Essay Global Warming Affect Human Health

The Impact of Global Warming on Human Health Essay

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When one hears the phrase “global warming,” what often comes to mind is melting ice caps and warmer winters but most people are horribly unaware of the effects that global warming will have on human health. Food shortages, contaminated water, extreme weather, and deadly heat threaten the world because of the warming temperatures of our earth. The effects of these can be seen today and their influence will be magnified in the not-so-distant future. But the most dangerous threat we face from global warming is the spread of disease.

The term global warming refers to an unnatural and accelerated increase in temperature. These increases are mostly due to the release of heat trapping gases such as methane, nitrous oxide, halocarbons, and…show more content…

To create fear, the campaign charges that limiting carbon emissions would be exorbitantly expensive...To sow doubt, the fossil fuel industries take alleged “uncertainties” in climate science out of context, blow them up out of proportion, and use them to stir up skepticism.(60)

These oil companies quietly fund groups that sound like environmental organizations but are actually used to further their cause. They also pay scientists to try and fool the public. One example is Dr. S. Fred Singer who has received somewhere around 165,000 dollars from companies including Exxon, Shell, UNOCAL, ARCO, and Sun Oil (Berger 62). Unfortunately there is a long list of organizations, publications, think tanks, and even so called scientists that are funded by the oil companies in an attempt to misinform and even endanger the public because of their own self-interest. These are the people telling us that global warming is not harmful, is not a problem, is not even real. But scientist who have been studying diseases like malaria, cholera, and dengue fever know differently.

We face a horrifying variety of illnesses that are being spread to areas where they never previously existed due to the warmer, more hospitable climates that are spreading northward. New Scientist magazine stated, “human disease is emerging as one of the most sensitive, and distressing,

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The effects of global warming include its effects on human health.[1][2] The observed and projected increased frequency and severity of climate related impacts will further exacerbate the effects on human health.[3][4] This article describes some of those effects on individuals and populations.

Impact on disease[edit]

Impact on vascular disease[edit]

A good example of the impact of global warming on health can be seen in the disease Erythromelalgia.[5] This is a vascular disease that is commonly triggered by the involvement of change in temperature, which leads to syndromes including (first and second degree) burning pain, increased temperature, erythema and swelling, of mainly the hands and feet that are affected.[5]

In a Chinese study, epidemic Erythromelalgia appears quite common in southern China, most likely due to a sharp decline in temperature following by a rapid increase of temperature and the effects this has on the body.[5] The acral small superficial arteries intensely constrict and dilate during the sharp decline of temperature, whereas a sharp increase of temperature, the intense expansion of capillaries irritate the nerve endings around, and thus lead to syndromes including burning pain, increased temperature, erythema and swelling.[5] As climate change proceeds, more Erythromelalgia outbreaks may occur because of the extreme weather events that are projected to increase in coming decades.[5]

Impact on infectious diseases[edit]

Warming oceans and a changing climate are resulting in extreme weather patterns which have brought about an increase of infectious diseases—both new and re-emerging.[6][7] These extreme weather patterns are creating extended rainy seasons in some areas,[8] and extended periods of drought in others,[9] as well as introducing new climates to different regions.[9] These extended seasons are creating climates that are able to sustain vectors for longer periods of time, allowing them to multiply rapidly, and also creating climates that are allowing the introduction and survival of new vectors.[6]

Impact of extreme weather[edit]

“The rise of extreme weather is itself a symptom of an unstable climate. Moreover, the variance around the long-term warming trend has begun to influence biological systems, Indeed, two main effects of climate change—warming and greater weather variability-mean that millions of people worldwide face a higher risk of infectious disease”.[8]El Nino is an extreme weather pattern that is often responsible for increased precipitation, resulting in increased flooding, creating a more promising breeding ground for a plethora of vectors that both carry and cause infectious diseases.[10]

Another result of the warming oceans are stronger hurricanes, which will wreak more havoc on land, and in the oceans,[10] and create more opportunities for vectors to breed and infectious diseases to flourish.[6][8]Extreme weather also means stronger winds. These winds can carry vectors tens of thousands of kilometers, resulting in an introduction of new infectious agents to regions that have never seen them before, making the humans in these regions even more susceptible.[6]

