Global Warming

Climate Changes and Why They Matter

Two examples to show that climate changes have made big influence on Earth:

·         Colder Times: temperature use to be very low and until as recently as 10 000 years ago, ice sheets called continental glaciers covered a lot of Canada

·         Warmer Times: suggested that earlier period of global warming allowed Vikings to settle in Newfoundland but temperatures had dropped so they abandoned the settlements

Life in a Greenhouse

Greenhouse gases in the atmosphere absorb some heat reflected from Earth’s surface before it can escape into space. If we didn’t have any greenhouse gases, temperature would be very low, but if we have too many, temperature would increase by a lot. Scientists suggested that human activity is increasing amount of greenhouse gases. Main greenhouse gases are carbon dioxide, methane, nitrous oxide, halo-carbons, ozone, and water vapor. Other than halocarbons, these occur naturally in atmosphere. Many sources of increase of greenhouse gases such as burning of fossil fuels that create carbon dioxide

Carbon Cycle

The Carbon cycle describes movement of carbon through plants, animals, water, soil, air, and rock. When carbon removed for certain amount of time, it’s called a carbon sink (ex. phytoplankton take in carbon). When carbon added to atmosphere, it’s called a carbon source (ex. animal recycles methane gas that has carbon in it. When carbon removed for very long time but then added back through deposit, called carbon fixation

How has fixed carbon been released?

1885-2005, population increased massively and carbon dioxide escaped as fossil fuels from heating and cooking and forests fell to create space for farming and urban growth. Also, during 1885-2005 lifestyle has changed now we have a lot more things that produce more carbon dioxide than before (ex. individual cars and lots of air conditioning and heating)