BIOLOGY UNIT 3B GCSE

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There are over SIX BILLION PEOPLE in the world

due to medicine and farming methods which have REDUCED the number of people dying from disease and hunger.

increasing population puts pressure on environment

higher standard of living

also use more energy for manufacturing processes

raw materials are being used up quicker than they're being replace

WE also producing more waste

water : sewage and toxic chemicals from industry can pollute, rivers and oceans affecting the plants and animals that rely on them for survival

land , we use toxic chemicals for farming. we also bury nuclear waste and dump lot of household waste in landfill sites

Air : smoke and gases released into the atmosphere can pollute the air e.g sulfur dioxide can cause acid rain

More people means Less land for plants and other animals

four main human activities we do :

building

farming

dumping waste

quarrying for metal ores

Carbon dioxide is removed from the air and stored in various places

carbon is present in atmosphere as CO2

may processes lead to CO2 being released e.g fossil fuels

too much CO2 cause global warming

CO2 can be LOCKED UP in NATURAL STORES :

Oceans, lakes and ponds

green plants

peat bogs

Deforestation means chopping down trees

done for reasons such as :

to provide timbre for building materials

clear more land for farming (more food)

to produce paper from wood

Leads to FOUR MAIN reasons :

more methane in the atmosphere

more carbon dioxide in the atmosphere

less carbon dioxide taken in

less biodiversity (variety of different species

Destroying peat bogs adds MORE CO2 to the atmosphere

human impact

greenhouse effect

peat bogs