Impact of warmer and wetter climates[edit]

Mosquito-borne diseases are probably the greatest threat to humans as they include malaria, elephantiasis, Rift Valley fever, yellow fever, and dengue fever.[11][12][13] Studies are showing higher prevalence of these diseases in areas that have experienced extreme flooding and drought.[11][12] Flooding creates more standing water for mosquitoes to breed; as well, shown that these vectors are able to feed more and grow faster in warmer climates.[6] As the climate warms over the oceans and coastal regions, warmer temperatures are also creeping up to higher elevations allowing mosquitoes to survive in areas they had never been able to before.[6] As the climate continues to warm there is a risk that malaria will make a return to the developed world.[6]

Ticks are also thriving in the warmer temperatures allowing them to feed and grow at a faster rate.[14] The black legged tick, a carrier of Lyme disease, when not feeding, spends its time burrowed in soil absorbing moisture.[8][15] Ticks die when the climate either becomes too cold or when the climate becomes too dry, causing the ticks to dry out.[8][15] The natural environmental controls that used to keep the tick populations in check are disappearing, and warmer and wetter climates are allowing the ticks to breed and grow at an alarming rate, resulting in an increase in Lyme disease, both in existing areas and in areas where it has not been seen before.[8][14]

Another impact that the warming global temperature has had is on the frequency and severity of heat waves. In addition to dehydration and heat stroke, these heat waves have also resulted in epidemics of Chronic Kidney Disease (CKD). Recent studies have shown that prolonged heat exposure, physical exertion, and dehydration are sufficient factors to developing CKD.[16] These cases are occurring across the world congruently with heat stress nephropathy.

Other diseases on the rise due to extreme weather include hantavirus,[17]schistosomiasis,[12][13]onchocerciasis (river blindness),[13] and tuberculosis.[7] It also causes the rise in hay fever, as when the weather gets warmer there is a rise in pollen levels in the air.[18]

Because of the wet-bulb temperature, parts of the globe could become uninhabitable.[19]

Warmer temperatures may also lead an increase in aggression levels. Research has shows links between higher temperatures and increased aggressive and criminal behaviour. Which can be seen by the rise in the rate of criminality during the warmer summer months.[20]

Impact of warmer oceans[edit]

The warming oceans are becoming a breeding ground for toxic algae blooms (also known as red tides) and cholera.[6][13][21] As the nitrogen and phosphorus levels in the oceans increase, the cholera bacteria that lives within zooplankton emerge from their dormant state.[21] The changing winds and changing ocean currents push the zooplankton toward the coastline, carrying the cholera bacteria, which then contaminate drinking water, causing cholera outbreaks.[21] As flooding increases there is also an increase in cholera epidemics as the flood waters that are carrying the bacteria are infiltrating the drinking water supply.[22] El Nino has also been linked with cholera outbreaks because this weather pattern warms the shoreline waters, causing the cholera bacteria to multiply rapidly.[21][22]

Toxic algae blooms (red tides) are the result of a changing and warming climate.[23] El Nino events precipitation resulting in flooding, which causes the coastal seawater to be infiltrated with runoff from the flooding land resulting in increased nitrogen and phosphorus which feed the algae and spur their growth.[24] These toxic blooms in turn infect shellfish, which threatens the health of the millions of people who depend on shellfish for protein.[24] Paralytic shellfish poisoning is the most common result of red tides, as was seen in the 1987 outbreak in Prince Edward Island.[24]Ciguatera fish poisoning is also a result of red tides.[25] Humans that ingest these infected reef dwelling fish become ill.[25] Further, red tides are so powerful that they also cause respiratory illness simply by breathing the air near them.[24]

Malaria[edit]

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.[26] The disease causes symptoms that typically include fever, headache, shaking chills, anemia, and in severe cases can progress to coma or death.

'About 3.2 billion people – nearly half of the world's population – are at risk of malaria. In 2015, there were roughly 214 million malaria cases and an estimated 438,000 malaria deaths.' [27]

Climate is an influential driving force of vector-borne diseases such as malaria. Malaria is especially susceptible to the effects of climate change because mosquitoes lack the mechanisms to regulate their internal temperature. This implies that there is a limited range of climatic conditions within which the pathogen (malaria) and vector (a mosquito) can survive, reproduce and infect hosts.[28] 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.[28] Changes in climate factors substantially affect reproduction, development, distribution and seasonal transmissions of malaria.

