GLOBAL WARMING

D. Crowley, 2008

GLOBAL WARMING

To know what causes global warming, and how this can affect the global climate

EARTH

The atmosphere is a thin layer of gases, surrounding the Earth

Certain gases in the atmosphere trap heat, reflecting it back to the Earth’s surface, warming it

This is similar to the glass in a greenhouse, which traps heat inside it (trapping of heat by the Earth’s atmosphere is known as the greenhouse effect)!

Without this atmosphere the Earth would be too cold for life to exist

GREENHOUSE EFFECT

INCREASING Carbon dioxide is the main greenhouse gas involved

with the warming of the Earth (as well as methane)

Human activity is producing more carbon dioxide (combustion engine) and methane (cattle and drilling)

Increasing the greenhouse gases increases the amount of heat the atmosphere traps

This increased greenhouse effect makes the Earth warmer, leading to global warming

TRAPPING HEAT Greenhouse gases trap some of the Sun’s heat, so

warming the surface of the Earth…

CAUSES There are a variety of reasons why more greenhouse

gases are present in the atmosphere, but certainly human activity is greatly responsible…

Huge numbers of cars and factories mean enormous levels of carbon dioxide are produced

Large scale deforestation reduces the number of plants which can remove the carbon dioxide (via photosynthesis)

Methane levels are also rising (via cattle farming; paddy fields; and drilling for oil and gas)

RATE Carbon dioxide has steadily risen as has the average

temperature of the Earth over the last 150 years…

EFFECTS Rises of just a few degrees in world temperature could

have a dramatic impact on the world climate – global weather patterns may change, causing drought for some areas, and flooding for others

Melting of ice caps could raise sea levels causing flooding of low-lying land (as well as habitat destruction)

ARGUMENT

SPEAK Your task is to summarise the effects of greenhouse

gases and global warming problems global warming will cause for the Earth / ways we can combat global warming

This can be done via a letter to Parliament / an add campaign to increase awareness of the problems / changes you can do to do your part in decreasing the production of greenhouse gases