The Carbon cycle

• Carbon dioxide in the atmosphere is the source of carbon in ecosystems
• Plants remove carbon dioxide from the air during photosynthesis and use it to build food compounds
• Animals obtain the carbon by eating the plants
• Carbon is released back into the atmosphere by animals, plants and micro-organisms when they respire
• It is also released back into the atmosphere by human activities such as burning fossil fuels
• Deforestation also leads to a build up of carbon dioxide in the atmosphere as there are fewer tress to photosynthesize

Greenhouse effect and global warming

• Recently there has been a noticeable build up of the amount of carbon dioxide in the atmosphere
• Carbon dioxide is one of the gases that acts as an insulator thus keeping the earth warm
• It traps the sun’s energy in the atmosphere
• When the amount of carbon dioxide in the atmosphere so does the overall temperature of the earth
• This is called the greenhouse effect
• The increase in temperature is very small but enough to cause changes in the earth’s climatic patterns
• The greenhouse effect has also resulted in the melting of ice caps at the in the polar regions
• It has also resulted in rising sea levels

Ways to reduce global warming

• Carbon dioxide emissions can be reduced by burning less fossil fuels
• Examples of fossil fuels are oil, coal and gas
• Alternative sources of energy such as solar, hydro(water) and wind must be used
• Deforestation has also to be reduced
• Reafforestation and afforestation will also reduce the amount of carbon dioxide in the atmosphere

To access more topics go to the Combined Science Notes page.