Climate Change

1

• Climate Change Effects
• Negative
• Ozone Holes
• Global warming of the atmosphere translates to
  stratospheric cooling
• Stratospheric cooling may enhance ozone
  destruction in Antarctic and make phenomenon more
  common in Arctic (Waibel et al. 1999)
• Health
• Consistently elevated temperatures can lead to
  immunosuppression
• Exacerbated by elevated levels of UV-B
• Ex Mass mortality of animals in last 10 years
  due to viral infections
• - Seals in North Sea
• - Lions in Serengeti (Africa)
• - Horses in Australia
• - Birds in western US
• Allergies could worsen due to increased pollen
  production, dust (desertification), mold
  (humidity)
• Additional human mortality from severe summer heat

2

• Climate Change Effects
• Negative
• Tropical Pests and Diseases
• Unusual weather favors opportunistic pests while
  making life difficult for the predators that
  typically control them
• Periods of anomalous weather tend to be followed
  by outbreaks of disease
• Many tropical diseases are transmitted by animal
  vectors insects, rodents

3

• Climate Change Effects
• Negative
• Tropical Pests and Diseases
• Cholera
• 1991 Freighter from Asia emptied bilge tanks
  off Peru during an ENSO event
• Cholera in bilge water ? plankton ? shellfish ?
  humans
• 500,000 infected 5000 dead
• Hantavirus
• Late 1980s/Early 1990s Drought in SW US led to
  increase in deer mouse population
• Transmitted lethal form of pulmonary hantavirus
• To date, hantavirus has appeared in 20 states
  100 dead

4

• Climate Change Effects
• Negative
• Tropical Pests and Diseases
• Plague
• 1994 Unusually long monsoon season in N India
  followed by 90 days of temperatures gt 100 oF
• Heat drove rats into cities ? Spread plague
• 2 billion to combat problem 63 dead
• Dengue fever
• 1995 Rising temperatures allowed a coastal
  mosquito species to cross mountains and spread
  across Costa Rica, carrying dengue fever
• Reached as far north as Texas border
• 140,000 people infected 4000 dead

5

• Climate Change Effects
• Negative
• Tropical Pests and Diseases
• Malaria
• Most prevalent vector-borne disease (1-2 million
  cases/year)
• Transmitted by Anopheles mosquitoes
• Warming could lead to
• Broader geographic range (estimate that 2oC
  could expand range from 42 to 60 of land area)
• Higher metabolic rate ? More food
• Faster maturation ? More rapid reproduction
• Faster parasite life cycle
• Potential spread into large urban areas (Nairobi,
  Kenya Harare, Zimbabwe) with immunologically
  naïve popns
• Projections are controversial and highly variable

6

• Climate Change Effects
• Positive
• Plant Growth
• Warmer temperatures and elevated concentrations
  of CO2 lead to faster plant growth and greater
  food production per acre
• Elevated concentrations of CO2 should lead to
  more efficient use of water, reduced runoff and
  less water pollution
• Enhanced plant growth should remove CO2 from
  atmosphere at a faster rate (Gaia Hypothesis)
• Agriculture
• Expansion of agricultural regions
• Longer growing season in areas that currently are
  marginal for agriculture

7

• Climate Change Effects
• Positive
• Rainfall Patterns
• Predictions of increased rainfall in major
  agricultural regions, especially in northern
  hemisphere
• Reduced irrigation required for plants/crops
• Increased precipitation should cause glaciers and
  ice sheets to grow
• Milder Winters
• Severe winters pose a health and safety risk
• Fewer expenses associated with less severe winter
  weather

8

• Climate Change Projections
• Complexity and uncertainty in climate models
• Response of earth climate system to a forcing
  function
• Accumulation of CO2 in the atmosphere
• What should we do??
• Lomborg

9

• Air Pollution Sources Effects
• Most local air pollution associated with cities,
  esp. large cities and industrial centers
• Average concentration of airborne particles in
  urban areas 10x concentration in rural areas
• Major cities air pollution causes thousands of
  deaths each year
• Mexico City Air quality so severe that some
  people estimate breathing is equivalent to
  smoking two packs of cigarettes a day
• China Controversy re monitoring by Chinese
  government vs. US embassy personnel
• Many air pollutants are hygroscopic
• Combine with water and promote fog formation

10

• Air Pollution Components
• Primary
• Problematic in the form in which theyre produced
• Ex Lead, carbon monoxide
• Secondary
• Form from precursors
• Ex Ozone
• Many are components of photochemical smog
  (react chemically with light)
• Legislation addressing air pollution requires
  consideration of both primary and secondary
  pollutants
• Clean Air Act 1970
• Clean Air Act Amendments 1990
• EPA NAAQS for six criteria pollutants

11
Distribution of national total emissions
estimates by source category for specific
pollutants, 2010
http//www.epa.gov/air/airtrends