Heat Stroke and Heat Disorders. Heat Waves and Deaths. Heat Waves and Deaths. MFE659 Lecture 4b: Heat waves, Drought, Dust Storms, and Wild Fires

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1 MFE659 Lecture 4b: Heat waves, Drought, Dust Storms, and Wild Fires Heat Stroke and Heat Disorders At temperatures above the body s core temperature (37 C) heat must be dissipated. ~90% of heat loss occurs through skin; sweating becomes less effective at high RH (hence the increase in apparent temperature. If heat gain exceeds heat loss, body core temperature rises, and heat disorders occur. Sunburn can retard the body s ability to shed heat, and may increase the severity of the heat disorder. 1 2 Heat Waves and Deaths Heat Waves and Deaths NASA Modis Several thousand people die each year worldwide from heat stress. Most deaths in North America occur in inner cities & in the southeastern US. Severe urban pollution may be a contributing factor. Europe ,000 deaths 3 4

2 Heat Waves and Deaths Human Tolerance of High Temperatures 180 Data: NASA Heat Index chart: apparent temperature 144 F 110 Relative humidity (%) Tolerance limit (min) core Air temperature ( C) 100 extreme danger danger "Apparent temperature" 5 6 Heat Disorders and Apparent Temperature >50 C: heatstroke/sunstroke highly likely with continued exposure : sunstroke, heat cramps likely, and heatstroke possible with prolonged exposure and/or physical activity : sunstroke, heat cramps and heatstroke possible with prolonged exposure and/or physical activity : fatigue possible with prolonged exposure and/or physical activity Heat disorders increase with age 20yr - heat cramps; 40yr - heat exhaustion; >60yr - heat stroke Mean Daily Mortality New York Shanghai Three times as many people die on extremely hot days as on normal summer days 60 0 Data: McMichael et al. (1996) Climate Change and Human Health. WHO/WMO/UNEP Maximum temperature ( C) 7 8

3 Heat Waves, Drought and Wildfires frequently occur together Global Wildfires 05! Wildfires, Portugal, 2003 Desiccated sunflowers, France, 2003 Photos: Munich Re 9 10 Global Wildfires Warmer Air: Floods and Droughts There is a non-linear increase in the amount of water vapor in the air at saturation as the temperature increases. Thus, given a source of vapor from the ocean, the amount of water available in the air to rain out increases rapidly with warmer ocean temperatures. Wildfires increased by 75% between 1970 and

4 Warmer Air: Floods and Droughts More Intense Hydrological Cycle If the amount of water in the air is limited as it is over inland areas, but the temperature increases, then the relative humidity drops. Lower relative humidity means drier conditions are experienced, e.g., droughts. Lake Lanier, GA Severe drought in SE US Drought A drought is an extended period of months or years when a region notes a deficiency in its water supply whether surface or underground water. Desertification and habitat damage Impacts crops and livestock Dust storms, Erosion and Dust bowls Famine due to lack of water for irrigation Malnutrition and dehydration Mass migration, resulting in internal displacement and international refugees Social unrest War over natural resources, including water and food Wildfires, such as bushfires, are more common during times of drought. Reduced electricity production due to reduced water flow through hydroelectric dams Shortages of water for industrial users Strategies for Drought Mitigation Dams Cloud seeding Desalination of sea water for irrigation or consumption. Drought monitoring Land use - Carefully planned crop rotation can help to minimize erosion and allow farmers to plant less waterdependent crops in drier years. Outdoor water-use restriction Rainwater harvesting Recycled water Transvasement - Building canals or redirecting rivers as massive attempts at irrigation in drought-prone areas

5 Drought: some early operational definitions Great Britain (1936): 15 consecutive days with daily precipitation totals of less than.25 mm India (1960): actual seasonal rainfall deficient by more than twice the mean deviation Bali (1964): a period of six days without rain Libya (1964): annual rainfall less than 180 mm Note: locally-specific criteria Drought Indices The Palmer Drought Index (PDI) now called the Palmer Drought Severity Index (PDSI) is a measurement of dryness based on recent precipitation and temperature (Wayne Palmer 1965). intermediate/ystone/palmer_more.html Drought Indices Standardized Precipitation Index (SPI) a probabilistic index based on rainfall amount compared to normals for the same period using a gamma distribution. Technically, the SPI is the number of standard deviations that the observed value would deviate from the long-term mean, for a normally distributed random variable. Since precipitation is not normally distributed, a transformation is first applied so that the transformed precipitation values follow a normal distribution. SPI and PDSI maps (North America)

6 The Dust Bowl The drought of the 1930 s: the Dust Bowl Boise City, Oklahoma, April 15, Precursors DUST BOWL Ten times increase in population in OK,TX,AK from Deep ploughing and wheat monoculture destroyed soil structure and increased soil erosion potential Drought ( ) world economic slump in 1930 s; virtually no federal funds for prairie farmers economic disaster - outmigration of Okies 22 Dust Bowl Kansas 1936 Cimarron County, Oklahoma. Date April

7 Dust storm during the 1930 s drought in the southern Great Plains The Dust Bowl: Contributing Factors overgrazing cropping of marginal soils soil erosion Drought climatology Temperate climates - blocking highs in zone of westerlies (Rossby waves) Seasonal tropical climates - ITCZ position on monsoon penetration Humid tropical climates - El Niño - Southern Oscillation (ENSO) zonal flow: no drought in Canada Storm tracks, blocking highs and drought in the US and Canadian Prairies drought in Manitoba drought in Alberta drought throughout 27 28

