CLIMATE

CLIMATE

1. Controls

   • Factors
     • Athropogenic
       • Aerosols, land use, and greenhouse gas emissions
         • Aerosols- fine particles or liquid drops in the air, natural and artificial, fog and geysers are natural, haze and dust and pollution are artificial, and cause an increase in greenhouse gases
         • Land use- loss of natural habitats, reflectivity change
         • Greenhouse gas emissions- increased because of humans, climate impact
     • Natural
       • Astrological- relates to Earth's position and movement
         • Solar radiation
           • radiant sun energy, long and short distances
         • Gravity-caused
           • Eccentricity, Obliquity, and Precession
             • Eccentricity: determines amount by which its orbit around another thing deviates from a perfect circle, operates on a ~100,000 year schedule, Earth moves faster closer to the sun
             • Obliquity- how much the Earth is tilted towards the sun, exposes the surface to the sun at different angles
             • Precession- gravity induced slow change in orientation of astrological body's axis, every 26,000 years it fully tilts, goes back and forth between facing Polaris (north star) and Vega
         • Albedo
           • reflectivity power of a surface, measured in percentages, affected by color
         • Milutin Milankovic
           • defined eccentricity, obliquity and precession, determined climate patterns, figured out whether or not Earth is in an ice age or warm period, all three gravity caused factors combined = Milankovic cycles
       • Terrestrial
         • arrangement of continents
           • influence ocean circulation, change air patterns and currents
         • elevation
           • pressure drops, less density, allows for less heat and humidity; IE- on top of a mountain, there's an arctic climate, while at the bottom it could be tropical or lowlands
         • volcanic activity
           • release greenhouse gases and aerosols, increased activity = increased temperatures, 90% of CO2 is released by natural things
         • topography
           • orientation of mountains in relation to equator and air; I.E.- the Alps are shielded from the heat because the mountains go E/W and the air goes N/S; North American mountains go N/S along with the wind, so they experience all season

2. Zones

   • Polar
     • tundra, ice caps, highlands
       • Tundra- always cold and dry
       • Ice caps- freezing all year round
       • highlands- temperatures vary widely with latitude, elevation, and direction of exposed areas
   • Dry
     • desert and semiarid
       • semiarid- slightly more than 10 inches of rain per year
       • desert- less than 10 inches of rain per year with hot days
   • Humid Tropical
     • tropical wet and tropical dry and wet
       • tropical wet- hot and rainy all year
       • tropical dry and wet- hot with dry and wet seaons
   • Moderate mid latitude
     • humid subtropical, marine west coast, and mediterranean
       • humid subtropical- hot humid summers and mild winters
       • mediterranean- hot and dry summers and mild winters
       • marine west coast- mild and rainy all year
   • Continental mid latitude
     • humid continental and subarctic
       • subarctic- short summers and long snowy winters
       • humid continental- warm summers with cold and snowy winters

3. Change

   • how do we know its happening?
     • seawater, sediment, snow, and ice chemicals
     • proportion of CaCo3 in sediment indicates temperature
     • oxygen isotopes 16O and 18O (lighter and heavier), 16 gets evaporated and snowed out first, then if its really cold, 18 will be present
       • discover this by drilling through ice and making ice cores
   • why do we care?
     • human life
       • heath- illness, death, and displacement rise with change, affect US through immigration
       • how did we cause it?- greenhouse gases (biggest) and mostly comes from using energy
       • decrease in food supply
     • animals and agriculture
       • add stress on ecosystems- can they adapt?, affects mainly polar bears, fish, and reefs
       • agriculture- affect food production, wood, and fiber, decrease in bio diversity
     • melting things
       • glaciers
         • lose irrigation and drinking water source; increase in sea levels, see shrinking in increasing locations
       • sea ice
         • sea ice reflects the sun's energy and cools the planet- if melted, it will instead absorb the energy and warm the planet, water warms up, increase in sea level, hard for ice to form
       • permafrost
         • positive feedback process, seen in Alaska, Canada, and Scandinavia, increase wetland presence, releases methane and CO2
     • sea levels are rising
       • by 2 mm every year, 2.4 cm per decade increase, predicted to rise 12 cm in 50 years
       • costly and widespread, causes ocean surfaces to warm
       • erosion of the coast will hurt coastal communities
     • responding
       • conservation- use less energy
       • conversion- switching to better energy resources
       • efficiency- technology that gets most from an energy source
       • waste reduction- eliminate materials that require landfilling- landfill mining
       • sequestration- take greenhouse gases out the air