Tuesday, December 6, 2011

EFest Semi Final Papers

   Weather changes all the time. The average pattern of weather, called climate, usually stays pretty much the same for centuries if it is left to itself. However, the earth is not being left alone.

What are the main indicators of Climate Change?
•    Sea level Rise
•    Predominance of Westerly Weather
•    Risk of Tidal Flooding in London
•    Marine Plankton
•    Appearance of Ice on Lake Windermere
•    Upstream Migration of Salmon

Causes of Climate Change

                        The causes of climate change can be divided into two categories, human and natural causes.
                       It is now a global concern that the climatic changes occurring today have been speeded up because of man's activities.

Natural Causes of Climate Change

                   The earth’s climate is influenced and changed through natural causes like volcanic eruptions, ocean current, the earth’s orbital changes and solar variations.

Volcanic eruptions -  When a volcano erupts it throws out large volumes of sulphur dioxide (SO2), water vapour, dust, and ash into the atmosphere. Large volumes of gases and ash can influence climatic patterns for years by increasing planetary reflectivity causing atmospheric cooling.

Ocean current - The oceans are a major component of the climate system. Ocean currents move vast amounts of heat across the planet. Winds push horizontally against the sea surface and drive ocean current patterns. Interactions between the ocean and atmosphere can also produce phenomena such as El Niño which occur every 2 to 6 years.

Earth orbital changes - The earth makes one full orbit around the sun each year. It is tilted at an angle of 23.5° to the perpendicular plane of its orbital path.. Slow changes in the Earth’s orbit lead to small but climatically important changes in the strength of the seasons over tens of thousands of years. Climate feedbacks amplify these small changes, thereby producing ice ages.
Solar variations - The Sun is the source of energy for the Earth’s climate system. Although the Sun’s energy output appears constant from an everyday point of view, small changes over an extended period of time can lead to climate changes. Some scientists suspect that a portion of the warming in the first half of the 20th century was due to an increase in the output of solar energy.

Human Causes of Climate Change

           "It has been demonstrated beyond reasonable doubt that the climate is changing due to man-made greenhouse gases. We are already committed to future substantial change over the next 30 years and change is likely to accelerate over
"There is strong evidence that the warming of the Earth over the last half-century has been caused largely by human activity, such as the burning of fossil fuels and changes in land use, including agriculture and deforestation."

The certainty of global warming can be seen through some of the natural phenomenon like the effect on crops and extreme weather conditions around the world. It is especially clear in the dramatic change of the polar caps, i.e. the Arctic ice cap is shrinking and the Antarctica ice shelf is melting.
 Main Contributors and Causes of Climate Change
* 4% of carbon emissions come from industrial processes

* 7% come from agriculture – for example methane emissions from livestock and manure, and nitrous oxide emissions from chemical fertilisers21% carbon emissions from transport

65% come from the use of fuel to generate energy (excluding transport)

About 40% of carbon emissions in the UK are the result of decisions taken directly by individuals. The biggest sources of emissions for most people are likely to be:


* energy use in the home (the main use is heating)

* driving a car

* air travel

Agriculture as a Contributor to the Causes of Climate Change

        According to the Intergovernmental Panel on Climate Change, the three main causes of the increase in greenhouse gases observed over the past 250 years have been fossil fuels, land use, and agriculture.

        Agriculture has been shown to produce significant effects on climate change, primarily through the production and release of greenhouse gases such as carbon dioxide, methane, and nitrous oxide.

The causes of climate change continued

Increase in global temperatures - Inter-government Panel

       The most recent assessment report from the Intergovernmental Panel on Climate Change (IPCC) says that the earth’s average temperature has risen by 0.74 degrees in the period from 1906 to 2005, and that the average temperature will continue to rise.
 Scientific Basis of Climate Change and Causes

       The IPCC's report "Climate Change 2011The Scientific Basis" is the most comprehensive and up-to-date scientific assessment of past, present and
future climate change.
The report:

• Analyses an enormous body of observations of all parts of the climate system

• Catalogues increasing concentrations of atmospheric greenhouse gases

• Assesses our understanding of the processes and feedbacks which govern the climate system

• Projects scenarios of future climate change using a wide range of models of future emissions of greenhouse gases and aerosols.

• Makes a detailed study of whether causes by a human influence on climate can be identified

• Suggests gaps in information and understanding that remain in our knowledge of climate change and how these might be
addressed

 
Climate Change and the IPCC (Intergovernmental Panel on Climate Change)

            The Intergovernmental Panel on Climate Change (IPCC) was jointly established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) in 1988.

