Earth has bestowed a bounty of non-renewable resources on humankind, but they won't last forever. The three R's – Reduce, Reuse and Recycle – represent the best strategy for conserving non-renewable oil, coal and natural gas. The United States Environmental Protection Agency champions this approach, which was popularized by environmental conservationists in the late 20th century. Increasing the reliance on renewable energy sources, such as solar, wind and geothermal generators, can also help conserve the dwindling supplies of fossil fuels that remain in the ground.

Fossil fuels are the remnants of millennia of organic decomposition. They formed about 350 million years ago during the Carboniferous Period, a name that evokes their predominant component – the element carbon. These fuels kept humans warm, and they powered the Industrial Revolution, but at a cost. Burning coal, petroleum and natural gas to create heat and electricity releases carbon into the atmosphere, mostly in the form of carbon dioxide. Scientists largely agree that carbon dioxide acts as a greenhouse gas to warm the atmosphere, and they have documented that it acidifies the oceans. Conserving fossil fuels reduces the amount of carbon dioxide in the atmosphere, and few scientists doubt that's good for the environment.

Nearly 200 countries signed onto a treaty in Paris in 2015 that addressed reducing the amount of carbon dioxide in the atmosphere. The strategy for doing this includes reducing reliance on fossil fuels. Partly in an effort to meet treaty goals, many countries incorporated renewable energy into their infrastructures in the form of wind and solar energy generators, electric vehicles, passive solar architecture and other innovations.

On an individual level, homeowners can take advantage of renewable energy as it becomes increasingly more available. They can install solar generators on their houses and choose energy providers that use renewable methods of generation. In communities that still rely heavily on fossil fuels, individuals can reduce their need for heat and electricity by properly insulating and leak-proofing their homes, turning off lights whenever possible and using energy-efficient appliances.

It takes energy to manufacture items that people use every day, such as clothing, personal appliances and electronic gadgets. You can minimize the energy used by the manufacturing sector by reusing things around the house, and you'll save money in the process. Here are a few ways to do it:

• Donate used clothing and buy used when possible.
• Repair your electronic equipment, car and appliances instead of replacing them with new products.
• Donate used or unwanted building materials and tools to a charity, such as Habitat for Humanity,  instead of taking them to the dump.

Recycling is a means of processing unwanted items and materials into new products instead of discarding them. This reduces the need for raw materials and the energy needed to produce them. On a global scale, many large manufacturers make a point of using recycled materials. Individuals can get in the game in many ways, including:

• Upcycling used home furnishings, which involves adapting them to serve different purposes or giving them fresh new appearances. 
• Discarding recyclable materials properly so they can be used to make new products. Such materials include objects made of plastic, glass, ceramic, metal and paper. Many waste management companies provide bins for this purpose to each household.
• Buying products made with recycled materials. 
• Composting leftover food and using the compost to grow more food. The more food you grow yourself, the less you have to buy. Food producers won't have to make as much, and they'll end up using less energy.

As a conservation strategy, Reduce, Reuse and Recycle works for large-scale manufacturers and global distributors as well as it does for individual householders. Even so, this strategy doesn't guarantee a limitless supply of fossil fuels. In the long term, a shift to renewable energy resources is necessary to ensure a comfortable and bountiful existence for each person on the planet.