Global Warming’s Effect On Humans

Charli Caston,Julie Densmore,Natalie Emadiazar, Mari Komperod, Manal Malallah

One Immediate Consequence

Global Rise In Temperature

Extreme Weather Rising Sea Levels

Increase in Disease Agriculture

Economic

“Even the best case scenario suggests substantially more warming over the next century than we have observed over the past 100 years” – Intergovernmental Panel On Climate Change

MANY EFFECTS

Global Warming:

Effects of Weather on Humans

Wind Patterns

• based on barometric pressure readings– differences in air pressure drive winds near

equator

• important wind circulation pattern over Pacific Ocean– marine food chain

Wind Patterns

• Walker circulation– huge loop– across the Pacific (east

to west); air rises in western Pacific; returns eastward at altitude of a few miles; sinks back to surface and starts loop again.

– Peru and Ecuador

• Computer simulations

Changes in Precipitation

• El Ninos– rainfall in the southern USA and western

South America

• shows an increase in the amount of precipitation falling in the next 100 years

Heat Waves• is an extended interval of abnormally hot

and usually humid weather

• lasts from a few days to over a week.

• will become more frequent and more intense.

• European heat wave of 2003– in France nearly 20,000 people died

• South Australian heat wave of 2006

• July 2006, USA– County of Los Angeles

“Since 1980, the earth has experienced 19 of its 20 hottest years on record, with 2005 and

1998 tied for the hottest and 2002 and 2003 coming in second

and third.”

-Natural Resources Defense Council

Droughts• El Ninos

– Indonesia, Malaysia and elsewhere in the western Pacific.

• Desertification– biodiversity loss

• 1928-1930, northwest China– resulted in over 3 million deaths.

• 1936, Sichuan Province, China– worst drought in the modern history– 34 million farmers were relocated and 25

million people starved

Wildfires

• Colorado, Arizona, and Oregon

• In 2002, they experienced the second worst wildfire season in the last 50 years.

• More than 7 million acres burned.

Tropical Cyclones

• A tropical cyclone is a warm-core, low pressure system that develops over the tropical or subtropical waters

• Also known as hurricanes or typhoons

Floods

• Flooding will occur due to rising sea levels from increased precipitation and melting glaciers.

• Eroded sea shores as consequence

References

• www.srh.noaa.gov/jetstream/tropics/tc.htm

• www.mpa-garching.mpg.de/.../cycloneresearch.html

• http://www.weather.com/encyclopedia/heat/impact.html

Localized Rise in Water levels• In an Ice-Jam, Alaska Waters Rise 15

Feet in 24 Hours

Rise in Sea Levels

A 40cm rise in Sea-level

• People at risk; 22–29 million by the 2020s, 50–80 million by 2050s, and 88–241 million by the 2080s (Nicholls et al., 1999).

• 70-90% located in Africa, Mediterranean, Asia, And small Island States

• Est. 30 Billion in land loss, USA, Zeidler (1997)

Overview of Effects

Direct Effects: Heat Extremes

• Elevated temperatures during summer months are associated with excess morbidity and mortality. Conservative estimates are that , on average, 240 heat related-deaths occur annually in the United States (McGeehin et al. 2001).

Direct Effects: Heat Extremes

• The most common cause of death and most acute illness directly attributable to heat is heat stroke. Other causes of death observed to increase following heat waves include ischemic heart disease, diabetes, stroke, respiratory disease, accidents, violence, suicide, and homicide (McGeehin et al. 2001).

Direct Effects: Heat Extremes

Indirect Effects: Air

• Experimental studies have found substantial increases in pollen production resulting from exposure to increased CO2

concentration.

Indirect Effects: Air

Indirect Effects: Air

• Climate change has received little attention for its potential in altering the burden of non-communicable disease such as asthma (Beggs et al. 2005).

Indirect Effects: Air

Climate change may affect exposures to air pollutants by a) affecting weather and thereby local and regional pollution concentrations; b) affecting anthropogenic emissions, including adaptive responses involving increased fuel combustion for power generation; c) affecting natural sources of air pollutant emissions; and d ) changing the distribution and types of aeroallergens (Bernard et al. 2001).

Indirect Effects: Water

• Xavier Rodo, a physical scientist of the University of Barcelona, and his colleagues have described a relationship between cholera and the El Nino/ Southern Oscillation patterns in Bangladesh from 1983 to 2001. The team found that ENSO, which causes warmer equatorial Pacific Ocean temperatures, was responsible for more than 70% of cholera mortality and morbidity (Weinhold 2004).

Indirect Effects: Mosquito-Borne Disease

• In the United States, the disappearance of malaria, dengue, and other mosquito-borne diseases was largely due to changes in lifestyles and living conditions. Given that living standards do not change drastically, such factors will remain dominant (Gubler et al. 2001).

Mosquito-Borne Diseases: Dengue

• Laboratory research found that replication rates in Dengue fever rose directly with increases in temperature. Models have been created to explore the influence of temperature on the virus. The models suggested that relatively small increases in temperature in temperate climates should increase potential for epidemics (Gubler et al. 2001).

Mosquito-Borne Diseases: Malaria

• Incidence and prevalence of malaria may be limited by altitude, and consequently also temperature; yet malaria transmission relies on several other factors.

• Changes in rainfall due to El Nino events are linked to variability in incidents of malaria (Gubler et al. 2001).

Mosquito-Borne Diseases: Malaria

• Some biologic modeling of potential impact of climate variables, primarily temperature increases, on malaria as done on a global scale project net increases in the geographic area and season for potential malaria transmission. However, a statistical empirical model approach found no significant net change in malaria projected for the year 2080 (Gubler et al. 2001).

