INTRODUCTION:

Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. This is a type of greenhouse effect. Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as "forcing" climate change.

Gases, such as water vapor, which respond physically or chemically to changes in temperature, are seen as "feedbacks."

Gases that contribute to the greenhouse effect include:

Water Vapour:

Water vapour increases as the Earth's atmosphere warms, but so does the possibility of clouds and precipitation, making these some of the most important feedback mechanisms to the greenhouse effect.

Carbon Dioxide (CO₂):

A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO₂ concentration by more than a third since the Industrial Revolution began. This is the most important long-lived "forcing" of climate change.

Methane:

A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as ruminant digestion and manure management associated with domestic livestock.

Nitrous Oxide:

A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning.

Chlorofluorocarbons (CFCs):

Synthetic compounds entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to destruction of the ozone layer. They are also greenhouse gases.

A stronger greenhouse effect will warm the oceans and partially melt glaciers and other ice, increasing sea level. Ocean water also will expand if it warms, contributing further to sea level rise.

Fig: Climate Change Effects on Earth

The Role of Human Activity:

The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to 400 parts per million in the last 150 years. The review also concluded that there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earth's temperatures over the past 50 years.

Solar Irradiance:

It's reasonable to assume that changes in the sun's energy output would cause the climate to change, since the sun is the fundamental source of energy that drives our climate system.

Fig: Process of Global Warming

But several lines of evidence show that current global warming cannot be explained by changes in energy from the sun:

Since 1750, the average amount of energy coming from the sun either remained constant or increased slightly.

If the warming were caused by a more active sun, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead, they have observed a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. That's because greenhouse gases are trapping heat in the lower atmosphere.

Causes of Global Warming:

Global warming is the increase in the earth’s average temperature due to release of several greenhouse gases to the atmosphere by humans. Global warming is affecting many parts of the world. Due to global warming, the glaciers are melting which is causing the rise in the sea level. When the level of the sea rises, it causes danger to the people living in the low lying areas.

When the level of the sea rises, it covers the plants and causes some of them to die. When they die, animals lose their main source of food. We, human beings lose our two sources of food, plants and animals. It may also force people to lose their homes. In other words, the whole chain will get affected if nothing is done on time to stop global warming from spreading its wings.

1. Forest Fires:

Deforestation by nature is another leading cause of global warming. Natural forest fires are usually televised on the news, showing the devastation of mountain homes and communities. While this loss is tragic, the effects of these natural occurring forest fires pose a problem for the earth’s air. Forest fires emit carbon-filled smoke into the atmosphere, and new forests’ growth is slow and not stable enough to produce the much needed oxygen into the newly, suffocating carbon air. Natural forest fires will eventually run their course, but left in the ashes are polluting gases that get trapped in the atmosphere.

2. Permafrost:

When frozen soil, constituting about 25% of the Northern Hemisphere, increases, it keeps in the carbon and methane gases. So, while you may be thinking how it can be global warming when you’re still freezing in Tibet, the permafrost is actually leaking carbon into the earth’s atmosphere. While scientists cannot stop permafrost from emitting these gases, the earth’s melting icecaps at incredibly fast rates, are cause for concern.

3. Sunspots:

According to the Environment Protectio Agency (EPA), sunspots are increasing global temperature. Sunspots restrict the passing of solar plasma, which in affect gives off radiation. You don’t have to work for NASA to know radiation is a bad thing. Sunspots and solar flares are powerful and unstoppable. They can change the energy radiating to earth’s atmosphere, and thus increase climate temperature. Solar flares, however have been a natural occurring event for millions of years.

4. Water Vapour:

The two-thirds of the gases stuck in the thick blanket is in the form of water vapour (NASA). This hitch in tow effect means rising temperature, rising vapor. The water vapor is unable to escape, and thus results in hotter climate changes.

5. Man-induced Deforestation:

Deforestation is the cutting down of trees and plants to make way for any development activity. Mother nature taking out an entire forest is one thing, but man doing it for the use of crop cultivation, fuel, and other consumption, is another. Each day our forests are bulldozed for the prospect of farms and factories. Fuel used for wood and charcoal only adds to the polluted gases in the atmosphere. Our consumer commodities provided by forestry includes paper and lumber. The loss of our forests results in a chain reaction where too much carbon is released into the air, with not enough oxygen to combat it.

This means that it is very important to protect our trees to stop the greenhouse effect, and also so we can breathe and live. Deforestation is blamed for rise in the greenhouse gases present in the atmosphere by cutting or burning them. New development projects, requirement of land for homes and factories, requirement for wood and also soil erosion are the major factors that are causing deforestation, which in turn leading to global warming.

