En-en adult card 21 temperature rise

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Card #21: Rising Air Temperatures

En-en adult card 21 front.png

The average air temperature at the surface of the Earth has increased by 1.2°C since 1900. Future emission scenarios predict that this increase will reach between 2 and 5°C by 2100. During the last ice age 20,000 years ago, the average air temperature was only 5°C lower than today and warming up took 10,000 years.

Explanation

This card can play two roles:

  • Either it's the temperature of the air, and therefore of the atmosphere. This is how it should be interpreted when you have kept cards 10, 14 and 15 in the game. In this case, the previous card is 14.
  • Either it represents the temperature of the Earth (and this is good because the definition of the temperature of the Earth is precisely the temperature of the air, at ground level, on average at the surface of the Earth). In this case, the previous card is 13 and we can link to cards 16, 17, 18 and 19.

At the current rate of warming, 0.2°C per decade, the warming will reach 1.5°C between 2030 and 2050.

Correction

Causes

Consequences

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Additional data

The ocean absorbs 93% of the excess energy on earth. How is it that it only warms up by a tenth of a degree at the surface and even less under water? This is because it is much more massive than the atmosphere and has a much greater calorific capacity. To measure this, we have to remember that the ocean covers 71% of the earth's surface and that it has a depth of 4000m on average. The atmosphere has a greater thickness, but if we bring it back to the same density as water, it is only 10m thick (this is why we gain one atmosphere of pressure every 10 m when we dive).

At the current rate of warming, 0.2°C per decade, warming will reach 1.5°C between 2030 and 2050.

The current level of ambition to slowly reduce the rate of greenhouse gas emissions would lead to a global warming of more than 3°C by 2100 and would therefore not respect the objective of the Paris Agreement.

Limiting global warming to well below 2°C would imply reducing CO2 emissions by 25% by 2030 and reaching a net zero rate by 2070.

Limiting global warming to 1.5°C would imply reducing CO2 emissions by 50% by 2030 and reaching a net zero level by 2050. This would require rapid, profound and unprecedented transitions in energy systems, land use, urban, industrial and infrastructure systems, using a range of technologies and behavioural changes.

References