Environmental Issues and Their Consequences

Environmental issues such as climate change and water and air pollution affect natural environments. These issues also have a major impact on vulnerable populations and people living in fragile environments.

Global warming is causing glaciers, including polar ice caps, to melt and sea levels to rise. According to NASA, the sea level will rise by one metre in the next 100 to 200 years.

Rising sea levels threaten to submerge archipelagos (groups of islands) in the Pacific Ocean as well as coastal cities (located on continents, but on  the seashore).

More intense hurricanes and cyclones are a consequence of global warming. While climate change does not directly cause weather events such as hurricanes, it does increase their intensity, frequency or duration. These events greatly affect coastal cities.

In addition to hurricanes, cyclones and floods, record temperatures and more intense heat waves have been observed. This leads to an increase in the frequency of forest fires caused by dry weather and high temperatures.

According to climatologist Thomas Stocker, a member of the Intergovernmental Panel on Climate Change (IPCC), global warming is causing more rainfall in wet regions and less rainfall in dry regions.

Global warming increases  the average temperature around the world over a long period of time. Greater temperature variations are also occurring. For instance, regions where the average temperature is higher are experiencing more intense heatwaves as well as periods of intense cold.

Heatwaves could eventually have consequences on human health. Heat can cause dehydration and even death from overheating. A study by the University of Hawaii identified 27 causes of death due to heatwaves. 

These weather events could also extend the season for mosquitoes, which spread disease. Some World Health Organization (WHO) studies show that two billion more people could be at risk of dengue fever by 2080. To find out more about dengue fever (a viral infection transmitted by mosquitoes), visit the following site: Dengue and severe dengue. 

Heatwaves are not the only thing that can have harmful impacts on health. Climate change affects air quality, water quality, drinking water availability, agricultural productivity (and therefore the amount of food available) and access to safe and clean housing that is not threatened by floods, hurricanes or other extreme weather. All of these important elements of human health are at risk due to climate change. The WHO claims that climate change is responsible for at least 150 000 deaths per year and this number is expected to reach 300 000 per year by 2030.

Water pollution also has an impact on ecosystems.

Groundwater,  which is water found underground, is replenished by rain or snow. Groundwater supplies drinking water. If it becomes polluted, it is no longer drinkable and must be treated, which is an  expensive and sometimes impossible process.

Some chemical pollutants found in water can cause illnesses or birth defects. This is more common in developing countries, where more people are forced to drink polluted water.

Other chemical pollutants in water can affect fish populations. For example, women who use birth control pills have more estrogen (a hormone that occurs naturally in women) in their urine. This hormone makes its way into the water, because it is not eliminated during water treatment. High concentrations of estrogen in the water cause some fish species to change from male to female. Pollutants that have the same effect as estrogen are also found in fungicides (pesticides), parabens and other preservatives used in cosmetics, medicines or food. There are indications that these substances can also have an impact on humans, such as reduced sperm production in men and increased breast tumours in women. These hormone disruptions can also impact the reproduction of some species.

When water contains too much phosphorus and nitrogen of human origin, it accelerates  the growth of plants such as algae. Algae consumes a lot of oxygen, often not leaving enough for other organisms in the water, causing them to die.

It is not common to drink polluted water in developed countries, since water is analyzed and purified, but it does occur from time to time. However, water pollution can indirectly impact human health. Fish, crustaceans and molluscs can absorb pollutants that are then  ingested by humans. To prevent this type of poisoning, strict measures have been put in place for commercial fishing, but not for recreational fishing. Therefore, it is important to be aware of water quality and the potential  risks when fishing.

Carbon dioxide |(\text{CO}_2)| in the atmosphere is not only absorbed by trees, but also by the ocean. Too much |(\text{CO}_2)| in the water upsets its acid-base balance. With the |(\text{CO}_2)| generated by human activities, ocean acidification could reach 120% by 2060.

Acidification has a major impact on marine life:  stunted growth and survival of sea urchins, starfish, mussels, lobsters, coral reefs and plankton (which form the basis of many food chains) and reduced habitat and food available for fish.
 

Air pollution affects many parts of the global ecosystem including soil, water, vegetation and animals.

One consequence of air pollution is acid rain. This rain is more acidic than normal rain. When certain gases are released into the atmosphere, they lower the pH of rainfall, making it more acidic. These gases can be released into the atmosphere naturally due to lightning, forest fires or volcanic eruptions, but human activity is also responsible.

Air pollution also reduces biodiversity and vegetation productivity. Acid rain is harmful to agriculture, forests and fishing. It depletes the soil, which slows down the growth of plants when they no longer have enough nutrients. Acid rain also reduces the number of fish available for fishing and other animals that feed on them.

Before falling to the ground, acid rain also contributes to the formation of smog. Smog is a mixture of air pollutants in the form of a thick haze or an invisible cloud. Smog can aggravate lung and heart problems and cause death in vulnerable populations.

Air pollution leads to poor air quality, which also affects human health. Health issues such as asthma, lung cancer, allergies and heart disease are linked to air pollution. It can also impact cognitive development. According to a 2016 WHO estimate, 600 000 children under the age of 15 died as a result of severe respiratory tract infections caused by air pollution. This air pollution occurred both indoors (due to fossil fuels used for cooking) and outdoors.

As mentioned above, climate change is causing an increase in the frequency of extreme weather events such as floods, cyclones and droughts. These events have a huge impact on certain populations, such as people living in coastal cities, in the Pacific Islands and in some developing countries. In 2019, the World Bank predicted that by 2050, these natural disasters will cause the displacement of 143 million people if no action is taken to fight climate change.

The degradation of soil used for agriculture and ecosystems, in addition to the depletion of precious natural resources, such as freshwater, is causing some people to migrate, creating a new type of refugee: the climate refugee. This concept is not recognized by the 1951 Geneva Convention, which did not foresee a climate crisis as a valid threat for seeking asylum. However, the UN Human Rights Committee has stated that refusing an asylum seeker because of a climate crisis could be an infringement of the right to asylum. Unfortunately, this opinion has no political weight and governments are not required to adhere to it.

Some populations are more affected by environmental issues than others. 

Many developing countries are more affected by environmental issues than developed countries. The population living in these countries relies heavily on their natural environment. They also lack the means and resources to adapt or rebuild in the face of climate change. They are most affected by crop failure and rising food prices due to extreme weather events. They do not have the same financial and technological resources as wealthier countries. 

The African continent is likely to be the hardest hit by climate change. Its populations are already more exposed to insect-borne diseases and more mosquitoes would make the situation worse. Drought in Africa could have a significant impact on the food security and water supply of millions of people due to reduced agricultural productivity. Food prices could increase by 12% by 2030 and 70% by 2080 which would also greatly affect food security.  To find out more about the impact of climate change in Africa, check out the following IPCC report: IPCC Special Report on Climate Change and Land. 

Because climate change affects basic needs in poor countries, many people see the risk of increased conflict over access and control of resources.