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{{POV-lead|date=November 2012}}
{{POV-lead|date=November 2012}}
In 2007, the UN's [[Intergovernmental Panel on Climate Change]] determined that a rise in global temperatures of more than 2 degrees C would lead to catastrophic{{Editorializing|date=November 2012}}<!-- They never said that word; when you supply adjectives not in the source you are injecting your opinion. I happen to agree with this opinion but as an editor it is a not allowed because we have to stay neutral.--> changes for planetary ecosystems. In 2009, the Hadley Centre for Meteorological Research concluded that global temperature could rise 4 degrees C by 2060[http://www.metoffice.gov.uk/media/pdf/j/9/HCTN_80.pdf 2060]. A November 5, 2012 report by global accounting firm [[Price Waterhouse Coopers]] calculated that a business-as-usual{{failed verification|date=November 2012}}<!-- That term was in the press release but was not clearly tied to the much more explicit rate of increase tied to the 6C figure. --> scenario would cause global temperature to rise by as much as [http://press.pwc.com/GLOBAL/News-releases/current-rates-of-decarbonisation-pointing-to-6oc-of-warming/s/47302a6d-efb5-478f-b0e4-19d8801da855 6 degrees C by 2100]. A November 9, 2012 report from the [[National Center for Atmospheric Research]] finds that the highest predictions of earth warming are still too low, according to new methods of modelling of cloud cover in the tropics<ref>{{cite journal|last=Fasullo|first=J.T.|coauthors=Trenberth, K.E.|title=Climate change: Constraining cloud feedbacks|journal=Science|year=2012|volume=338|issue=6108|pages=755–756|doi=10.1126/science.1231083}}</ref>. The report predicts 8 degrees C of warming by 2100 and does not consider positive feedback of Arctic methane.{{cn|date=November 2012}} The average world land temperature has risen approximately 1.5 degrees C in the past 250 years, and about 0.9 degrees in the past 50 years ([http://berkeleyearth.org/results-summary/ Berkeley Earth Surface Temperature Study ]) ([[global warming]]). Arctic temperatures have risen even more. Worldwide [[greenhouse gas]] emissions continue to rise.
In 2007, the UN's [[Intergovernmental Panel on Climate Change]] determined that a rise in global temperatures of more than 2 degrees C would lead to changes in planetary ecosystems not seen since humans evolved. In 2009, the Hadley Centre for Meteorological Research concluded that global temperature could rise 4 degrees C by 2060[http://www.metoffice.gov.uk/media/pdf/j/9/HCTN_80.pdf 2060]. A November 5, 2012 report by global accounting firm [[Price Waterhouse Coopers]] calculated that at current rates of emissions growth global temperature would rise by as much as [http://press.pwc.com/GLOBAL/News-releases/current-rates-of-decarbonisation-pointing-to-6oc-of-warming/s/47302a6d-efb5-478f-b0e4-19d8801da855 6 degrees C by 2100]. A November 9, 2012 report from the [[National Center for Atmospheric Research]] finds that the highest predictions of earth warming are still too low, according to new methods of modelling of cloud cover in the tropics<ref>{{cite journal|last=Fasullo|first=J.T.|coauthors=Trenberth, K.E.|title=Climate change: Constraining cloud feedbacks|journal=Science|year=2012|volume=338|issue=6108|pages=755–756|doi=10.1126/science.1231083}}</ref>. The report predicts 8 degrees C of warming by 2100.{{cn|date=November 2012}} The average world land temperature has risen approximately 1.5 degrees C in the past 250 years, and about 0.9 degrees in the past 50 years ([http://berkeleyearth.org/results-summary/ Berkeley Earth Surface Temperature Study ]) ([[global warming]]). Arctic temperatures have risen even more. Worldwide [[greenhouse gas]] emissions continue to rise.


