The Scientific, Ethical, Political. and Social Impacts of Climate Change The Science of Climate Change
The four greenhouse gases in order of abundance are carbon dioxide (CO
), nitrous oxide (N
O), and fluorinated gases. Carbon dioxide is the most prevalent
2 greenhouse gas that is emitted into the atmosphere. It is released in many processes, mainly industrial, including the burning of fossil fuels and through certain chemical reactions. It is the least potent of all greenhouse gases when compared in an equal amount; however it is so abundant that it has the greatest effect. Carbon dioxide is also dangerous because it is not destroyed in the atmosphere. Other greenhouse gases, such as methane and nitrous oxide decay over time in the atmosphere, but carbon dioxide merely moves around between the ocean, land, and atmosphere. Some of it may be absorbed into the ocean fairly quickly, but some of the carbon dioxide can last for thousands of years. Global warming potential (GWP), the measurement of the amount of heat a greenhouse gas traps, uses carbon dioxide as the standard;
Carbon dioxide has a GWP of 1. Methane is emitted naturally and artificially, during the production of natural gas, oil, and coal as well as many agricultural processes. It is nearly 25 times more potent to the atmosphere than carbon dioxide; however it makes up a much smaller amount of greenhouse gas emissions. In recent years a positive feedback loop has been created by the melting permafrost in the arctic. As the permafrost melts, methane stored in the soil is released which contributes to the warming of the atmosphere, which causes more of the permafrost to melt. Nitrous oxide is mainly added to the atmosphere by fertilizers used in agricultural processes, but is also emitted by the burning of transportation fuels. Only 40% of nitrous oxide emissions are a result of human activity. Nitrous oxide can be removed from the atmosphere by bacteria which absorb it, or it can be destroyed by ultraviolet light. Nitrous oxide makes up small portion of greenhouse gas emissions, but it has a GWP of approximately 310, making it very damaging to the Earth’s climate. Fluorinated gases are potentially the most dangerous of all greenhouse gas emissions. Emitted in many different industrial processes,
Fgases have incredibly high global warming potentials. One type of fluorinated gas, sulfur hexafluoride, can trap approximately 24,000 times the amount of heat that carbon dioxide can.
Fgases are used to replace chlorofluorocarbons, which depleted the ozone layer. Fgases account for less than 1% of greenhouse gas emissions.
In the most northern areas of the globe, permafrost is present, and is frozen soil and plant debris that is frozen year round, and can be present in layers of up to 30 feet in areas such as
Siberia or Alaska. This permafrost has been frozen for thousands of years, and due to the increase in global temperatures, is melting, and will continue to melt unless the global temperature is reduced. Permafrost is composed of organicrich matter, and when it melts, is capable of releasing large amounts of carbon dioxide and methane gas. According to Seth
Borenstein, “Yedoma [a type of permafrost present particularly in Siberia] is much more prevalent than originally thought and may [release] 100 times the amount of carbon released into the air each year by the burning of fossil fuels.” As more methane and carbon dioxide is released by thawing permafrost, the global temperature will increase, causing more permafrost to melt, resulting in yet another positive feedback loop.
Evidence of climate change can be seen in the change in temperature of the ocean.
Compared to the air of the atmosphere, the specific heat of the ocean is much larger, thus with the expression mC=ΔT, we can see that as the C increases,