Introduction to Climate Change – Science and Impacts

Greenhouse Gases Allow sunlight to pass through while trapping heat- opposite of sulfites (1970’s cooling) Allow sunlight to pass through while trapping heat- opposite of sulfites (1970’s cooling) 4 types of anthropogenic gases 4 types of anthropogenic gases Carbon dioxide (50%)Carbon dioxide (50%) MethaneMethane Nitrous OxideNitrous Oxide CFC’sCFC’s

Carbon Cycle

Effects of Industrialization Unearthed and burned sedimentary deposits of fossil fuels at an unnatural rate Unearthed and burned sedimentary deposits of fossil fuels at an unnatural rate 3 billion tons of CO2 a year 3 billion tons of CO2 a year If states can reduce to 1994 levels and maintain levels, CO2 concentration will still increase for at least 2 centuries If states can reduce to 1994 levels and maintain levels, CO2 concentration will still increase for at least 2 centuries

Carbon connection Avg. global temperatures already increased.6 degrees C since late 1800’s Avg. global temperatures already increased.6 degrees C since late 1800’s International Panel on Climate Change (IPCC) predicts degree C increase by 2100 International Panel on Climate Change (IPCC) predicts degree C increase by 2100

International Response UNEP and WMO formed the IPCC in 1988 to gain consensus on climate change – political will UNEP and WMO formed the IPCC in 1988 to gain consensus on climate change – political will - Working group I – science - II – Impacts and policy - III - Economic and social impacts IPCC’s assessments lead to UNCED framework and Kyoto targets and timetables

Impacts of Climate Change Most contentious part of debate – will they happen, when will they happen, how severe will they be Most contentious part of debate – will they happen, when will they happen, how severe will they be 2001 WG II IPCC – Impacts from climate change occurring by chance is negligible 2001 WG II IPCC – Impacts from climate change occurring by chance is negligible Hard to attribute regional and specific changes to particular causes (regional differences – north warming faster than south) Hard to attribute regional and specific changes to particular causes (regional differences – north warming faster than south)

Types of Impacts Sea level rise – 10 to 20 cm so far (9 to 88 by next century) Sea level rise – 10 to 20 cm so far (9 to 88 by next century) Greenland Ice sheet- over 1000 years, could result in 3-7 meter riseGreenland Ice sheet- over 1000 years, could result in 3-7 meter rise West Antarctic sheet (maybe- precipitation)West Antarctic sheet (maybe- precipitation) Coastal and Marine Ecosystems Coastal and Marine Ecosystems Erosion, increased salinity of freshwater, loss of delta Low lying areas flooded (New Orleans) Increased salinity affects organisms, bleaching of coral

Impacts Cont’d Weather impacts – increased storms, droughts, floods; very uncertain Weather impacts – increased storms, droughts, floods; very uncertain Public health – more insect borne disearses, water borne; north v. south Public health – more insect borne disearses, water borne; north v. south Agriculture and Food – regional – positive in north worst around equator – too hot to grow Agriculture and Food – regional – positive in north worst around equator – too hot to grow Forest loss – types of forests will change – increase in short term production, worst in high latitudes – beech, sugar maple (Adr.) Forest loss – types of forests will change – increase in short term production, worst in high latitudes – beech, sugar maple (Adr.) Deserts – increase in desertification Deserts – increase in desertification More precipitation – increased runoff and flooding More precipitation – increased runoff and flooding Loss of ice cover – Glacial National Park Loss of ice cover – Glacial National Park

Biodiversity Loss and Discussion Warm water fish will flourish, cold water may die out; changing habitats for terrestrial animals – will have to migrate – synergistic impacts with pre-existing habitat loss Warm water fish will flourish, cold water may die out; changing habitats for terrestrial animals – will have to migrate – synergistic impacts with pre-existing habitat loss All these impacts are speculative, and regional – how do you make a country with no coastal resources, or who may benefit try and reduce emissions All these impacts are speculative, and regional – how do you make a country with no coastal resources, or who may benefit try and reduce emissions Public perception – Page 606 question 5 – media impact – confusion of weather and climate – hot summer, a lot of coverage; climate cannot be effected by man – volcano’s Public perception – Page 606 question 5 – media impact – confusion of weather and climate – hot summer, a lot of coverage; climate cannot be effected by man – volcano’s Clinton’s meeting of weathermen – is that a good tactic to gain support? Regional effects v. national trends Clinton’s meeting of weathermen – is that a good tactic to gain support? Regional effects v. national trends