The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

The ampere, or amp, is the most commonly used measurement for electric current.

The ampere, or amp, is the most commonly used measurement for electric current.

The ampere, or amp, is the most commonly used measurement for electric current.

U.S. energy consumption is projected to rise 9% by 2040, or 0.3% per  year, while global consumption will increase about 50% over the same period 

U.S. energy consumption is projected to rise 9% by 2040, or 0.3% per  year, while global consumption will increase about 50% over the same period 

U.S. energy consumption is projected to rise 9% by 2040, or 0.3% per  year, while global consumption will increase about 50% over the same period 

U.S. energy consumption is projected to rise 9% by 2040, or 0.3% per  year, while global consumption will increase about 50% over the same period 

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

The most recent federal efficiency standards, finalized by the U.S. National Highway Traffic Safety Administration (NHTSA) and the Environmental Protection Agency (EPA) in 2012, are projected to increase fuel economy to the equivalent of 54.5 mpg for cars and light-duty trucks by model year 2025, while also reducing CO2 emissions. 

The most recent federal efficiency standards, finalized by the U.S. National Highway Traffic Safety Administration (NHTSA) and the Environmental Protection Agency (EPA) in 2012, are projected to increase fuel economy to the equivalent of 54.5 mpg for cars and light-duty trucks by model year 2025, while also reducing CO2 emissions. 

The most recent federal efficiency standards, finalized by the U.S. National Highway Traffic Safety Administration (NHTSA) and the Environmental Protection Agency (EPA) in 2012, are projected to increase fuel economy to the equivalent of 54.5 mpg for cars and light-duty trucks by model year 2025, while also reducing CO2 emissions. 

The most recent federal efficiency standards, finalized by the U.S. National Highway Traffic Safety Administration (NHTSA) and the Environmental Protection Agency (EPA) in 2012, are projected to increase fuel economy to the equivalent of 54.5 mpg for cars and light-duty trucks by model year 2025, while also reducing CO2 emissions. 

CO2 concentration in the atmosphere has risen about 43% since the beginning of the industrial revolution in the mid-eighteenth century-half of that since 1980

CO2 concentration in the atmosphere has risen about 43% since the beginning of the industrial revolution in the mid-eighteenth century-half of that since 1980

CO2 concentration in the atmosphere has risen about 43% since the beginning of the industrial revolution in the mid-eighteenth century-half of that since 1980

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.

U.S. energy consumption was about 98 quads in 2014.

U.S. energy consumption was about 98 quads in 2014.

U.S. energy consumption was about 98 quads in 2014.