This document is the intellectual property of Dr Raywat Deonandan c. 2014 No part may be reproduced without his written permission (
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29/10/2014
Prof R Deonandan –
[email protected]
Climate Change
HSS4331 – International Health Theory Climate Change and Health
Example: Guyanese AmerIndian village of Mashabo, Feb 2010 -> drought leading to depleted water quality
Climate Change will affect population health everywhere But there will be a particularly dramatic effect on developing and poor nations.
From WHO website:
“Developing country populations, particularly in Small Island States, arid and high mountain zones, and in densely populated coastal areas, are considered to be particularly vulnerable.”
What are some of the ways that Climate Change can affect health?
From Stephen Lewis:
“Those places expected to be hardest hit by Climate Change are precisely those places currently being affected by HIV/AIDS, i.e. Southern Africa.”
(not a precise quote)
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Heat Waves What are the mechanisms with which Climate Change can affect population health?
•Heat waves •Floods and storms •Water scarcity and quality •Communicable diseases •Air pollution •Changing agriculture
-heat waves already kill hundreds, even thousands, every year -in August 2003, 35000 people were killed in one week of intense heat in Europe -exacerbated in urban environments -less vegetative cover -artificial surfaces are less cool -greater local CO2 production
•Migration •Insecurity •Economic effects
-frequency of heat waves are expected to increase -according to WHO, heat deaths in California alone will double by 2100 -will also mean fewer cold waves globally, but this is only relevant in countries with winter -poor countries tend to be tropical, therefore more susceptible to heat waves
Heat Waves Floods and Storms
“Heatwaves aresunburn already the most deadly weatherSevere related exposure in the U.S., and account for more deaths than hurricanes, tornadoes, floods, annually Heat cramps and earthquakes combined.” (CDC)
Heat exhaustion Heat stroke
-the largest and fastest growing cities are on coasts -construction patterns have led to less natural protection (eg erosion) -poor quality housing makes people more vulnerable -inadequate drainage in poor cities -according to WHO, flooding will affect 200 million people by 2080 -in instances of flooding, it is always the poor who suffer most -eg, Hurricane Katrina -poor live in less secure structures Asian tsunami anyone? -poor live in more exposed areas
Places most susceptible to floods and storms? -Nile delta in Egypt -Ganges delta in Bangladesh -small islands like the Maldives, the Marshall Islands and Tuvalu
Communicable Diseases
-waterborne and vector borne diseases are strongly influenced by climate -mosquitoes that carry dengue fever prefer high heat and humidity -increasing global warming makes more habitats for mosquitoes -increased population density means faster spread of such diseases
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Water quality and scarcity Air Pollution Because rivers are changing paths and rainfalls are misscheduling, the predictability of the safety of drinking water is uncertain.
•Already, 2 million deaths a year, mostly among young children, are due to diarrhea, directly caused by unsafe water. •WHO estimates that today 2.4% of diarrheal deaths are due to climate change. (WHO uses very conservative methods to reach these estimates.) -Atmospheric pollutants tend to be greater on hotter days (eg ozone) -U.S. model predicts that by 2050, due to global warming, ozone-related deaths will increased by 4.5% and there will be 60% more alert days -exacerbated in emerging nations with lesser urban planning schemes (China)
Changing Agriculture
Changing Agriculture
Agriculture is affected by temperature, precipitation and soil quality. But in the long run, Climate Change affects agriculture by affecting: •productivity •agricultural practices (through changes of water use, pesticides, etc) •environmental effects (frequency and intensity of soil drainage, etc) •rural space (loss of land due to desertification) •adaptation (change in biology of species)
Agriculture is affected by temperature, precipitation and soil quality
"southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia losses of many regional staples, such as rice, millet and maize could top 10%". –Science (2008)
Poorest countries will be hit hardest. Reduction in crop yield in tropical and sub-tropical regions caused by decreased water and changed insect behaviour. -IPCC (2001)
Poor agriculture leads to poor nutrition leads to poor health
In Africa and Latin America many rainfed crops are near their maximum temperature tolerance, so that yields are likely to fall sharply for even small climate changes; falls in agricultural productivity of up to 30% over the 21st century are projected. Marine life and the fishing industry will also be severely affected in some places. -IPCC (2001)
Environ Health Perspect. 2011 Dec 1;119(12):a524. More Lack in the World The Complex Connection between Undernutrition and Climate Change -by A Spivey
Anthropogenic climate change is projected to reduce cereal yields and food security and therefore to undermine future efforts to reduce child undernutrition.