6. Fossil Fuels:

Pollution whether it is vehicular, electrical or industrial is the main contributor to the global warming. Everyday billions of vehicles release various gases into the atmosphere. This causes earth to warm up and increase its average temperature. Electricity causes pollution in many ways. Over 75% of the electricity worldwide is produced by burning of fossil fuels. Many gases are sent into the air when fossil fuels are burnt of which main is the carbon dioxide gas.

Fossil fuel like coal is burnt to produce electricity. Coal is the major fuel that is burnt to produce power. Coal produces around 1.7 times as much carbon dioxide per unit of energy when flamed as does natural gas and 1.25 times as much as oil. We’re all well aware of the vast amounts of energy consumed everyday by humans everywhere since our first memories. Nearly 40% of the U.S. release of carbon dioxide is due to the burning of fossil fuels-gasoline and electricity in our homes. Finding sources for renewable energy, clean burning fuel options, and methods to cut back the amount of energy exhausted, could cut that 40% significantly.

Industries on the other hand release various gases into the water and air. Carbon dioxide, methane and nitrous oxide are the major greenhouse gases. Different gases have different heat trapping capabilities. Some of them trap more heat than carbon dioxide. Methane is much more effective then carbon dioxide in entrapping heat in the atmosphere. By driving cars, using electricity from coal fired plants and heating up our homes from natural gases, we release carbon dioxide and other heat trapping gases in the atmosphere.

7. Landfills:

When we throw garbage out of our house it goes to landfills. Landfills are those big chunks of garbage that stink and can be seen in so many places around the world. The garbage is then used by big recycling companies to make some useful products out from it. Most of the time that garbage is burnt which releases toxic gases including methane into the atmosphere. These enormous amounts of toxic greenhouse gases when go into the atmosphere make global warming worse.

8. Overpopulation:

Another cause of global warming is overpopulation. Since carbon dioxide contributes to global warming, the increase in population makes the problem worse because we breathe out more carbon dioxide in the atmosphere. More people means more demand for food, more carbon dioxide in the atmosphere, more demand for cars and more demand for homes.

More demand for food will lead to more transportation since movement of goods and services is done by transportation sector. More demand for cars means more pollution in the air and more traffic on the roads which means longer waiting time on the traffic lights and that will result in burning of more fuel. More demand for homes means cutting down of plants and trees to make way for homes, schools and colleges.

9. Mining:

Oil and coal are two main culprits in producing greenhouse gases. Methane, like carbon dioxide creates a thick shield over the atmosphere trapping the sun’s rays. With the continued use of mining operations, these harmful gases will only increase.

10. Fertilizer Use :

Think of the countless farmlands across the heartland of America. The unique thing about fertilizer is that it produces nitrous oxide once it absorbs the soil. Nitrous oxide is 300 times more dangerous than carbon dioxide. The EPA strongly warns that the farming industry’s use of fertilizer is one of the leading causes of global warming.

11. Meat Consumption:

Remember earlier when the animal world was sort of to blame for emitting carbon dioxide into the air? Well, the bigger party to blame is us. Due to our Western diet and habits, the raising, grazing, and manufacturing of animal products contributes greatly to the rise of global temperature. According to research, 51% of the greenhouse gases: methane, carbon dioxide, and nitrous oxide are caused by animal agriculture. If we would stop ordering juicy cheeseburgers, excessive amounts of carbon dioxide by animals stop emitting the atmosphere.

Impact of Global Warming on Health:

Exposure to extreme heat can lead to heat stroke and dehydration, as well as cardiovascular, respiratory, and cerebrovascular disease. Excessive heat is more likely to affect populations in northern latitudes where people are less prepared to cope with excessive temperatures. (USGCRP (2016) et al, Wasington DC) Certain types of populations are more vulnerable than others: for example, outdoor workers, student athletes, and homeless people tend to be more exposed to extreme heat because they spend more time outdoors. Low-income households and older adults may lack access to air conditioning which also increases exposure to extreme heat. Additionally, young children, pregnant women, older adults, and people with certain medical conditions are less able to regulate their body temperature and can therefore be more vulnerable to extreme heat.

Air Quality Impacts:

Changes in the climate affect the air we breathe both indoors and outdoors. Warmer temperatures and shifting weather patterns can worsen air quality, which can lead to asthma attacks and other respiratory and cardiovascular health effects. Wildfires, which are expected to continue to increase in number and severity as the climate changes, create smoke and other unhealthy air pollutants. Rising carbon dioxide levels and warmer temperatures also affect airborne allergens, such as ragweed pollen.