Mosquitoes have a small window for preferential conditions for breeding and maturation. The ultimate breeding and maturing temperature for mosquitoes range from sixteen to eighteen degrees Celsius.[29] If the temperature is decreased by two degrees, most of the insects will succumb to death. This is why malaria is unsustainable in places with cool winters. If a climate with an average of approximately 16 degrees Celsius experiences an increase of about two degrees, the mature bugs and the larvae flourish.[6] Female mosquitoes will need more food (human/animal blood) to sustain life and to stimulate production of eggs. This increases the chance of spread of malaria due to more human contact and a higher number of the blood sucking insects surviving and living longer. 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.[30] These prime temperatures are creating large breeding grounds for the insects and places for the larvae to mature. Increased temperature is causing snow to melt and stagnant pools of water to become more common.[6] Bugs that are already carrying the disease are more likely to multiply and infect other mosquitoes causing a dangerous spread of the deadly disease.

Climate change has a direct impact on people’s health in places where Malaria is not prevalent. In communities of higher altitudes in Africa and South America, people are at higher risk for developing malaria in recent years because of an increase temperature. Mosquitos are sensitive to temperature changes and the warming of their environment will boost their rates of production.[31] A fluctuation of two or three degrees is creating exceptional breeding grounds for mosquitoes, for larvae to grow and mature mosquitoes carrying the virus to infect people that have never been exposed before.[6] This is a severe problem because people in these communities have never been exposed to this disease causing an increased risk for complications from malaria such as cerebral malaria (a type of malaria that causes mental disability, paralysis and has a high mortality rate) and death by the disease.[6] Residents of these communities are being hit hard by malaria because they are unfamiliar with it; they do not know the signs and symptoms and have little to no immunity.

The population at risk of malaria in the absence of climate change is projected to double between 1990 and 2080 to 8820 million, however; unmitigated climate change would, by the 2080s, further increase the population at risk of malaria by another 257 to 323 million.[32] Therefore, reducing the effects of climate change in the present would reduce the total by about 3.5%, saving tens of thousands of lives worldwide.

If there is a slight discrepancy in the normal temperature, the perfect conditions for the insects to multiply are created. People that have never been infected before are unknowingly at risk for this deadly disease and do not have the immunity to combat it.[6] An increase in temperature has the potential to cause a widespread epidemic of the disease that has the capacity to wipe out entire populations of people. It is important to track the prevalence, species and number of insects carrying the disease as well as the number of humans infected in countries and places that have never seen malaria before. It is simple for the slightest of fluctuation in temperature to cause a catastrophic epidemic that has the possibility to end the lives of many innocent and unsuspecting people.[29]

Dengue fever[edit]

Dengue fever is an infectious disease caused by dengue viruses known to be in the tropical regions.[33] It is transmitted by the mosquito Aedes, or A. aegypti.[34]

The cases of dengue fever have increased dramatically since the 1970s and it continues to become more prevalent.[33] The greater incidence of this disease is believed to be due to a combination of urbanization, population growth, increased international travel, and global warming.[35] The same trends also led to the spread of different serotypes of the disease to new areas, and to the emergence of dengue hemorrhagic fever. There are four different types of viruses in dengue fever. If someone is infected with one type of dengue virus, he or she will have permanent immunity to that type of dengue virus, but will have short term immunity to the other type of dengue fever.[33] Some of the symptoms of dengue fever are fever, headache, muscle and joint pains and skin rash.[36] There is no vaccine for dengue fever right now and there is no true treatment to get rid of it, but there are treatments to assist with some of the work of dengue, such as the use of oral or intravenous fluids for rehydration.[36]

