Atmospheric Carbon Watch

In this blog I wanted to flag a couple of numbers from the Mauna Lao atmospheric carbon dioxide monitoring station. The main point to note is that the planet is on track to exceed 395 parts per million Atmospheric Carbon Dioxide in March or April 2011. We are already effectively in uncharted territory in terms of CO2 levels however the coming months will represent a new high in global atmospheric carbon readings within the human evolutionary timeframe.

For those not aware of it Mauna Lao is the original observatory established to measure atmospheric CO2 at a location that was remote enough to not be effected by local industrial and transportation pollutants. The isolated site was selected to represent a benchmark to monitor global change in CO2 parts per million in the atmosphere. As an aside I often wonder about the thinking that went into choosing Mauna Lao…. I’m sure the scientists involved thought long and hard about locating their long term observatory and research station in other globally isolated locations like Siberia, Antarctica, the Amazon, the Sahara however for purely scientifically justifiable reasons, they settled on that climatic hell-pit Hawaii….

The US Dept Commerce funds the National Oceanic and Atmospheric Administration CO2 Observatory at www.esrl.noaa.gov/gmd/ccgg/trends/#mlo. it is a site everyone should familiarize themselves with if they haven’t already.

A quick review of the recent monthly trend of Atmospheric CO2 indicates the December/January reading typically represents the trend line for the current annual cycle. In round terms the current reading is 391ppm which is 2.5ppm above the 388.5ppm recorded at the same time last year. For those not familiar with it, 2.5 parts per million change in the level of atmospheric carbon dioxide in a year is extreme.

In 2010 the reading peaked in April at 5ppm above the December/January figure. Assuming the current trend and growth rate continues the 395 figure is definitely in danger of being breached this year, with 2012 the year we are likely to exceed 400ppm.

To put those figures into perspective: 250 parts per million is approximately where the planet was when cities and agriculture emerged around 10,000 years ago. 200 parts per million typically ushers in an ice age. 300 parts per million is the upper limit of where the level typically peaks out between ice ages.

For some reason a global warming event doesn’t frighten people the way I suspect discussion of the threat of an imminent Ice Age would. Talk of oceans rising several feet or more extreme weather events doesn’t seem to alarm people or motivate action. By contract I’m sure widespread scientific agreement and discussion on the probability of a mile high glacier rapidly emerging over most of the continental USA, say in a line from somewhere near Washington DC to Los Angeles, in the time frame of many people’s current home loans would definitely draw attention. The scale of change being envisaged is three times the difference between the birth of agriculture and an ice age – only warmer instead of cooler.

Somehow it doesn’t sound nearly as threatening but that is an intuitive response to a threat of imminent ‘warmth’ rather than a rational one.