From Ecopedia

Overview

Carbon Dioxide (CO2) is a greenhouse gas composed of Carbon and oxygen elements. Carbon dioxide is only a trace gas in the earth’s atmosphere, currently occurring at average concentrations of around 383 parts/million by volume or 582 parts/million by mass. The total mass of the gas in the atmosphere amounts to 3,000 gigatonnes (3.0×1015 kg).

Photosynthesis

Carbon dioxide, produced during plant respiration, plays a significant role in the photosynthesis process of plants.

A major constituent of the carbon cycle, Carbon dioxide is emitted as a by-product during fossil fuel combustion, combustion of vegetable material or other inorganic processes.

Environmental Information

Carbon dioxide is considered to be a major air pollutant, contributing significantly to the greenhouse effect and global warming phenomenon.

Carbon Sinks

Compared to the atmospheric presence, around fifty times additional carbon in the form of carbon dioxide, carbonic acid, bicarbonate as well as carbonate ions exists in ocean waters.

Oceans acting as enormous carbon sinks, take up around one third of carbon dioxide emitted during human activity.

Since the solubility of CO2 decreases with increasing sea temperatures, excess heat in oceans leads to decreased solubility of the gas.

Greenhouse effect

Greenhouse Gases (GHGs), after absorbing the infrared radiation, trap the generated heat making the earth’s atmosphere warmer by about 33°Celsius, producing the Greenhouse effect.

Physical processes such as anthropogenic or enhanced human activities significantly contribute to the greenhouse effect.

Human activities are found to significantly increase carbon dioxide levels in the atmosphere leading to the greenhouse effect.

As per observations of Intergovernmental Panel on Climate Change (IPCC), most of the increase in global temperatures since mid-twentieth century could be attributed to extensive human activity, resulting in increased concentrations of Greenhouse Gases (GHGs) like carbon dioxide.

Due to excessive burning of fossil fuels (natural gas, oil and coal) as well as solid waste, wood and wood products, carbon dioxide is getting released into the earth’s atmosphere in large quantities.

Cement production, combustion and deforestation are other major causes for increased atmospheric CO2 levels. Environmentalists observed that CO2 contribution to the greenhouse effect is between 9-26%.

Global Warming

Main Article: Global Warming

The Greenhouse effect is the major contributing factor for the Global warming phenomenon. If the current trend of increased Greenhouse Gases (GHGs) production continues, severe climate changes such as severe droughts, floods, rising sea levels, altered rainfall patterns are bound to occur.

As per IPCC estimates, over the past hundred years, earth’s climate warmed up between 1.1° -1.6°F due to increased carbon dioxide and other GHG concentrations and human activity found to be the crucial contributing factor.

Deforestation

Main Article: Deforestation

Deforestation is leading to loss of vegetation, which means most of the carbon dioxide present in the air is not being absorbed by the trees and plants for photosynthesis. As a result, large amounts of atmospheric carbon dioxide is getting accumulated.

Fossil Fuel Combustion

Increased fossil fuel usage over the years is leading to excess release of carbon dioxide into the atmosphere resulting in global warming.

Measures to Curb CO2 Emissions

Many countries across the world started adopting stringent measures to reduce CO2 emissions in order to combat global changes in climate.

Carbon Sequestration

Main Article: carbon sequestration

Carbon sequestration, a geo engineering technique, is being increasingly considered today for dealing with already-released carbon forms. The technique allows long-term storage of carbon forms including carbon dioxide, which aid in mitigating global warming.

Photosynthesis is a commonly occurring carbon sequestration in nature that allows plants and trees to soak up and store carbon, which would otherwise get released in the air and trap the atmosphere heat.

In the past, the Bush administration embraced carbon sequestration to minimize carbon dioxide emissions in the US. By granting over $49 millions as an annual fund for the technology’s R&D (Research and Development), the Bush administration strived to keep the greenhouse gas emissions, especially carbon footprint (measure of CO2 emissions) in check.

International Agreements

Two major UN (United Nations) treaties, UN Framework Convention on Climate Change (UNFCCC) agreed in 1992 and Kyoto Protocol, signed in 1997 set to minimize carbon dioxide emissions. The Kyoto Protocol, in particular, committed the member countries to set binding targets for minimizing carbon dioxide gas emissions by about 5% against the levels recorded in 1990. The protocol set a time period of five years, from 2008 to 2012, to achieve the target level. The rules set for the implementation of the protocol, known as “Marrakesh Accords”, were finalized and adopted at COP7 in the year 2001, in Marrakesh.

References

http://en.wikipedia.org/wiki/Carbon_dioxide http://environmentalchemistry.com/yogi/environmental/200611CO2globalwarming.html http://www.oism.org/pproject/s33p36.htm http://wiki.answers.com/Q/What_negative_effects_does_carbon_dioxide_have_on_the_environment http://www.bbc.co.uk/weather/features/gases_carbondioxide.shtml http://en.wikipedia.org/wiki/Carbon_sequestration http://www.globalwarming.org.in/ http://en.wikipedia.org/wiki/Greenhouse_effect http://unfccc.int/kyoto_protocol/items/2830.php