Carbon neutrality in 2050: a necessarily transversal approach to the energy transition

An extract from “Energy and climate”, by Alexandre ROJEY

Energy is everywhere in our lives. It contributes to our comfort and is essential to all of our industries and technologies. The progress of the previous century was made possible by abundant and relatively available energy, particularly oil. However, this fossil energy has a significant negative impact on our environment and our climate, to the point that today we are increasingly faced with numerous extreme weather events. The urgency is therefore to limit global warming and, consequently, to reduce the gas emissions which are responsible for it. How can we achieve this in a global context, also marked by geopolitical crises and when demand for energy is growing?

More and more greenhouse gases

Carbon dioxide is the human-made gas contributing the most to the greenhouse effect. It mainly comes from fossil fuels and industry, but also from deforestation and the decomposition of biomass.

All greenhouse gas emissions are measured in terms of CO₂ equivalent (eq CO₂), the quantities of which are increasing in the atmosphere. This increase, estimated at +4°C by the end of our century, would lead to potentially catastrophic consequences. According to IPCC experts, it is imperative to limit it to 1.5°C by 2100. This objective is only achievable by achieving carbon neutrality by 2050, and this through a massive reduction of fossil fuel consumption, as well as offsetting residual emissions through CO capture and sequestration₂ in biomass or the subsoil.

2020 saw emissions decrease due to the Covid-19 crisis. However, they had increased considerably again in 2022, to such a level that the scenario of carbon neutrality by 2050 seems to be moving inexorably away. We must therefore imagine new solutions, not just technical ones, to achieve it. This is how we must rethink our lifestyles and our behaviors, but also our habitat and the means of getting around, while preserving the quality of life or improving that of developing countries.

Reducing energy consumption will also help to reduce our energy dependence on hydrocarbons, but requires better energy efficiency and control of demand, as well as an increase in the share of renewable and nuclear energies.

Compensate or reduce, should we choose?

CO capture and underground storage₂ emitted by thermal or coal-fired industries, then recycling this gas are other solutions to reduce emissions. Having become “negative emissions”, they are essential in the fight against global warming. Increasing biomass production, through the planting of trees under controlled conditions, will allow the creation of these carbon sinks, which will in fact be “compensated”. This practice is, however, sometimes controversial, given the difficulty of rigorously controlling the carbon footprint over the long term.

Regulation will also be an important support in terms of energy efficiency. In France, in particular, RT2020 now imposes constraints on primary energy consumption for all new construction. Also targeted are thermal strainers, which are numerous in old homes, but also transport, with a limitation of CO₂ per kilometer traveled and a possible ban on sales of thermal vehicles from 2035. Likewise, energy suppliers are required to achieve, support or finance energy savings.

Penalties through taxes or purchases of emissions permits are also put in place to limit greenhouse gas emissions.

All of these solutions must absolutely not present the disadvantages of fossil fuels, whether in the form of resource depletion or greenhouse gas emissions. Alternative energies, nuclear and renewable, will therefore have to find their place, but it will take time before they manage to supplant fossil fuels. However, at present, these solutions are not always economically profitable, not necessarily well accepted, or even present a risk in terms of security. It is therefore a combination of means that should be implemented throughout the energy transition period to achieve carbon neutrality globally by 2050.