Last month I tackled the question “How worried should we be”? Since then I’ve begun to read Mark Lynas’ book “Six Degrees”, subtitled “Our future on a hotter planet”. It’s the best review of the available science, economic and political analyses that I’ve discovered and I’ve allowed myself the indulgence of studying the last chapter before reading all the preceding ones so I can pass on without delay the essence of the exhaustive studies which earned Mark the Royal Society’s medal for Communicating Science.
Summarised brutally for the sake of brevity, he reports that:
Past CO2 emissions will cause global temperatures to rise by 0.5 to 1 degree Celsius:
-
Alpine glaciers, Nebraskan grazing lands and coral reefs are condemned.
Modelling suggests we probably have time to stabilise at 2 degrees warmer:
-
Slowing melting of Greenland ice and the rise in sea levels
-
And avoiding dangerous global feedbacks likely around 3 degrees.
Avoidance is vital to prevent Amazonian rainforest collapse and soil carbon release:
-
Which would lead to a 4 degree world
-
Siberian permafrost would release carbon and methane quicker
-
Perhaps leading to a 5 degree world.
At 5 degrees release of oceanic methane could catapult us to 6 degrees:
-
And the “ultimate mass extinction apocalypse”.
The lesson is clear: we must hold to a 2 degree rise.
How do things stand now?
One analyst calculates a 7% chance that we are already too late.
But that means we have a 93% chance of limiting the rise to 2 degrees:
-
But only if we hold atmospheric CO2 concentrations at the present level
-
Every year of rising levels shortens the odds.
The level was 382 ppm in 2007:
-
And it is still rising at about 2 ppm per year
For a 75% chance of limiting to 2 degrees:
-
Emissions must peak at 400 ppm in 2015
-
Then decline by 85 % by 2050.
-
However politically impossible that seems at present.
How can it be done?
That’s another story, one which hasn’t been written yet. However, it should begin with recognition that climate change is the key question facing humanity, more significant than terrorism, war, healthcare, education, religion, etc. It will be a story of over-population, human behaviour in all its forms: greed, frailty, inertia, selfishness. If we wish we could just call it, as the filmmakers did, “Stupidity”.
While waiting for policy makers and scientists to reconcile their differences nationally and internationally, we should do whatever we can to help: assuring the policy makers that we recognise the importance of the science, and that we need action and leadership to safeguard our future.
We should be pleased that, “The world is waking up to climate change”. And be pleased that in North Leigh we are doing our own little bit to help.
Geoff Feasey
12th August 2009
Loading ...