human influences on the environment

A source of sulfur dioxide pollution in the environment is the combustion of fossil fuels that contain sulfur impurities, e.g. car exhausts.

Sulfur dioxide can combine with water droplets in the air to form acid rain.

Consequences of acid rain pollution include:

False. Carbon monoxide is released when fossil fuels are burned with an insufficient oxygen supply. Burning impure fossil fuels can produce sulfur dioxide pollution.

Carbon monoxide is damaging to living organisms because it binds to haemoglobin inside red blood cells, reducing the oxygen carrying capacity of the blood. Breathing in carbon monoxide for extended periods can be fatal.

A greenhouse gas is a gas that absorbs infrared radiation from the Sun, trapping it in the Earth's atmosphere.

True. Greenhouse gases trap infrared radiation in the atmosphere, causing atmospheric warming.

Examples of greenhouse gases include:

Carbon dioxide is released by human activities such as:

True. Methane traps more radiation per molecule than carbon dioxide, so is a powerful greenhouse gas.

Human activities that increase atmospheric methane are:

The greenhouse effect occurs when radiation from the sun is absorbed by greenhouse gases in the earth's atmosphere. This traps heat and warms the atmosphere.

False. Greenhouse gases occur in the atmosphere with no input from human activities, where they are essential for keeping the earth warm enough to support life. Human activities result in an enhanced greenhouse effect.

The enhanced greenhouse effect is the increased warming of the earth's atmosphere beyond normal levels due to human activities.

Global warming refers to the long-term increase in the earth's average temperature, primarily due to human activities that increase the levels of greenhouse gases in the atmosphere.

Some consequences of global warming include:

False. ** Global warming is increasing ocean temperatures**, leading to impacts such as melting polar ice caps, rising sea levels and coral bleaching.

Human activities that result in water pollution are:

Consequences of untreated sewage runoff into water systems include:

Eutrophication is the process by which increased nutrient availability in a body of water leads to a decrease in dissolved oxygen levels.

Human activities that can lead to eutrophication include:

Leaching occurs when nutrients are washed out of the soil and into bodies of water by rain. This is a particular problem when highly soluble chemical fertilisers are used.

An algal bloom is the rapid growth of algae that occurs on the surface of water bodies when nutrient levels increase. Algal blooms can can block out sunlight to deeper water.

False. Algal blooms occur when nutrient availability in water bodies is high, e.g. due to sewage or fertiliser run off.

Algal blooms block out sunlight, meaning that aquatic plants below the surface do not have enough light to photosynthesise. These plants are likely to die.

The role of microorganisms in eutrophication is as follows:

The process of eutrophication is as follows:

Deforestation is the process of clearing trees, usually on a large scale. This is often done to make way for building or agriculture.

Environmental effects of deforestation include:

Soil erosion is the process by which soil is removed from its original location, e.g. by rainwater or wind.

False. Deforestation can disrupt the water cycle. The removal of trees reduces water vapour entering the atmosphere by transpiration, reducing cloud formation and therefore reducing rainfall.

False. ** Deforestation increases **atmospheric carbon dioxide concentration. This is because living trees absorb carbon dioxide during photosynthesis; removal of these trees therefore reduces the rate at which carbon dioxide is removed from the atmosphere.