Environmental Problems

Humans, since their inception, have changed their environment to suit themselves.  For a long time this had no significant effects on the ecosystems in which they lived, although already in Ancient Greece, their effect on the Mediterranean was notable.
The Industrial Revolution, and especially the last 150 years, has resulted in significant changes:
- intensive use of natureal resources, especially coal, oil and iron
- increased production and increased consumption, resulting in a consumer society and associated with globalization
Since the Industrial Revolution there has been a steady increase in the world's population, a steady improvement in the lifestyle people live and a steady increase in the use of technology

Population growth leads to resource limitations/shortages.  The resources in shortest supply are land and water, which leads to food shortages.  A vicious circle exists in areas with shortages between the shortages, poverty and lack of education.
In response to shortages, agricultural use of fertilizers, herbicides and pesticides was increased to result in increased production.  Additionally, agricultural watering has help increase food production, while intensifying the issue of water shortages.  Likewise, there has been an increase in land use, where land of poorer agricultural quality has been brought into use, resulting in increased deforestation, use of virgin lands and draining of wetlands.
These actions have resulted in decreased habitat for many species and overall decreased in species numbers (biodiversity) and extinctions.
Since the end of the 1990's, the rate of food production is no longer increasing at such a rapid rate.
In a nutshell:
- high water consumption decreases groundwater levels
- use of fossil fuels and deforestation has resulted in increased levels of greenhouse gases (CO2, CH4, N2O, halogens, O3)
- increased greenhouse gases result in increased temperatures which cause increased evaporation, decreasing levels of surface water, decreases in summer precipitation and increased sea levels.
- fossil fuel use also increases levels of SO2, resulting in acid rain
- disparities in fossil fuel use vs. availability can result in political instability
- production of goods and consumption of goods results in significant amounts of garbage (physical and chemical)

Environmental Pollution

Environmental pollution refers to anything that affects the environment's stability.  It can be caused by natural catastrophes or by humans

 1. Soil Degradation 

a.  Naturally caused by erosion (water, wind, ice):  erosion is usually observed on slopes and is decreased by the presence of plants.  Human activity often increases erosion as it is associated with a removal of plants (eg. deforestation)
b.  Destruction of soil quality:  caused by humans, primarily through agriculture - growing inappropriate plants, poor water use, too much mechanical disturbance
c.  Soil pollution:  a process by which pollutants (garbage or chemicals) enter the soil, eg.  improper use of pesticides or fertilizers

2.  Water Degradation

Water is necessary for life, therefore its quality is very important
Aspects of quality include:
- physical characteristics: temperature, density, clarity
- chemical characteristics: dissolved gases, ions dissolved or solid organic content, which affect pH, water hardness and electrical conductivity
- biological characteristics:  determined by all the living organisms found in the water.  Living organisms can only survive in water with appropriate physical and chemical characteristics

Water pollution is considered any factor which affects water quality negatively.   Water pollution is caused by industry, agriculture and household use.  
Pollutants can be poisons, compounds that change the colour, taste or smell of the water, or compounds that cause eutrophication.
Water naturally cleans itself, as long as it isn't too polluted.  
Dissolved oxygen has a significant effect on the self-cleaning process and the temperature of the water and the amount of organic material it contains affect how much oxygen is found in the water.  Less oxygen dissolves in warmer water and the more organic material in the water, the better bacteria multiply and the more oxygen they use.    Low oxygen levels result in the death of living organisms, which in turn, increases the organic matter leading to eutrophication.
Poisons in the water destroy the self-cleaning mechanism, as well as increase deaths of living organisms.  Many herbicides, fungicides and pesticides are enzyme-blockers.  Often they also build up in living organisms (bioaccumulation), and their effects are only noticiable much later.  DDT is such an example.  
It was used as an insecticide, killing many types of insects, while not appearing to affect mammals.  It was used in agriculture and in areas with high levels of malaria (it kills the mosquitos) from the 1940's until the 1970's.  In 1962, Rachel Carson wrote "Silent Spring", in which she brought attention the fact that insectivore birds  where dying off in areas where DDT was used.  This led to increased research into the effects of using DDT and it was found to be present even in mammals' milk in areas distant from where it was used.  DDT's primary break-down product binds to androgen hormone receptors, therefore affecting male hormone systems.

 Oil and oil products are some of the worst water polluters:
- oil slicks on the water's surface block oxygen and light
- oil coats living organisms, causing problems ranging from suffocation or inability to fly to blindness

Bird affected by an oil spill

Synthetic detergents usually come from household wastewater
- create a foam on the water's surface that blocks gas exchange
- high phosphate content speeds up eutrophication
- allow non-water soluble substances (eg. pesticides, oil, etc) to become solutes, directly endangering living organisms

3.  Degradation of the Atmosphere
Air pollution refers to any solid, liquid or gas that has a negative effect on air quality
Industry, agriculture, transporation and households all produce significant amounts of air pollutants.
Eg.
Heating - soot, carbon dioxide, etc
Transportation - exhaust fumes, lead, carbon monoxide, nitrogen oxides, soot, etc
Mining - carbon dust, cement dust, iron oxide, etc

While all air pollutants are problematic, some have global effects  Eg. carbon dioxide
While carbon dioxide is an important component of the atmosphere in small quantities (eg. for photosynthesis), its ability to trap long wavelength heat radiation is problematic when its concentration rises. It is the cause of the greenhouse effect, which has resulted in global warming. 

