Green House Gases and Global Warming Issues

Name- Shashwat Jain

A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal

infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone.

Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would average about 33 °C colder, which is about 59 °F below the present average of 14 °C (57 °F).

Since the beginning of the Industrial Revolution (taken as the year 1750), the burning of fossil fuels and extensive clearing of native forests has contributed to a 40% increase in the atmospheric concentration of carbon dioxide, from 280 to 392.6 parts per million (ppm) in 2012 and has now reached 400 ppm in the northern hemisphere.

This increase has occurred despite the uptake of a large portion of the emissions by various natural

"sinks" involved in the carbon cycle. Anthropogenic carbon dioxide emissions come from combustion of carbon-based fuels, principally wood, coal, oil, and natural gas.

Under ongoing greenhouse gas emissions, available Earth System Models project that the Earth's surface temperature could exceed historical analogs as early as 2047 affecting most ecosystems on Earth and the livelihoods of over 3 billion people worldwide. Greenhouse gases also trigger ocean bio-geochemical changes with broad ramifications in marine systems.

The Greenhouse Effect and Global Warming

How the Greenhouse Effect Works

Carbon dioxide (CO2) is an atmospheric constituent that plays several vital roles in the environment. It absorbs infrared radiation in the atmosphere. It plays a crucial role in the weathering of rocks. It is the raw material for photosynthesis and its carbon is incorporated into organic matter in the biosphere and may eventually be stored in the Earth as fossil fuels.

Most of the sun's energy that falls on the Earth's surface is in the visible light portion of the electromagnetic spectrum. This is in large part because the Earth's atmosphere is transparent to these wavelengths (we all know that with a functioning ozone layer, the higher frequencies like ultraviolet are mostly screened out). Part of the sunlight is reflected back into space, depending on the albedo or reflectivity of the surface. Part of the sunlight is absorbed by the Earth and held as thermal energy. This heat is then re-radiated in the form of longer wavelength infrared radiation. While the dominant gases of the atmosphere (nitrogen and oxygen) are transparent to infrared, the so-called greenhouse gasses, primarily water vapor (H2O), CO2, and methane (CH4), absorb some of the infrared radiation.

They collect this heat energy and hold it in the atmosphere, delaying its passage back out of the atmosphere.

Due in part to the warming effects of the greenhouse gases, the global average temperature is about 15°C (59°F). Without the greenhouse gases the global average temperature would be much colder, about -18°C (0°F).

Greenhouse Gas Induced Global Warming

Since the industrial revolution got into full swing in the 19th century we have been burning ever increasing amounts of fossil fuels (coal, oil, gasoline, natural gas) in electric generating plants, manufacturing plants, trains, automobiles, airplanes, etc. Burning releases CO2 into the atmosphere (much the same as respiration does). These fossil fuels may have formed tens or hundreds of millions of years ago from the buried and preserved remains of plant and animal matter whose carbon originated via photosynthesis.

Photosynthesis and respiration in plants, animals, fungi, bacteria, etc. exchange carbon between the CO2 in the atmosphere and carbon compounds in organisms. But humans are now putting this natural carbon cycle out of balance. Because of the emission of CO2 long-stored

Sidebar: Photosynthesis - Respiration-Combustion

photosynthesisCO2 + H2O + sunlight -> CH2O + O2

respirationO2 + CH2O -> energy + H2O + CO2

combustionO2 + hydrocarbons -> energy + H2O + CO2

in fossil fuels the percentage of CO2 in the atmosphere has increased from about 289 parts per million before the industrial revolution to over 360 parts per million and rising. Sometime during the 21st century the concentration of CO2 will be twice what it was before the industrial revolution.

With higher CO2 concentrations come expectations of a stronger greenhouse effect and therefore warmer global temperatures. This was originally proposed by a chemist named Arrhenius about a century ago. Global average temperatures have risen by a small, but measurable amount in the past 100 years, apparently in large part because of the higher level of atmospheric CO2. Global average temperatures are expected to be on the order of 2-5°C (3.6-9°F) higher by the time CO2 doubles the pre-industrial concentration.

Consequences of Global Warming

A whole host of consequences will result. Some are probably already occurring. Temperature measurements of the sea surface and deep ocean indicate that the oceans are warming. Rising ocean temperature causes rising sea level from thermal expansion of the water. Rising temperature also means melting glaciers and rising sea level through addition of melt water to the oceans.

Rising sea level will cause increasing coastal erosion, flooding, and property damage during coastal storms on

top of the potential for major loss of life from storms in low-lying coastal countries like Bangladesh and island nations in the Indian and Pacific Oceans.