Indirect Effects: Ozone

The results of an integrated 03 health impacts assessment suggested that changes in climate alone, resulting from growth in greenhouse gas emissions could case 4.5% increase in the number of summer 03 related deaths across the New York Metropolitan region by the 2050s (Knowlton et al. 2004)

Potential Impacts

• There is usually at best only long-term data on potentially pertinent disease, and many confounding factors, such as changes in pest control practices, travel patterns, and human settlement density and locations (Weinhold 2004).

Potential Impacts

• Climate change may lead to increases and changes in clinical behavior in fungal infections that penetrate into subcutaneous tissues, such as sporptrichoisis (Bernard et al. 2001).

Potential Impacts

• Some infectious diseases may change in tandem with climate. Based on increasing evidence, disease suspected of changing with climatic conditions are malaria, dengue fever, cholera, and yellow fever. But extensive long-term research is limited (Weinhold 2004).

Potential Impacts

• Asthma is etiologically complex. There are several factors that make up its causal web, many of which are modified by climate. There is some evidence that suggests that asthma prevalence may have plateaued in some countries, but it is too early to determine whether leveling off will be sustained. The hypothesis still stands that the rise in asthma prevalence is related to climate change (Beggs et al. 2005).

Potential Impacts• Researchers from the U.S. Geological Survey have

written that hundreds of millions of tons of dust circle the world each year. Just 1 million tons of dust may contain 10 quadrillion microbes. Some of the microbes are killed during transport, but researchers have found that far more are able to survive. Microbes in airborne dust known to be pathogenic to people include those causing plague, anthrax, tuberculosis, influenza, hantavirus pulmonary syndrome, meningococcal meningitis, coccidiodomyosis, and aspergillosis; however there are no proven links between infectious disease outbreak and airborne dust (Weinhold 2004).

Summary

• The WHO estimated that climate change was responsible for approximately 2.4% of diarrhea cases worldwide, 6% of Malaria cases, and 7% of dengue fever cases in 2000. On the whole, climate change was estimated to be responsible for 0.3% of deaths and 0.4% of disability adjusted life years (WHO 2002)

Summary

• The WHO concluded that climate change may play a small but nonetheless very real role in the world’s death tolls, already killing more than 150,000 people per year, in part through increases in infectious disease.

Agricultural Effects On Humans

Precipitation

• Timing: Rainfed crops need moisture at critical periods during the growing season. Once germinated, millet dies after 17 days of no rain.

• Amount: Climate models indicate that storms will be less frequent but more intense in many parts of the world. Crops need fairly consistent rain during the season. Maize requires adequate soil moisture as it sets its cobs – yet too much moisture late in the season can lead to the development of aflatoxin, a potent and dangerous fungal carcinogen.

Global temperatures will rise by 1.5oC to 4.5oC under the scenario of a doubling of CO2 from preindustrial levels which is likely to be reached by 2030

Projected Temperature Increase

Consequences• An increase of temperature

can cause dairy cattle to have trouble keep their body temperatures regulated

• Decreased milk production• Reproduction decreases due

to heat stress lowering the fertility rate

• Heat stress can decrease animal production, reproduction and profitability

Production Decrease• As many as 63 to 369 million people could be at risk of

hunger in 2060 if global warming is not controlled

• Overall global production would decline by 1 to 8 percent, this decline will lead to higher food prices and the increase in the number of people at risk of hunger

• Risk of hunger in 2060 could decline by 12 million people if alternative methods such as shifting planting times and vast amounts of irrigation are constructive

• Or the death toll could increase by 119 million depending on the climate scenario by 2060

The Impact of Global Warming on the Economy

Wealth is distributed according to climate

Change in GDP due to climate change

2010

2100

Real Estate (and Agriculture)

• Industry and population are likely to follow food production, water resources, and pleasant weather (moderate temperatures and low risks of natural disasters)

• Assuming a rise in temperature and shift in climate– Warm, low-altitude real estate value would drop.– Cold, high-altitude real estate value would rise.– Coastal property could disappear altogether.

• A favoring of cold, high-altitude land might increase the gap between rich and poor.

Stern Review• “Climate change may initially have small positive

effects for a few developed countries, but is likely to be very damaging for the much higher temperature increases expected by mid- to late-century under BAU conditions.”– In higher-latitude regions, 2-3˚C means higher

crop yields, lower energy requirements– In lower-latitude regions, higher temperatures

means lower crop yields and water availability– Example: Southern Europe

• 2˚C increase in temp = 20% decline in agriculture yields and water

• Heat waves like 2003 ($15 billion crop losses) will be common by 2050.

Natural Disasters World-Wide• U.S. in 2003: $65 billion• U.S. in 2004: $145 billion• Economic damage 1985-1999

– The world’s wealthiest countries • 57.3% of economic losses • 2.5% of GDP

– The world’s poorest countries• 24.4% of economic losses• 13.4% of GDP

• These numbers will of course increase along with an increase in natural disasters

• IPCC’s Fourth Assessment Report: – More than 66% certainty of increase in

droughts, tropical cyclones, and extreme high tides.

IPCC 2001

Example: Alaska

Coastal erosion, floods, and melting permafrost causes high costs by requiring– Build new

buildings – Build new bridges

and roads– Lay new pipelines– Repair power

grids

Total Costs

• Stern Review: – Business-as-usual: 5-20% GDP– Mitigate: 1% GDP

• UN’s IPCC: trying to reverse global warming will be cheaper than business-as-usual.