Dengue fever used to be considered a tropical disease, but climate change is causing dengue fever to spread. Dengue fever is transmitted by certain types of mosquitoes, which have been spreading further and further north. This is because some of the climate changes that are occurring are increased heat, precipitation and humidity which create prime breeding grounds for mosquitoes.[37] The hotter and wetter a climate is, the faster the mosquitoes can mature and the faster the disease can develop. Another influence is the changing El Nino effects that are affecting the climate to change in different areas of the world, causing dengue fever to be able to spread.[38]

There are many things that can be done, both on a governmental level and on an individual basis. One improvement would be having a better system of detecting when dengue outbreaks may happen. This can be done by monitoring environments, such as temperatures, rainfall and humidity that would be attractive to these types of mosquitoes and help them to flourish. Another useful plan is to educate the public by letting them know when a dengue outbreak is occurring and what they can do to protect themselves. For example, people should create a living environment that is not attractive to mosquitoes (no standing water), dress in appropriate clothing (light colours, long sleeves), and wear insect repellent.

HIV/AIDS[edit]

HIV/AIDS and climate change are both long wave issues that cause fear and uncertainty in the population. One of the main reasons why climate change appears to have such an impact on HIV/AIDS seems to be related to food shortage. “In the fight against hunger we could now be facing a perfect storm of challenges, including climate change and increasingly severe droughts and floods, soaring food prices and the tightest supplies in recent history, declining levels of food aid, and HIV/AIDS, which also aggravates food insecurity” says Sheeran.[39] The lack of food security, due to climate change, in South Africa has been affected by HIV/AIDS. In Sub-Saharan Africa over 70% of the population are farmers and human capital has decreased due to HIV/AIDS.[40] “This reduction in the household labour capabilities severely decreases agricultural output. The source of nourishment and income for the bulk of Sub-Saharan Africa’s population, agricultural output, is further hurt by a loss in the transfer of intergenerational knowledge, as the productive adult population with experience in agricultural labour is the most severely affected by AIDS”.[40] This has been made worse as 90% of the people infected with HIV/AIDS in sub-Saharan Africa are adults. This not only greatly reduces human capital, but it leaves many children to tend to themselves. Malnutrition, brought about by food security in Sub-Saharan Africa, exacerbates the effects of HIV/AIDS.[40] A study done in Ethiopia showed that chronic malnutrition was a predictor of first line antiretroviral therapy failure.[41] This has the potential to create more HIV deaths each year, as immune capabilities are further weakened by malnutrition. Another important factor about food insecurity is that it could increase the spread of HIV/AIDS from the use of transactional sex. Women who are desperate and suffer malnutrition are more likely to sell their bodies in order to support themselves. Also food insecurity and poverty may prevent people from seeking a diagnosis or prevent them from having the ability to afford treatment.

Secondly, the spread of malaria due to climate change will also be degrading to the burden of the disease of HIV/AIDS.[42] As people become infected by HIV/AIDS and are then exposed to malaria, it will create an even more substantial loss of life because AIDS victims will be less likely to be able to fight the malarial infection.

Climate change may also increase the spread of HIV/AIDS. As climate change disasters sweep the globe, more people will become displaced, and be forced to live in close quarters to one another. There is evidence to suggest that this could “aggravate gender inequalities"[42] that have the potential to raise the possibility of transmission of the disease. Migrants often have poor living conditions, are separated from their spouses and families, perform demanding and dangerous jobs and have limited access to health care.[43] This can all lead to an increased risk of contracting HIV/AIDS.

Lastly, climate change will reduce the funds available to mitigate HIV/AIDS. As more money is spent on repairing infrastructure due the increasing nature of extreme weather, less money will be available for programs to prevent HIV/AIDS and to look after those that are already infected.[44] This is especially true in underdeveloped countries where they are least able to cope. The governments in these countries are less able to provide for their populations, and will even more under strain from the climate change related costs. This raises the possibility of bankrupt countries that may leed to the Failed state phenomenon. The twin effects of HIV/AIDS and climate change therefore will be degrading to human health.

