Start-Up:The hole in the ozone layer does not cause global warming. In fact, the hole in the ozone layer slows down global warming. Why is this a misconception some people have?

Greenhouse effectGreenhouse gases in the atmosphere trap heat that would otherwise be reflected back into space

This is a natural process!Life on earth cannot exist without it!

Greenhouse gases:water vapor, carbon dioxide, ozone, methane

VENUS

Extreme greenhouse effect!

Carbon cycle

Process by which carbon moves from inorganic to organic compounds and back

Matter and energy are not created nor destroyed! They are only converted from one form to another!

Humans have caused an increase in the amount of carbon released into the atmosphere

Fossil fuels burned to run cars and trucks, heat homes and businesses, and power factories are responsible for about 98% of U.S. carbon dioxide emissions

Compare the increase in CO2 output with this…

Monthly changes in atmospheric CO2 concentration

6CO2 +6H2O   C6H12O6 + 6O2

Photosynthesis

Trees act like carbon “sinks”, absorbing carbon from the atmosphere

Because trees are carbon “sinks”, when you cut them down, all the carbon they have absorbed get released into the environment

Without Human ActivitiesNon-human events do not account for the trend

With Human ActivitiesBoth human and non-human events togetheraccount for the trend

What will the increasing level of carbon dioxide (a greenhouse gas) do to the greenhouse effect?

PredictionsDifferences are due to natural variability and human choices

Climate Change on the Antarctic Peninsula

(1) Antarctica is in the southern hemisphere, so the timing of the seasons is the opposite of what we experience in North America.

(2) Because most of the Antarctic continent is covered by a permanent ice sheet, terrestrial habitat for sea birds is limited to the coastline and small islands.

(3) The western Antarctic Peninsula has a maritime climate, and therefore is warmer on average than the rest of the Antarctic continent.