There are tipping points ([[tipping point (climatology)]]) of climate change beyond which nothing can be done to reverse the positive feedback systems of the planet, resulting in [[runaway climate change]].{{cn|date=November 2012}} Many of those tipping points of climate change are located in the [[Arctic]]<ref>{{cite journal|last=Duarte|first=C.M.|coauthors=Agusti, S., Wassmann, P., Arrieta, J.M., Alcaraz, M., Coello, A., Marba, N., Hendriks, I.E., Holding, J., Garcıa-Zarandona, I., Kritzberg, E., Vaque, D.|title=Tipping elements in the Arctic marine ecosystem|journal=AAMBIO|year=2012|volume=41|pages=44–55|doi=10.1007/s13280-011-0224-7}}</ref>. These Arctic tipping points include melting of the [[Greenland]] and [[Antarctic]] ice sheets, melting of Arctic [[permafrost]]<ref>{{cite journal|last=Harden|first=J.W.|coauthors=Koven, C.D., Ping, C., Hugelius, G., McGuire, D.A., Camill, P., Jorgenson, T., Kuhry, P., Michaelson, G.J., O’Donnell, J.A., Schuur, E.A.G., Tarnocai, C., Johnson, K., & Grosse, G.|title=Field information links permafrost carbon to physical vulnerabilities of thawing|journal=Geophysical Research Letters|year=2012|volume=39|pages=L15704|doi=10.1029/2012GL051958|issue=15}}</ref>, [[Arctic sea ice]] melt, [[methane]] release from the [[Arctic ocean]] and sea bed<ref>{{cite journal|last=Phrampus|first=B.J.|coauthors=Hornback, M.J.|title=Recent changes to the gulf stream causing widespread gas hydrate destabilization|journal=Nature|year=2012|volume=490|pages=527–530|doi=10.1038/nature11528|issue=7421|pmid=23099408}}</ref>, and loss of Arctic [[albedo]]. The extent of [[Arctic sea ice]] in the months of April, May and June inclusive has been at record lows every year in [[Eurasia]] since 2008, and in 3 of the past 5 years in North America<ref>{{cite journal|last=Derksen|first=C.|coauthors=Brown, R.|title=Spring snow cover extent reductions in the 2008–2012 period exceeding climate model projections|journal=Geophysical Research Letters|year=2012|volume=39|pages=L19504|doi=10.1029/2012GL053387|issue=19}}</ref>. In September, 2012, the [[Arctic sea ice]] set a new record low. The loss of Arctic sea ice changes the behaviour of the jet stream, creating extreme weather events, drought and flooding, resulting in widespread crop failures<ref>{{cite journal|last=Frances|first=J.A.|coauthors=Vavrus, S.J.|title=Evidence linking Arctic amplification to extreme weather in mid-latitudes|journal=Geophysical Research Letters|year=2012|pages=L06801|doi=10.1029/2012GL051000,+2012}}</ref>.
There are tipping points ([[tipping point (climatology)]]) of climate change beyond which nothing can be done to reverse the positive feedback systems of the planet, resulting in [[runaway climate change]].{{cn|date=November 2012}} Many of those tipping points of climate change are located in the [[Arctic]]<ref>{{cite journal|last=Duarte|first=C.M.|coauthors=Agusti, S., Wassmann, P., Arrieta, J.M., Alcaraz, M., Coello, A., Marba, N., Hendriks, I.E., Holding, J., Garcıa-Zarandona, I., Kritzberg, E., Vaque, D.|title=Tipping elements in the Arctic marine ecosystem|journal=AAMBIO|year=2012|volume=41|pages=44–55|doi=10.1007/s13280-011-0224-7}}</ref>. These Arctic tipping points include melting of the [[Greenland]] and [[Antarctic]] ice sheets, melting of Arctic [[permafrost]]<ref>{{cite journal|last=Harden|first=J.W.|coauthors=Koven, C.D., Ping, C., Hugelius, G., McGuire, D.A., Camill, P., Jorgenson, T., Kuhry, P., Michaelson, G.J., O’Donnell, J.A., Schuur, E.A.G., Tarnocai, C., Johnson, K., & Grosse, G.|title=Field information links permafrost carbon to physical vulnerabilities of thawing|journal=Geophysical Research Letters|year=2012|volume=39|pages=L15704|doi=10.1029/2012GL051958|issue=15}}</ref>, [[Arctic sea ice]] melt, [[methane]] release from the [[Arctic ocean]] and sea bed<ref>{{cite journal|last=Phrampus|first=B.J.|coauthors=Hornback, M.J.|title=Recent changes to the gulf stream causing widespread gas hydrate destabilization|journal=Nature|year=2012|volume=490|pages=527–530|doi=10.1038/nature11528|issue=7421|pmid=23099408}}</ref>, and loss of Arctic [[albedo]]. The extent of [[Arctic sea ice]] in the months of April, May and June inclusive has been at record lows every year in [[Eurasia]] since 2008, and in 3 of the past 5 years in North America<ref>{{cite journal|last=Derksen|first=C.|coauthors=Brown, R.|title=Spring snow cover extent reductions in the 2008–2012 period exceeding climate model projections|journal=Geophysical Research Letters|year=2012|volume=39|pages=L19504|doi=10.1029/2012GL053387|issue=19}}</ref>. In September, 2012, the [[Arctic sea ice]] set a new record low. The loss of Arctic sea ice changes the behaviour of the jet stream, creating an increase in extreme weather events, drought and flooding, resulting in crop failures<ref>{{cite journal|last=Frances|first=J.A.|coauthors=Vavrus, S.J.|title=Evidence linking Arctic amplification to extreme weather in mid-latitudes|journal=Geophysical Research Letters|year=2012|pages=L06801|doi=10.1029/2012GL051000,+2012}}</ref>.


