Dealing with the Rise of the Greenhouse Gas Jokers
Photo credit : Nadia Hatoum
Say the words 'global warming', and the chances are that the perp you'll conjure up is a smoke-stack, coughing carbon dioxide into the atmosphere. The world has been fixated on the black-stuff – carbon – ever since scientists put the plot-lines of rising CO2 levels and global temperatures next to each other – and started to worry.
But today's release of the 7th Greenhouse Gas Bulletin sees the World Meteorological Office shining the light on a pair of oft-neglected gaseous jokers – methane and nitrous oxide. It seems that these greenhouse gases are on the rise too – and eager to take the spotlight away from big bad CO2. Because, while CO2 levels continue to rise remorselessly – despite all our decades of carbon hand-wringing – we haven't been able to stop this pair of jokers from playing tag-along.
No laughing matter
That matters. Methane and nitrous dioxide – or laughing gas – may be at much lower levels, but they pack a lot more warming-bang-per-buck, than CO2. The potency of a greenhouse gas depends a lot on its shape, and these two gases are shaped just right for planet-warming. They soak up the heat which the earth emits, as it is warmed by the sun; the more of the gas there is, the more of that emitted heat is being trapped.
So what does the WMO Bulletin have to say on these two tricksy greenhouse gas players? For methane, the story is of a newly renewed strike upwards – after a decade in the doldrums. Last year, methane rose by 5 part per billion, building on three years of similar sized increases. As tiny as that increase may sound, methane is 18 times more powerful a greenhouse gas than CO2. And the level of methane now in the atmosphere is two-and-half times that which lingered around 18th century Planet Earth.Continued on the next page