Impact on mental health[edit]

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.[45] According to 2011 in American Psychologist Clayton & Doherty, concluded that global climate change is bound to have substantial negative impacts on mental health and wellbeing, effects which will primarily be felt by vulnerable populations and those with pre-existing serious mental illness.[46] Research done by Berry, Bowen, and Kjellstrom in 2008 found that climate change exposes populations to trauma, which negatively impacts mental health in very serious ways.[47] Both the Clayton study and the Berry study identify three classes of psychological impacts from global climate change: direct, indirect, and psychosocial.[46][47] The Clayton study claims that in order to appreciate these impacts on psychological wellbeing, a basic understanding of certain aspects is required. One must recognize the multiple meanings and cultural narratives associated with climate change, as well as how climate change, global phenomena like increased population, are interrelated. Climate change does not impact everyone equally; those of lower economic and social status are at greater risk and experience more devastating impacts.[46]

Direct impacts[edit]

Direct impacts on mental health happen when a community experiences extreme weather and changed environment.[46] Direct impacts like landscape changes, impaired place attachment, and psychological trauma are all immediate and localized problems resulting from extreme weather events and environmental changes.[46] Extreme weather events cause negative changes to landscape and agriculture. This leads to communities facing economic aspects, especially for communities that use agriculture as a main source of income. After economic fall, communities face loss of livelihoods and poverty. Many communities will also face isolation, alienation, grief, bereavement, and displacement from these effects.[47][48] Individuals will have an increased rate of anxiety and emotional stress. The rate of effects on mental health increases in already-vulnerable communities.[48] Clayton reinforces that the more powerful the extreme weather event, and the more frequent these weather events are, the more damage is done to the mental health of the community.[46] Some of the extreme weather events responsible for these mental health changes include wildfires,[48] earthquakes, hurricanes, fires, floods,[47] and extreme heat.[49]

Indirect impacts[edit]

Indirect impacts on mental health occur via impacts on physical health and community wellbeing. Physical health and mental health have a reciprocal relationship.[47] If the physical health of an individual is negatively impacted, the decline in mental health will soon follow.[47] These impacts are more gradual and cumulative. They are threats to emotional wellbeing through concern and uncertainty about future risks.[46] They are also large-scale community and social effects, like conflicts related to migration and subsequent shortages or adjustment after a disaster. Extreme weather events play a major role here; their impacts can be indirect, not just direct.[47] This is due to the effect on physical health from extreme weather events. Each extreme weather event effects humans in different ways, but they all lead to the decline of mental health.[47]Heat indirectly causes mental health issues through physical health issues. The World Health Organization presents the fact that high extreme heat is directly related to certain ailments like cardiovascular disease, respiratory disease, and asthma. One piece of their evidence is that in summer 2003, during Europe’s big heat wave, there were 70,000 recorded deaths related to the heat.[49] Heat exhaustion also occurs during extreme heat. As climate change continues, heat will continue to rise and these problems will exacerbate. These physical problems lead to mental health problems. As physical health worsens and is less curable, mental stability starts to deteriorate.[47]

As extreme heat makes landscapes dry, nature is more prone to fire. Research shows that rising heat due to climate change has caused an increase in fires around the United States.[50]Burns and smoke inhalation from the increasing number of fires lead to a decline in physical health, which leads to mental health problems. Deaths of family and friends cause individuals to suffer from stress and other conditions. Many suffering from loss of family and friends will internalize their emotions, feel extreme guilt and helplessness, and become paranoid. Others will develop fear of future loss and have an overall displacement of feelings that could last for years.[51] Anderson published research in the American Psychological Association that shows the increase in murders in the United States directly correlates with the temperature increase. For every one-degree Fahrenheit, there will be nine more murders in the country, which leads to an additional 24,000 murders or assaults per year in the United States.[52]

There is also an increased risk in suicide in communities that suffer from extreme weather events. Studies show that suicide rates increase after extreme weather events. This is evidence for the decline in mental health.[53] The increased suicide risk has been demonstrated in Australia, where drought has resulted in crop failures and despair to the Australian countryside. After the event, farmers were left with almost nothing. They were forced to sell their belongings, reduce their stock, and borrow large sums of money to plant crops at the start of the next season.[53] These consequences have caused a growing increase in depression, domestic violence, and suicide. More than one hundred farmers in the Australian countryside had committed suicide by 2007.[53] An individual’s suicide often leads to mental health problems of loved ones. They face issues like those who have lost loved ones due to fire: grief, sadness, anger, paranoia, and others.[51]