A rise in the overall temperature of the planet has already resulted in an increase in the number of and the extremity of weather events and this rise is expected to continue.  In the last 100 years, the average temperature has risen 0.6C, of this 0.15C was in the last decade.  The world's snow and ice cover has decreased 10% in the last 40 years.  And yet the production of greenhouses gases is still rising.

Hungary has exhibited a higher increase in average temperature, 0.68C.  In this area, the increased temperature results in droughts, while elsewhere the result is increased flooding and destructive storms.

In the upper zone of our atmosphere oxygen is converted to ozone.  This layer of ozone absorbs UV radiation, protecting living organisms from dangerous doses of UV radiation.  Unfortunately, this layer is thinning, primarily as the result of chlorofluorocarbons (CFCs) entering the atmosphere from used refrigerators, spray cans, etc.

On the other hand, near the Earth's surface, the concentration of ozone is growing, particularly as the result of chemical reactions between nitrogen oxides and volatile organic compounds (VOC) in the presence of sunlight.  Industry, motor vehicles and chemical solvents are major sources of nitrogen oxides and VOCs.  Ozone affects oxygen uptake, causes damage to the mucous membrane and destroys chlorophyll.

The burning of fossil fuels produces large amounts of sulfur dioxide, which is released into the atmosphere.  It is taken up by plants and reacts with the water in the leaves, creating acid that destroys the plants' tissues.  It also reacts with water in the air, causing acid rain.  This results in an acidification of soil and water, killing off living organisms with narrow pH tolerances.

Result of acid rain

Smog is another form of air pollution, that forms in large cities.  It is the result of polluted air and specific meteorological conditions.  There are 2 basic types:  photochemical (Los Angeles) and sulphurous (London).  Photochemical smog occurs when it is warm and sunny and the high levels of polutants from vehicles (nitrogen oxides, hydrocarbons) react with the high humidity levels in the air in the presence of sunlight to create smog.  Sulphurous smog develops in cooler conditions, when there are high levels of SO2, CO, soot and dust (from fossil fuel burning).  This is a reductive smog.  Both kinds of smog do occur in Hungary.  Smog can cause asthma and even deadly lung edemas. Complaints can include
 coughing, difficulty breathing, sore throats, congestion, etc.

Sulphurous smog

Photochemical smog

Noise Pollution

Humans produce physical waste (eg. household garbage, wastewater, etc) and energy-based waste (eg. heat, noise).  Energy-based wastes can also cause significant damage.

Noise sources include:
- road traffic
- air traffic
- railroad traffic
- industry
- hobbies

In humans hearing loss is known to occur at volumes above 85 decibels, which is approximately the volume in a movie theatre.  Outdoor concerts are frequently 110-120 decibels.

Reducing noise caused by traffic is fairly easy, through improvements in roadways, noise walls, speed limits, and prohibition of heavy vehicles.

Noise walls and proper insulation can help reduce industrial noise.
Other vibrations, such as infra- and ultrasound can also affect the functioning of the human body.

Radioactive Pollution

Humans are constantly bombarded by natural and artificial radioactivity.  Natural sources of radioactivity are not of great concern, since their levels are constant and life on Earth evolved in their presence, hence is adapted to them. Artificial sources (eg. nuclear radiation, medical radiation, etc) can have significant, even deadly effects.

Waste

Waste is a product of civilization.  The damage it does to the environment depends on the type of waste and also on the amount of waste produced.  Worldwide, waste levels are rising from year to year, although in Hungary there does seem to be a decreasing trend.

Waste generation by type in the EU, Croatia, Macedonia, Norway and Turkey - 2008

Waste:  Those materials and objects that have become useless to their owner and the owner disposes of them.

One way to reduce waste is to find ways to reuse it, such as refillable glass bottles, increasing the lifetime of the product before it becomes waste.
Recycling is another means to keep things out of landfills, by turning waste items into other useful items (eg. plastic bottles become polar fleece jackets).  This requires the selective collection of waste, in order for the different industries to make use of the objects.

Waste treatment refers to activities that ensure that waste has the least impact on the environment.  This include chemical, biological or physical treatment of different kinds of wastes.

Processes like reusing, recycling and composting significantly reduce the amount of solid household waste that must be dealt with.

Waste management refers to the systems in place to deal with different kinds of waste.  This includes the creation of facilities, as well as treatment techiques, right down to the collection of waste.