Coal, natural gas, and oil are all fossil fuels. Solar energy and wind energy are renewable energy sources.

China is the largest producer of coal, accounting for over half of the world's production.

China is also the largest consumer of coal, accounting for over half of the world's consumption.

The United States is the largest producer of natural gas, accounting for over a quarter of the world's production.

The United States is also the largest consumer of natural gas, accounting for over a quarter of the world's consumption.

Saudi Arabia is the largest producer of oil, accounting for over a tenth of the world's production.

The United States is the largest consumer of oil, accounting for over a fifth of the world's consumption.

Fossil fuel production and consumption can lead to air pollution, water pollution, land degradation, and climate change.

Renewable energy sources, nuclear energy, energy efficiency, and conservation are all alternatives to fossil fuels.

Cost, technology, policy, and public acceptance are all challenges to transitioning to a clean energy economy.

Reduced air pollution, reduced water pollution, reduced land degradation, and reduced climate change are all benefits of transitioning to a clean energy economy.

Using public transportation, walking or biking instead of driving, turning off lights when you leave a room, and unplugging electronics when you're not using them can all help to reduce fossil fuel consumption.

Investing in renewable energy research and development, providing incentives for businesses to adopt clean energy technologies, implementing policies that reduce fossil fuel consumption, and educating the public about the benefits of clean energy can all help to promote a clean energy economy.

Using energy-efficient technologies, investing in renewable energy, reducing waste, and educating employees about energy conservation can all help to reduce fossil fuel consumption.

Fossil fuels are still a major source of energy worldwide and will continue to be for many years to come. However, the use of fossil fuels is declining in some countries as renewable energy sources become more affordable and accessible.