Some impacts pertaining to mental health are even more gradual and cumulative than the others, like social interaction, media, and communication.[46] The social interaction between communities and within communities is greatly affected by migration. Communities choose to migrate, or are forced to migrate, due to stressors on limited resources. This is worsened by extreme weather events caused by climate change.[48] Common mental health conditions associated indirectly from these extreme weather events include acute traumatic stress, post-traumatic stress disorder, depression, complicated grief, anxiety disorders, sleep difficulties, and sexual dysfunction. Drug abuse and alcohol abuse are also common aftereffects, and can lead to both physical and mental issues, addiction and substance reliance being the most common.[48]

The effects of Hurricane Katrina, a past extreme weather event in New Orleans, lead to a variety of mental health problems due to the destruction of resources[53] Many people impacted by Hurricane Katrina were left homeless, disenfranchised, stressed, and suffering physical illness. This strain on the public health system decreased access and availability of medical resources.[53] 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.[48] 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. Less medication and medical resources means fewer people can get the help they need to recover. Slowed recovery and lack of recovery worsen overall mental health.[48]

Psychosocial impacts[edit]

Psychological impacts are the effects that heat, drought, migrations, and climate-related conflicts have on social life and community life. This includes post-disaster adjustment.[46] Most of these effects are indirect instead of direct, but Clayton and Berry place them in a separate category because they deal with the relationships within a community.[47][46] Many of the results are from how people use and occupy territory.[46] Human migration of large communities causes discord within those communities because the already scarce resources are even more limited during migration.[48] Agriculture and aquaculture are severely impacted by the extreme weather events of climate change, the suitability of territory being the most notable kind of change.[46] During and after migration, the geographical distribution of populations is altered.[46] Children and parents may be separated at these times. The early separation of kids from their parents can cause symptoms of grieving, depression, and detachment in both the young and old.[51] The loss in resources can also lead to inter-community violence and aggression. Two groups may fight over remaining natural resources. A community may choose to migrate to find better resources, and encroach on another community’s territory, either accidentally or purposefully.[46] Civil unrest can occur when governments fail to adequately protect communities against the extreme weather events that cause these effects. When this happens, individuals lose confidence and trust in their government. A loss in trust can be the beginning of oncoming mental health problems.[51][54] The disruption of a community when they are forced to relocate results in the deterioration of geographic and social connections. This leads to grief, anxiety, and an overall sense of loss.[55]

Climate change and permafrost[edit]

Permafrost is an important part of our environment and plays an important role in maintaining the stability of many ecosystems around the world. Below are a few brief descriptions of how climate change has contributed to the melting of permafrost and the associated impacts on different aspects of ecosystems.

Fresh water supplies[edit]

Permafrost plays and integral role in the regulation of fresh water supplies in the arctic and high alpine regions.[56] Three general ground water systems found in permafrost regions include supra-permafrost, intra-permafrost and sub-permafrost.[56] Supra-permafrost system involves the water that is present above the frozen ground layer.[56] Intra-permafrost water system involves the water present within channels or holes that run through the frozen ground layer.[56] Supra-permafrost water systems exist below the frozen layer of earth.[56] Together, these systems regulate and support aquifer water supply as well as above ground fresh water sources such as lakes and streams.[56] When permafrost melts many freshwater lakes drain into the newly exposed soil below.[56] The surrounding ecosystems are affected as arctic lakes provide important habitat for migratory waterfowl, ungulates such as moose and many aquatic species.[57] Fresh water evaporation also occurs as permafrost melts.[56] When the frozen ground disappears, associated surface air temperatures increase causing increased evaporation of fresh water supplies. Increased ground surface temperature also increases the rate of spring glacier melt.[56] This associated increase in freshet causes water to run over soil and into muskeg areas where the water stagnates and becomes acidic.[56] Once the acidified water enters into aquatic systems, it impacts the associated ecosystem.[56]

Plants[edit]

