Atmosphere & Climate Part 1 Mr. Sierra

Margaret Mead: “The atmosphere is the key symbol of global interdependence”. What did Margaret mean by that statement? What is it that makes our atmosphere so important? EcoLog Question #1 on p.172: Why do you think the warming of Earth by gases such as Carbon Dioxide is called “the greenhouse effect”?

Composition

Carbon Dioxide cellular respiration photosynthesis

Carbon Dioxide Organisms absorb oxygen as they break down food molecules during cellular respiration. Carbon dioxide is released into the atmosphere. Plants and bacteria get their food by absorbing water and carbon dioxide during photosynthesis, using sunlight for energy. They release oxygen as a by-product. O2O2 O2O2 CO 2

Carbon Dioxide Industrial Revolution about 200 years ago Today: 397 ppm Any guess where it is today?

Layers of the Atmosphere

Thermosphere - Weather Water Vapor Layers of the Atmosphere

Ozone Ozone is beneficial in the stratosphere but dangerous in the troposphere. Ground level ozone is classified as a pollutant because it reduces lung functionality AND it can degrade plant surfaces. The smog that frequently exists in major metropolitan areas such as Los Angeles, CA is known as brown smog and consists primarily of ozone. The protective layer of stratospheric ozone absorbs over 99% of incoming UV-B and UV-C radiation.

Ozone The depletion of ozone is largely due to chlorofluorocarbons (CFCs) - also commonly known by the DuPont brand name Freon. These were mostly used in aerosol cans (spray paint and air fresheners) Montreal Protocol The Montreal Protocol in 1987 was an international agreement that allowed for a reduction, and eventual elimination, of CFC production (at least within the 197 participating countries).

Ozone Ozone is depleting over Antarctica - faster during August through November (when it’s spring in the southern hemisphere)

Ozone antarctica antarctica one_resource_page.html one_resource_page.html