Increases in Ozone:

Scientists project that warmer temperatures from climate change will increase the frequency of days with unhealthy levels of ground-level ozone, a harmful air pollutant, and a component in smog.

People exposed to higher levels of ground-level ozone are at greater risk of dying prematurely or being admitted to the hospital for respiratory problems.

Ground-level ozone can damage lung tissue, reduce lung function, and inflame airways. This can aggravate asthma or other lung diseases. Children, older adults, outdoor workers, and those with asthma and other chronic lung diseases are particularly at risk. (USGCRP (2016) et al, Wasington DC)

Because warm, stagnant air tends to increase the formation of ozone, climate change is likely to increase levels of ground-level ozone in already-polluted areas of the United States and increase the number of days with poor air quality.

The higher concentrations of ozone due to climate change may result in tens to thousands of additional ozone-related illnesses and premature deaths per year by 2030 in the United States, assuming no change in projected air quality policies.

Changes in Particulate Matter:

Particulate matter is the term for a category of extremely small particles and liquid droplets suspended in the atmosphere. Fine particles include those smaller than 2.5 micrometers (about one ten-thousandth of an inch). Some particulate matter such as dust, wildfire smoke, and sea spray occur naturally, while some is created by human activities such as the burning of fossil fuels to produce energy. These particles may be emitted directly or may be formed in the atmosphere from chemical reactions of gases such as sulfur dioxide, nitrogen dioxide, and volatile organic compounds. (USGCRP (2016) et al, Wasington DC)

· Inhaling fine particles can lead to a broad range of adverse health effects, including lung cancer, chronic obstructive pulmonary disease (COPD), and cardiovascular disease.

· Climate change is expected to increase the number and severity of wildfires. Particulate matter from wildfire smoke can often be carried very long distances by the wind, affecting people who live far from the source of this air pollutant.

· Older adults are particularly sensitive to short-term particle exposure, with a higher risk of hospitalization and death. Outdoor workers like fire fighters can also have high exposure.

Due to the complex factors that influence atmospheric levels of fine particulate matter, scientists do not yet know whether climate change will increase or decrease particulate matter concentrations across the United States.Particulate matter can be removed from the air by rainfall, and precipitation is expected to increase in quantity though not necessarily frequency. Climate-related changes in stagnant air episodes, wind patterns, emissions from vegetation and the chemistry of atmospheric pollutants will also affect particulate matter levels.

Changes in Allergens and Asthma Triggers:

Climate change may affect allergies and respiratory health. The spring pollen season is already occurring earlier in the United States for certain types of plants, and the length of the season has increased for some plants with highly allergenic pollen such as ragweed. In addition to lengthening the ragweed pollen season, rising carbon dioxide concentrations and temperatures may also lead to earlier flowering, more flowers, and increased pollen levels in ragweed.

Impacts from Extreme Weather Events:

Increases in the frequency or severity of some extreme weather events, such as extreme precipitation, flooding, droughts, and storms, threaten the health of people during and after the event. The people most at risk include young children, older adults, people with disabilities or medical conditions, and the poor. Extreme events can affect human health in a number of ways by:

· Hurricane Katrina was one of the most devastating hurricanes in the United States, responsible for an estimated 971 to 1,300 deaths.

· Damaging roads and bridges, disrupting access to hospitals and pharmacies.

· Interrupting communication, utility, and health care services.

· Contributing to carbon monoxide poisoning from improper use of portable electric generators during and after storms.

· Increasing stomach and intestinal illness, particularly following power outages.

Creating or worsening mental health impacts such as depression and post-traumatic stress disorder (PTSD).

In addition, emergency evacuations pose health risks to older adults, especially those with limited mobility who cannot use elevators during power outages. Evacuations may be complicated by the need for concurrent transfer of medical records, medications, and medical equipment. Some individuals with disabilities may also be disproportionally affected if they are unable to access evacuation routes, have difficulty in understanding or receiving warnings of impending danger, or have limited ability to communicate their needs. USGCRP (2016) et al, Wasington DC)

Vector borne Diseases:

Vector borne diseases are illnesses that are transmitted by disease vectors, which include mosquitoes, ticks, and fleas. These vectors can carry infectious pathogens, such as viruses, bacteria, and protozoa, from animals to humans. Changes in temperature, precipitation, and extreme events increases the geographic range of diseases spread by vectors and can lead to illnesses occurring earlier in the year. The geographic range of ticks that carry Lyme disease is limited by temperature. As air temperatures rise, ticks are likely to become active earlier in the season, and their range is likely to continue to expand northward. Typical symptoms of Lyme disease include fever, headache, fatigue, and a characteristic skin rash.

