Sign with the slogan there is no planet B during a demonstration against global warming

Does CO2 contribute to global warming?

The Earth's atmosphere is a mixture of gases, some of which are known to be 'greenhouse gases'.

These gaseous components - the best known of which are carbon dioxide (CO2), ozone (O3) and water vapour (H20) - share the characteristic of being excellent absorbers of infrared radiation.

The usefulness of greenhouse gases

Greenhouse gases (GHGs) have the ability to absorb radiation from the sun as well as infrared radiation from the earth. Without the presence of GHGs, heating of the ground by radiation would not be possible: the fraction of energy captured by the gases could not be returned to the surface and the Earth would cool down.

In concrete terms, without greenhouse gases, the Earth would have an average temperature of about -18°C instead of the 13.7°C average we experienced in 2019. To sum up: without greenhouse gases, life on Earth would not be possible - that's how important they are!

Carbon dioxide: an ideal culprit?

The World | Understanding global warming in 4 minutes

Of all the greenhouse gases, carbon dioxide (CO2) is the one that gets the most attention when it comes to global warming. The reason is obvious: CO2 is a by-product of burning fossil fuels, one of the main sources of energy in our global economy.

Over the past 100 years, the massive use of fossil fuels has led to an increase in the concentration of CO2 in the atmosphere of the order of 300 to 400 ppmv (particles per million by volume). This concentration far exceeds anything the Earth's atmosphere has experienced in at least the last 800,000 years. By way of comparison: the concentration of CO2 was only 280 ppmv in 1850 (before the industrial era), which makes CO2 the ideal culprit for global warming.

Changes in atmospheric carbon dioxide concentration between 1850 and 2006
Changes in atmospheric carbon dioxide concentration between 1850 and 2006

But act on CO2 be enough to counteract the rise in the earth's temperature? There are many factors at play and in our view CO2 cannot be held solely responsible for global warming. The only thing that is certain is that carbon dioxide is a greenhouse gas: the more of it that is present in our atmosphere, the greater the warming effect.

According to the latest projections, if global warming continues at the current rate, then the average temperature of our Earth is expected to rise by 1.5° Celsius by 2030 to 2052.

Would you like to learn more?

The French government has been committed to the fight against global warming since 2011 with its national plan for adaptation to climate change. In 2018, This plan has been replaced by the PNACC2, which is articulated around 4 objectives:

  • Protecting people and property
  • Avoiding risk inequalities
  • Limiting costs and reaping the benefits
  • Preserving the natural heritage

For a better understanding of climate change and France's actions in this area, we suggest you discover the infographic released by the government, available at : https://www.ecologie.gouv.fr/

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