Its terms of reference include:

             1. To assess available scientific and socio-economic information on climate change and its impacts and on the options for mitigating climate change and adapting to it and
              2. To provide, on request, scientific/technical/socio-economic advice to the Conference of the Parties  (COP) to the United Nations Framework Convention on Climate Change (UNFCCC). From 1990, the IPCC has produced a series of Assessment Reports, Special Reports, Technical Papers, methodologies and other products that have become standard works of reference, widely used by policymakers, scientists and other experts.

What is Global Warming  (Effect by Climate Change)

            Global warming and climate change refer to an increase in average global temperatures. Natural events and human activities are believed to be contributing to an increase in average global temperatures. This is caused primarily by increases in “greenhouse” gases such as Carbon Dioxide (CO2).

                A warming planet thus leads to a change in climate which can affect weather in various ways, as discussed further below.
What is the Greenhouse

          A greenhouse (also called a glasshouse) is a building where plants are grown. These structures range in size from small sheds to very large buildings. A miniature greenhouse is known as a cold frame.Greenhouses can be divided into glass greenhouses and plastic greenhouses. Plastics mostly used are PEfilm and multiwall sheet in PC or PMMA.

What is the Greenhouse Effect?

         These gases, which are all naturally occurring, act as a blanket, trapping in the heat and preventing it from being reflected too far from the Earth. They keep the Earth's average temperature at about 15°C: warm enough to sustain life for humans, plants and animals. Without these gases, the average temperature would be about  -18°C... too cold for most life forms. This natural warming effect is also sometimes called the greenhouse effect

•    Energy from the sun drives the earth’s weather and climate, and heats the earth’s surface;
•    In turn, the earth radiates energy back into space;
•    Some atmospheric gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse;
•    These gases are therefore known as greenhouse gases;
•    The greenhouse effect is the rise in temperature on Earth as certain gases in the atmosphere trap energy.



         Six main greenhouse gases are carbon dioxide (CO2), methane (CH4) (which is 20 times as potent a greenhouse gas as carbon dioxide) and nitrous oxide (N2O), plus three fluorinated industrial gases: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). Water vapor is also considered a greenhouse gas.

Carbon dioxide (CO2):

Carbon dioxide is the main culprit

         The single human activity that is most likely to have a large impact on the climate is the burning of "fossil fuels" such as coal,
oil and gas. These fuels contain carbon. Burning them makes carbon dioxide gas. Since the early 1800s, when people began burning large amounts of coal and oil, the amount of carbon dioxide in the earth's atmosphere has increased by nearly 30%, and average global temperature appears to have risen between 1° and 2°F.

         Carbon dioxide gas traps solar heat in the atmosphere, partly in the same way as glass traps solar heat in a sunroom or a greenhouse. For this reason, carbon dioxide is sometimes called a "greenhouse gas."

         If global warming occurs, not every day or every place will be warmer. But on average most places will be warmer. This will cause changes in the amount and pattern of rain and snow, in the length of growing seasons, in the frequency and severity of storms, and in sea level. Farms, forests, and plants and animals in the natural environment, will all be affected.
The ozone hole is a different problem:

         Many people confuse the hole in the ozone layer with climate change. However, these two problems are not closely related. The ozone layer protects the earth from harmful ultraviolet light that can cause skin cancer and damage plants and animals. The main cause of the hole in the ozone layer is chlorofluorocarbons (CFCs), gases that are used in refrigerators, air conditioners, and industrial applications.                      

         While CFCs alone cause warming, their ozone destruction can cause cooling. So far these warming and cooling influences have approximately balanced. Prior to 1978 CFCs were used as a propellant in aerosol spray cans, but that use has ended in the U.S. Under an international agreement most uses of CFCs are now being phased out to protect the ozone layer.

CO2 - the major cause of global warming

            Global warming is caused by the emission of greenhouse gases . 72% of the totally emitted greenhouse gases is carbon dioxide (CO2), 18% Methane and 9% Nitrous oxide (NOx). Carbon dioxide emissions therefore are the most important cause of global warming. CO2 is inevitably created by burning fuels like e.g. oil, natural gas, diesel, organic-diesel, petrol, organic-petrol, ethanol. The emissions of CO2 have been dramatically increased within the last 50 years and are still increasing by almost 3% each year, see graph below:


Graph 1: CO2 emissions world-wide by year and CO2 concentration in the atmosphere by year
 Chart 2: Increase of global average temperature for the last 20 years (source: wri.org)
            The carbon dioxide is released to the atmosphere where it remains for 100 to 200 years. This leads to an increasing concentration of carbon dioxide in our atmosphere (see above on the right hand side), which in turn causes the average temperature on Earth to raise (see graph below).
            Recent investigations have shown that inconceivable catastrophic changes in the environment will take place if the global temperatures increase by more than 2° C (3.6° F). A warming of 2° C (3.6° F) corresponds to a carbon dioxide (CO2) concentration of about 450 ppm (parts per million) in the atmosphere.

