15 June 2014

Big trouble in the Antarctic has been brewing for a long time

by David Spratt

"A game changer" is how climate scientist Dr Malte Meinshausen describes newly published research that West Antarctic glaciers have passed a tipping point much earlier than expected and their disintegration is now "unstoppable" at just the current level of global warming. The research findings have shocked the scientific community. "This Is What a Holy Shit Moment for Global Warming Looks Like," ran a headline in Mother Jones magazine.

08 June 2014

Carbon budgets, climate sensitivity and the myth of "burnable carbon"

by David Spratt

Breakthrough National  Climate Restoration
Forum 21-22 June,  Melbourne
In my previous post explaining why there is no carbon budget left for burning fossil fuels for a 2-degree Celsius (°C) target, I explained that these carbon budget calculations are expressed in probabilities of not exceeding the target. This reflects a number of uncertainties in understanding, including climate sensitivity, ocean heat uptake inertia, the influences of non-carbon dioxide forcing agents, and because results vary somewhat among model ensembles.

Of these, climate sensitivity is the biggest issue, because of the possibilities that climate change might proceed more rapidly than currently estimated because of reinforcing feedbacks, thresholds or tipping points in the climate system, or less rapidly because of dampening feedbacks.