Environmental Engineering Reference
In-Depth Information
And since the Industrial Revolution, the average air temperature on Earth has increase between 3°C and 5°C.
The temperature increase in the past 260 years is double the amount we have historically seen in any
1,000-year period.
There are many possible consequences of higher air temperatures, including changes in weather patterns, a de-
crease in glaciers and polar ice caps, and rising sea levels. Additionally, as the polar regions warm, there will
be an increase in greenhouse gases released from organisms currently frozen in permafrost and from the de-
composition of organic matter currently preserved in permafrost. In ocean water, recent studies show that CO
2
dissolved in the water is released into the atmosphere as the oceans warm. This action is similar to the release
of carbon dioxide when opening a bottle of warm soda.
The following graph illustrates the steady increase of global temperature changes in the atmosphere.
Source: Environmental Protection Agency
Weather Patterns
An increased temperature will result in higher evaporation rates and an increase in water vapor in the atmo-
sphere, altering precipitation patterns. These changes ultimately alter the hydrologic cycle worldwide. In-
creased evaporation and sea temperatures also could increase the frequency of hurricanes. Since 1970, the per-
centage of hurricanes that are category 4 or 5 hurricanes has increased from 20 percent of the total hurricanes
to 35 percent of the total hurricanes. Increased rainfall in areas degraded by deforestation and plowing will lead
to an increase in soil erosion, which may lead to decreased land productivity and, as sediment washes into wa-
ter sources, decreased productivity in both freshwater and saltwater ecosystems. Other areas may see an in-
crease in desertification and a loss of biodiversity.
Rise in Sea Level
The most obvious contribution to rising sea levels due to global warming is from the melting of ice, most not-
ably in the polar regions. Additionally, warmer water expands, and with higher temperatures, the existing
