Sometimes species can find it hard to survive when humans upset the balance of different populations in a natural ecosystem or change the environment in some way. Due to the fact that there are so many people on Earth, unless the situation is carefully managed there’s a real risk of permanent damage not just in the local environment but also globally. Humans rely on the ecosystem for water, food and shelter.

By the end of this section for GCSE Biology you should understand:

• how to analyse scientific data which deals with environmental issues
• how to evaluate the different methods used to collect environmental data and be able to comment on the validity and reliability of the evidence in regards to environmental change
• how to evaluate methods which are used to feed and provide water to an increasing human population both short and long-term
• how to evaluate biogas generators
• how to evaluate the positive and negative effects of food production management and distribution
• that practical solutions for human needs may require some form of compromise between competing priorities

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Peat bogs

The destruction of peat bogs and other areas containing peat also release carbon dioxide into the atmosphere. For the last 200 years humans have been damaging peat bogs in the UK and they’ve started drying out, releasing carbon dioxide as they do so. It has been estimated that peat is able to store double the amount of carbon that forests can worldwide.

Peat is used as a form of compost. However, today people are being encourages to use peat-free compost instead. This form of compost is becoming increasingly important because:

• peat can store large amounts of carbon
• peat develops very slowly: in fact, every metre of it that’s extracted will take 1,000 years to replace
• an increase in carbon dioxide is not the only issue: wildlife that live in peat land, like butterflies, dragonflies and bird, are having their habitat destroyed

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Waste from human activity

About seven billion people live on Earth and this number is constantly increasing. Due to this rapid growth, coupled with an increase in the standard in which people live, more and more waste is being produced.

Waste management

If waste isn’t properly handled then this can lead to pollution. Pollution can occur in:

• water by sewage, toxic chemicals or fertiliser
• land due to toxic chemicals like pesticides and herbicides which can also get washed from the land and pollute the surrounding waterways
• air with smoke and gases like sulphur dioxide which is a main cause of acid rain