There is a strong interdependence between permafrost and vegetation in permafrost regions.[58] The melting of permafrost has a significant effect on soils, such as the moisture content and the availability of nutrients. Permafrost functions to serve terrestrial ecosystems; when permafrost thaws it decreases the number of species that can grow in the low temperatures and high moisture soils.[58] The effects that thawing permafrost has on vegetation greatly depends on the depth of the regions active layer.[58] In some regions the thawing of permafrost leads to increased soil drainage and in others it leads to increased soil moisture; both causing changes to the dominant species in an area.[58] In areas where the thawing permafrost causes increased soil drainage, wet plant species like Kobresia tibetica and Kobresia humilis decrease and drought plants such as Poa annua and Agropyron cristatum begin to take over.[58] Unfortunately the decreased soil moisture leads to the disappearance of Alpine meadows and creates Alpine deserts.[58] As Ice-rich permafrost regions begin to thaw the terrestrial ecosystems turn to aquatic or wetland ecosystems.[58] Due to this process “wet sedge meadows, bogs, thermokarst ponds and lakes are replacing forests”.[58] In Alaska the permafrost degradation has caused a decrease in birch forests by 25%.[58] Permafrost degradation in the lowlands of Alaska has caused tussock-tundra communities to turn into shrub-tundra communities.[58] Shrubs and woody plants are extending their northern ecological range and encroaching on lichen-dominated ecosystems.[57]

As a result, the number of lichens found in the affected areas decrease.[57] This affects the entire ecosystem, as lichens are a vital food source for caribou that are commonly found in arctic regions.[57] The degradation of permafrost and its effects on vegetation is a complex and intricate cycle; thus far the thawing permafrost has two major effects on vegetation: 1. Permafrost thaw in ice-rich soils equates to a loss of terrestrial ecosystems and an increase in aquatic or wetland ecosystems. 2. Permafrost thawing in the upland regions results in improved soil drainage leading to the alpine meadows undergoing a transformation to either shrub communities or drought communities.[58]

Soil sustainability[edit]

Permafrost is integral to soil stability in arctic regions.[59] Melting permafrost causes the surrounding soil to become unstable and settle.[59] As permafrost melts, surrounding lakeshore destabilization takes place.[60] Consequently, bank materials slump into the lakes decreasing oxygen concentration.[56] As a result, water temperature increases which allows bacteria to flourish.[56] The abundant bacteria produce carbon dioxide and methane gas causing the lakes and ponds to produce a significant source of greenhouse gas.[56] This increased methane release is further amplified as melting permafrost exposes previously buried soil. Methane and carbon dioxide stored in the organic matter seep into the atmosphere and contribute further to the climate change problem.[56] Similar to lake shore destabilization, melting permafrost causes bank materials to slump into river water which causes sedimentation of fish bearing streams and adversely effects habitat and health of salmon and other aquatic species.[61] Settlement of surface soil associated with melting permafrost leads to significant infrastructure instability and damage to roads, bridges, buildings, homes, pipelines and airstrips in affected areas.[59]

Impact on natural resources[edit]

Drinking water[edit]

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.[62]

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.[63]

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.[64] During drought, water supplies are even more susceptible to harmful algal blooms and microorganisms.[65] 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 Celsius), 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.[66][67][68]

Fresh water[edit]

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.[69]

Food depletion[edit]

Further information: Effects of global warming on agriculture

Impact on livestock[edit]

Climate change is beginning to lead the global population into a food shortage, greatly affecting our livestock supply. Although the change in our climate is causing us to lose food, these sources are also contributing to climate change, essentially, creating a feedback loop. Greenhouse gases, specifically from livestock, are one of the leading sources furthering global warming; these emissions, which drastically effect climatic change, are also beginning to harm our livestock in ways we could never imagine.

Greenhouse gas effects[edit]

Our agricultural food system is responsible for a significant amount of the greenhouse-gas emissions that are produced.[70][71]

According to the IPCC, it makes up between, at least, 10-12% of the emissions, and when there are changes in land due to the agriculture, it can even rise as high as 17%. More specifically, emissions from farms, such as nitrous oxide, methane and carbon dioxide, are the main culprits, and can be held accountable for up to half of the greenhouse-gases produced by the overall food industry, or 80% of all emissions just within agriculture.[71]

