How much of a problem are non-CO2 greenhouse gases? Together, they are responsible for around a third of human-caused warming so far, and the Paris agreement climate targets won’t be reached ...

Levels of the three most significant human-caused greenhouse gases – carbon dioxide, methane and nitrous oxide – continued their steady climb in 2023.

Of course, CO2 isn't the most potent greenhouse gas – that's methane (CH4), which comes from burning of fossil fuels, decomposition of landfill waste and more.