The document discusses the greenhouse effect and its history. It explains that the greenhouse effect occurs when greenhouse gases in the atmosphere absorb and re-radiate thermal radiation from the surface, warming the lower atmosphere and surface. It then discusses the work of Svante Arrhenius in the 1890s recognizing this phenomenon and the subsequent research verifying it. The document also outlines the main greenhouse gases and their varying impacts on global temperatures. Finally, it discusses some of the environmental, economic, and human health impacts of increased greenhouse gas emissions and potential solutions like transitioning to renewable energy and reducing emissions and pollution.

2. Presented By:
– Shamim
Mukhtar

3. Contents
• Greenhouse effect
• History
• Mechanism
• Greenhouse gases
• Impacts of Greenhouse effect
• Control of Greenhouse effect

4. Greenhouse Effect
• The greenhouse effect is a process by which thermal radiation
from a planetary surface is absorbed by
atmospheric greenhouse gases, and is re-radiated in all
directions
• Since part of this re-radiation is back towards the surface and
the lower atmosphere, it results in an elevation of the average
surface temperature

5. HISTORY OF GREENHOUSE EFFECT
• Svante Arrhenius (1859-1927) was a Swedish scientist that was the first to
claim in 1896 that fossil fuel combustion may eventually result in enhanced
global warming
• He proposed a relation between atmospheric carbon
dioxide concentrations and temperature
• He found that the average surface temperature of the earth is about 15oC
because of the infrared absorption capacity of water vapor and carbon
dioxide-Natural Greenhouse Effect
• This was not actually verified until 1987.

6. HISTORY OF GREENHOUSE EFFECT
• In the 1940's at that time it was proven that increasing the amount of atmospheric
carbon dioxide resulted in more absorption of infrared radiation
• In the 1950's evidence was found that carbon dioxide has an atmospheric lifetime
of approximately 10 years
• In the 1990's scientists started to question the greenhouse effect theory, because
of major uncertainties in the data sets and model outcomes

7. HISTORY OF GREENHOUSE EFFECT
• Global warming discussion is still continuing today and data is constantly
checked and renewed
• Models are also updated and adjusted to new discoveries and new theory
• But climate change is a global problem that is hard to solve by single
countries
• Therefore in 1998 the Kyoto Protocol was negotiated in Kyoto, Japan
– It requires participating countries to reduce their anthropogenic greenhouse
gas emissions (CO2, CH4, N2O, HFCs, PFCs, and SF6) by at least 5% below 1990
levels in the commitment period 2008 to 2012
– The Kyoto Protocol was eventually signed in Bonn in 2001 by 186 countries

11. How much of these gases are in the
atmosphere?
• Greenhouse gas concentrations are
measured in
– parts per million, parts per billion, and even
parts per trillion
• Larger emissions of greenhouse gases
lead to higher concentrations in the
atmosphere
• We produce more carbon dioxide than
any other greenhouse gas, and it's
responsible for most of the warming

13. How long do they stay in the
atmosphere?
• Each of these gases
can remain in the
atmosphere for
different amounts of
time, ranging from a
few years to
thousands of years

14. How strongly do they impact global
temperatures?
• Some gases are more effective than others at
making the planet warmer and "thickening the
Earth's blanket."
• For each greenhouse gas, a Global Warming
Potential (GWP) has been calculated to reflect
how long it remains in the atmosphere, on
average, and how strongly it absorbs energy.
• Gases with a higher GWP absorb more energy,
per pound, than gases with a lower GWP, and
thus contribute more to warming Earth.

15. The Recent Role of the Greenhouse
Effect
• Since the Industrial Revolution began around
1750, human activities have contributed
substantially to climate change by adding CO2 and
other heat-trapping gases to the atmosphere.
These greenhouse gas emissions have increased
the greenhouse effect and caused Earth’s surface
temperature to rise. The primary human activity
affecting the amount and rate of climate change
is greenhouse gas emissions from the burning of
fossil fuels.