Other tipping points outside the Arctic include boreal forest dieback ([[tipping point (climatology)]]), methane release from boreal peat, Amazon forest dieback ([[tipping point (climatology)]]), [[ocean acidification]] <ref>{{cite journal|last=Honisch|first=B.|coauthors=Ridgwell, A., Schmidt, D.N., Thomas, E., Gibbs, S., Sluijs, A., Zeebe, R., Kump, L, Martindale, R.C., Greene, S.E., Kiessling, W., Ries, J., Zachos, J.D., Royer, D.L., Barker, S., Marchitto, T.M., Moyer, R., Pelejero, C., Ziveri, P., Foster, G.L., Williams, B.|title=The geological record of ocean acidification|journal=Science|volume=335|pages=1058–63|doi=10.1126/science.1208277|year=2012|issue=6072|pmid=22383840}}</ref>, loss of [[biodiversity]]<ref>{{cite web|title=U.N. Convention on Biological Diversity|url=http://www.cbd.int/doc/?meeting=cop-10|accessdate=9 November 2012}}</ref>, loss of plankton and phytoplankton <ref>{{cite journal|last=Boyce|first=D.G.|coauthors=Lewis, M.R.|title=Global phytoplankton decline over the past century|journal=Nature|year=466|pages=591–596|doi=10.1038/nature09268|volume=466|issue=7306|pmid=20671703}}</ref><ref>{{cite journal|last=Gao|first=K.|coauthors=Xu, J., Gao, G., Li, Y., Hutchins, D.A., Huang, B., Wang, L., Zheng, Y., Jin, P., Cai, X., Häder, D-P., Li, W., Xu, K., Liu, N., & Riebesell, U.|title=Rising CO2 and increased light exposure synergistically reduce marine primary productivity|journal=Nature Climate Change|year=2012|pages=519–523|doi=10.1038/nclimate1507}}</ref>. [[groundwater]] depletion<ref>{{cite journal|last=Famiglietti|first=J.S.|coauthors=Lo, M., Ho, S.L., Bethune, J., Anderson, K.J., Syed, T.H., Swenson, S.C., de Linage, C.R., & Rodell, M.|title=Satellites measure recent rates of groundwater depletion in California's Central Valley|journal=Geophysical Research Letters|year=2011|volume=38|doi=10.1029/2010GL046442|issue=3}}</ref>, and damage to the [[thermohaline circulation]] of the world’s oceans, prompting the conclusion that the Earth’s sixth [[mass extinction]] has begun<ref name=Barnosky2011>{{cite journal|last=Barnosky|first=A.D.|coauthors=Matzke, N., Tomiya, S., Wogan, G.O.U., Swartz, B., Quental, T.B., Marshall, C., McGuire, J.L., Lindsey, E.L., Maguire, K.C., Mersey, B., & Ferrer, E.A.|journal=Nature|year=2011|volume=471|pages=51–57|doi=10.1038/nature09678|title=Has the Earth's sixth mass extinction already arrived?|issue=7336|pmid=21368823}}</ref>. Interdisciplinary modelling has predicted that the “mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved.”<ref name=Barnosky2011/>
Other tipping points outside the Arctic include boreal forest dieback ([[tipping point (climatology)]]), methane release from boreal peat, Amazon forest dieback ([[tipping point (climatology)]]), [[ocean acidification]], loss of [[biodiversity]], [[groundwater]] depletion, and damage to the [[thermohaline circulation]] of the world’s oceans.


Modern health care depends on fossil fuels and a highly developed industrial civilization, but the thermodynamic and ecological evidence is that human civilization has reached the end of growth because there is not enough net energy and resources entering the global industrial economy to support the current global population<ref>{{cite journal|last=Garrett|first=T.J.|title=Are there basic physical constraints on future anthropogenic emissions of carbon dioxide?|journal=Climatic Change|year=2009|volume=104|pages=437–455|doi=10.1007/s10584-009-9717-9|issue=3–4}}</ref>. Austerity budgets in a [[de-growth]] scenario will affect employment, food, fresh water, shelter and health care, but the time line is unclear.
[[Ocean acidification]] is rising into dangerous levels, having not been this elevated in 80,000 years, and is proceeding at a rate that has never before been recorded<ref>{{cite journal|last=Honisch|first=B.|coauthors=Ridgwell, A., Schmidt, D.N., Thomas, E., Gibbs, S., Sluijs, A., Zeebe, R., Kump, L, Martindale, R.C., Greene, S.E., Kiessling, W., Ries, J., Zachos, J.D., Royer, D.L., Barker, S., Marchitto, T.M., Moyer, R., Pelejero, C., Ziveri, P., Foster, G.L., Williams, B.|title=The geological record of ocean acidification|journal=Science|volume=335|pages=1058–63|doi=10.1126/science.1208277|year=2012|issue=6072|pmid=22383840}}</ref>. This is affecting fish and shellfish viability in addition to the effects of over harvesting. [[Ocean acidification]] also adversely affects [[plankton]] and [[phytoplankton]], which perform 70% of the [[photosynthesis]] of the planet<ref>{{cite book|last=Epstein|first=P.|title=Changing Planet, Changing Health|year=2011|publisher=University of California Press|location=Berkeley, CA|isbn=978-0520269095|coauthors=Ferber, D.}}</ref>. The global population of [[phytoplankton]] has decreased 40% since 1950 because of [[ocean acidification]]<ref>{{cite journal|last=Boyce|first=D.G.|coauthors=Lewis, M.R.|title=Global phytoplankton decline over the past century|journal=Nature|year=466|pages=591–596|doi=10.1038/nature09268|volume=466|issue=7306|pmid=20671703}}</ref><ref>{{cite journal|last=Gao|first=K.|coauthors=Xu, J., Gao, G., Li, Y., Hutchins, D.A., Huang, B., Wang, L., Zheng, Y., Jin, P., Cai, X., Häder, D-P., Li, W., Xu, K., Liu, N., & Riebesell, U.|title=Rising CO2 and increased light exposure synergistically reduce marine primary productivity|journal=Nature Climate Change|year=2012|pages=519–523|doi=10.1038/nclimate1507}}</ref>. When the world’s oceans can no longer absorb carbon emissions, the CO2 levels in the atmosphere will rise more quickly.

