COPENHAGEN: The 7 Things Scientists Want You to Know About Climate Change.
In advance of this month’s UN talks in Copenhagen, The University of New South Wales Climate Change Research Centre (CCRC) has published a special report called ‘The Copenhagen Diagnosis’. 26 researchers, most of whom are authors of previously published IPCC reports, conclude that the diagnosis is not good, and that previous models may have been too conservative.
Full disclosure: The report includes contributions from the now famous and controversial University of East Anglia Climate Group, so I am sure the skeptics will find much to object to (see my previous post “The Myths and Logic of Climate Skeptics.”) But I believe we have a serious problem.
The conclusion from this report is basically that we are trying to patch up a severed artery with a band-aid, and quite frankly, I would welcome a different diagnosis (“It’s just a flesh wound!”), since I don’t the think the outcome of the Copenhagen round will be a tourniquet. But until we get a rosier forecast that is based in science, denial will have to stay nothing more than a river in Egypt. We need to move very quickly beyond random acts of greenness, and towards a more holistic and comprehensive commitment to reduce emissions.
Here are their seven key findings:
1. Greenhouse gas emissions are surging: Global carbon dioxide emissions from fossil fuels in 2008 were nearly 40% higher than those in 1990. Simply stabilizing global emissions at these levels is not enough, and will lead to an increasing chance of crossing the critical 2 degrees (C) threshold.
2. Recent global temperatures demonstrate human-based warming: Over the past 25 years temperatures have increased at a rate of 0.19 (C) per decade. The report points out that while natural, short-term fluctuations are occurring as usual, there have been no significant changes in the underlying warming trend.
3. Melting of ice-sheets, glaciers and ice-caps is accelerating: A wide array of satellite and ice measurements now demonstrate beyond doubt that both the Greenland and Antarctic ice-sheets are losing mass at an increasing rate. Melting of glaciers and ice-caps in other parts of the world has also accelerated since 1990.
4. Rapid Arctic sea-ice decline: Summer-time melting of Arctic sea-ice has accelerated far beyond the expectations of climate models. This area of sea-ice melt during 2007-2009 was about 40% greater than the average prediction from previous IPCC models.
5. Sea-levels are rising more than predicted: Satellites show global average sea-level rise (3.4 mm/yr over the past 15 years) to be 80% above past IPCC predictions, due to the more rapid melting of glaciers, ice caps and the Greenland and West-Antarctic ice-sheets. Sea-levels are expected to continue to rise for at least a century after global temperature have been stabilized, and could rise several meters over the next few centuries.
6. By delaying action, we risk irreversible damage: The most vulnerable elements of our biosphere such as continental ice-sheets and rainforest could be pushed towards abrupt or irreversible change if warming continues in a business-as-usual way. The risk of passing a tipping point increases the longer that we wait. In other words, waiting for higher levels of scientific certainty could mean that some bridges will be crossed and burned before they are recognized.
7. Peak carbon needs to happen soon: If global warming is to be limited to a maximum of 2 degrees (C) above pre-industrial values, global emissions need to peak between 2015 and 2020 and then decline rapidly.
The most startling point was that to stabilize our climate, a decarbonized global society – with average annual per-capita emissions of well under one metric ton of CO2 – has to happen by 2050. The report points out that this is 80-90% below the per-capita emissions in developed nations in 2000.
Chart provided courtesy of The NSW Climate Change Research Centre.