We hear more and more about the need to reduceCO2 emissions. But what exactly is the impact ofCO2 on climate change? Why is it necessary to reduce our carbon dioxide emissions? What is the link between global warming, the greenhouse effect, andCO2? The CNRS recently published a book entitled "Tout comprendre (ou presque) sur le climat" (Understanding (almost) everything about the climate), which addresses this issue in particular. Explanations.
What isCO2?
Carbon dioxide, orCO2, is one of the most prevalent gases in the atmosphere. It plays an active role in the respiration of living beings and photosynthesis in plants. It enables plants, animals, and other species to live. This balance helps preserve ecosystems.
It is when it is too abundant in the atmosphere that its effects become harmful.
The causes of the increase inCO2 emissions
The recent increase inCO2 in the atmosphere is accelerating. In fact, the concentration ofCO2 in the atmosphere has increased by more than 40% in 170 years (since the beginning of the industrial era), which has had a significant impact on the climate.
Human activity is the main cause of this massive increase.
40 billion tons ofCO2 emitted each year, mainly from the burning of fossil fuels and deforestation.
By way of comparison, 360 million tons ofCO2 per year is what 1,500 terrestrial and underwater volcanoes combined produce.
However, the Earth's climate results from a balance between the energy it absorbs and the energy it releases.
The consequences of increasedCO2 in the atmosphere
Anything that disrupts this balance (such as an excess of greenhouse gases, likeCO2) affects the temperature because the planet cannot release the excess energy in any other way than by changing its temperature.
The massive increase inCO2 emissions has created an imbalance in the Earth's energy balance, which in turn has caused:
- temperature increase
- ocean acidification (decline in marine biodiversity)
- greening (increased water consumption and disruption of the natural balance of ecosystems)
What is the link betweenCO2 and global warming?
CO2 emitted into the atmosphere is mainly linked to human activity, particularly the burning of fossil fuels. The massive increase observed since the industrial revolution has had a significant impact on the climate. It has created an imbalance in the Earth's energy balance: the energy absorbed is less than the energy released. The consequences of this imbalance are an increase in the Earth's temperature, ocean acidification, and greening. These climate changes are therefore linked to the increase inCO2 in the atmosphere.
To go further:
Carbon footprint calculator: simulate your carbon footprint and discover ways to reduce it.
Source: Excerpt from "Tout comprendre (ou presque) sur le climat" (Understanding(almost) everything about climate), published by Éditions CNRS, Paris, 2022. Copyright ©CNRS Éditions