Rising Sea Levels

            Water expands when heated, and sea levels are expected to rise due to climate change. Rising sea levels will also result as the polar caps begin to melt.
            Rising sea levels is already affecting many small islands.
            Rising sea levels will impact many coastlines, and a large mass of humanity lives near the coasts or by major rivers.               Analysis by the World Wildlife Fund has found that many cities are unprepared for climate change effects such as rising sea levels
Agriculture and livelihoods are already being affected
            Failing agriculture in the future have long been predicted.
            Looking to 2100, scientists who looked at projections of global warming’s impact on the average temperatures during the growing season fear that rising temperatures will have a significant impact upon crop yields, most noticeably in the tropics and sub tropics.
            While warm weather can often be good for some crops, hotter than average temperatures for the entire season is often not good for plants.
            This would affect at least half the world’s population that either live in the region or rely on food coming from that region.

Effects of Global Warming

            The increase in the warming of the atmosphere has significant effects on both natural environment and human life. Obvious effects include glacial retreat, Arctic shrinkage, and worldwide sea level rise. There are also less obvious effects such as economic trouble, ocean acidification, and population risks. As climate changes, everything changes from the natural habitats of wildlife to the culture and sustainability of a region.
Melting of the Polar Ice Caps

             One of the most obvious effects of global warming involves the melting of the polar ice caps. According to the National Snow and Ice Data Center, there are 5,773,000 cubic miles of water, ice caps, glaciers, and permanent snow on our planet. As these continue to melt, sea levels rise. Rising sea levels are also caused by expanding ocean water, melting mountain glaciers, and the ice sheets of Greenland and Antarctica melting or sliding into the oceans. Rising sea levels result in coastal erosion, coastal flooding, increased salinity of rivers, bays, and aquifers, and shoreline retreat.

             Melting ice caps will desalinize the ocean and disrupt natural ocean currents. Since ocean currents regulate temperatures by bringing warmer currents into cooler regions and cooler currents into warmer regions, a halt in this activity may cause extreme climate changes, such as Western Europe experiencing

Another important effect of melting ice caps lies in a changing albedo. Albedo is the ratio of the light reflected by any part of the earth's surface or atmosphere. Since snow has one of the highest albedo level, it reflects sunlight back into space, helping to keep the earth cooler. As it melts, more sunlight is absorbed by the earth's atmosphere and the temperature tends to increase.
To Control Climate Change, Alternative Energy Technologies Must Be Developed

           To Control Climate Change, Alternative Energy Technologies Must Be Developed

            Uncertainty in the climate sensitivity to growing levels of atmospheric carbon dioxide has been a stumbling block to policy makers addressing the climate change issue. A study published in the March 28 issue of the journal Science, however, concludes that huge reductions in fossil-fuel carbon emissions will be required by the middle of this century -- regardless of the likely climate sensitivity.

               "To reduce carbon dioxide emissions and avoid dangerous interference with the climate system, we must switch to alternative, carbon-free energy sources," said Atul Jain, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign and a co-author of the study.

          Jain and his colleagues -- lead author Ken Caldeira, a senior scientist at the Lawrence Livermore National Laboratory, and Martin Hoffert, a professor of physics at New York University -- found that even if climate sensitivity is in the low end of the accepted range, climate stabilization will require a massive transition to carbon-emission-free energy technologies during this century.

         Climate sensitivity is the global mean temperature change that would result from doubling the amount of carbon dioxide in the atmosphere. Based on current models, climate sensitivity is thought to lie between 1.5 degrees Celsius and 4.5 degrees Celsius.

         If climate sensitivity is at the high end of the range, then by the end of this century nearly all of our power will have to come from non-carbon-dioxide-emitting sources, the researchers found. "We must begin replacing fossil fuels with alternative energy technologies that support economic growth and equity," Jain said. "To achieve stabilization at a 2 degree Celsius warming, we would need to bring the equivalent of a large carbon-emission-free power plant into production somewhere in the world every day for the next 50 years."

Prediction for future temperature increase (global warming predictions)

        According to different assumption about the future behaviour of mankind, a projection of current trends as represented by a number of different scenarios gives temperature increases of about 3° to 5° C (5° to 9° Fahrenheit) by the year 2100 or soon afterwards. A 3°C or 5° Fahrenheit rise would likely raise sea levels by about 25 meters (about 82 feet).


