Global Climate—Vulnerability and Resistance Flashcards
Define: albedo, anthropogenic
Albedo: amount of incoming solar energy reflected back to atmosphere
Anthropogenic: human-related processes or impacts
What are the atmospheric layers?
Dif altitude = change in gas concentration
< 17km, troposphere: weather, temp drops with height
17 to 50 km, stratosphere: stable, thin, increase temp with height from solar radiation
*35 km is ozone max concentration
50 to 80 km, mesosphere: temp decrease bc no energy absorption
80+ km, thermosphere: vacuum, temp increase from short wave
What is the atmospheric energy balance?
Atmosphere is open-energy system recieving from sun (insolation) and earth
Sun drives weather + climate, most energy absorbed at tropics and lost at poles → resist from low to high latitudes by wind + ocean currents
Earth energy causes microclimates
Describe earth’s atmospheric energy budget
Was balance between insolation and re-radiation, now global warming
Naturally, balance via: radiation, convection, conduction
Short-wave:
46% reach surface:↑long wave re-rad, atmospheric conduction, latent heat
31% reflected to space
22% water cycle
1% wind + ocean currents
Atmosphere heated from below
Greenhouse gases trap outgoing long-wave radiation
What are the characteristics of short- and long-wave radiation?
Incoming short-wave: main input, varies with sun angle and cloud type
Mainly in visible wavelengths → not absorbed, but heat earth
Long-wave from earth: on cloudless nights big loss, on cloudy nights some is reflected
Seen in change of day to night temps
What is the greenhouse effect?
Greenhouse gases allow short-wave radiation into earth, but trap long-wave radiation
Vital in keeping stable temps to support life
Water vapor: 50% of effect, not an issue for warming
CO2: 20% of effect, increasing from deforestation, fossil fuels
Methane: increasing presence from wetlands, cows
Chlorofluorocarbons: destroy ozone, increasing
How do changes to solar radiation effect temperature?
11-year solar cycle and longer earth orbit cycles → seasonal changes and ice ages
Change in atmosphere or albedo = change in temp
What is global dimming?
Air pollution decreases temperature—global dimming
After 9/11, 3 days w/o US air fleet → increased temp
Short-term cycles for <10 yrs after volcanos; long-term trends from humans
Normal air particles form a few water droplets → rain
Polluted air has more particles with small drops, so better reflection → not rain
What are negative and positive feedback loops for global warming?
Positive: melting ice
Melting ice caps → lower albedo → less reflection → higher temps → melting
Positive: methane
Thawing permafrost → trapped methane released → more greenhouse → melting
Negative: evaporation
Low-lat precipitation → evaporation → snowfall in high-lat → lower temp
Negative: CO2
Atmosphere CO2 → more photosynthesis → more plants → less CO2
Describe case study: negative feedback in Greenland
Since 2002, new areas of Greenland ice shelf are melting, more each year
Maybe:
Melting → rising sea levels → shut off Gulf Stream current → depressions → Britain snow → Greenland has time to freeze each winter
What is the enhanced greenhouse effect?
Impact of increasing greenhouse gases from humans
Also called global warming
Linked to industrialization, trade, globalization
Per-capita, it’s an HIC problem
How does climate change effect the hydrosphere?
Hydrosphere: freshwater, seawater, ice, glaciers
Rising sea levels (40 avg cm) could displace 200 mil
Glacier flood could threaten 5% of world pop
High risk of storm surge in coastal cities
How would climate change effect sea ice / ice caps?
Arctic sea ice declining since 70s, ice isn’t there for as long (1988 25% > 4 y/o, 8% in 2013)
Positive feedback loop: less ice → more waves → ice breakage → less ice
Impacts: methane emissions, wet Europe summers, plankton blooms, loss of polar bears
Himalayan glaciers are retreating, likely to cause water shortage in high altitudes
How do changes in carbon effect oceans?
Oceans have much more carbon than atmosphere, both rising
Ocean acidification from carbon diffused into water endangers marine species + shells
May decrease some phytoplankton
How do changes in carbon effect the biosphere?
More carbon often = plant growth (25% of human carbon absorbed by terrestrial plants)
When farmland is abandoned, plants grow and store carbon; fires to clear land release it
Deforestation releases carbon from forests to atmosphere