Stanley J. Kabala, Ph.D.Center for Environmental Research &

EducationDuquesne UniversityPittsburgh, 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 21st century will very likely be larger than those observed in the 20th

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.”