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This lecture highlights the main threats to a sustainable Earth, including the disappearance of Arctic sea ice, instability of Greenland ice sheets, increase in heat waves and intensity of tropical storms. It also examines the economic costs of climate risk and the role of developing countries in addressing sustainability issues.
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Center of Ocean-Land-Atmosphere studies CLIM 101: Weather, Climate and Global Society Projected Regional Changes Jagadish Shukla Lecture18: Oct 30, 2008
Main threat to a sustainable Earth • Arctic summer sea ice likely to disappear in second half of century • Dynamic instability of Greenland ice sheets • Very likely increase in heat waves • Likely increase in intensity of tropical storms • Etc… SST
Main threat to a sustainable Earth • Damages from business-as-usual scenario would be at least 5% and up to 20% of Global GDP a year • Costs of removing most of the climate risk are around 1% of GDP per year • This is equivalent to paying on average 1% more for what we buy • “We can grow and be green” Sir Nicholas Stern
Main threat to a sustainable Earth • According to IPCC AR4/WGIII, the cost of avoiding the worst would be only a fraction of what Stern Report projected
Sustainability issues – LDCs • China, India and Brazil: now among the main drivers of the world’s economy China’s GDP has grown on average 9.6% per year in the last quarter century China replaced EU as the main importer of Brazilian soybeans Nepstad et al., Conservation Biology (2006)
Cultivated land area went from 1,307,400 km² in 1991 to 1,282,400 km² in 2000 Construction accounted for 56.6% of reduction 60% of China’s 669 cities face water scarcity Sustainability issues – LDCs Economic losses due to pollution in China amounted to US$ 12.8 billion annually – 1.4% of GDP (1990-1998) Source: Gaoming Jiang & Jixi Gao, 2007
Sustainability issues - LDCs • 2006: 2.6% increase in global CO2 from fossil fuel • Mainly due to 4.5% increase in coal consumption • China contributed more than two-thirds • China’s CO2 emissions surpassed those of the USA by 8% Total emissions LDCs are now part of the problem and part of the solution
Sustainability issues - LDCs Per capita emissions US But LDCs: small contribution to climate change, at least in per capita terms China Remember 1992 UNFCCC: “Common but differentiated responsibilities”
Impacts hit the poor hardest • 30 to 200 million people at risk of hunger with temperature rises of 2 to 3°C • 0.7 to 4.4 billion people will experience growing water shortages with a rise of 2°C Yields across Africa and Western Asia may fall by 15% to 35%
Impacts hit the poor hardest Climate impacts will decrease water availability and drought in semi-arid latitudes “It’s exactly what we don’t want; it makes the world much less even, more inequitable” Martin Parry, co-chair IPCC WGII
Purification of air and water Mitigation of droughts and floods Preservation of soils Pollination of crops and vegetation Dispersal of seeds Challenges to be addressed ECOSYSTEM SERVICES • Cycling and movement of nutrients • Control of potential agricultural pests • Maintenance of biodiversity • Protection of coastal shores erosion • Stabilization of climate etc.
Sustainability issues – LDCs • Under threat: Cerrado, Brazilian savanna • One of Brazil’s two biodiversity hotspots • At the current rate of loss, gone by 2030 CI/Nature
Impacts hit the poor hardest • Adaptation will cost LDCs $10 bns anually • Even more for the necessary infrastructure
Impacts hit the poor hardest • Nearly 200 million people live in coastal flood zones at risk • South Asia alone: more than 60 million people Source: Gordon et al., 2004
Impacts Future climate change will affect water availability, increasing water stress in already stressed regions...
Extreme rainfall variability: the case of Kenya Kenya: extreme rainfall variability around mean 160% 140% 120% 100% 80% 60% 1956 1958 1960 1962 1964 1966 1968 1970 1972 1974 1976 1978 1980
Kenya’s97-98 flood & 1998-2000 drought Hirji et al, World Bank (2003)
Mozambique’s2000 floods Real GDP - 23%
Correlation between GDP and Rainfall in Zimbabwe Rainfall affects growth…. the case of Zimbabwe
Temperature and Precipitation Changes over North America(A1B )
Temperature and Precipitation Changes over South America(A1B )
PROJECTED SCENARIOS OF DEFORESTATION ... 50% 20% Control 40% 60% 80% 100% or Soybean Vegetation classification Dorman and Sellers (1989) Sampaio et al., 2007 Source: Soares-Filho et al., 2006 and Amazon Scenarios Project, LBA
Annual Surface Temperature Changes (A1B ) 2080 to 2099 minus 1980 to 1999
GEC goes beyond climate change Global dust deposition Jickells et al. (2005)
2060s observations HadCM3 Medium-High (SRES A2) 2040s 2003 Temperature anomaly (wrt 1961-90) °C GEC is more acute than ever • 2003 • Heat wave hits Europe • 30,000 people die in Western Europe
Main threat to a sustainable world • Arctic summer sea ice likely to disappear in second half of century • Very likely increase in heatwaves • Likely increase in intensity of tropical storms SST
Heat stress • Drought stress • Wildfires Case study: Summer heat wave 2003 Schär et al. 2004 Precipitation Max. temperature August 2003 Rebetez et al. 2006
THANK YOU! ANY QUESTIONS? Center of Ocean-Land-Atmosphere studies