The spread of climate-sensitive diseases will depend on both climate and non-climate factors such as land use, socioeconomic and cultural conditions, pest control, access to health care, and human responses to disease risk. The United States has public health infrastructure and programs to monitor, manage, and prevent the spread of many diseases. The risks for climate-sensitive diseases can be much higher in poorer countries that have less capacity to prevent and treat illness.

West Nile virus is maintained in transmission cycles between birds (the natural hosts of the virus) and mosquitoes. Human infections can occur from a bite of a mosquito that has previously bitten an infected bird. Warmer winters, longer frost-free season, and earlier spring arrival may influence the migration patterns and fledgling survival of birds that are the natural host of West Nile virus. In addition, rising temperature, changing precipitation patterns, and a higher frequency of extreme weather events are likely to influence the distribution and abundance of mosquitoes that transmit West Nile virus.

Water-Related Illnesses:

People can become ill if exposed to contaminated drinking or recreational water. Climate change increases the risk of illness through increasing temperature, more frequent heavy rains and runoff, and the effects of storms. Health impacts may include gastrointestinal illness like diarrhea, effects on the body's nervous and respiratory systems, or liver and kidney damage. (USGCRP (2016) et al, Wasington DC)

· Climate impacts can affect exposure to waterborne pathogens (bacteria, viruses, and parasites such as Cryptosporidium and Giardia); toxins produced by harmful algal and cyanobacterial blooms in the water; and chemicals that end up in water from human activities.

· Changing water temperatures mean that waterborne Vibrio bacteria and harmful algal toxins will be present in the water or in seafood at different times of the year, or in places where they were not previously threats.

· Runoff and flooding resulting from increases in extreme precipitation, hurricane rainfall, and storm surge will increasingly contaminate water bodies used for recreation (such as lakes and beaches), shellfish harvesting waters, and sources of drinking water.

· Extreme weather events and storm surges can damage or exceed the capacity of water infrastructure (such as drinking water or wastewater treatment plants), increasing the risk that people will be exposed to contaminants.

Water resource, public health, and environmental agencies in the United States provide many public health safeguards to reduce risk of exposure and illness even if water becomes contaminated. These include water quality monitoring, drinking water treatment standards and practices, beach closures, and issuing advisories for boiling drinking water and harvesting shellfish.

Food Safety and Nutrition:

Climate change and the direct impacts of higher concentrations of carbon dioxide in the atmosphere are expected to affect food safety and nutrition.Extreme weather events can also disrupt or slow the distribution of food. (USGCRP (2016) et al, Wasington DC)

· Higher air temperatures can increase cases of Salmonella and other bacteria-related food poisoning because bacteria grow more rapidly in warm environments. These diseases can cause gastrointestinal distress and, in severe cases, death. Practices to safeguard food can help avoid these illnesses even as the climate changes.

· Climate change will have a variety of impacts that may increase the risk of exposure to chemical contaminants in food. For example, higher sea surface temperatures will lead to higher mercury concentrations in seafood, and increases in extreme weather events will introduce contaminants into the food chain through storm water runoff.

· Higher concentrations of carbon dioxide in the air can act as a "fertilizer" for some plants, but lowers the levels of protein and essential minerals in crops such as wheat, rice, and potatoes, making these foods less nutritious.

· Extreme events, such as flooding and drought, create challenges for food distribution if roads and waterways are damaged or made inaccessible.

The food system involves a network of interactions with our physical and biological environments as food moves from production to consumption, or from "farm to table." Rising CO2 and climate change will affect the quality and distribution of food, with subsequent effects on food safety and nutrition.

Mental Health:

Any changes in a person's physical health or surrounding environment can also have serious impacts on their mental health. In particular, experiencing an extreme weather event can cause stress and other mental health consequences, particularly when a person loses loved ones or their home.( USGCRP (2016) et al, Wasington DC)

· Individuals with mental illness are especially vulnerable to extreme heat; studies have found that having a pre-existing mental illness tripled the risk of death during heat waves.People taking medication for mental illness that makes it difficult to regulate their body temperature are particularly at risk.

· Even the perceived threat of climate change (for example from reading or watching news reports about climate change) can influence stress responses and mental health.

