Our planet receives energy from the sun. Some of this energy, which is not reflected by the atmosphere, is absorbed by the earth’s surface. Rising temperatures and global warming are mainly due to increasing concentrations of greenhouse gases in the atmosphere…
So, if an 8-year-old asks you the question: why is the earth warming up? If you have read the previous episodes of Café climat and if you have carefully watched all my videos, you are probably thinking that the increase in greenhouse gases in the atmosphere increases the ambient temperature.
True, but that’s not the only thing. You may even be surprised at the multiplicity of direct impacts which I am going to present to you.
The increase in greenhouse gases in the atmosphere
We saw it in the first article of the series, the increase in the concentration of greenhouse gas (CO2, methane, nitrous oxide, etc.) in the atmosphere has the consequence of maintaining infrared rays in the atmosphere.
More infrared in the atmosphere means more energy left in the atmosphere. And this is theincrease in this energy which has far-reaching consequences on Earth.
But just before seeing these consequences on the Global warmingI want to explain a technical term that you probably hear about if you are interested in climate change: the radiative forcing.
What is radiative forcing?
Radiative forcing is the measure of the increase in energy that remains in the atmosphere. More precisely, if we want to be a purist, it is the difference between the energy which arrives on the earth/atmosphere unit and that which leaves it every second.
the radiative forcing is the difference between the yellow arrow minus the red arrow in the diagram.
Since there is more energy coming in than energy going out, that is why we talk about radiative forcing.
Now we will see what this energy increase is for. This is the crux of the climate change because this is where we begin to address the consequences for the planet.
Consequences for global warming
This energy that accumulates on our planet has the consequence, in order of importance, of:
- Warming the oceans: 93%
- Melting ice cream: 3%
- Warm the floors: 3%
- Warm the atmosphere: 1%
An interesting point to our is that the warming of the atmosphere is the one that we perceive the most on an individual basis, as a human, especially if you’re my age or older. ” I’m talking to you about a time that those under 20…” as Charlez Aznavour said.
The 2003 heat wave was unprecedented but ultimately constituted the first of a long series… Well, the warming of the atmosphere represents only 1% of the radiative forcing.
So imagine the impact it can have on the rest of the planet: oceans, glaciers, soils…
Conclusion
If you only have to remember one thing: the greenhouse gases increase the energy that remains in the atmosphere and this energy leads to global warming: first the oceans, then the soil and ice, and finally the atmosphere.
I explain the impact of each of these points in the following articles of the series.
- The consequences of ocean warming
- The consequences of melting glaciers and sea ice
- The impact of global warming on soils
