celsius of warming
Making finance flows consistent with a pathway towards low greenhouse gas emissions and
climate-resilient development
low greenhouse gas emissions development, in a manner that does not threaten food production
Increasing the ability to adapt to the adverse impacts of climate change and foster climate
resilience
The International Solar Alliance (ISA) is an alliance of more than 122
countries initiated by India.
20. Global Warming and SDGs
Climate action and sustainable development are inseparable.
SDG goal 13, ‘Climate Action’ wholly concerned about climate change/global warming.
Target 13.a: Implement the commitment undertaken by developed-country parties to
the UNFCC to a goal of mobilizing jointly $100 billion annually by 2020 from all sources
to address the needs of developing countries in the context of meaningful mitigation
actions and transparency on implementation and fully operationalize the Green Climate
Fund through its capitalization as soon as possible
Target 13.b: Promote mechanisms for raising capacity for effective climate change-
related planning and management in least developed countries and small island
developing States, including focusing on women, youth and local and marginalized
communities.
21. India's approach
In June 2008 India announced its National Action Plan on Climate Change.
The Plan covers eight broad areas through its National Missions which takes care
The National Missions
1. National Solar Mission
2. National Mission for Enhanced Energy Efficiency
3. National Mission on Sustainable Habitat
4. National Mission for Sustaining the Himalayan Ecosystem
5. National Mission for a “Green India”
6. National Mission for Sustainable Agriculture
7. National Mission on Strategic Knowledge for Climate Change
8. National Water Mission
22. What can be done/What can we do
Replacing fossil fuels by Renewable energy
setting a price on carbon
protecting forests, Plantation
Reduce, Reuse, Recycle
Use less heat and air conditioning
Drive less drive smart
Buying energy efficient products (e.g. CFL)
Boycott plastic bags
Reduce use of sprays
