Climate change is one of the biggest issues facing humanity. As the global population continues to grow and our need for energy continues to rise there are no perfect solutions, but with sustainable and renewable energy humanity can reduce the flow of carbon into the atmosphere and slow global warming.

“Renewable energy” and “sustainable energy” are often used interchangeably to mean “green power”, but whilst there is some overlap between the two, as many sustainable energy sources are also renewable, the two terms do describe different ideas.

What is renewable energy?

Renewable energy is produced from sources that naturally regenerate or replenish themselves over time and take advantage of the Earth’s ability to recycle organisms. Renewable energy contrasts with fossil fuels as they are regenerated within a few years rather than the millions of years required to create coal, oil, or natural gas, and will there fore theoretically be able to supply our energy needs indefinitely.

Renewable energy may solve our growing requirements for energy as they are not finite like coal, oil, and natural gas, but many renewable energy sources will emit carbon dioxide into the atmosphere and add to climate change. Some of these carbon-emitting renewable sources include biomass, such as trees, and biofuels such as ethanol and biodiesel as well as carbon-neutral sources such as wind, hydroelectric, solar, and geothermal.

What is sustainable energy?

Sustainable energy is a more complex idea. Energy is generally considered to be sustainable if it meets the needs of the present without compromising the ability of future generations to meet their own needs and considers greenhouse gas emissions as well as social and economic aspects such as energy poverty. As such, energy sources that are carbon neutral, such as wind, hydroelectric power, solar, and geothermal are considered more sustainable than biomass and other biofuels, as their production may include clearing forests or other less environmentally friendly actions.

Sources of renewable and sustainable energy

Solar energy

Solar energy comes from the Sun and is the most abundant of all energy resources. The Earth intercepts around 10,000 times more energy from the Sun than that consumed by all of humankind each year, but we currently only convert a limited amount of this energy into electricity with solar panels. Every country could benefit from installing more solar panels, even those with cloudier weather, and the plummeting cost of solar panel production over the last decade makes solar panel one of the cheapest of all forms of electricity production.

Wind energy

Wind energy harnesses the kinetic energy of moving air by using large wind turbines either located on land (onshore) or in the sea (offshore). Offshore wind is considered to have significant untapped potential and the UK is already one of the largest producers of wind energy in the world, producing of 27 GW of electricity.

Geothermal energy

Geothermal energy utilizes thermal energy from the Earth’s interior, with heat extracted from naturally hot underground geothermal reservoirs to produce steam which turns turbines and creates electricity.

Hydroelectric energy

Hydropower harnesses the energy of water moving from higher to lower elevations to turn turbines and produce electricity. Hydropower can be generated from the natural flow or rivers and reservoirs, which often have multiple uses such as providing drinking water, water for agricultural irrigation, and flood and drought control.

Ocean energy

Ocean energy, or wave power, harnesses the kinetic and thermal energy from seawater to produce electricity. Whilst ocean energy is considered to have significant potential, as the energy in the seas is considerably more than used by every human on the planet, but the technology is still in its testing phase of development.


Bioenergy is created from burning a variety of organic materials, such as wood, charcoal, and manure, collectively known as biomass and does produce greenhouse gas emissions, although less than fossil fuels. It is a renewable resource, but considered less sustainable and experts say it should be eventually phased out after fossil fuels and replaced with other more sustainable options.

Can sustainable energy stop climate change?

Climate change is caused by a variety of factors, but the release of carbon dioxide into the atmosphere from energy production and the burning of fossil fuels is the single greatest contributor. Therefore, a shift from fossil fuels to more sustainable sources of energy production will slow global warming.

To accelerate the changeover to greener sources of energy, several governments around the world have committed to net zero within a few years. On a more international level, bodies like the EU have introduced new regulations to try and prevent “greenwashing” and encourage the private sector to consider the climate alongside their shareholders. For example, the Sustainable Finance Disclosure Regulations (SFDR) imposes mandatory ESG disclosure obligations for asset managers and other financial markets participants to refocus elements of the financial sector on sustainability. Meanwhile, companies like Greenly have emerged to help businesses measure and offset their carbon emissions and provide them with a better overview of their impact on the planet.


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