Warmer sea surface temperatures will result in more and stronger tropical storms (hurricanes and typhoons). Coastlines already ravaged by these storms will expect to see more strong storms than before, increasing the loss of life and damage to infrastructure.

Natural ecosystems will be hard pressed to keep up with the changing climate because the rate of change will be faster than typical long-term natural climate change.

What Can We Do About Global Warming?

We can't realistically stop the rise of CO2 in the near term, but we can slow it and therefore reduce the consequences that will occur. More fuel-efficient cars, less frivolous driving, more use of mass transit, improved insulation to decrease the fuel burned to heat and cool our homes, more efficient appliances, use of fluorescent rather than incandescent light bulbs , and careful monitoring of home electricity usage (turn off the lights and TV when not using them) can reduce our energy needs. Conversion to alternatives like wind and solar power which don't burn

All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012.

fossil fuels and emit CO2 into the atmosphere. Planting large areas with trees will consume CO2 as the trees grow,

until the forests mature. Stopping deforestation in the tropical forests around the world, especially in the Amazon and Indonesian rain forests, will keep that carbon in the forest rather than sending it back into the atmosphere as the trees are burned or decay and are not replaced by more. Other techniques have also been proposed such as the chemical removal of CO2 from smokestacks and burial in deep underground reservoirs, though only certain areas can benefit from this, or disposal in the deep ocean where they will form a semi-stable compound under the cold temperatures and high pressures, though the CO2 could too easily come bubbling back up. These latter solutions are not well studied and wouldn't be especially cheap.

Moreover, leaders, societies, communities, local planners, farmers, health organizations, need to recognize the changing climate and rising sea level as they make plans for the future. Our citizens need to be educated as to likely changes and how best to deal with the changing conditions.

 

Total Emissions in 2012 = 6,526  Million Metric Tons of CO2  equivalent

Overview of Greenhouse Gases

Gases that trap heat in the atmosphere are called greenhouse gases. This section provides

information on emissions and removals of the main greenhouse gases to and from the atmosphere.

Carbon dioxide (CO2) : Carbon dioxide enters the atmosphere through burning fossil fuels, solid waste, trees and wood products, and also as a result of certain chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere (or "sequestered") when it is absorbed by plants as part of the biological carbon cycle.

Methane (CH 4)   : Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.

Nitrous oxide (N 2O)   : Nitrous oxide is emitted during agricultural activities.

Fluorinated gases   : Hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes.

Total U.S. Greenhouse Gas Emissions by Economic Sector in 2012

Total Emissions in 2012 = 6,526 Million Metric Tons of CO2  equivalent  Total U.S. Greenhouse Gas Emissions, 1990-2012

Each gas's effect on climate change depends on three main factors:

How much of these gases are in the atmosphere?Concentration, or abundance, is the amount of a particular gas in the air. Larger emissions of greenhouse gases lead to higher concentrations in the atmosphere. Greenhouse gas concentrations are measured in parts per million, parts per billion, and even parts per trillion. One part per million is equivalent to one drop of water diluted into about 13 gallons of liquid (roughly the fuel tank of a compact car).

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.

Sources of Greenhouse Gas Emissions

Overview

Greenhouse gases trap heat and make the planet warmer. Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years. The largest source of greenhouse gas emissions from human activities in the United States is from burning fossil fuels for electricity, heat, and transportation.

The primary sources of greenhouse gas emissions in the United States are:

Electricity production    (32% of 2012 greenhouse gas emissions) - Electricity production generates the largest share of greenhouse gas emissions. Over 70% of our electricity comes from burning fossil fuels, mostly coal and natural gas.

Transportation    (28% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90% of the fuel used for transportation is petroleum based, which includes gasoline and diesel.

Industry    (20% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from industry primarily 

come from burning fossil fuels for energy as well as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials.

Commercial and Residential    (10% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that contain greenhouse gases, and the handling of waste.

Agriculture    (10% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from agriculture come from livestock such as cows, agricultural soils, and rice production.

Land Use and Forestry    (offset of 15% of 2012 greenhouse gas emissions) - Land areas can act as a sink (absorbing CO2 from the atmosphere) or a source of greenhouse gas emissions. In the United States, since 1990, managed forests and other lands have absorbed more CO2 from the atmosphere than they emit.

GHG data from UNFCCC

In accordance with Articles of the Climate Change Convention, countries that are Parties to the Convention submit national greenhouse gas (GHG) inventories to the Climate Change secretariat. The inventory data are provided in the annual GHG inventory submissions by Annex I Parties and in the national communications under the Convention by non-Annex I Parties.

