In the early history of the Earth, the atmosphere was dominated by carbon dioxide ( $CO_2$ ) and nitrogen, with surface temperatures regulated by a strong greenhouse effect. Over geological timescales, atmospheric $CO_2\,$ levels decreased dramatically.

Which planetary-scale process was primarily responsible for this long-term drawdown of atmospheric carbon dioxide?

Direct thermal decomposition of $CO_2$ into elemental carbon and oxygen gas in the thermosphere.

The weathering of silicate rocks by acidic rainfall, leading to the deposition of carbonate minerals on the seafloor.

The physical entrapment of gaseous carbon dioxide inside clathrate hydrates within the deep oceanic crust.

The reduction of carbon dioxide by hydrogen gas during intense volcanic outgassing events to form methane.

Which planetary-scale process was primarily responsible for this long-term drawdown of atmospheric carbon dioxide?

Direct thermal decomposition of $CO_2$ into elemental carbon and oxygen gas in the thermosphere.

The weathering of silicate rocks by acidic rainfall, leading to the deposition of carbonate minerals on the seafloor.

The physical entrapment of gaseous carbon dioxide inside clathrate hydrates within the deep oceanic crust.

The reduction of carbon dioxide by hydrogen gas during intense volcanic outgassing events to form methane.

Interpreting and interacting with earth systems

Question 4

Markscheme

Interpreting and interacting with earth systems

Question 4

Markscheme

Interpreting and interacting with earth systems

Question 4

Interpreting and interacting with earth systems Questions

Interpreting and interacting with earth systems

Question 4

Interpreting and interacting with earth systems Questions