The study adds to the evidence suggesting that climate change is likely to increase future hunger and undernutrition even under optimistic assumptions of future emissions and economic growth.
climate change will lead to an average relative increase in moderate stunting (height that is more than two standard deviations below the expected height-for-age) of 1–29%, depending on region, compared with a future without climate change. Climate change is likely to affect undernutrition through a variety of means in addition to crop production, including impacts on infectious diseases in humans, plant pests and diseases, labor productivity, and water availability.
Migration There is a long established intersection between migration and health: -sudden stress of large numbers of people is ecologically bad -environmental refugees must be fed, sheltered and cared for -the world has a poor track record of caring for mass migrants
-”Climate Refugees” (first used in 1988)
"The growing number of disasters and conflicts linked to future climate change will push the numbers far higher unless urgent action is taken. We estimate that between now and 2050 a total of 1 billion people will be displaced from their homes.“ –Christian Aid (2007)
In 2005, half of Bhola Island in Bangladesh became permanently flooded, leaving 500,000 people homeless. They are being called the world's first Climate Refugees. Washington Post (2007)
1400 residents of Papua New Guinea's Carteret Islands are permanently homeless because their islands sank under rising sea levels -Sydney Morning Herald (2002)
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Insecurity
Insecurity
War is bad for health. Need I explain why?
War is bad for health. Need I explain why?
-high tension areas already exist with respect to water: -South Asia (India, Pakistan, Bangladesh) -Middle East (Lebanon, Israel, Iraq, Iran) -freshwater needed for drinking and agriculture -flowing water needed for industry, transportation and clean energy -with fossil fuels out of fashion, greater need for hydroelectic power -->dams --> denial of flowing water downstream -->conflict
War has been known to be triggered by climate. Swings in temperature were correlated with times of war in Eastern China between 1000 and 1911. Human Ecology (2007)
"Water at large is the central [global warming] problem for the USA" Princeton University
Israel and Lebanon almost went to war in 2003 over fresh water from the Hasbani river.
Global warming constitutes a security threat to the USA, as there will be wars based on diminishing fresh water supplies, refugees, and higher rates of famine and disease -The Pentagon (2007)
Less money means less public health. Economic Effects
Aside: Psychosocial effects Coral bleaching can lead to collapse of the world’s fisheries in a matter of decades –Am J Prev Med (2008)
Case study: Washington State(Dept of Ecology, 2008): •Direct costs of fighting wildfires > $75 million per year by the 2020s. •Water conservation costs = $16 million by 2040 •Public health costs •Tourism and recreation losses •Hydropower revenues down by $166 million by 2020 •Water price increases in some basins = $680,000 per million gallons per day. •Dairy revenue loss = $6 million per year by the 2040s •Crop losses = $66 million •Shoreline protection = $50 million •Flooding costs •Cumulative economic effects (As one industry declines, another may follow.)
Health Canada 2007 report “Climate Change and Health Vulnerability Assessment: The Public Health Agency of Canada is undertaking a study on the projected mental health effects of environmental stressors resulting from Climate Change.
Health Canada breaks down the climate change – health relationship like so: Synergy of Climate Effects Floods can cause cholera and diarrhea, damage infrastructure for years, and can contribute to a pathway making oral vaccines less effective.
Drought exacerbates malnutrition, causes populations to migrate, where they are exposed o new patterns of vectorborne diseases.