8 Sahel Drought 1980 s Drought 5M people affected; >200K died from malnutrition and associated diseases Livestock herds decimated (80% died) Loss of livestock loss of wealth massive social dislocation and emigration to urban areas Changing rainfall patterns in the Sahel region Drought in Monsoon Climates: the Sahel 20 N Rainfall Drought in monsoon climates: the Sahel Inter-Tropical Front / Inter-Tropical Convergence Zone Population density (orange >25 people km -2 ) Source: Vegetation (max.) 500 km 31 32

9 Hypotheses to explain Sahelian drought Climatological - northward penetration of ITCZ controlled by variations in atmospheric temperature in northern tropics, due to: SST anomalies in northeastern Atlantic linked to general circulation (especially El Niño/La Niña), or Industrial pollution (particularly SO2 aerosols) from N.America, Europe and Asia (intense drought of ). Anthropogenic - changes in vegetation and surface albedo caused by varying land-use result in changes in regional climate. These may be influenced by global warming Rapp s albedo feedback model rainfall vegetation 40 N July January July January grazers 40 S Evidence for Rapp s Model ENSO and drought in western Pacific (Indonesia and N. Australia) 35 36

10 ENSO and Australian Drought Dust storm, E. Australia, 2002 July, 1997 (El Niño) July, 1998 (La Niña) Rainfall relative to historical records Effects of drought in Indonesia Agricultural production: 20-30% reduction of rice crop in eastern Indonesia (parts of Kalimantan, Sulawesi and Irian Jaya. Markedly lower yam production in Irian Jaya. In some villages in the latter 20-30% of people died from malnutrition 95% incidence of malaria reported. Summary: Evidence for Recent Warming The global average surface temperature increased by 0.6 C since the bulk of the warming has occurred at higher latitudes. Hydrological cycle is more intense (droughts and storms have intensified) Increased in number and size of wild fires Pronounced decrease in sea ice thickness and extent in last 40 years Widespread melting of permafrost. Widespread retreat of mountain glaciers seen in non-polar regions. Snow cover extent decreased ~20% in last 40 years A gradual rise in sea level shows recent signs of acceleration. Sea surface temperature rise increasing incidence of coral bleaching 39 40

11 Future Heat Waves and Climate Change Future Heat Waves and Climate Change During the summer of 2010, Russia recorded the warmest temperatures in 1000 years. This was a 1 in 1000 year heat wave. What will the recurrence time be in the x2 CO 2 summers of the mid-21st century? Future Heat Waves and Climate Change Global Oil Past and Projected Production Percent summers hotter than the hottest on record. Experts agree, oil prices will rise significantly in the future as production begins to drop

12 Global Oil Past and Projected Production Pessimistic view vs the optimistic view. Possible responses to climate change threat Reduce greenhouse gas emissions Global approach required Assistance to developing world key Economic costs not unmanageable Economists suggest a 20% reduction in GHG emissions would require a GDP cost of <1% (loss of 6 months economic growth or less) and indicate the costs may even be negative Past air pollution regulations suggest costs are often much lower than claimed by industry (e.g., catalytic converters, CFC elimination, SO2 emissions reductions) Engineer to mitigate possible climate consequences e.g., sea walls, agricultural adaptation, Strategies to Control Warming Stabilize world population Initiate a no-coal world energy strategy Vastly enhance renewable energy dependence Institute strong energy conservation Develop treaties strongly controlling greenhouse gases Initiate CO2 sequestration Discover counter-greenhouse technologies Energy Conservation Promote mass transit where appropriate. Promote electric car technology. Expand use of natural gas (cleaner fuel). Improve quality of gas lines, especially in Eastern Europe. Recover methane from landfills. Promote co-generation technologies - e.g., recovery of waste heat; produce electricity as a by-product of production. Improve manufacturing techniques - e.g., electronic inventories; automated manufacturing where inventories are eliminated. Promote alternative energy-wind and solar power - local energy sources eliminate transmission loss. Strengthen efficiency standards throughout the economy. Improve building codes: insulation, improve lighting and appliance efficiencies, promote use of passive solar

13 Wind and Solar Energy Strategies to Live With Warming Improve irrigation efficiency Develop new sources of irrigation water Stop deforestation increase forestry plant trees Conserve soil prevent erosion Grow salt tolerant food plants and expand aqua culture Plan for increased ocean height In Hawaii Gasoline in Hawaii is not only expensive, the oil consumed represents an export of cash from our economy that literally just goes up in smoke. Ethanol from sugar cane: Cultivation requires significant fossil fuels, reduction in soil fertility, water consumption high, competition with food production. Hawaii's pre-1985 sugar production on 180,000 acres could have produced enough ethanol to cut gasoline consumption currently by 15% percent. Wind energy. The trade winds provide reliable source of energy. Wind farms must located in areas of enhanced winds, but with a minimum of terrain-induced turbulence, which causes wind turbines to wear out faster. Solar energy sources. Photovoltaic cells are becoming more efficient and economical. Geothermal energy sources Wave and tidal energy sources 51