Intergovernmental Panel on Climate Change (IPCC)

This extended report of the IPCC Expert Meeting on the Science of Alternative Metrics that was held in Oslo 18-20 March 2009 is provided in response to an invitation from the UN Framework Convention on Climate Change Ad Hoc Working Group on Further Commitments for Annex I Parties under Kyoto Protocol (UNFCCC AWG-KP) to the Intergovernmental Panel on Climate Change (IPCC) to undertake further technical assessment of alternative common metrics which are used to calculate the CO2 equivalence of anthropogenic emissions by sources, and removals by sinks, of greenhouse gases listed in Annex A to the Kyoto Protocol. The outcome of the expert meeting was an agreed set of key conclusions and recommendations to UNFCCC in response to the request of the AWG-KP as well as more specific recommendations to the scientific community regarding research needs and ones relevant to the scoping of the IPCC's Fifth Assessment Report (AR5). These were presented to the IPCC Plenary in a short report at its 30th session in Antalya, 21-23 April 2009. The current full report of the expert meeting amplifies those conclusions and recommendations and includes the extended abstracts of the meeting presentations as well as a general bibliography

Multimodel projections of stratospheric ozone in the 21st century

Simulations from eleven coupled chemistry-climate models (CCMs) employing nearly identical forcings have been used to project the evolution of stratospheric ozone throughout the 21st century. The model-to-model agreement in projected temperature trends is good, and all CCMs predict continued, global mean cooling of the stratosphere over the next 5 decades, increasing from around 0.25 K/decade at 50 hPa to around 1 K/ decade at 1 hPa under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario. In general, the simulated ozone evolution is mainly determined by decreases in halogen concentrations and continued cooling of the global stratosphere due to increases in greenhouse gases (GHGs). Column ozone is projected to increase as stratospheric halogen concentrations return to 1980s levels. Because of ozone increases in the middle and upper stratosphere due to GHGinduced cooling, total ozone averaged over midlatitudes, outside the polar regions, and globally, is projected to increase to 1980 values between 2035 and 2050 and before lower stratospheric halogen amounts decrease to 1980 values. In the polar regions the CCMs simulate small temperature trends in the first and second half of the 21st century in midwinter. Differences in stratospheric inorganic chlorine (Cly) among the CCMs are key to diagnosing the intermodel differences in simulated ozone recovery, in particular in the Antarctic. It is found that there are substantial quantitative differences in the simulated Cly, with the October mean Antarctic Cly peak value varying from less than 2 ppb to over 3.5 ppb in the CCMs, and the date at which the Cly returns to 1980 values varying from before 2030 to after 2050. There is a similar variation in the timing of recovery of Antarctic springtime column ozone back to 1980 values. As most models underestimate peak Cly near 2000, ozone recovery in the Antarctic could occur even later, between 2060 and 2070. In the Arctic the column ozone increase in spring does not follow halogen decreases as closely as in the Antarctic, reaching 1980 values before Arctic halogen amounts decrease to 1980 values and before the Antarctic. None of the CCMs predict future large decreases in the Arctic column ozone. By 2100, total column ozone is projected to be substantially above 1980 values in all regions except in the tropics

Intergovernmental Panel on Climate Change, 4th Session, Sundsvall, Sweden, 27-30 August 1990

The Fourth session of the IPCC highlighted that developed (industrialized) countries are responsible for some 75% of the total emission of carbon dioxide and a clear commitment to stabilize and then reduce greenhouse gas emission is necessary. Also, the Panel emphasized the need for massive expansion of research and development in new energy sources and more efficient resource management procedures. discussed on the IPCC work program for 1991 and beyond and provided objective analysis of scientific and technical assessment of the issue of climate change. The Panel also approved the report of the fourth session

Intergovernmental Panel on Climate Change, 16th Session, Montreal, Canada, 1-8 May 2000

This meeting focused on the future of the IPCC. Among other isues, the Panel considered the budget and assessed the National greenhouse gas inventories program (IPCC NGGIP)

Intergovernmental Panel on Climate Change, Twenty First Session, Vienna, Austria, 3 and 6-7 November 2003

The Chair gave his opening address, outlining the issues faced by the Panel in preparing for the Fourth Assessment Report and highlighted the rigorous efforts undertaken thus far in scoping the structure and contents of the report. The Panel noted that the preparation of an AR4 SYR that would meet the expectations of most delegations would require extensive consultation and the early and full commitment of many of those who would also be involved in the preparation of the individual Working Group (WG) reports. It noted that the AR4 SYR could: Bring together the main messages from the individual WG reports: Synthesise cross-cutting information from the individual WG reports, including the AR4 cross-cutting themes: Provide a top-down perspective for decision makers on issues covered by the AR4: Produce an overview of the key conclusions of AR4 in non-technical and readily translatable language: Re-assess the policy relevant questions addressed in the TAR SYR

Intergovernmental Panel on Climate Change, Twenty-Ninth Session, Geneva, [Switzerland], 31 August - 4 September 2008

The focus of this meeting was on the future of the IPCC, in particular the scoping of the 5th Assessment Report. The Panel was also invited to consider the outcome of the Scoping Meeting for a possible Special Report on "Extreme events and disasters: managing the risks", and of the Expert Meeting on "Alternative common metrics to calculate the CO2 equivalence of anthropogenic emissions by sources and removals by sinks of greenhouse gases"

Intergovernmental Panel on Climate Change, Twenty Fourth Session, Montreal, Canada, 26-28 September 2005

The meeting highlighted recent progress in the work of the IPCC, in particular the completion of the two Special Reports on Safeguarding the Ozone Layer and the Global Climate System (SROC), and on Carbon Dioxide Capture and Storage (SRCCS) and the preparations for the Fourth Assessment Report (AR4). Among other speakers, the Executive Director of the United Nations Environment Program (UNEP), Mr Klaus Töpfer addressed the Session on the linkages between science and climate change policy and the increasing need for information from the IPCC. He reaffirmed UNEP's commitment to the IPCC and supported early planning for the period beyond AR4. The Deputy Secretary-General of the World Meteorological Organization (WMO), also addressed the Panel on the importance of the principles of impartiality, transparency, scientific authority and integrity for the past success of the IPCC, the linkages of WMO programmes and IPCC assessments, and WMO's commitment to the IPCC