The last United Nations Intergovernmental Panel on Climate Change (IPCC) report was based on data collected by 2006. A new report, labeled ‘The Copenhagen Diagnosis’ updates that report with data and analysis since that time. The Copenhagen Diagnosis is the work of 26 scientists and consists of material already peer-reviewed and published, so there isn’t much that’s new. However, the report is intended to summarize the ‘state-of-knowledge’ concerning global climate change, prior to the summit meeting at the Copenhagen Climate Conference. Here are some of the points:
- The ice sheets are both losing mass (and hence contributing to sea level rise). This was not certain at the time of the IPCC report.
- Arctic sea ice has declined faster than projected by IPCC.
- Greenhouse gas concentrations have continued to track the upper bounds of IPCC projections.
- Observed global temperature changes remain entirely in accord with IPCC projections, i.e. an anthropogenic warming trend of about 0.2 ºC per decade with superimposed short-term natural variability.
- Sea level has risen more than 5 centimeters over the past 15 years, about 80% higher than IPCC projections from 2001.