[[Groundwater]] depletion is affecting agriculture worldwide. [[Groundwater]] depletion can even be detected from space<ref>{{cite journal|last=Famiglietti|first=J.S.|coauthors=Lo, M., Ho, S.L., Bethune, J., Anderson, K.J., Syed, T.H., Swenson, S.C., de Linage, C.R., & Rodell, M.|title=Satellites measure recent rates of groundwater depletion in California's Central Valley|journal=Geophysical Research Letters|year=2011|volume=38|doi=10.1029/2010GL046442|issue=3}}</ref>.
[[Biodiversity]] loss is proceeding at a pace of 200 species per day<ref>{{cite web|title=U.N. Convention on Biological Diversity|url=http://www.cbd.int/doc/?meeting=cop-10|accessdate=9 November 2012}}</ref>, prompting the conclusion that the Earth’s sixth [[mass extinction]] has begun<ref name=Barnosky2011>{{cite journal|last=Barnosky|first=A.D.|coauthors=Matzke, N., Tomiya, S., Wogan, G.O.U., Swartz, B., Quental, T.B., Marshall, C., McGuire, J.L., Lindsey, E.L., Maguire, K.C., Mersey, B., & Ferrer, E.A.|journal=Nature|year=2011|volume=471|pages=51–57|doi=10.1038/nature09678|title=Has the Earth's sixth mass extinction already arrived?|issue=7336|pmid=21368823}}</ref>. Interdisciplinary modelling has predicted that the “mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved.”<ref name=Barnosky2011/>

Modern health care depends on fossil fuels and a highly developed industrial civilization, but the thermodynamic and ecological evidence is that human civilization has reached the end of growth because there is simply not enough net energy and resources entering the global industrial economy to support the current global population<ref>{{cite journal|last=Garrett|first=T.J.|title=Are there basic physical constraints on future anthropogenic emissions of carbon dioxide?|journal=Climatic Change|year=2009|volume=104|pages=437–455|doi=10.1007/s10584-009-9717-9|issue=3–4}}</ref>. Austerity budgets in a [[de-growth]] scenario will affect employment, food, fresh water, shelter and health care, but the time line is unclear and it is difficult to predict ongoing developments.


Developed countries are ill prepared to adjust to reduced fossil fuel availability and health care has not prepared to downsize. The following effects on human health will need to be addressed.
Developed countries are ill prepared to adjust to reduced fossil fuel availability and health care has not prepared to downsize. The following effects on human health will need to be addressed.

Revision as of 22:11, 13 November 2012

In 2007, the UN's Intergovernmental Panel on Climate Change determined that a rise in global temperatures of more than 2 degrees C would lead to changes in planetary ecosystems not seen since humans evolved. In 2009, the Hadley Centre for Meteorological Research concluded that global temperature could rise 4 degrees C by 20602060. A November 5, 2012 report by global accounting firm Price Waterhouse Coopers calculated that at current rates of emissions growth global temperature would rise by as much as 6 degrees C by 2100. A November 9, 2012 report from the National Center for Atmospheric Research finds that the highest predictions of earth warming are still too low, according to new methods of modelling of cloud cover in the tropics[1]. The report predicts 8 degrees C of warming by 2100.[citation needed] The average world land temperature has risen approximately 1.5 degrees C in the past 250 years, and about 0.9 degrees in the past 50 years (Berkeley Earth Surface Temperature Study ) (global warming). Arctic temperatures have risen even more. Worldwide greenhouse gas emissions continue to rise.

There are tipping points (tipping point (climatology)) of climate change beyond which nothing can be done to reverse the positive feedback systems of the planet, resulting in runaway climate change.[citation needed] Many of those tipping points of climate change are located in the Arctic[2]. These Arctic tipping points include melting of the Greenland and Antarctic ice sheets, melting of Arctic permafrost[3], Arctic sea ice melt, methane release from the Arctic ocean and sea bed[4], and loss of Arctic albedo. The extent of Arctic sea ice in the months of April, May and June inclusive has been at record lows every year in Eurasia since 2008, and in 3 of the past 5 years in North America[5]. In September, 2012, the Arctic sea ice set a new record low. The loss of Arctic sea ice changes the behaviour of the jet stream, creating an increase in extreme weather events, drought and flooding, resulting in crop failures[6].

