CO2 levels to identify habitability of planets

Source– This post is based on the article “CO2 levels in planet atmosphere could be a sign of its habitability: study” published in “The Hindu” on 3rd January 2024.

Why in the News?

A recent study by a team of researchers suggests that lower levels of CO2 in a planet’s atmosphere may indicate the presence of liquid water, rendering the planet ‘habitable.’

What are the Findings of the study?

1) The researchers have devised a new ‘habitability signature’ as a “practical method for detecting habitability” of a planet.

2) According to the researches, lower levels of CO2 in a planet’s atmosphere compared to neighbouring planets suggests potential absorption by an ocean or isolation by biomass on a planetary scale.

3) Planets positioned at an ideal distance from their star— neither too close leading to excessive heat nor too far resulting in extreme cold— are deemed to be in the habitable zone and may be capable of hosting water on their surface.

What is the Significance of the Study?

1) The habitability signature can help us identify planets with oceans, increasing the likelihood of their ability to support life.

2) Studying CO2 levels of other planets may also offer insights into Earth’s environmental tipping points and the associated carbon levels at these points that could render our planet uninhabitable.

– For example Venus and Earth share similarities, but Venus’ high carbon levels suggest a past climatic tipping point that may have rendered it uninhabitable.

3) The team suggested that the ‘habitability signature’ they developed could also function as a biosignature, considering that living organisms also capture carbon dioxide.

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