The world uses a variety of energy sources. Fossil-based fuels such as natural gas, petroleum and coal–accounted to more than 80 percent of the energy consumed in 2018. Renewables such as solar power, wind power biomass, hydroelectricity and biomass comprise 14 percent. Nuclear energy is 5 percent. Different countries have different energy sources to balance economic needs and environmental concerns.

Energy is found in nature in many forms, including sunlight, wind, waves, oceans, and more. These sources of energy transform into more efficient energy forms, such as heat or electricity, when they are harnessed. Once these energies are used up, they become nonrenewable energy sources.

Many fossil fuels and some of other energy sources that are not renewable have been causing environmental harm. Oil mining, for example can cause the destruction of our forests of the earth. Hydraulic fracturing (fracking) can trigger earthquakes and pollute the water. Carbon dioxide is released when coal is burnt and contributes to global warming.

Fortunately, a majority of the most dal protocollo di kyoto e oltre promising sources of energy are renewable and sustainable. Solar, wind and hydropower create, for instance, electricity without the need to dig for new sources.

Other sources of sustainable energy are emerging, such as waves and tidal power. But, in order to be utilized in a large-scale manner these technologies need effective distribution networks. This requires the use non-renewable energy sources to construct these networks. Therefore, these sources aren’t sufficient to meet the majority of our energy requirements. It’s important to remember that the cost of renewable energy equipment have decreased dramatically in recent times and the efficiency of these equipments is growing.