6.1 Renewable and Nonrenewable Resources

Renewable vs. Nonrenewable

Renewable resources are replenished naturally over relatively short timescales (solar, wind, biomass, hydropower). Nonrenewable resources form over millions of years faster than they're used, so supplies are finite (fossil fuels, nuclear fuel/uranium). Whether a resource counts as renewable depends on the rate of replenishment vs. rate of consumption.

Fossil Fuels Dominate Energy Use

Coal, oil, and natural gas formed from ancient buried organic matter under heat/pressure over millions of years. They currently supply most of the world's energy because they're energy-dense and infrastructure already exists, but burning them releases CO2 and other pollutants, and reserves are limited.

Sustainability Depends on Use Rate

Even renewable resources can be overexploited (e.g., overharvesting biomass faster than regrowth), making them act nonrenewable. Conversely, careful management extends nonrenewable resource availability. Energy choices involve tradeoffs among availability, cost, environmental impact, and reliability.

Key terms

Renewable resource

A resource replenished naturally over a relatively short timescale, like solar, wind, or biomass.

Nonrenewable resource

A resource that forms far slower than it is consumed, such as fossil fuels or uranium.

Fossil fuels

Coal, oil, and natural gas formed from ancient organic matter under heat and pressure over millions of years.

Overharvesting a renewable resource

Using a renewable resource faster than it regenerates, causing it to function like a nonrenewable resource.

Why fossil fuels dominate energy use

High energy density and existing infrastructure make them cheap and convenient, despite finite supply and pollution.

Try an AP-style question

Which energy source is nondepletable?

1. Solar
2. Natural gas
3. Coal
4. Wood