Climate change causes urban heat waves, causing increased use of air conditioners, increasing demand for electricity, leading to further use of coal plants...
Temperature-related morbidity and mortality: -cold and health related illnesses -respiratory and CV illnesses -increased occupational health risks Health effects of extreme weather events: -damaged public health infrastructure -injuries and illnesses -social and mental stress -occupational health hazards -population displacement
Air pollution related illnesses: -changed exposure to outdoor allergens -asthma, etc -CV diseases (heart attacks, strokes, etc) -cancer
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Water and food borne contamination: -diarrhea -toxic algal blooms
Socioeconomic impacts:
Vector and zoonotic diseases: -changed patterns of diseases caused by insects, bacteria, etc
-loss of income and productivity -social disruption -diminished quality of life -increased costs to health care -health effects of mitigating technologies (eg, air conditioners)
Exposure to UV rays -skin damage and cancer -cataracts -disturbed immune function Vulnerable populations -seniors -kids -chronically ill people -poor people -Northern residents -disabled people -people “living off the land”
In 2006, the WHO did a study of project health impacts on Oceania for the year 2050, based on expected changes in global climate.
In addition, they computed for Sub-Saharan Africa, for the year 2030:
-mortality from flooding would be almost twice as likely -increase in malaria -increase in malnutrition due to destruction of crops and change in harvest season -increase in diarrhea due to reduced water control
VOLUME
114 | NUMBER 12 | December 2006 • Environmental Health
Perspectives
Sobering statistic: WHO's official position:
“Measurement of health effects from climate change can only be very approximate. Nevertheless, a WHO quantitative assessment, taking into account only a subset of the possible health impacts, concluded that the effects of the climate change that has occurred since the mid1970s may have caused over 150,000 deaths in 2000. It also concluded that these impacts are likely to increase in the future.”
WHO considers that rapid climate change poses substantial risks to human health, particularly among the poorest populations. The organization therefore supports actions to reduce human influence on the global climate.
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Another word about water...
Important issues:
-Case study: China -In China, by 2030, population will be 1.6 billion and water demand will equal 100% of China's supply -climate change denial slows down investment in projects to address these issues -climate change affects different regions in very different ways -poor countries cannot afford to do basic risk assessment -global rush to cities and to coasts is ever accelerating -effects on food production are impossible to predict (though Africa is thought to be most vulnerable) -mass migration (environmental refugees) highly likely -conflict resulting from both mass migration and competition for resources is also likely
-70% of China's lakes and 5 of its rivers are too polluted for human use -China's glaciers are shrinking 7% each year, due to global warming ->this threatens the source of these rivers: Yangtze, Yellow, Brahmaputra, Mekong and Salween, which feed 500 million people downstream -China uses 7-15 times more water to produce a unit of GDP than do more developed nations ->therefore some of this is preventable!
-a global issue requires a global solution
Water Availability Per Capita, 2007
www.earthtrends.wri.org
A word about scientific uncertainty....
the Canadian Environmental Protection Act (1999) states: “...where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing costeffective measures to prevent environmental degradation.”
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So what is being done? WHO: -continue what they've always done, addressing infectious disease, malnutrition, etc -workshops to “raise awareness” of climate change in developing world -advocate for green infrastructure, such as public transportation -advocate for improved urban infrastructure, such as better drainage -proposed creation of “global climate change fund”
BMJ 2011;343:d7386 doi: 10.1136/bmj.d7386 (Published 15 November 2011) More things that need to be done: “What on earth we can do to tackle climate change” by Stott -improved global disease surveillance -improved response systems to disease outbreaks -better global risk assessment, to identify vulnerable areas and possible interventions -international bodies for managing shared resources, like water
Our narrative is that climate change is bad for health, particularly for those living in poor and marginalised communities.
what’s good for the climate is good for health. -research, research, research --> how will crops behave as climate changes? --> how will vector populations (insects, rodents) behave? --> where will freshwater be most needed? -->etc
we need an overarching global framework to control carbon emissions and synergistically transfer resources to poorer societies in such a way that a low carbon future is in all our financial interest.