Other tipping points outside the Arctic include boreal forest dieback (tipping point (climatology)), methane release from boreal peat, Amazon forest dieback (tipping point (climatology)), ocean acidification [7], loss of biodiversity[8], loss of plankton and phytoplankton [9][10]. groundwater depletion[11], and damage to the thermohaline circulation of the world’s oceans, prompting the conclusion that the Earth’s sixth mass extinction has begun[12]. Interdisciplinary modelling has predicted that the “mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved.”[12]

Modern health care depends on fossil fuels and a highly developed industrial civilization, but the thermodynamic and ecological evidence is that human civilization has reached the end of growth because there is not enough net energy and resources entering the global industrial economy to support the current global population[13]. Austerity budgets in a de-growth scenario will affect employment, food, fresh water, shelter and health care, but the time line is unclear.

Developed countries are ill prepared to adjust to reduced fossil fuel availability and health care has not prepared to downsize. The following effects on human health will need to be addressed.

Health

Access to health care

Access to health care has a major impact on human health and quality of life. The report of the WHO Commission on Social Determinants of Health points out that disadvantaged communities are likely to shoulder a large share of the burden of climate change because of their increased exposure and vulnerability to health threats. Over 90 percent of malaria and diarrhea deaths are borne by children aged 5 years or younger, mostly in developing countries.[14] Other severely affected population groups include women, the elderly and people living in small island developing states and other coastal regions, mega-cities or mountainous areas.[15]

Infectious diseases

Climate change can lead to dramatic increases in prevalence of a variety of infectious diseases. Beginning in the mid-70s, there has been an “emergence, resurgence and redistribution of infectious diseases”.[16] Reasons for this are likely multicausal, dependent on a variety of social, environmental and climatic factors, however, many argue that the “volatility of infectious disease may be one of the earliest biological expressions of climate instability”.[16] Though many infectious diseases are affected by changes in climate, vector-borne diseases, such as malaria, dengue fever and leishmaniasis, present the strongest causal relationship. Malaria in particular, which kills approximately 300,000 children annually, poses the most imminent threat.[17]

Malaria

Malaria is a mosquito-borne parasitic disease that infects humans and other animals caused by microorganisms in the Plasmodium family. It begins with a bite from an infected female mosquito, which introduces the parasite through its saliva and into the infected host’s circulatory system. It then travels through the bloodstream into the liver where it can mature and reproduce. The disease causes symptoms that typically include fever, headache, shaking chills, anemia, and in severe cases can progress to coma or death. Climate is the most influential driving force of vector-borne diseases such as malaria. Changes in climate factors substantially affect reproduction, development, distribution and seasonal transmissions of malaria. [18]

Malaria is especially susceptible to changes in the environment as both the pathogen (Plasmodium) and its vector (mosquitoes) lack the mechanisms necessary to regulate internal temperature and fluid levels. This implies that there is a limited range of climatic conditions within which the pathogen and vector can survive, reproduce and infect hosts.[18] Vector-borne diseases, such as malaria, have distinctive characteristics that determine pathogenicity. These include: the survival and reproduction rate of the vector, the level of vector activity (i.e. the biting or feeding rate), and the development and reproduction rate of the pathogen within the vector or host.[18] These depend on climatic conditions such as temperature, precipitation and humidity.

The ideal temperature range for malaria-carrying mosquitoes is 15–30 °C. Mosquitoes are also highly sensitive to changes in precipitation and humidity. Increased precipitation can increase mosquito population indirectly by expanding larval habitat and food supply. Mosquitoes are, however, highly dependent on humidity, surviving only within a limited humidity range of 55-80%.[citation needed]

Modelling malaria is particularly complex given the two common pathogen variants (Plasmodium falciparum and Plasmodium vivax) and many regionally dominant mosquito species.[19] These models must therefore incorporate a variety of factors including: human-induced changes in climate (e.g. temperature, precipitation, and humidity), environmental factors (e.g. drought and deforestation), disease factors (e.g. parasite development rate, vector population, and drug resistance) and other factors (e.g. changes in immune status of hosts and spread of disease into new areas).[20] Various models suggest, conservatively, that people living in developing countries’ risk of malaria will increase 5-15% by 2100 due to climate change.[20] In Africa alone, according to the MARA Project (Mapping Malaria Risk in Africa).[21], there is a projected increase of 16-28% in person-month exposures to malaria by 2100.[22]

One of the factors involved in an increase of infectious disease during times of drought is a decrease in personal hygiene. Individuals may respond to a real or perceived need to save water by reducing or eliminating hand-washing, showering, and the washing of clothing and eating utensils. This increases the risks of them contracting, as well as transmitting, infectious diseases, especially acute respiratory and gastrointestinal diseases that are spread by direct contact.[23]