· Some groups of people are at higher risk for mental health impacts, such as children and older adults, pregnant and post-partum women, people with pre-existing mental illness (see above), people with low incomes, and emergency workers.

Populations of Concern:

Some groups of people are more vulnerable than others to health risks from climate change.Three factors contribute to vulnerability: sensitivity, which refers to the degree to which people or groups are affected by a stressor such as higher temperatures; exposure, which refers to physical contact between a person and a stressor; and adaptive capacity, which refers to an ability to adjust to or avoid potential hazards. For example, while older adults are sensitive to extreme heat, an older person living in an air-conditioned apartment won't be exposed as long as she stays indoors, and as long as she can afford to pay for the electricity to run the air conditioner. Her ability take these actions is a measure of her adaptive capacity.

Some populations are especially vulnerable to climate health risks due to particular sensitivities, high likelihood of exposure, low adaptive capacity, or combinations of these factors.

· Communities of color (including Indigenous communities as well as specific racial and ethnic groups), low income, immigrants, and limited English proficiency face disproportionate vulnerabilities due to a wide variety of factors, such as higher risk of exposure, socioeconomic and educational factors that affect their adaptive capacity, and a higher prevalence of medical conditions that affect their sensitivity.

· Children are vulnerable to many health risks due to biological sensitivities and more opportunities for exposure (due to activities such as playing outdoors). Pregnant women are vulnerable to heat waves and other extreme events, like flooding. USGCRP (2008) et al, Wasington DC)

· Older adults are vulnerable to many of the impacts of climate change. They may have greater sensitivity to heat and contaminants, a higher prevalence of disability or preexisting medical conditions, or limited financial resources that make it difficult to adapt to impacts.

· Occupational groups, such as outdoor workers, paramedics, fire fighters, and transportation workers, as well as workers in hot indoor work environments, will be especially vulnerable to extreme heat and exposure to vector borne diseases.

· People with disabilities can be very vulnerable during extreme weather events, unless communities ensure that their emergency response plans specifically accommodate them.

· People with chronic medical conditions are typically vulnerable to extreme heat, especially if they are taking medications that make it difficult to regulate body temperature. Power outages can be particularly threatening for people reliant on certain medical equipment.

Other Health Impacts:

Other linkages exist between climate change and human health. For example, changes in temperature and precipitation, as well as droughts and floods, will affect agricultural yields and production. In some regions of the world, these impacts may compromise food security and threaten human health through malnutrition, the spread of infectious diseases, and food poisoning. The worst of these effects are projected to occur in developing countries, among vulnerable populations. USGCRP (2009) et al, USA) Declines in human health in other countries can affect the United States through trade, migration, and immigration and has implications for national security.

Although the impacts of climate change have the potential to affect human health in the United States and around the world, there is a lot we can do to prepare for and adapt to these changes—such as establishing early warning systems for heat waves and other extreme events, taking steps to reduce vulnerabilities among populations of concern, raising awareness among healthcare professionals, and ensuring that infrastructure is built to accommodate anticipated future changes in climate. Understanding the threats that climate change poses to human health is the first step in working together to lower risks and be prepared.

CONCLUSION:

The impact of global warming or the climate change on the earth is very dangerous to human health. There is greater advancement in science and technology in the world today but even such advancements may not help to preserve human life on earth, unless we the humans take the responsibility of protecting the earth by adopting the policy of recycle, reuse and repair of the goods we use.

REFERENCES:

1. USGCRP (2016)et al. Impacts of Climate Change on Human Health in the United States: A Scientific Assessment. U.S. Global Change Research Program, Washington, DC. 312 pp. dx.doi.org/ 10.7930/ J0R49NQX.

2. USGCRP (2016). Et al 2014: Ch. 9: Human Health. Climate Change Impacts in the United States: The Third National Climate Assessment, J. M. Melillo, Terese (T.C.) Richmond, and G. W. Yohe, Eds., U.S. Global Change Research Program, 220-256. doi:10.7930/J0PN93H5.

3. USGCRP (2009). Global Climate Change Impacts in the United States. United States Global Change Research Program. Cambridge University Press, New York, NY, USA.

4. CCSP (2008). Analyses of the effects of global change on human health and welfare and human systems. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. U.S. Environmental Protection Agency, Washington, DC, USA.www.google.com

Received on 03.03.2017 Modified on 01.05.2017

Int. J. Nur. Edu. and Research. 2017; 5(4): 370-376.

DOI: 10.5958/2454-2660.2017.00078.3