The types of farm animals, as well as the food they supply can be put into two categories: monogastric and ruminant. Typically, beef and dairy, in other words, ruminant products, rank high in greenhouse-gas emissions; monogastric, or pigs and poultry-related foods, are low. The consumption of the monogastric types, therefore, yield less emissions. This is due to the fact that these types of animals have a higher feed-conversion efficiency, and also do not produce any methane.[71]

As lower-income countries begin, and continue, to develop, the necessity for a consistent meat supply will increase.[71][72] This means the cattle population will be required to grow in order to keep up with the demand, producing the highest possible rate of greenhouse-gas emissions.[71]

There are many strategies that can be used to help soften the effects, and the further production of greenhouse-gas emissions. Some of these strategies include a higher efficiency in livestock farming, which includes management, as well as technology; a more effective process of managing manure; a lower dependence upon fossil-fuels and nonrenewable resources; a variation in the animals' eating and drinking duration, time and location; and a cutback in both the production and consumption of animal-sourced foods.[71][72][73][74]

Heat stress[edit]

Heat stress on livestock has a devastating effect on not only their growth and reproduction, but their food intake and production of dairy and meat. Cattle require a temperature range of 5-15 degrees Celsius, but upwards to 25 °C, to live comfortably, and once climate change increases the temperature, the chance of these changes occurring increases.[72] Once the high temperatures hit, the livestock struggle to keep up their metabolism, resulting in decreased food intake, lowered activity rate, and a drop in weight. This causes a decline in livestock productivity and can be detrimental to the farmers and consumers. Obviously, the location and species of the livestock varies and therefore the effects of heat vary between them. This is noted in livestock at a higher elevation and in the tropics, of which have a generally increased effect from climate change. Livestock in a higher elevation are very vulnerable to high heat and are not well adapted to those changes.

Impact on plant based food[edit]

Climate change has many potential impacts on the production of food crops—from food scarcity and nutrient deficiency to possible increased food production because of elevated carbon dioxide (CO2) levels—all of which directly affect human health. Part of this variability in possible outcomes is from the various climate change models used to project potential impacts; each model takes into account different factors and so come out with a slightly different result.[75] A second problem comes from the fact that projections are made based on historical data which is not necessarily helpful in accurate forecasting as changes are occurring exponentially.[76][77] As such, there are many different possible impacts—both positive and negative—that may result from climate change affecting global regions in different ways.[77][78]

Food scarcity[edit]

Food scarcity is a major key for many populations and is one of the prominent concerns with the changing climate. Currently, 1/6 of the global population are without adequate food supply.[79] By 2050, the global population is projected to reach 9 billion requiring global food productions to increase by 50% to meet population demand.[79][80] In short, food scarcity is a growing concern that, according to many researchers, is projected to worsen with climate change because of a number of factors including extreme weather events and an increase in pests and pathogens.

Extreme weather[edit]

Rising temperatures[edit]

As the temperature changes and weather patterns become more extreme, areas which were historically good for farmland will no longer be as amicable.[81][82] The current prediction is for temperature increase and precipitation decrease for major arid and semi-arid regions (Middle East, Africa, Australia, Southwest United States, and Southern Europe).[81][83] In addition, crop yields in tropical regions will be negatively affected by the projected moderate increase in temperature (1-2 °C) expected to occur during the first half of the century.[84] During the second half of the century, further warming is projected to decrease crop yields in all regions including Canada and Northern United States.[83] Many staple crops are extremely sensitive to heat and when temperatures rise over 36 °C, soybean seedlings are killed and corn pollen loses its vitality.[76][85] Scientists project that an annual increase of 1 °C will in turn decrease wheat, rice and corn yields by 10%.[83][86]

There are, however, some positive possible aspects to climate change as well. The projected increase in temperature during the first half of the century (1-3 °C) is expected to benefit crop and pasture yields in the temperate regions.[75][76][87] This will lead to higher winter temperatures and more frost-free days in these regions; resulting in a longer growing season, increased thermal resources and accelerated maturation.[77][78] If the climate scenario results in mild and wet weather, some areas and crops will suffer, but many may benefit from this.[75]

Drought and flood[edit]

This alpine valley is entirely above the tree line
Freshet in Pangnirtung, Nunavut -f
Lichen-covered tree, Tresco

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