Global warming is a reality. The increase in temperatures is contested per person. For the vast majority of scientists the cause is heard: the rise in temperatures is due to the increase in the atmosphere of the concentration of greenhouse gases, gases that hold on the surface of the globe the heat emitted by sunlight. Temperatures are rising because we emit in the atmosphere a lot of greenhouse gases such as carbon dioxide from coal combustion, natural gas oil from which we consume massive quantities. Other gases such as methane, which are abundant in natural gas, also play a significant role. The leakage of methane from production, transport (e.g. pipeline leaks), and use is easier to reduce than the CO2 emissions from our consumption of products essential to our economies, but the removal of these leaks requires measures that can be costly and that operators are reluctant to implement.

The energy transition, the transition from one energy to another or the rapid development of new energy is not a novelty. In the 18th century, wood was the main source of energy especially in the nascent industry. But the forests, too exploited, disappeared. Coal then appeared and allowed the first industrial revolution. Then oil became a dominant energy after the Second World War. For many years electricity has become an increasingly important energy source. Transition does not mean replacement. More and more wood, coal and oil are being consumed. For many, experts there is no shift from one energy to another but superposition of energies. Currently, the consumption of wood and coal, despite the development of oil, gas, nuclear power, renewable energy, remains higher or even much higher than it was a century ago.

The energy transition at the beginning of the 21st century consists in gradually shifting from fossil fuels (coal, oil, natural gas) that contain carbon to decarbonized energies. About 80% of fossil fuels contribute to greenhouse gas emissions and about 10% contribute to methane.

Reducing fossil energy consumption is therefore a priority. The hydraulic energy provided by dams, wind energy, solar energy that does not emit CO2 are in the midst of development. Their production has increased threefold in just 15 years, but they still cover only a small part of our energy needs, 7 to 14% very coarsely according to the calculation methods. Nuclear energy, which does not emit CO2, accounts for about 5% of our energy consumption.

For several years, and especially since COP 21 in Paris in 2015 (COP: Conference of the Parties organized within the framework of a United Nations structure and which brings together thousands of representatives from governments, industry companies and NGOs each year), the aim is to limit it to 2° Celsius increased temperature compared to the 1990s to limit the frequency and severity of natural disasters (tornades, typhoons, floods, floods, etc.). At COP21 it was even suggested to limit the increase to 1°5.

Already this last objective will not be achieved. In 2024 in many regions the temperature increase is already 1.5°. Various recent events (fires in Canada, the United States, Greece ..., floods in Pakistan, Spain, storm in Mayotte etc...) are not necessarily new but are probably more frequent and violent. However, fossil energy consumption continues to increase (1 to 2% per year) and thus CO2 emissions.

Only positive point: The share of renewable energy, although still limited, is increasing rapidly. Most of the new electricity generation capacity now comes from wind farms, photovoltaic plants or other equally renewable sources (solar by concentration, geothermal energy in particular). Already, large solar power capacities exist in most countries, particularly China, the United Arab Emirates, some European countries and the United States. China expands non-CO2 energy projects: large dams (China and Brazil share the largest dams in the world), solar parks, wind farms

Hydrogen could play an important role in the future. There are no hydrogen sources or reservoirs (small chemical reaction production in the soil is nevertheless possible). Most of the hydrogen currently used is produced from natural gas or coal with very high CO2 emissions. The future is therefore to green hydrogen obtained by electrolysis of water (which supplies hydrogen and oxygen) with electricity of wind or solar origin. Very important "green" electricity projects (wind and solar) are being studied in Africa, particularly in countries such as Morocco, Mauritania, Namibia and generally in countries with very high sunshine. This hydrogen could be used in transport (by equipping vehicles with fuel cells) or in certain industries where it could replace fossil fuels.

The energy transition, the transition from fossil energy to renewable energy is in progress but slow. Fossil energy consumption is still very high (80% of our needs), it continues to increase and it will probably not stabilize and decrease until 2030. China, now the largest emitter of CO2, is expected to stabilize its coal consumption in the coming years but will achieve carbon neutrality (no net CO2 emissions) only in 2060 according to Beijing commitments.

Unfortunately, therefore, there is concern that temperatures will continue to rise. The two components of the fight against climate change must therefore be implemented: reducing greenhouse gas emissions and adapting to higher temperatures.