Currently made up of fossil fuels for more than 80%, the global primary energy mix has entered a period of transformation. In 2015, oil is still the first energy source with 33% of the total followed by coal (27%) and gas (21%). But by 2040, major changes could happen according to several studies anticipating a rise of the gas share in the energy mix. Natural gas could take the second place and oil would only account for 25% of the total.
Gas is often seen as the lesser of two evils. Indeed, while coal emits 1,12teqC per toe (ton of oil equivalent) and oil 0,83teqC per toe, natural gas only emits 0,65teqC per toe. Such a difference explains why natural gas is more and more preferred to the two other fossil fuels. This is why some projects based on the Clean Development Mechanism are replacing oil or coal by natural gaz. This substitution is often complementary with the setup of energy efficient technologies.
The discovery of shale gas has had a huge impact on gas markets. This silent revolution first began in the United States. It represented 23% of the US gas production in 2010 against only 14% one year before. In the future, shale gas exploitation will put pressure on traditional gas exporters which are Russia, Iran and Saudi Arabia. They have to anticipate this future competition and potentially declining prices. Currently, the European Union and Asia are not particularly concerned by this evolution of energy markets. In addition, several environmental threats caused by shale gas remain: contamination of water tables, release of greenhouse gas, increased risks of earthquakes. These well-founded fears remind us that, to prevent temperatures from rising above +2°C by 2100, 80% of fossil fuel reserves need to stay in the ground.