16. The Main Greenhouse Gases
• Carbon dioxide
• Methane
• Nitrous oxide
• Other Greenhouse Gases
• Water vapor
• Tropospheric ozone (O3)
• Chlorofluorocarbons (CFCs),
hydrochlorofluorocarbons (HCFCs),
hydrofluorocarbons (HFCs),
perfluorocarbons (PFCs), and sulfur
hexafluoride (SF6), together
called F-gases
• Other Climate Forcers(black carbon
and sulpates etc)

20. Changes in the sun’s energy
• Changes in solar energy continue to affect climate.
• Changes occurring in the sun itself can affect the intensity of
the sunlight that reaches Earth’s surface.
• Changes in the shape of Earth’s orbit as well as the tilt

21. • Sunlight reaches earth, it can be reflected
or absorbed
• Light-colored objects and surfaces,
• Darker objects and surfaces
• Earth as a whole has an albedo of about
30%, meaning that 70% of the sunlight that
reaches the planet is absorbed
• Result of absorbance
Changes in the reflectivity

22. Changes in the reflectivity
• Reflectivity is also affected by aerosols.
• The climate effects of aerosols vary depending on what
they are made of and where they are emitted.
• Melting of sea ice or increases in cloud cover
• Volcanoes have played a noticeable role in climate
• Deforestation, reforestation,
desertification, and
urbanization often
contribute to changes in climate

23. Impacts of Greenhouse Gas Emissions
• Continued warming from the release of greenhouse gases (GHGs)
into the atmosphere is expected to have substantial impacts on the
environment, human health and the economy.
• Environmental impacts
• Overall average annual temperatures are expected to increase.
• Global warming will decrease snow, sea ice and glacier coverage,
resulting in rising sea levels and increased coastal flooding. Rising
temperatures will also thaw permafrost in the Arctic.
• Storms and heat waves are likely to increase in frequency and
severity.
• Many wild species will have difficulty adapting to a warmer climate
and will likely experience greater stress from diseases and invasive
species.

24. Human health impacts
• People living in Canada’s northern communities, and
vulnerable populations such as children and the
elderly, are expected to be the most affected by the
changes.
• Increased temperatures and more frequent and severe
extreme weather events could lead to increased risks
of death from dehydration and heat stroke.
• There may be an increased risk of respiratory and
cardiovascular problems and certain types of cancers,
as temperatures rise and exacerbate air pollution.

25. ECONOMIC IMPACS
• Agriculture, forestry, tourism and recreation could be affected
by changing weather patterns.
• Human health impacts are expected to place additional
economic stress on health and social support systems.
• Damage to infrastructure (e.g., roads and bridges) from
extreme weather events is expected to increase.

26. Greenhouse Gas Control:
• Legislation is being considered at the federal
and state levels that would control
greenhouse gas emissions thought to be the
cause of “global warming.”
• Laws mandating emission reductions are very
expensive, cause slower economic growth

27. What are some solutions to the
greenhouse effect?
• We need the greenhouse effect to keep the earth warm. What we don't need is the accelerated
greenhouse effect which we are experiencing now.
• The only solution is to move entirely to renewable energy, so we stop burning fossil fuels. There are
proven technologies working now. What we need is the will to change.
• Some solutions to the greenhouse effect are reducing pollution and carbon emissions. Another way
is to go green with our technologies, like with power plants and transportation.
• There is no complete solution to the greenhouse effect, because we don't know how to remove
carbon dioxide directly from the atmosphere, but we only know how to not add any more CO2 to
the atmosphere.
• We have to stop adding greenhouse gases to the atmosphere. (This means cutting down on burning
fossil fuels. Finding new ways of producing electricity. Reducing our use of electricity till we do.)
• And we have to plant more trees, millions and millions more.
• As trees absorb and store more carbon dioxide it will help. Trees also helps in bringing rain.