The GHG data reported by Parties contain estimates for direct greenhouse gases, such as:

CO2 - Carbon dioxide;CH4 – Methane;N2O - Nitrous oxide;PFCs – Perfluorocarbons;HFCs – Hydrofluorocarbons;SF6 - Sulphur hexafluoride

as well as for the indirect greenhouse gases such as SO2, NOx, CO and NMVOC.

Why is global warming a problem?The cost and benefits of global warming will vary greatly from area to area. For moderate climate change, the balance can be difficult to assess. But the larger the change in climate, the more negative the consequences will become. Global warming will probably make life harder, not easier, for most people. This is mainly because we have already built enormous infrastructure based on the climate we now have.

People in some temperate zones may benefit from milder winters, more abundant rainfall, and expanding crop production zones. But people in other areas will suffer from increased heat waves, coastal erosion, rising sea level, more erratic rainfall, and droughts.

The crops, natural vegetation, and domesticated and wild animals (including seafood) that sustain people in a given area may be unable to adapt to local or regional changes in climate. The ranges of diseases and insect pests that are limited by temperature may expand, if other environmental conditions are also favorable.

The problems seem especially obvious in cases where current societal trends appear to be on a “collision course” with predictions of global warming’s impacts:

at the same time that sea levels are rising, human population continues to grow most rapidly in flood-vulnerable, low-lying coastal zones;

places where famine and food insecurity are greatest in today’s world are not places where milder winters will boost crop or vegetation productivity, but instead, are places where rainfall will probably become less reliable, and crop productivity is expected to fall;

the countries most vulnerable to global warming’s most serious side effects are among the poorest and least able to pay for the medical and social services and technological solutions that will be needed to adapt to climate change.

In its summary report on the impacts of climate change, the Intergovernmental Panel on Climate Change stated, “Taken as a whole, the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.”

http://earthobservatory.nasa.gov/

Effects of Global Warming

Signs Are EverywhereThe planet is warming, from North Pole to South Pole, and everywhere in between. Globally, the mercury is already up more than 1 degree Fahrenheit (0.8 degree Celsius), and even more in sensitive polar regions. And the effects of rising temperatures aren’t waiting for some far-flung future. They’re happening right now. Signs are appearing all over, and some of them are surprising. The heat is not only melting glaciers and sea ice, it’s also shifting precipitation patterns and setting animals on the move.

Some impacts from increasing temperatures are already happening.

Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice.

Researcher Bill Fraser has tracked the decline of the Adélie penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.

Sea level rise became faster over the last century.

Some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas.

Precipitation (rain and snowfall) has increased across the globe, on average.

Spruce bark beetles have boomed in Alaska thanks to 20 years of warm summers. The insects have chewed up 4 million acres of spruce trees.

Other effects could happen later this century, if warming continues.

Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters) by the end of the century, and continued melting at the poles could add between 4 and 8 inches (10 to 20 centimeters).

http://environment.nationalgeographic.com/environment/global-warming/gw-effects/

Hurricanes and other storms are likely to become stronger.

Species that depend on one another may become out of sync. For example, plants could bloom earlier than their pollinating insects become active.

Floods and droughts will become more common. Rainfall in Ethiopia, where droughts are already common, could decline by 10 percent over the next 50 years.

Less fresh water will be available. If the Quelccaya ice cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who rely on it for drinking water and electricity without a source of either.

Some diseases will spread, such as malaria carried by mosquitoes.

Ecosystems will change—some species will move farther north or become more successful; others won’t be able to move and could become extinct. Wildlife research scientist Martyn Obbard has found that since the mid-1980s, with less ice on which to live and fish for food, polar bears have gotten considerably skinnier.  Polar bear biologist Ian Stirling has found a similar pattern in Hudson Bay.  He fears that if sea ice disappears, the polar bears will as well.

Source for climate information: IPCC, 2007

http://environment.nationalgeographic.com/environment/global-warming/gw-effects/

Conclusion

Global warming is indeed a serious issue which needs to be tackled before it is too late. Various measures have been taken and more ought to be taken not only by the government organizations alone, but people too should participate equally.

The greatest problem is to make people aware about this threat and to make them realize that every step counts. Focus should be on to invent more efficient technologies which can promote sustainable development. Strict rules should be imposed on industries regarding their waste emissions and they should be monitored periodically.

Proper planning should be done before cutting forests so that the area taken under cutting should be equally planted in nearby areas.

People should be made to believe and understand that they can make a change and help in making the Earth a safer place to live for our future generations. It is our duty to take care of our ancestral and holy Earth. We should realize that sustainable development alone can help us in meeting our current demands and preserving the precious earth for future needs.