With less than 5% of the world's population, the United States is home to one-third of the world's automobiles.

With less than 5% of the world's population, the United States is home to one-third of the world's automobiles.

In 2008, industry used 31% of the total energy used; next was transportation at 28%, then residential at 22%, and commercial at 19%.

In 2008, industry used 31% of the total energy used; next was transportation at 28%, then residential at 22%, and commercial at 19%.

In 2008, industry used 31% of the total energy used; next was transportation at 28%, then residential at 22%, and commercial at 19%.

The United States and Canada are both developed countries. China and India are projected to have the greatest growth in energy consumption between 2006 and 2030.

The United States and Canada are both developed countries. China and India are projected to have the greatest growth in energy consumption between 2006 and 2030.

Tidal energy is gravitational in origin. Solar energy comes from nuclear reactions in the sun.

Tidal energy is gravitational in origin. Geothermal energy comes from radioactive decay inside the earth.

Tidal energy is gravitational in origin. Solar energy comes from nuclear reactions in the sun, and geothermal energy comes from radioactive decay inside the earth.

Renewable energy accounted for 7% of the total U.S. energy supply in 2008, less than any other type of energy source.

Renewable energy accounted for 7% of the total U.S. energy supply in 2008, less than any other type of energy source.

Almost 20% of the world's CO2 is released by the United States.

Almost 20% of the world's CO2 is released by the United States.

Mining coal disturbs the land and modifies the chemistry of rainwater runoff, which in turn affects stream and river water quality.

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

The energy we capture for use on Earth comes largely from the sun or from nuclear forces local to our own planet.

The energy we capture for use on Earth comes largely from the sun or from nuclear forces local to our own planet.