Which of the following is not considered a greenhouse gas?

Hydrogen is not a greenhouse gas, as it does not absorb infrared radiation the way heat-trapping gases do.

Methane is a potent greenhouse gas from farming and fossil fuels.

Chlorofluorocarbons are strong greenhouse gases and also deplete ozone.

Ozone acts as a greenhouse gas in the lower atmosphere.

The heat-trapping gases share the ability to absorb and re-emit infrared radiation.

Water vapour is the most abundant naturally occurring greenhouse gas.