For rural populations in dry countries like Sudan, drought can sometimes lead to devastating cholera outbreaks. When the wet season finally arrives, torrential downpours become common. However, with the ground so dry from drought season, the water cannot be absorbed into the soil. Instead, it lays on top of the dirt and areas are quickly flooded. This alone can be dangerous. In refugee camps and heavily-populated areas such as slums, the vehicles that deliver safe drinking water to different parts of the community can become unable to drive through the floods, forcing people in the camps to resort to drinking the unsafe floodwaters that easily carry disease such as cholera. Even before the floodwaters of the rainy season arrive, as drought dries up rivers that flow to and from lakes, pools of water become stagnant. In this state, both algae and parasites multiply, poisoning the water supply.[24][25]

Droughts affect mosquito activity worldwide. In the beginning of drought season in sub-Saharan Africa, mosquito activity is initially increased as small rivers, ponds and lakes shrink, resulting in shallow, warm, stagnant pools of water. As drought continues, mosquito activity decreases- seemingly a welcome break from the infectious insects, but in actuality a serious hazard. Once a person contracts malaria, they are less likely to become infected again due to antibodies. As mosquito activity decreases, the population of non-infected and therefore non-immune people increases (including babies and children, the group most likely to die from malaria). Eventually, when the drought breaks, there is a large number of susceptible hosts now vulnerable to infection. In the long term, the number of cases of malaria decreases with drought, as the mosquitoes lack the necessary water for breeding, but there are typically pockets in the beginning and at the break in drought where cases increase quite substantially. A similar pattern is true, too, for West Nile Disease-carrying mosquitoes in North America.[26]

For North Americans, lack of rain can actually spread diseases caused by virus or parasites that prefer dry climates. Deer ticks, which spread Lyme Disease, live on deer and mice, animals that, in times of low water supply, wander closer to human territory and homes in search of a drink. This may mean bringing ticks out of the forests and closer, more often, to human homes.[27]

Respiratory disease

Heat waves that accompany droughts have a tendency to incite wildfires, which heavily pollutes the air for hundreds, or even thousands, of miles in every direction. The particulate matter floating in the air has the serious potential to aggravate the lining of the respiratory tract, especially in people who already suffer from respiratory diseases like asthma and bronchitis. Dust storms that blow from parched land, much more likely to occur in times of severe drought, do the same. Though much of the particulate matter in the air during dust storms is too course to reach much of the respiratory tract, some is fine enough to make its way through the bronchioles that attach to the lungs, irritating the lining and causing inflammation. (Changing Planet, Changing Health)[citation needed]

Drinking Water

In rural Africa and the Middle East, when droughts dry up the regular water supply, rural and impoverished families are forced to resort to drinking the dirty, sediment-and-parasite-laden water that sits in puddles and small pools on the surface of the earth. Many are aware of the presence of contamination, but will drink from these sources nonetheless in order to avoid dying of dehydration. It has been estimated that up to 80% of human illness in the world can be attributed to contaminated water.[28]

When there is an adequate amount of drinking water, humans drink from different sources than their livestock. However, when drought occurs and drinking water slowly disappears, catchment areas such as streams and depressions in the ground where water gathers are often shared between people and the livestock they depend on for financial and nutritional support, and this is when humans can fall seriously ill. Although some diseases that are transferred to humans can be prevented by boiling the water, many people, living on just a litre or two of water per day, refuse to boil, as it loses a certain percentage of the water to steam.[29]

The sharing of water between livestock and humans is one of the most common factors in the transmission of non-tuberulosis mycobacteria (NTM). NTM is carried in cattle and pig feces, and if this contaminates the drinking water supply, it can result in pulmonary disease, disseminated disease or localized lesions in humans with both compromised and competent immune systems.[30] During drought, water supplies are even more susceptible to harmful algal blooms and microorganisms.[31] Algal blooms increase water turbidity, suffocating aquatic plants, and can deplete oxygen, killing fish. Some kinds of blue-green algae create neurotoxins, hepatoxins, cytotoxins or endotoxins that can cause serious and sometimes fatal neurological, liver and digestive diseases in humans. Cyanobacteria grow best in warmer temperatures (especially above 25 degrees Celcius), and so areas of the world that are experiencing general warming as a result of climate change are also experiencing harmful algal blooms more frequently and for longer periods of time. During times of intense precipitation (such as during the “wet season” in much of the tropical and sub-tropical world, including Australia and Panama, nutrients that cyanobacteria depend on are carried from groundwater and the earth’s surface into bodies of water. As drought begins and these bodies gradually dry up, the nutrients are concentrated, providing the perfect opportunity for algal blooms.[32][33][34]

Mental health

Rates of suicide in Australian farmers are higher than the national average, but during times of drought these rates increase. This is due to a number of reasons. Firstly, there is intense financial pressure on farmers. Farmers also tend to be of lower socio-economic standing and so have less of a financial reserve. A few years of decreased production can be quite devastating. This pressure can lead to high rates of depression and suicide. There are also less medical, let alone mental health, resources available in rural communities, making it difficult for this group to access resources such as counselling. For older farmers, there are the added stresses of aging and coping with rapid agricultural and societal change, including new procedural demands from governments. Studies have also shown increased rates of substance use by farmers during drought, which can have an impact on individual safety (especially when operating heavy machinery), as well as on family and community health.[35]

