A greenhouse stays warm because sunlight can come in through the transparent glass, but long wave (infrared) radiation cannot be transmitted out because the glass is opaque to infrared radiation. The radiation trapped inside warms the interior surfaces of ground plants and other materials. A greenhouse is also effective because it does not let convection (air movement) remove heat to the external environment except through controlled vents.
(figure available in print form)
In the atmosphere, certain gases (carbon dioxide and water vapor) act like the glass of the greenhouse. Sunlight is allowed to pass through the earth’s surface, where it is absorbed, but they interfere with the passing of long wave radiation outward. This process is known as the greenhouse effect, it balances the incoming and outgoing radiation at a level that warms the earth’s surface.
The earth’s surface and atmosphere maintain a balance between the incoming flux of solar radiation and the outgoing infrared radiation. As a result of the radiation balance the mean surface temperature of the earth is about 15 degrees Celsius. If this balance is disturbed then the temperature may go up or down. Increased cloud cover can reflect sunlight to space, reduce the amount of sunlight reaching the ground and cause cooling. Increasing amounts of carbon dioxide and water vapor can cause warming of the global climate.
Climatologists study these changes, by using computer models, it is found that by doubling the amount of carbon dioxide concentration in the atmosphere, there can be an increase in the global mean temperature of the earth of about 3 degrees Celsius +/- 10 degrees Celsius. This much increase in the mean surface temperature is very significant and is in fact greater than any naturally occurring changes in temperature during the past 10,000 years.
Evidence has shown that the concentration of carbon dioxide in the atmosphere and the resulting greenhouse effect is caused by human activities, such as the burning of fossil fuels, and the cutting of forests (deforestation).
If this warming trend continues then there could be serious consequences. Glaciers may melt, sea levels may rise, agricultural production may be affected, and the ecosystem may undergo substantial changes.
Readings in Ecology to learn Mathematics, New Connections, Questions and Challenges, Using the Window Planter to Provide Hands-on Activities.
Given the recent considerations about pollution concerns for the environment, the effects of global warming, and the role that human activities play in this, there is need to change the school curriculum to reflect these developments.
The role of writing and reading in the mathematics curriculum must be considered. This unit will attempt to incorporate readings from the topic of ecology, and articles that deal with the current concerns of global warming, waste management and any other discussions that may be relevant in the math class.
From these readings, students will be shown the interconnections between science and mathematics, and that in many cases mathematical concepts are necessary to understand ecological concerns.
By planting a window garden and experimenting with bottle biology, students will not only be taught mathematics, but will be forced to consider that planting a seed and maintaining growing things in their environment not only help to beautify the space, but contribute to the global cycles that maintain the global balance.