If you want to see the latest figures for the state of our atmosphere, the Global Monitoring Division of the US National Oceanic and Atmospheric Administration’s Earth System Research Laboratory is a good place to start. They consolidate data from a huge global network of monitoring stations.
Select your greenhouse gas (carbon dioxide – CO2, methane – CH4, nitrous oxide – N2O) and watch the graphs climb. We’re perhaps used to seeing graphs for carbon dioxide, so for the sake of a little variety in your gloomy global warming news, here’s a graph for increases in nitrous oxide.
Otherwise known as “laughing gas” or “happy gas”, nitrous oxide is somewhat less amusing in increasing concentrations in large swaths of atmosphere. Over a hundred year period, it is 298 times more potent a greenhouse gas than CO2. At the moment, it apparently accounts for 6% of the human-related warming effect. It’s released by industrial activity, burning coal for example. Also released by tropical soils and from the oceans, human activity has till recently been thought to account for 30% of what’s now in the atmosphere. But it appears releases from nitrogen-based fertilisers may have been greatly underestimated. Overall, atmospheric levels have increased 15% since 1750. It’s also an ozone-depleting gas – in fact, it’s now the key ozone depleting gas.