1Carbon dioxide is rising
Carbon dioxide in the air has risen from about 280 parts per million (ppm) in 1800 to over 420 ppm today, mostly since 1950.
ppm
Lesson 26.4 notes
Climate and resources
Carbon dioxide, the greenhouse effect, climate change, limited resources and recycling.
2Why it is rising
Burning fossil fuels releases carbon that was stored underground for millions of years. Volcanoes add only a tiny amount, and the oceans take some in.
3The greenhouse effect
Sunlight warms the Earth, which gives off heat. Greenhouse gases such as carbon dioxide trap some of that heat, keeping the Earth warm.
greenhouse gas
4A warming world
As carbon dioxide has risen, the Earth's average temperature has gone up by more than 1 °C since 1850. This is global warming.
global warming
5The effects
Warming melts land ice and makes sea water expand, so sea levels rise. It also brings more heatwaves, droughts and floods: climate change.
climate change
6Finite resources
Metal ores and fossil fuels took millions of years to form. They are finite: once we have used them up, they are gone.
finite
7Recycling
Recycling saves raw materials and energy and keeps waste out of landfill. Recycling aluminium saves about 95% of the energy needed to make it from ore.
recycling
Explore: Greenhouse lab
Change what is in the air. Watch how much of the Earth's heat escapes to space, and what happens to its average temperature.
Common mistake: Climate is not the same as weather
Weather is the day-to-day state of the air. Climate is the average over many years. One cold winter doesn't mean warming has stopped: the long-term trend matters.
Remember
- Carbon dioxide has risen from about 280 parts per million in 1800 to over 420 today, mostly from burning fossil fuels.
- Greenhouse gases trap heat given off by the Earth. More carbon dioxide traps more heat, so the Earth warms, sea levels rise and weather becomes more extreme.
- Metal ores and fossil fuels are finite. Recycling saves raw materials and energy, and keeps waste out of landfill.
Going further at GCSE
GCSE: The greenhouse effect → GCSE: Climate change → GCSE: Reduce, reuse, recycle →