Global Climate 1. Climate
Climate is the average weather conditions over long periods of time (over a
year)
Weather is the daily conditions of a certain area.
Weather is described in terms of temperature and precipitation.
Factors affecting Climate:
1. Factors related to the Sun:
a. The Greenhouse Effect in the Atmosphere:
The greenhouse effect is a natural process in which certain gases in the
atmosphere, like H 2 O, CO 2 , CH 4, N 2 O and O 3, keep heat near Earth and
prevent it from radiating into space. They absorb heat and release it
slowly.
i. Sunlight and Heat:
The angle at which the sunlight reaches Earth affects how much
heat a certain region receives.
The angle is affected by the fact that the Earth is a sphere, the
tilt of the Earth and the distance an area is from the Sun due to
the curve of the Earth in that area.
Solar insolation is the amount of sun rays an area receives at a
given period of time.
Greenhouse gases absorb some of the heat radiated from Earth’s
surface and prevent it from radiating back into space causing heat
to be trapped and rise in temperature.
b. The effect of Latitude:
Latitude is a measurement of a place’s distance from the equator. The
farther a place is from the equator, the cooler its climate.
The climate zones are: the tropical, the temperate and the polar.
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2. Factors related to the Wind:
Winds move heat and moisture from one place to another.
3. Factors related to the Oceans:
El Nino and La Nina are changes in air pressure, wind patterns, ocean
temperature, and ocean circulation in the Pacific Ocean.
El Niño: Warmer ocean waters in the Pacific cause extreme weather—heavy
rain in some areas, drought in others.
La Niña: Cooler ocean waters lead to opposite effects—dry areas get wetter,
and wet areas get drier.
4. Other Factors:
a. Topography:
Topography describes the surface characteristics of an area, including
elevation and features such as mountains, rivers and lakes.
i. Altitude:
The greater the altitude, or elevation, the cooler the air
temperature will be.
ii. Mountain Ranges:
The windward side of mountain ranges get more precipitation than
the leeward side of mountain ranges.
b. Volcanoes:
Winds can carry gases and particles from erupting volcanoes to areas
that are a long way from the volcano.
These gases and particles may block the sunlight and cause temporary
cooling of temperatures.
c. Regional Vegetation:
Plant life, or vegetation, can promote cloud formation and rainfall. It can
also affect the amount of carbon dioxide in the air by consuming it for
photosynthesis.
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2. Climate Change
Climate change includes changes in temperature, rainfall, wind patterns and
storm frequency.
Global warming is one aspect of climate change.
Evidence of a warming Earth
1. Rising Temperatures:
The average atmospheric temperature is rising and most of the increase has
occurred in the last few decades.
2. Changes in Precipitation:
Heavy rainstorms have increased in both dry and moist regions over the past
100 years.
These severe storms have caused flooding too.
3. Melting Ice:
Glaciers are large, slowly moving sheets of ice, and many have taken
thousands of years to form.
Warming temperatures are causing portions of the ice to break away and
melt.
4. Rising Sea Levels:
As the temperature increases, the liquid expands, and its level goes up.
When seawater becomes warmer, its volume increases, making sea levels
rise.
Studying Climate Change
Scientists study changes in climate by 3 ways:
1. Taking direct measurements.
2. Inferring past climate characteristics.
3. Using models to predict the future.
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Finding the Cause of Climate Change
The main cause of global warming is the increase in greenhouse gases in the
atmosphere.
Causes of increase in greenhouse gases:
1. Burning fossil fuels.
2. Changes in use of land, such as the cutting of forests.
3. Effects of Climate Change
1. Shifting Habitats for organisms
2. Changing Migration Times
3. Problems obtaining Food for organisms.
4. Effects on the Ocean
5. Impact on People regarding:
a. Agriculture
b. Economic Effects
c. Health Effects
d. Water Supply
4. Responding to Climate Change
There are 2 basic ways:
1. Adaptation
2. Mitigation by reducing greenhouse gas emissions.
Mitigation is more important because it addresses the causes of global
warming.
Everyone should be trying to reduce their carbon footprints.
A carbon footprint is the amount of carbon dioxide emissions for which
an individual or group is responsible.
In order to reduce the amount of greenhouse gases released during the
generation of electricity we need to encourage energy efficiency and
conservation.
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Examples of efficiency and conservation include better choices
regarding:
a. Transportation
b. Energy Sources
c. Carbon Economy:
i. Cap and Trade programs in industry.
ii. Carbon Tax
iii. Carbon Offsets
iv. Carbon Sequestration
The Kyoto Protocol is an international agreement that seeks to limit greenhouse
gas emissions.