ABOUT CLIMATE CHANGE
What affect do I have on Climate Change?
What are greenhouse gases (GHGs)?
What are CO2 equivalents (CO2e) and what is Global Warming Potential?
Climate change, as discussed here and in current events, refers to the increased amounts of greenhouse gases in the earth’s atmosphere, as a result of human activity, that are causing the Earth’s temperature to increase and the climate to change. While this concept was once debatable, that is no longer the case. A body of scientists from around the world,The Intergovernmental Panel on Climate Change (IPCC), states in their 2007 synthesis report:
“Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level.”
http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf
The main causes of climate change are certain types of human activity, most notable are the burning of fossil fuels (oil, coal, natural gas) and deforestation, both of which release greenhouse gases into the atmosphere. Since the industrial revolution these types of activities have greatly increased and so have the amounts of greenhouses gases in the atmosphere. These gases trap heat close to the Earth, creating a warming effect thereby changing the climate.
Climate change brings with it much uncertainty. No one knows for sure what the effect of this increase in global temperature will be and the how the effects will differ from region to region, however some widely accepted possibilities include:
- Rise in sea-levels due to melting of polar ice caps.
- Increased incidence of severe weather such as hurricanes, droughts, heavy precipitation, and strong winds.
- Increased acidity of oceans threatening marine populations worldwide.
- Greater pressure on wildlife exacerbating the already high extinction rates.
The IPCC 2007 synthesis report cited above lists possible effects of climate change by region in great detail.
More about the IPCC: http://www.ipcc.ch/about/index.htm
More on global warming: http://www.nrdc.org/globalWarming/default.asp
What affect do I have on Climate Change?
Climate change is caused by the release of carbon dioxide and other greenhouse gases into the atmosphere. In the U.S. some of primary sources for greenhouse gases include coal-burning power plants, automobiles and the livestock industry. Most of us use the electricity from these power plants, drive cars and consume meat or dairy. In addition, flying is also a major contributor to climate change. The emissions from airplanes have been found to be especially harmful due to how much fuel is used per person and to the fact that emissions occuring at such high altitudes compound the affects of the greenhouse gases (see “how do you calculate my emissions”).
On the other side, each and everyone one of us can influence the status quo and help slow climate change. Everything we do to help, such as conserve and offset, prevents greenhouse gases from being released into the atmosphere or removes them. If these effects are multiplied by the number of people taking action then the effects can be quite pronounced. In addition, it has been argued that big businesses and governments will not act until there is support from their customers and constituents. Therefore, by changing our habits and mindsets we can help affect greater change around us.
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What are greenhouse gases (GHGs)
Greenhouse gases are gases that trap heat in the atmosphere. They have been in the atmosphere to varying levels since it’
s inception and come from a variety of sources; both natural processes and as the result of human activity. Since the industrial revolution (c. 1750), however, the concentration of GHG’s in the atmosphere has increased dramatically leading to global warming and now climate change.
The most common greenhouse gas is carbon dioxide (CO2). It is the most prolific but there are other GHGs that are better at trapping heat in the atmosphere. The table below shows the GHGs listed by the IPCC as the most important contributors to climate change. It also shows the activities which emit the greenhouse gases, their global warming potential (what this?) and their percentage of global emissions.
| Greenhouse Gas | Primary Sources | Global Warming Potential (what’s this?) | Percentage of global emissions |
| Carbon dioxide (CO2) | Burning of fossil fuels, land-use conversion (deforestation) production of iron, steel and cement. | 1 | 73.9% (56.6% fuel use/cement, 17.3% land use/forestry) |
| Methane (CH4) | Landfills, Natural gas systems, Coal mining, manure management (livestock), wastewater treatment, rice cultivation. | 23 | 14.3% |
| Nitrous oxide (N20) | Agricultural soil management, manure management | 296 | 7.9% |
| Hydrofluorocarbons (HFCs) | Substitute of ozone-depleting substances, HCFC-22 production, electrical transmission and distribution. | 120 –12,000 | < 1% |
| Perfluorocarbons (PFCs) | Semiconductor manufacture, aluminum production. | 5,700 –11,900 | <1% |
| Sulphur hexafluoride (SF6) | Electrical transmission distribution, Magnesium production, semiconductor manufacture. | 22,900 | <1% |
IPCC TAR GWP, 100 yrs – US EPA, inventory of US greenhouse gas emissions and sinks 1990-2002, annex 6
US Inventory of Greenhouse Gases and Sinks: 1990-2006 http://www.epa.gov/climatechange/emissions/downloads/08_CR.pdf
Percentage of global emissions comes from: http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf
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What are CO2 equivalents (CO2e) and what is Global Warming Potential?
CO2e is a unit used when discussing greenhouse gases. Since all the gases have different abilities to trap heat in the atmosphere (some stronger than others), in order to be able to compare them they are all related to CO2, the weakest of the greenhouse gases. For example methane is 23 times stronger as a greenhouse gas than CO2. One ton of Methane has the same affect on the atmosphere as 21 tons of CO2. One ton of methane is equal to 23 tons CO2e. It is also said that methane has a global warming potential of 23.
Global warming potentials are measured by a greenhouse gas’ ability to affect global warming over a 100 year period. This is because GHGs not only differ in strength, but in also in how long they persist in the atmosphere.
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