Green house gases emissions

Presented By:

– Shamim Mukhtar

Contents

• Greenhouse effect

• History

• Mechanism

• Greenhouse gases

• Impacts of Greenhouse effect

• Control of Greenhouse effect

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

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 carbondioxide 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.

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

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

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

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

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.

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.

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)

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

• 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

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

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.

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.

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.

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

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.