Background on Climate Change and Rising Sea Levels

Before delving into my main subject, endangered island nations, I believe further background discussion is in order. First of all, on reflection, I think I oversimplified when placing blame for climate change. I’m not saying that industrialized nations don’t emit a lion’s share of the carbon dioxide; of that, I think, there is little doubt. Where I oversimplified was in implicating only industrialism and industrialized nations, failing to discuss other activities and parties which also bear responsibility. Thus, I will briefly summarize several of the major causes of climate change, accompanied by a discussion of which parties are complicit. According to the U.S. Environmental Protection Agency, energy production and industrial processes were responsible for approximately 45% of global greenhouse gas emissions in 2004. It is tempting at first to blame profit-hungry oil and coal industries for this problem; however, we must remember also that we, as regular citizens in the industrialized world, are continually taking advantage of these activities or have become dependent on them. Thus, while the producers may be causing the most direct damage, it is consumer need and appetite providing the economic motive. Forestry is another major factor, including deforestation or clearing land for farm use. The same 2004 data indicates that forestry was responsible for 17% of greenhouse gas emissions. Perhaps the most intense deforestation happens in the jungles of South America, Africa, and Southeast Asia. A lot of this is due to criminal groups taking advantage of a black market for jungle woods, or corporations clearing land for mass-production farms: both easy targets for blame. However, much of the rainforests are also cleared by impoverished parties compelled to seek new farmland or pasture for economic subsistence. On the subject of farming, agriculture is responsible for a similar level of greenhouse emissions. While there are other sources as well, I believe I’ve made my point: given the above information, it seems clear that the cause of greenhouse emissions (and, by extension, the blame for climate change) is spread across different economic sectors and socio-economic classes. One other topic I would like to cover briefly is the cause-effect relationship between climate change and rising sea levels, and what it means for the future. According to the Climate Institute, there are three significant factors affecting sea level rise: melting of glaciers and ice caps, ice loss from Antarctic and Greenlandic ice sheets, and thermal expansion. In the first two phenomena, land-based bodies of ice are melting and thus adding more liquid water into the ocean. Sea-based bodies of ice, which already displace their mass of liquid ocean water, do not directly contribute to rising sea levels when they melt. Now to the third factor, thermal expansion. Water, like all fluids, increases in volume as it increases in temperature. With a rise in average global temperatures, sea temperatures have risen as well, and the volume of Earth’s oceans has expanded accordingly. This manifests at the surface as a further rise in sea level. Though these factors are known, how much each will affect sea levels in the future is uncertain, especially considering the mutual effects each of these will have on the other. As a result, there are no widely-accepted predictions regarding the rate of future sea level rise. With that, I think there is enough foundational context to begin looking at the endangered island communities in my next post. Global Greenhouse Emissions: <http://www.epa.gov/climatechange/ghgemissions/global.html> Climate Change and Sea Level Rise: <http://www.climate.org/topics/sea-level/>