While the physical health impacts of climate change are well known, the impact on mental health has only begun to be recognized in the last decade.[36] One well known correlation between climate change and mental is Seasonal variation disorder. Seasonal variation is the cause of seasonal affective disorder as described in the diagnostic and statistical manual and is characterized by the onset of depression in the winter months and causes reappearance of mania during the in spring. “Hospital admission studies have shown that apart from seasonality, various climatic parameters including daily ambient temperature, relative humidity, atmospheric pressure, rainfall and hours of sunshine contribute to seasonal variations in bipolar disorder admissions”.[37] “Another association between climate change and mental health is acute psychosis. One of the hypotheses of acute psychosis is an increased association with posed viral infections. For example, “studies from tropical countries like India suggest an increased prevalence of acute psychosis following viral fever, especially in winter”.[38] Furthermore, extreme weather events and conditions contribute to increasing mental health issues such as confusion, delirium, and persisting neuropsychological deficits. This article discusses the link between environmental issues caused by changes in climate; drought, flooding, and environmental disasters all of which lead to the mental health issues.

Research has shown that extreme weather events lead to a variety of mental health disorders from the impacts of loss, social disruption, and displacement.[39] Some examples of common mental health conditions associated with such events include: acute traumatic stress, post-traumatic stress disorder, depression, complicated grief, anxiety disorders, sleep difficulties, sexual dysfunction, and drug or alcohol abuse.[39] Events such as wildfires and hurricanes can lead to anxiety and emotional stress, further exacerbated in already vulnerable populations with current mental health issues.[39] Extreme weather events can lead to the migration of large communities due to stressors upon already limited resources.[39] For example, the devastating effects of Hurricane Katrina lead to a variety of mental health problems due to destruction of resources.[40] Many people were left homeless, disenfranchised, stressed, and suffering physical illness.[40] This strain on the public health system decreased access and availability of medical resources.[40] Some climate change adaptation measures may prevent the need for displacement; however, some communities may be unable to implement adaptation strategies, and this will create added stress, further exacerbating already existing mental health issues.[39] Extreme weather events and population displacement lead to limited availability of medications, one of the primary resources required to meet psychological and physical needs of those affected by such events.[39]

One of the more devastating impacts of climate change on mental health is the increased risk in suicide. Studies show that suicide rates increase after extreme weather events.[40] This has been demonstrated in Australia, where draught has resulted in crop failures and despair to the Australian countryside.[40] Farmers were left with nothing, forced to sell everything, reduce their stock, and borrow large sums to plant crops at the start of the season.[40] This has caused a growing increase in depression, domestic violence, and most alarmingly suicide.[40] More than one hundred farmers in the countryside had committed suicide by 2007.[40]

Extreme weather events

Infectious disease often accompanies extreme weather events, such as floods, earthquakes and drought. These local epidemics occur due to loss of infrastructure, such as hospitals and sanitation services, but also because of changes in local ecology and environment. For example, malaria outbreaks have been strongly associated with the El Nino cycles of a number of countries (India and Venezuela, for example). El Nino can lead to drastic, though temporary, changes in the environment such as temperature fluctuations and flash floods.[16] Because of global warming there has been a marked trend towards more variable and anomalous weather. This has led to an increase in the number and severity of extreme weather events. This trend towards more variability and fluctuation is perhaps more important, in terms of its impact on human health, than that of a gradual and long-term trend towards higher average temperature.[16]

Floods

Many health concerns globally can be linked to floods; they have short term and long term negative implications[41]

Drought

Arguably one of the worst effects that drought has directly on human health is the destruction of food supply. Farmers who depend on weather to water their crops lose tons of crops per year due to drought. Plant growth is severely stunted without adequate water, and plant resistance mechanisms to fungi and insects weaken like human immune systems. The expression of genes is altered by increased temperatures, which can also affect a plant’s resistance mechanisms. One example is wheat, which has the ability to express genes that make it resistant to leaf and stem rusts, and to the Hessian fly; its resistance declines with increasing temperatures. A number of other factors associated with lack of water may actually attract pestilent insects, as well- some studies have shown that many insects are attracted to yellow hues, including the yellowing leaves of drought-stressed plants. During times of mild drought is when conditions are most suitable to insect infestation in crops; once the plants become too weakened, they lack the nutrients necessary to keep the insects healthy. This means that even a relatively short, mild drought may cause enormous damage- even though the drought on its own may not be enough to kill a significant portion of the crops, once the plants become weakened, they are at higher risk of becoming infested.[42]

The results of the loss of crop yields affect everyone, but they can be felt most by the poorest people in the world. As supplies of corn, flour and vegetables decline, world food prices are driven up. Malnutrition rates in poor areas of the world skyrocket, and with this, dozens of associated diseases and health problems. Immune function decreases, so mortality rates due to infectious and other diseases climb. For those whose incomes were affected by droughts (namely agriculturalists and pastoralists), and for those who can barely afford the increased food prices, the cost to see a doctor or visit a clinic can simply be out of reach. Without treatment, some of these diseases can hinder one’s ability to work, decreasing future opportunities for income and perpetuating the vicious cycle of poverty.[43]