In Oct/2012, WHO launched the Atlas of Health and Climate Following are some of the slides from their new productP
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Changes in environmental indicators, 1750 - 2000 Atmos N2O conc
Atmos CH4 conc
Sea-level riseover over the coming centuries Sea-Level Rise, coming millennium following 70 years of excess greenhouse gas emissions 1.5
Atmos ozone loss Av surface temp (NH)
Climate disasters
Fully exploited fisheriesCoastal shrimp farms Coastal N2 flux
Sea-level rise (m)
Atmos CO2 conc
Total sea level rise 1.0
Ocean Expansion
Ice-melt
0.5
Greenhouse gas emissions (“super-Kyoto” action)
Loss of trop forest, woodland Domesticated landGlobal biodiversity 0.0
200
400
600
Time from start (years)
Peaking in 2050
IPCCIPCC, 20012001
From: Steffen et al. In press 2004
SLR Risks to Small Island-States • • • •
Coastal flooding Amplified storm surges Damaged coastal infrastructure (roads, etc.) Salination of island fresh-water (esp. subterranean cells) • Impaired crop production • Population displacement: diverse health risks (nutrition, infection, mental health)
Estimated population at risk of dengue fever under “standard” climate change scenario: 1990, 2085
1990
800
Modulating influences
Health Healtheffects Effects Temperature-related Temperature -related illness and death Extreme weatherExtreme(floods, weather -storms, related related health effects etc.) health effects
Human exposures
Climate Change
Regional weather changes •Heat waves •Extreme weather •Temperature ••Precipitation •Sea-level rise
Air pollution-related pollution -related health effects Microbial changes: Contamination pathways Contamination paths Transmission dynamics Transmission dynamics
Water Water and and food-borne food -borne diseases diseases Vector Vector-borne borne and and rodent rodent- borne borne diseases diseases
Changes in agroecosystems, hydrology
Effects of food and water shortages
Socioeconomic and demographic disruption
Mental, nutritional, infectious-disease and other effects
Modelling Malaria Transmissibility in Zimbabwe. I
Baseline 2000 Courtesy: Kris Ebi
2085 .
Source. Hales S et al. Lancet (online) 6 August 2002. http://image.thelancet.com/extras/01art11175web.pdf
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Modelling Malaria Transmissibility in Zimbabwe. II
Baseline 2000 2025 Courtesy: Kris Ebi
Modelling Malaria Transmissibility in Zimbabwe. III
Baseline 2000 2025 2050
Courtesy: Kris Ebi
What Should Health Ministries Do? • Commission/conduct national assessments of risks to health from CC (and SLR) • Participate in emergency management preparedness (communications, facilities, skills) • Argue the centrality of population health as the real “bottom line” in the sustainability debate • Make links with other ministries – education, primary industry (agriculture), fisheries, development planning, etc. • Highlight the sense and cost-savings of adaptation strategies, to lessen adverse impacts
Populatio n
Damming of rivers
Urban population
Motor vehicles
Total real GDP
Water use
Foreign direct investment
GHG: Coming Decades The International Energy Agency predicts that the increase in greenhouse gas emissions from 2000 to 2030 in China alone will almost equal the increase from the entire industrialized world. China is the world's second largest emitter of such gases, after the United States – even though China's per-person emissions are, for example, still only one-eighth of those in the United States.
CDC framework for policy approach
Fertiliser consumption
MacDonalds Restaurants
International tourism
From: Steffen et al. 2003
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CDC priorities statement
Issues to Leave You With • Barrier to addressing Climate Change is economic <-> but poor health has negative effect on economy, as well • Most focus is on reducing greenhouse gas emissions, to slow Climate Change, but health effects will only reverse years/generations later • Currently no strategies for reversing Climate Change health effects. Suggested policies are for mitigating the known effects (i.e., treating the symptoms)
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