Ten Personal Solutions to Global Warming

Individual choices can have an impact on global climate change.

1.    The car you drive: the most important personal climate decision.
         When you buy your next car, look for the one with the best fuel economy in its class. Each gallon of gas you use is responsible for 25 pounds of heat-trapping gases in the atmosphere. Better gas mileage not only reduces global warming, but will also save you thousands of dollars at the pump over the life of the vehicle.
2.     Choose clean power:       More than half the electricity in the United States comes from polluting coal-fired power plants. And power plants are the single largest source of heat-trapping gas. None of us can live without electricity, but in some states, you can switch to electricity companies that provide 50 to 100 percent renewable energy.
3.     Look for Energy Star:     When it comes time to replace appliances, look for the Energy Star label on new appliances (refrigerators, freezers, furnaces, air conditioners, and water heaters use the most energy). These items may cost a bit more initially, but the energy savings will pay back the extra investment within a couple of years. Household energy savings really can make a difference: If each household in the United States replaced its existing appliances with the most efficient models available, we would save $15 billion in energy costs and eliminate 175 million tons of heat-trapping gases.
4.    Unplug a freezer.

         One of the quickest ways to reduce your global warming impact is to unplug the extra refrigerator or freezer you rarely use (except when you need it for holidays and parties). This can reduce the typical family's carbon dioxide emissions by nearly 10 percent.
5.    Get a home energy audit.

         Take advantage of the free home energy audits offered by many utilities. Simple measures, such as installing a programmable thermostat to replace your old dial unit or sealing and insulating heating and cooling ducts, can each reduce a typical family's carbon dioxide emissions by about 5 percent.
6.     Light bulbs matter.

        If every household in the United States replaced one regular light bulb with an energy-saving model, we could reduce global warming pollution by more than 90 billion pounds over the life of the bulbs; the same as taking 6.3 million cars off the road. So, replace your incandescent bulbs with more efficient compact fluorescents, which now come in all shapes and sizes.
7.    Think before you drive.
If you own more than one vehicle, use the less fuel-efficient one only when you can fill it with passengers. Driving a full minivan may be kinder to the environment than two midsize cars. Whenever possible, join a carpool or take mass transit.
8.    Buy good wood.
When buying wood products, check for labels that indicate the source of the timber. Supporting forests that are managed in a sustainable fashion makes sense for biodiversity, and it may make sense for the climate too..
9.    Plant a tree.
You can also make a difference in your own backyard. Get a group in your neighborhood together and contact your local arborist or urban forester about planting trees on private property and public land
10.    Let policymakers know you are concerned about global warming.
          Our elected officials and business leaders need to hear from concerned citizens. Sign up for the Union of Concerned Scientists Action Network to ensure that policymakers get the timely, accurate information they need to make informed decisions about global warming solutions.

Global Warming Solutions:

          Even if we stopped emitting greenhouse gases (GHGs) today, the Earth would still warm by another degree Fahrenheit or so. But what we do from today forward makes a big difference.  Depending on our choices, scientists predict that the Earth could eventually warm by as little as 2.5 degrees or as much as 10 degrees Fahrenheit.

          A commonly cited goal is to stabilize GHG concentrations around 450-550 parts per million (ppm), or about twice pre-industrial levels. This is the point at which many believe the most damaging impacts of climate change can be avoided.  Current concentrations are about 380 ppm, which means there isn’t much time to lose.  According to the IPCC, we’d have to reduce GHG emissions by 50% to 80% of what they’re on track to be in the next century to reach this level.

          Researchers Stephen Pacala and Robert Socolow at Princeton University have suggested one approach that they call “stabilization wedges.” This means reducing GHG emissions from a variety of sources with technologies available in the next few decades, rather than relying on an enormous change in a single area.  They suggest 7 wedges that could each reduce emissions, and all of them together could hold emissions at approximately current levels for the next 50 years, putting us on a potential path to stabilize around 500 ppm.

           Some of these technologies have drawbacks, and different communities will make different decisions about how to power their lives, but the good news is that there are a variety of options to put us on a path toward a stable climate.
Conclusion

          Global warming  (or) Climate Change  is affecting plants, animals, humans and the earth. We need to learn how to conserve our use of fossil fuels to minimize carbon dioxide production. This will slow down the effects of global warming

1 comment:

  1. Thank you for sharing this information.
    It will really helpful to solve my confusion

    Process $ Chemical Engineering

    ReplyDelete