Climate change: Is there a problem?
Professor David Karoly
School of Earth Sciences, University of Melbourne
Some views from leaders
• Ban Ki Moon “Climate change is the greatest threat facing humanity. It threatens to undo 50 years of our development work and it will impact the poor in the greatest sense.”
• Barack Obama “We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.”
• Kevin Rudd: Climate change is “the greatest moral, economic and social challenge of our time”
Intergovernmental Panel on Climate Change (IPCC)
• Joint body of UN Environment Program and World
Meteorological Organization, established in 1988
• Every 5-6 years, carries out a comprehensive assessment of climate change science, impacts, and approaches for mitigation and adaptation to climate change
• Includes representatives from all countries
• Fourth Assessment Report prepared by more than 500 scientists over the last three years
• Summaries for Policy Makers approved by consensus
(including representatives of the Australian govt) at meetings in Paris (Feb 07), Brussels (Apr 07) and Bangkok (May 07)
• Received the 2007 Nobel Peace Prize jointly with Al Gore
IPCC Fourth Assessment Report 2007
• ‘Warming of the climate system is unequivocal’
• ‘Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations’
• ‘Continued greenhouse gas emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century’
• ‘21st century anthropogenic CO2 emissions will contribute to warming and sea level rise for more than a millennium, due to the long timescales
required