GREENHOUSE EFFECT

GREENHOUSE EFFECT

Earth is unique in the solar system in that it is the only planet that supports life as we know it.

Several factors account for this:– Position near the sun: not too close, not too far– Abundance of water– Right mixture of chemical compounds needed for

life– Right types of gasses in the right combination

making up our atmosphere

GREENHOUSE EFFECT

Let’s look at the last factor…

Right types of gasses in the right combination make up our atmosphere

Why is this so important?

GREENHOUSE EFFECT The earth’s

atmosphere is a protective blanket which surrounds our planet.

It allows the right amounts of sun’s energy in and out, creating a climate that is supportive of life

SUN’S ENERGY The sun’s energy reaches the earth in the form of

electromagnetic radiation. Electromagnetic radiation includes visible light,

infrared (heat), ultraviolet wave lengths and others forms of energy.

SOLAR ENERGY

Two things can happen to solar radiation as it approaches earth’s atmosphere

1. Solar radiation can be reflected back into space

2. Solar radiation can be absorbed by clouds, gases like ozone or earth’s surface - or scattered by the atmosphere.

SOLAR RADIATION

Some of the solar radiation is reradiated or emitted by the earth in the form of long-wave radiation

This long-wave radiation is absorbed by certain gasses in the earth’s atmosphere.

These gasses are called “greenhouse gasses”

GREENHOUSE GASSES

Naturally Occurring Water Vapor Methane Nitrous Oxide Carbon DioxideInfluenced by humans Carbon Dioxide Nitrous Oxide Methane CFC’s Ozone (?)

The level of greenhouse gases can be affected by man-made and

natural processes

MAN-MADE PROCESSES Burning fossil

fuels→CO2 and NOx Removing vegetation

(deforestation)→CO2

Using aerosols→CFC Polluting of oceans and

waterways →methane

NATURAL PROCESSES Volcanic Eruptions Carbon Cycle Water Cycle Decay→methane Oceans and

bacteria in soil→nitrous oxide

MAN-MADE CONTRIBUTIONS

Man-made contributions to greenhouse gases are potentially devastating

The rise in greenhouse gases, especially carbon dioxide, are being attributed to a general rise in earth’s temperature.

These two graphs show the relationship between carbon dioxide concentrations in ice core data/Mauna Loa data and global average temperatures.

There seems to be a direct correlation between the two

So what are the consequences of an overall rising temperature on

Earth?

CONSEQUENCES Several theories exist

as to what may become of our earth if temperature continue to rise

Rise in sea level due to melting glaciers

Balance of salt water in oceans will change, possibly affecting wildlife

More tropical, dry weather in parts of world

Increase in severe weather

rst.gsfc.nasa.gov/Sect16/Sect16_2.html

VIDEO CITATIONS

Greatest Discoveries with Bill Nye: Earth Science. Discovery Channel School. 2005.unitedstreaming. 1 July 2007<http://www.unitedstreaming.com/>