12 - Kohlenstoffsenken

Source : GIEC 12 1 / 2 1/4 1/4 Jährliche Verteilung des anthropogenen CO 2 ( GtC /Jahr) Photosynthese Atmosphäre Ozeane Kohlenstoffsenken
Set 2 www.climatefresk.org 12 Die Hälfte des CO 2 , das wir jedes Jahr emittieren, wird von Kohlenstoffsenken aufgenommen: - 1 / 4 von der Vegetation (Photosynthese) - 1 / 4 von den Ozeanen Die andere Hälfte bleibt in der Atmosphäre.

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Causes

CO2-Emissionen

CO2-Emissionen

These two cards can be put border-to-border in order to reconstitute the original graph. Ask the participants: "Have a look at card 12. What do you notice ? - It's written upside down - Exact. This is an enigma. The answer to it is on the table." When they have found that 12 and 7 go together, then explain the resulting graph: it shows where the CO2 comes from and where it goes to. This is why the outer curves are symetricals. Each year, the CO2 emitted by Human beings has to go somewhere. If it's not in the carbon sinks, then it's in the atmosphere.
Methanhydrate

Methanhydrate

CO2 is absorbed at the surface of the ocean. Thermohaline circulation helps mix watersurface and deep ocean which is essential to the absoption of CO2 by the ocean.

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Consequences

CO2-Konzentration (ppm)

Kohlenstoffsenken

the card n11 represents the concentration in CO2, understood in the atmosphere (it's written behind the card).
Versauerung der Ozeane

Kohlenstoffsenken

The word "Ocean" is written on both sides.

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Other possible causes

Entwaldung

Entwaldung

Participants often think that deforestation reduces carbon sinks. In reality, the impact is minimal because deforested areas represent a very small part of the total forest area. Moreover, a mature forest has reached its equilibrium and no longer absorbs carbon. Therefore, as mainly mature forests are deforested, this does not impact carbon sinks. On the other hand, the amount CO2 released is very high.
Landwirtschaft

Landwirtschaft

It doesn't matter if this link is not made, but it is true that agriculture can improve storage capacity through photosynthesis. This is the 0.4% principle (if we increased the soil's capacity to sequester carbon by even 0,4%, we would have a significant impact on CO2).
Dürren

Dürren

If a lack of rain occurs while plants are growing, there is less photosynthesis and therefore a reduction in capacity of the carbon sink. In Europe, in 2018, carbon sinks declined by 18%.

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Other possible consequence

Rückgang der Ernteerträge

Kohlenstoffsenken

Studies have shown that yields increase with increased CO2, but that the nutrient content of vegetables is reduced as a result, because trace elements are not more abundant when yields increase.

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Wrong cause

CO2-Konzentration (ppm)

CO2-Konzentration (ppm)

It can be argued that CO2 emissions take place before reaching carbon sinks. But the opposite link has our preference.

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Wrong consequence

Energiebilanz der Erde

Kohlenstoffsenken

The idea here is not to say there is no link between these two cards, but to make sure they are not mixed up. The carbon sinks card tells us where the carbon goes. The energy budget card tells us where the excess energy goes. Both distribute something, but not the same thing. To make it even more confusing, the atmosphere and the ocean are present in both.
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