Stanley J. Kabala, Ph.D. Center for Environmental Research & Education Duquesne University Pittsburgh, Pa. U.S.A.

 Observed changes in climate and their effects  Causes of changes  Projected climate change and impacts  Adaptation and mitigation options  The long-term perspective

 “Warming of the climate is unequivocal”:  Eleven of last 12 years rank in the 12 warmest years on record  Global sea level has risen an avg. of 3.1 mm/yr since 1993

 Arctic sea ice shrinking at 2.7%/decade (7.4% summer rate)  Fewer cold days/nights, more hot days/nights since 1950  Last 50-years hotter than any other period in the last 500 years

 Increased number and size of glacial lakes, decreased stability of permafrost  Increased runoff in many snow-fed hydrological systems  Poleward and upward shifts in plant and animal ranges Research has found timber lines have moved upward in response to global climate change

 Atmospheric concentrations of greenhouse gases, especially CO2  Change in land cover, particularly deforestation  Varying degrees of solar radiation

 Broad agreement that global GHG emissions will continue to grow over the next few decades  Growth in GHG emissions projected from 25-90% by 2030

 Changes in 21 st century will very likely be larger than those observed in the 20 th  0.2˚ C projected increase per decade over the next two decades  The report avoids specific long-term projections because of the uncertainty surrounding feedback loops

 Warming will be greatest on land and at highest Northern latitudes  Contraction of snow cover, increased permafrost thaw  Increase in heat extremes and heat waves  Increase in tropical cyclone intensity  Decreases in subtropical precipitation

 Decrease in crop yields  Higher risk for coastal communities: rising sea level, more frequent storms and floods  Increased strain on drinking water resources  Potential health crises arising from effects listed above, and from altered distribution of some disease vectors

 Further drift of species range poleward and to higher altitudes  Decrease in biodiversity as some species fail adapt to warmer climate or decline in precipitation  Marine ecosystems adversely effected from ocean acidification, coral bleaching and disruptions in oceanic circulation

 Wide array of adaptive measures, but many associated barriers, limits and costs  Adaptive capacity highly correlated to economic and social development, but with vast differences within societies  Key constraints typically include technological and financial, political, and logistical

 High potential for leveling off and reducing GHG emissions across several sectors  Most important mitigation sectors include energy supply, transportation, buildings/utilities, industry, agriculture and forestry

 Integrate climate policy into wider development policies  Develop regulations and standards  Impose proper taxes and fees  Use tradable permits- appropriate carbon pricing  Employ financial incentives  Promote voluntary agreements  Increase research and development

 Broad agreement that mitigation policies can result in co-benefits in the short-run- like improved health and energy efficiency  These co-benefits may offset a significant portion of the mitigation costs  Some countries, notably those exporting fossil fuels, will see reduced GDP resulting from mitigation actions  Changes in lifestyle, behavior and management practices can have significant mitigation effects without policy measures

 Science must play an important role in informing what constitutes ‘dangerous’ levels of warming  Neither adaptation nor mitigation alone can avoid all impacts of climate change  Stabilization levels achievable using technology either currently available or expected within the coming decades

“Many impacts can be reduced, delayed or avoided by mitigation. Delayed emission reductions significantly constrain the opportunities to achieve lower stabilization levels and increase the risk of more severe climate change impacts.”