The Atmosphere, Climate, and Global Warming Chapter 23 The Atmosphere, Climate, and Global Warming

Videos Layers of the atmosphere, sorry, a bit boring, but all the info you need here. Greenhouse effect Global Warming

The Atmosphere The thin layer of glass that envelops the Earth Chemical reactions Atmospheric circulation produces weather and climates

Climate Climate: Microclimate Urban Dust Dome the representative or characteristic atmospheric conditions for a region on Earth Microclimate The climate of a very small local area Urban Dust Dome Polluted urban air produced by the combination of lingering air and abundance of particulates and other pollutants in the urban air mass

Climatic Change Major climatic changes have occurred during the past 2 million years Appearances and retreats of glaciers During the past 100 years, the mean global annual temperature ahs increased by .5 degrees Celsius

Global Warming A natural or human induced increase in the average global temperature of the atmosphere near the earth’s surface 4 factors Amount of sunlight Earth receives Amount of sunlight Earth reflects Retention of heat by atmosphere Evaporation and condensation of water vapor

Electromagnetic Radiation and Earth’s Energy Balance Electromagnetic spectrum The collection of all possible wavelengths of electromagnetic energy, considered a continuous range

The Greenhouse Effect Greenhouse Effect Greenhouse Gasses The process of trapping heat in the atmosphere Water vapor and several other gases warm the Earth’s atmosphere because they absorb and emit radiation Greenhouse Gasses Gasses that have a greenhouse effect Water vapor, carbon dioxide, methane, CFCs

Global Warming Negative and Positive feedback cycles affect the atmosphere Increase in emission of greenhouse gasses Solar Forcing, Natural Cycles, Aerosols (global dimming), Volcanic Eruptions, El Nino

Effects of Global Warming Changes in climatic patterns Rise in sea level Changes in biosphere

Global Climate Patterns Earth’s global climate patterns Are determined largely by the input of solar energy and the planet’s movement in space

LALITUDINAL VARIATION IN SUNLIGHT INTENSITY Plays a major part in determining the Earth’s climate patterns Figure 50.10 Low angle of incoming sunlight Sunlight directly overhead North Pole 60N 30N Tropic of Cancer 0 (equator) 30S 60S Atmosphere LALITUDINAL VARIATION IN SUNLIGHT INTENSITY Tropic of Capricorn South pole

SEASONAL VARIATION IN SUNLIGHT INTENSITY June solstice: Northern Hemisphere tilts toward sun; summer begins in Northern Hemisphere; winter begins in Southern Hemisphere. March equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness. 60N 30N 0 (equator) 30S Constant tilt of 23.5 September equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness. December solstice: Northern Hemisphere tilts away from sun; winter begins in Northern Hemisphere; summer begins in Southern Hemisphere. SEASONAL VARIATION IN SUNLIGHT INTENSITY Figure 50.10

GLOBAL AIR CIRCULATION AND PRECIPITATION PATTERNS Air circulation and wind patterns Play major parts in determining the Earth’s climate patterns Descending dry air absorbs moisture Ascending moist air releases 30 23.5 0 Arid zone Tropics 60N 30N 0 (equator) 30S 60S GLOBAL AIR CIRCULATION AND PRECIPITATION PATTERNS Figure 50.10

GLOBAL WIND PATTERNS Figure 50.10 Arctic Circle 60N Westerlies 30N Northeast trades Doldrums Southeast trades Antarctic Circle 60S 30S 0 (equator) 30N 60N Arctic Circle Figure 50.10

Adjustments to Global Warming Evidence based decision-making??? Mitigate warming through reduction of greenhouse gasses Energy conservation Alternative energy sources Danger: rapid climatic change

Antarctic Heat Sink

Not always that easy to understand… Ice levels don’t always decrease neatly with AGW Check this out as well.