Greenhouse Gases
What is a greenhouse gas?
- A greenhouse gas is a gas that contributes to the greenhouse effect by absorbing infrared radiation, e.g., carbon dioxide, methane and chlorofluorocarbons. (U.S Department of Interior, 2009)
- These gases often come from anthropogenic sources such as factories and human made products.
- The melting of ice caps has also produced carbon dioxide and methane.
- Erupting volcanoes spew carbon dioxide into the atmosphere as well.
What is the Greenhouse Effect?
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Positive Feedback
There are many examples of positive as well as negative feedback regarding global warming yet the positive feedback ones are stronger, resulting in climate change.
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Types of Smog
Climate Change Effects
Effects on Temperature
- The direct effect of global warming and the greenhouse effect will be the warming of the atmosphere.
- This can lead to other, bigger problems as atmospheric temperatures can affect weather, topography, and sea levels.
- The northern areas of Russia and Canada may become more productive as global circulation ensures that the regions become warmer. The soils may be able to support more agriculture and other life. But on the other hand, soil temperatures at lower latitudes will become too arid to support food production. (Botkin & Keller, 2007)
- Large climate changes such as El Nino can also affect temperature as warm pacific waters are blown west across the pacific and this warm ocean water provides an atmospheric heat source. El Nino therefore changes weather in regions far away from the tropical Pacific. (Botkin & Keller, 2007)
Effects on Precipitation
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Effects on Sea Level
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Effects on Global Ice
- The glaciers of North America, Europe, and other areas such as mountaintops of the Alps and Himalayas are retreating at an accelerated rate. (Botkin & Keller, 2007)
- For example, glaciers in Glacier National Park have already been reduced from 150 to 35 and are purported to disappear entirely by 2030. (Botkin & Keller, 2007)
- The other side of global ice movement, which occurs in Antarctica, is actually consistent with global climate models. The Central ice cap has been increasing as more snow precipitation has fallen there. (Botkin & Keller, 2007)
Effects on Biota
- Changes in surface temperatures and the manipulation and even disappearance of entire biomes altogether, will affect the ranges of plants and animals in terms of seasons and certain behaviors.
- For example, spring now arrives 2 weeks earlier than it did 3 decades ago and so this is affecting many species of wildlife including the North Carolina woodpecker, which is laying its eggs a week earlier. (Botkin & Keller, 2007)
- Rapid change in climate can also stress species that cannot adapt fast enough to survive and compete for food.
Summary
The below video gives a general recap of how all the information on this page is connected, from greenhouse gases, all the way to their effects on the planet in our future.
The below video gives a general recap of how all the information on this page is connected, from greenhouse gases, all the way to their effects on the planet in our future.
Proxy Indicators
What is a proxy indicator?
- A proxy indicator is some local aspect of the environment that can showcase the direct effects of temperature and climate change and therefore the past climates in an area. This can give an idea to scientists how much variation is normal for a certain area as well as the past ranges in climate. (Ferrio, 2005)
- There are several aspects of the environment that can allow a glimpse of the past: ice cores, tree cores, ocean sediment, coral, and pollen.
Ice Cores
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Tree Cores
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Ocean Sediment
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Coral
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Pollen
- Because pollen are relatively hardy, they can survive in collectible amounts through many thousands of years. Because abundance of pollen will be based on the abundance of the particular flora, scientists can use this knowledge to construct the vegetation of the past.
- Depending on which plants produced the pollen that is found, climate conditions that are ideal or close to ideal for a certain plant can be imitated. (Ferrio, 2005)
- Therefore, scientists can extrapolate information about the climate from a certain place and time based on the climate that the plant most likely flourished in.
- Most current studies show that pollen from the last 2 millennia have shown anthropogenic influences as they mostly consists of the pollen from cereal crops like grain. (Ferrio, 2005)
Case Study
The coffee industry is supported by millions of small farmers from all around the world. The Arabica coffee serves some 70% of the coffee market but this plant is very sensitive to temperature changes. Because of recent warming and future predicted warming, scientists and economists alike predict a shrinking of the crop and thus a scarcity in the crop which will drive up prices. Countries like Brazil, Vietnam, and Indonesia will all suffer because of this. Simply moving the fields to cooler areas either by relocation closer to the poles, or by elevation change is not feasible for many independent farmers in these third world countries. Coffee trade supports much of the income for many countries and this global warming will severely affect the livelihoods of these people. (Jones, 2015)
http://www.theguardian.com/global-development/2015/may/01/coffee-catastrophe-beckons-as-climate-change-threatens-arabica-plant
http://www.theguardian.com/global-development/2015/may/01/coffee-catastrophe-beckons-as-climate-change-threatens-arabica-plant