Carbon cycle and Human
activity
Carbon cycle
• Carbon cycles though the atmosphere,
living things, soils, and the ocean.
Sources and Sinks
• Carbon Sinks are where carbon is stored
– For example: in trees, the ocean, limestone, and
underground as fossil fuels
• Carbon sources are processes that release carbon
back into the atmosphere
– For example: burning trees, volcanic activity, and burning
fossil fuels
Fossil fuels
• are energy-rich substances formed from the
remains of dead organisms
– Coal, petroleum, & natural gas are all fossil fuels.
Atmospheric Carbon
• Carbon enters the
atmosphere as CO2
• CO2 is a
greenhouse gas
which helps keep
our planet warm
• When CO2 levels
increase, global
temperatures
increase.
Rise in Greenhouse Gases
• Over the past 200 years
there has been a rapid
increase in greenhouse
gases which include:
•Methane, water vapor,
nitrous oxide, & carbon
dioxide
•The burning of carbonrich fossil fuels & the
removal of forests
worldwide is the primary
cause.
Global Warming
• The increase of
greenhouse gases has
caused an increase in
global temperatures by
1°C.
• It is predicted that it
will increase by another
5°C in 100 years.
• The temperature
increase is
greatest at the
poles.
Impact of Global Warming
•Melting of the polar ice caps
•Rising sea levels
•Acceleration of warming due
to release of methane from
the permafrost & also less ice
reflecting sunlight.
•Change in global weather
patterns
•More severe storms and
droughts
•Extinctions