Quirks & Quarks

Understanding the most important greenhouse gas — water vapour

Fossil fuel driven climate heating has increased the amount of water being evaporated from oceans, lakes and soils, exacerbating storms and increasing rainfall.

'It's approximately doubling the amount of warming that we're experiencing now.'

Increased water vapour in the atmosphere is fueling more intense and frequent storms. (Johannes Eisele/AFP via Getty Images)

Rising fossil fuel associated emissions of carbon dioxide and methane are in turn fuelling the increase of the most important greenhouse gas on Earth: water vapour.

The more fossil fuel emissions we release into the atmosphere, the warmer our climate becomes, and the more water evaporates from oceans, lakes and soils. In addition, the warmer the atmosphere gets, the more water it can hold.

Today there is an average of four per cent more water vapour in our atmosphere than there was in the 1990s, which is fuelling more intense storms and heavier precipitation in some regions, and drying out soils creating drought and wildfire conditions in other regions.

Increased evaporation from the soil is leading to drought conditions, especially in regions like California in western North America. (Frederic J. Brown/AFP via Getty Images)

To understand our changing climate, a prominent climate scientist says we have to understand water vapour, which is why she felt the need to write about it in a recent article in Scientific American

Jennifer Francis, a senior scientist at the Woodwell Climate Research Center in Massachusetts, told Quirks & Quarks host Bob McDonald that water vapour is approximately doubling the amount of warming we're experiencing today.

Increased water vapour in the atmosphere leads to more intense storms and flooding due to increased precipitation. Canadian police officers stand a boat on a flooded street in in the suburbs of Montreal in April 2019. (Sebastien St-Jean/AFP via Getty Images)

As the fossil fuel emissions continue to drive the heat up on our planet, more water is evaporating which then traps even more heat at the Earth's surface, leading to even more water evaporation in a vicious circle that's accelerating global warming. 


Produced and written by Sonya Buyting. Click on the link above to hear the interview with Jennifer Francis.

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