Habitat loss

Climate change may dramatically impact habitat loss, for example, arid conditions may cause the collapse of rainforests, as has occurred in the past.[44]

Deforestation

The deforestation and cultivation of natural swamps in the African highlands has created conditions favourable for the survival of mosquito larvae, and has, in part, led to the increasing incidence of malaria.[17]

Fresh water

As the climate warms, it changes the nature of global rainfall, evaporation, snow, stream flow and other factors that affect water supply and quality. Freshwater resources are highly sensitive to variations in weather and climate. Climate change is projected to affect water availability. In areas where the amount of water in rivers and streams depends on snow melting, warmer temperatures increase the fraction of precipitation falling as rain rather than as snow, causing the annual spring peak in water runoff to occur earlier in the year. This can lead to an increased likelihood of winter flooding and reduced late summer river flows. Rising sea levels cause saltwater to enter into fresh underground water and freshwater streams. This reduces the amount of freshwater available for drinking and farming. Warmer water temperatures also affect water quality and accelerate water pollution.[45]

Displacement/migration

Climate change causes displacement of people in several ways, the most obvious—and dramatic—being through the increased number and severity of weather-related disasters which destroy homes and habitats causing people to seek shelter or livelihoods elsewhere. Slow onset phenomena, including effects of climate change such as desertification and rising sea levels gradually erode livelihoods and force communities to abandon traditional homelands for more accommodating environments. This is currently happening in areas of Africa’s Sahel, the semi-arid belt that spans the continent just below its northern deserts. Deteriorating environments triggered by climate change can also lead to increased conflict over resources which in turn can displace people.[46]

Extreme environmental events are increasingly recognized as a key driver of migration across the world. According to the Internal Displacement Monitoring Centre, more than 42 million people were displaced in Asia and the Pacific during 2010 and 2011, more than twice the population of Sri Lanka. This figure includes those displaced by storms, floods, and heat and cold waves. Still others were displaced drought and sea-level rise. Most of those compelled to leave their homes eventually returned when conditions improved, but an undetermined number became migrants, usually within their country, but also across national borders.[47]

Asia and the Pacific is the global area most prone to natural disasters, both in terms of the absolute number of disasters and of populations affected. It is highly exposed to climate impacts, and is home to highly vulnerable population groups, who are disproportionately poor and marginalized. A recent Asian Development Bank report highlights “environmental hot spots” that are particular risk of flooding, cyclones, typhoons, and water stress.[48]

To reduce migration compelled by worsening environmental conditions, and to strengthen resilience of at-risk communities, governments should adopt polices and commit financing to social protection, livelihoods development, basic urban infrastructure development, and disaster risk management. Though every effort should be made to ensure that people can stay where they live, it is also important to recognize that migration can also be a way for people to cope with environmental changes. If properly managed, and efforts made to protect the rights of migrants, migration can provide substantial benefits to both origin and destination areas, as well as to the migrants themselves. However, migrants – particularly low-skilled ones – are among the most vulnerable people in society and are often denied basic protections and access to services.[48]

The links between the gradual environmental degradation of climate change and displacement are complex: as the decision to migrate is taken at the household level, it is difficult to measure the respective influence of climate change in these decisions with regard to other influencing factors, such as poverty, population growth or employment options.[49] This situates the debate on environmental migration in a highly contested field: the use of the term 'environmental refugee', although commonly used in some contexts, is disrecommended by agencies such as the UNHCR who argue that the term 'refugee' has a strict legal definition which does not apply to environmental migrants.[50] Neither the UN Framework Convention on Climate Change nor the Kyoto Protocol, an international agreement on climate change, includes any provisions concerning specific assistance or protection for those who will be directly affected by climate change.[51]

Security

Conflicts are typically extremely complex with multiple inter-dependent causalities, often referred to as ‘complex emergencies.’ Climate change has the potential to exacerbate existing tensions or create new ones — serving as a threat multiplier. It can be a catalyst for violent conflict and a threat to international security.[52][53]

The United Nations Security Council held its first-ever debate on the impact of climate change in 2007. The links between climate change and security have been the subject of numerous high-profile reports since 2007 by leading security figures in the United States, United Kingdom and the European Union. The G77 group of developing nations also considers climate change to be a major security threat which is expected to hit developing nations particularly hard. The links between the human impact of climate change and the threat of violence and armed conflict are particularly important because multiple destabilizing conditions are affected simultaneously.

Social impacts

The consequences of climate change and poverty are not distributed uniformly within communities. Individual and social factors such as gender, age, education, ethnicity, geography and language lead to differential vulnerability and capacity to adapt to the effects of climate change. Climate change effects such as hunger, poverty and diseases like diarrhea and malaria, disproportionately impact children, i.e. about 90 percent of malaria and diarrhea deaths are among young children.[14]

See also

References

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Further reading