sustainability of natural resources
natural resources 
anything in nature that people value
air water fossil fuels plants and animals are natural resources.
there are 2 types which are renewable and non renewable
plastics are not natural resources
reducing reusing and recycling helps to conserve our resources.
population growth
climate change
global warming is the average temperature of earth
earth gets warmer naturally but this is happening a lot faster
global warming is caused by gases that trap heat.
humans burning fossil fuels is putting more green house gases in the atmosphere.
trees remove carbon dioxide so we need to plant more trees.
global warming is causing bad weather and diesease, but we can still fix the problem.
humans should use less fossil fuels and more renewable resources.
about 200 years, the human population increased by alot
earth can only hold a certian amount of people
in 10 years, there will be more than 8 billion people on earth
more people are on earth is using up our resources more quickly.
recycling can reduce how much resources are being used.
soil
erosion moves the sediment to other places
soil has different layers and the top soil has the most humus
soil is mix of rocks, water, and dead stuff
weathering breaks rocks into small pieces called sediments
plants need rocks and humus to grow
plants cannot grow in bed rock, so we must protect our top soil
Greenhouse effect
greenhouse effect is the warming of earth
greenhouse gases such as carbon dioxide, trap heat on earth
without the green house gases, earth would be too cold to live on
too much greenhouse gases can cause global warming
humans are causing global warming
humans can reduce global warming by burning less fossil fuels and rasing less cows.
humans and their environment
in the last 200 years humans have greatly impacted the environment.
during the industrial revolution, there was more people and more population.
using nonrenewable resources cause lots of pollution and will eventually run out.
for our survival we need to do things to help the environment
air pollution
conserving our resources will cause less air pollution.
cows produce lots of methane, which is a greenhouse gas.
air pollution can mix with clouds to cause acid rain
Ozone when its up high protect from the sun, but becomes poisonous when it's near us.
air pollution can cause cancer and global warming
burning fossil fuels releases poisonous gases, such as Co2
air pollution can come from different places such as cars.