How climate change will affect our energy consumption
- Global warming is leading to an overall reduction in heating requirements, although this trend varies depending on the region and the season.
- In France, the reduction in heating requirements is accompanied by a fragmentation of electricity consumption, which complicates the management of peak demand.
- Climate change is increasing the need for air conditioning, especially in tropical regions, which offsets the fall in heating requirements.
- Societal choices and the dynamics of air conditioning adoption have a strong influence on energy consumption.
- There are several ways of improving thermal comfort for residents: repainting buildings, insulating, planting vegetation, etc.
How does climate change affect heating requirements ?
As a general rule, a warmer climate means lower heating requirements. However, this general observation conceals a number of disparities, which vary from region to region and from season to season. Demand is particularly high during cold spells. France, for example, is a special case because of the extensive electrification of its heating system. Though we will always experience cold snaps, they will occur less frequently. And yet our heating needs will, on average, decrease with climate change. As a result, electricity consumption will become increasingly fragmented, with higher and higher peaks. This could make it more difficult for the electricity system to manage.
In 2023, renewable energies will have accounted for 86% of new energy capacity installed1. Does this transition to renewable energy represent a risk in the face of these consumption peaks ?
In France, the electrical grid is designed to cope with peaks in demand, and the grid operators are subject to severe constraints in terms of their ability to supply energy. But even this high degree of variability in consumption does not improve the problems associated with the variability of renewable energy production. All other things being equal, climate change brings an additional constraint that could lead to the system becoming oversized.
And what about cooling requirements ?
Climat change is affecting air conditioning requirements. The probability of exceeding a temperature threshold requiring air conditioning increases with climate change. The tropical belt is the region most at risk from extreme heat. But beware : these energy requirements do not necessarily translate into energy consumption : will the impact of climate change really result in the installation of more air conditioning units ? It’s very difficult to say.
What is the impact of climate change on energy demand ?
Another commonly used method of assessing the impact of climate change is to estimate the number of days of cooling or heating required to maintain thermal comfort in buildings. It is based on estimating the number of days of air conditioning or heating needed to maintain thermal comfort in buildings. The combination of the two provides an approximation of the variation in energy demand. By taking demographics into account, one study estimates that, on a global scale, the gradual increase in the need for air conditioning will offset the decrease in the need for heating in many regions around the world, for almost all the greenhouse gas emission scenarios and global warming levels studied (1.5°C, 2°C, 3°C or 4°C)23. Overall, energy demand is set to increase everywhere except in the middle and high latitudes of Eurasia and south-west South America. Equatorial Africa and India will be particularly hard hit by the rise in demand. Please note : this indicator is based solely on temperature variations linked to climate change and demographics. It therefore is limited in that it does not take into account the actions actually taken by the population.
What are the factors that influence societal choices during heatwaves ?
The dynamics behind the adoption of air conditioning vary greatly : for example, it is very widespread in the United States, but much less so in Europe. The type of air conditioning used also varies. With my colleagues André Mounier and Louis-Gaëtan Giraudet from CIRED, we are finalising an as yet unpublished study illustrating the differences in adoption dynamics between fixed and portable air conditioners. The latter are only half as energy-efficient, with potentially significant consequences for energy consumption. While rising temperatures appear to be the main reason for the purchase of fixed air conditioners, heatwaves, which occur more frequently, appear to be the main reason for the purchase of portable air conditioners.
Energy consumption is not just about the climate ; it is also about the choices we make as a society. There are a number of ways of combating heat peaks : repainting buildings, insulating, planting vegetation, installing air conditioners, etc. A team led by French researcher Vincent Viguié has shown4 that adaptation measures other than air conditioning are useful for improving the thermal comfort of residents and reducing energy consumption in the Île-de-France region. When optimised, they can reduce outside air temperature by up to 4.2°C at night. However, they cannot totally replace air conditioning.
Given this context, is it really possible to anticipate the impact of climate change on energy requirements ?
Converting a requirement into energy is not straightforward. It depends on the dynamics of adoption, which are linked more to economic development than to climate change. In the case of France, modelling heating needs is fairly easy, because the technologies are already well-known. Cooling, on the other hand, is more complicated. Air conditioning is not widespread, so we have little data. But historical data is essential for any simulation.
Can we expect the fall in heating requirements to offset the rise in cooling requirements ?
Models based solely on demand, independent of actual use, show that this is indeed the case on a global scale (see box). We have carried out simulations for France that also include scenarios for the installation of air conditioning units. We have shown that energy consumption in the region should fall, and that consumption linked to air conditioning should only exceed the fall in heating in scenarios involving massive use of air conditioning. On a regional scale, as in the south of France, however, it is much more likely that electricity consumption from air conditioning will exceed that from heating.
