Greenhouse Gases 2

Hi everyone,

       Last time you knew that Carbon dioxide is one of the stimulants causing global climate change. What else do you think it can lead to greenhouse effect?

1)      Methane (CH₄) and Nitrous Oxide (N₂O)

2)      Ozone (O₃) and water vapor (H₂O (g))

3)      Both 1) and 2)

Methane (CH₄) is originated from decomposition of living things and can remain in the atmosphere around 9-15 years. Although there is methane approximately 1.7 ppm in the atmosphere, interestingly it is over 20 times more effective in trapping heat than carbon dioxide, that is, it can absorb more infrared than carbon dioxide does in the same volume. Nowadays, “Methane is increasingly emitted from a variety of natural and human-influenced sources. Human-influenced sources include landfills, natural gas and petroleum systems, agricultural activities, coal mining, stationary and mobile combustion, wastewater treatment, and certain industrial process.” U.S. Environmental Protection Agency, 2011. Methane http://www.epa.gov/methane/, 1/4/11

Nitrous Oxide (N₂O) is a clear and colorless gas. Naturally, nitrous oxide is derived from a wide variety of biological sources i.e. the decomposition of living things. On a global basis, it is estimated that natural sources account for over 60% of the total N₂O emissions. Nonetheless, it highly increases these days due to the industries (especially in the United States) using nitric acid in their production, such as chemical and plastic industries, nylon fiber manufacturing, agricultural soil management, mobile and stationary combustion of fossil fuel,  and adipic acid production. It is considered to be a potent greenhouse gas because of its long atmospheric lifetime which is roughly 120 years! Moreover, it can trap heat 310 times more influential than carbon dioxide on a per molecule basis! (IPCC, 2001c)

Global average atmospheric concentrations of N₂O have increased from about 270 parts per billion by volume (ppbv) in 1750 to 314 ppbv in 1998, which equates to a 16% increase for the period. In the last two decades, atmospheric concentrations of N₂O continue to increase at a rate of 0.25% per year. There has been significant multi-year variance in the observed growth of N₂O concentrations, and the reasons for these trends are not yet fully understood (IPCC, 2001b). 
http://www.ghgonline.org/humaninfluencebig.htm

This image is a work of the National Oceanic and Atmospheric Administration, taken or made during the course of an employee's official duties. As works of the U.S. federal government. NASA, Global Climate Change http://ete.cet.edu/gcc/?/resourcecenter/slideshow/3/48

Robert A. Rohde/Global Warming Art.  http://www.globalwarmingart.com/wiki

This figure shows the relative fraction of man-made greenhouse gases coming from each of eight categories of sources, as estimated by the Emission Database for Global Atmospheric Research version 3.2, fast track 2000 project. These values are intended to provide a snapshot of global annual greenhouse gas emissions in the year 2000.

The top panel shows the sum over all greenhouse gases, weighted by their global warming potential over the next 100 years. This consists of 72% carbon dioxide, 18% methane, 8% nitrous oxide and 1% other gases. Lower panels show the comparable information for each of these three primary greenhouse gases, with the same coloring of sectors as used in the top chart. Segments with less than 1% fraction are not labeled.

         The increase in greenhouse gas concentrations in the Earth's atmosphere is believed to be the primary cause of global warming.