Climates of the WorldSection 1

2.5 relate major climate and vegetation regions of the world

• The sun, the brightest star in our sky, is a major factor in creating Earth’s climates. The sun, composed of hydrogen, helium, and other gases, rotates on an axis at about the same angle as the earth’s axis. Only a tiny fraction of the power generated by the sun reaches the earth.

Sun video

Climate and Weather

• Weather is the condition of the atmosphere in a certain place at a specific time.

• The climate of an area is its long-term typical weather pattern.

• The climate of an area is determined by many things; the most important is the earth’s position in relation to the sun.

2.6 describe factors that influence climate regions

Weather & climateVideo

Earth’s Tilt and Rotation

• Earth is currently tilted at an angle of about 23½°. Because of the tilt of this axis, not all places on Earth receive the same amount of direct sunlight at the same time.

Earth’s Revolution

• Earth travels in an orbit around the sun, completing one trip about every 365 days.

• The seasons are caused by the earth’s revolution around the sun and the earth’s tilt.

• The Equator divides Earth into the Northern and Southern Hemispheres. When one hemisphere experiences winter, the other experiences summer.

Tilt video

The Tropics of Cancer and Capricorn

• The line of latitude at 23½°N is called the Tropic of Cancer–the northernmost latitude on the earth to receive the sun’s direct rays.

• The line of latitude at 23½°S is called the Tropic of Capricorn–the southernmost latitude to receive the sun’s direct rays.

The Poles

• The North Pole and the South Pole are located at either end of the earth’s axis.

• Each Pole receives continuous indirect sunlight six months each year.

• While one receives continuous sunlight, the other receives little to no sunlight.

South pole video

The Greenhouse Effect• Part of the sun’s radiation passes through

Earth’s atmosphere.• Like the glass in a greenhouse, the

atmosphere keeps the heat from escaping back into space too quickly.

• Humans have altered Earth’s atmosphere by burning fuels that release carbon dioxide and other greenhouse gases into the atmosphere.

Greenhouse video