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Green house gases emissions
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.
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Green house gases emissions
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- 3. Contents • Greenhouse effect •History • Mechanism • Greenhouse gases • Impacts of Greenhouse effect • Control of Greenhouse effect
- 4. Greenhouse Effect • Thegreenhouse 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 GREENHOUSEEFFECT • 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 GREENHOUSEEFFECT • 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 GREENHOUSEEFFECT • 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 ofthese 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 dothey 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 dothey 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 Roleof 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 GreenhouseGases • 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 thesun’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 reachesearth, 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 thereflectivity • 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 GreenhouseGas 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 somesolutions 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.
Editor's Notes
- #5 The trapping of heat due to Greenhouse gases
- #6 This is called the
- #7 there were developments in infrared spectroscopy for measuring long-wave radiation.
- #12 Concentration, or abundance, is the amount of a particular gas in the air
- #14 All of these gases remain in the atmosphere long enough to become well mixed, meaning that the amount that is measured in the atmosphere is roughly the same all over the world, regardless of the source of the emissions.
- #17 Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change. CO2 is absorbed and emitted naturally as part of the carbon cycle, through animal and plant respiration, volcanic eruptions, and ocean-atmosphere exchange. Human activities, such as the burning of fossil fuels and changes in land use, release large amounts of carbon to the atmosphere, causing CO2 concentrations in the atmosphere to rise. Methane is produced through both natural and human activities. For example, natural wetlands, agricultural activities, and fossil fuel extraction and transport all emit CH4. Nitrous oxide is produced through natural and human activities, mainly through agricultural activities and natural biological processes. Fuel burning and some other processes also create N2O. Concentrations of N2O have risen approximately 18% since the start of the Industrial Revolution, with a relatively rapid increase towards the end of the 20th century. [Water vapor is the most abundant greenhouse gas and also the most important in terms of its contribution to the natural greenhouse effect, despite having a short atmospheric lifetime. Some human activities can influence local water vapor levels. However, on a global scale, the concentration of water vapor is controlled by temperature, which influences overall rates of evaporation and precipitation. [1]Therefore, the global concentration of water vapor is not substantially affected by direct human emissions. Tropospheric ozone (O3), which also has a short atmospheric lifetime, is a potent greenhouse gas. Chemical reactions create ozone from emissions of nitrogen oxides and volatile organic compounds from automobiles, power plants, and other industrial and commercial sources in the presence of sunlight. In addition to trapping heat, ozone is a pollutant that can cause respiratory health problems and damage crops and ecosystems. Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), together called F-gases, are often used in coolants, foaming agents, fire extinguishers, solvents, pesticides, and aerosol propellants. Unlike water vapor and ozone, these F-gases have a long atmospheric lifetime, and some of these emissions will affect the climate for many decades or centuries.
- #19 Altering the Energy Balance The power of a process to alter the climate is estimated by its "radiative forcing," the change in the Earth's energy balance due to that process. Some climate forcings are positive, causing globally averaged warming, and some are negative, causing cooling. Some, such as from increased CO₂ concentration, are well known; others, such as from aerosols, are more uncertain.
- #21 Changes occurring in the sun itself can affect the intensity of the sunlight that reaches Earth’s surface. The intensity of the sunlight can cause either warming (during periods of stronger solar intensity) or cooling (during periods of weaker solar intensity). The sun follows a natural 11-year cycle of small ups and downs in intensity, but the effect on Earth’s climate is small. [1] [5] Changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis can also affect the amount of sunlight reaching Earth’s surface. [