UNIT 2: Global climate Flashcards
Define global dimming
mixture of fog and pullutants that reflecrt light but trap long-wave radiation.
Define terrestial albedo
ratio of incoming solar energy and amount of energy that is relfected.
long vs short wave radiation
short wave–> emitted by sun
long-wave–> reflected from earth into atmosphere.
Describe the atmospheric energy budget
balance of inputs (isolation incoming solar radiation), and outputs (re-radiarion (albedo)–> this keeps the erath from overheating +freezing.
What are the natural conditions through which the atmospheric energy budget is achieved
1. Radiation–> short and long waves
2. convection–> circulation of hot and cold ocean currents.
3. Conduction– >transfer of heat through direct contact
Explain the greenhouse effect (normal/natural one)
- short wave radiation is emitted by the sun and some is reflected to the atmosphere, and some is absorbed.
- long-wave radiation is re-emitted back into the atmosphere
- greenhouse gases trap long-wave radiation which re emits heat back into the erath (warms the earth)
What are the types of greenhouse gases
- water vapour –> the most abundant
- carbon dioxide–> from human activity
- methane–> from cattle, permafrost
- CFCs (choloflurocarbons)
Describe the effect of polar ice melting and urbanisation
polar ice caps absorb incoming solar radiation (terrestail albedo)
as the ice melts due to increasing temperatures more sunlight is absorbed by the oceans and raises temperture
* This raise in temperature melts more the ice (positive feedback loop)
URBANISATION–> decrease/increase albedo depending on albedo
dark surfaces–> absorb heat
light surfaces –> reflect heat
Positive vs negative feedback loops
- positive:
- natural system amplified due to arrangement
- if one element changes–> reinforces system (amplifies)
- Negative
- cancels out or lowers the effect of original change
- balanced
What are factors that affect global climate
- Volcanic activity–> emit dust particles/ashes
- Sunspot activity
- positive feedback loops (amplify changes) example–> increase CO2 in atmosphere–> polar ice mealts–> less albedo (earth gets warmer)
- increase of greenhouse gases (human activity)–> burning of fossil fuels
*
Describe the consequences of climate change
- Sea level rise–> flooding, migration and economic loss
- Melting of glaciers–> flooding, affects water supplied, droughts
- increase in storm activity–> affects agriculture, infrastructure etc.
- Changes in weather patterns–> droughts, agricultural losses, hunger.
- Extinction of wildife–> changing biome distributions, affects food chains.
Impact climate change has on the carbon cycle:
- stored in ice, oceans and biosphere
- release of carbon due to fossil fuels has increases–> harder for organisms to adapt
- more carbon that what enviorment can absorb.
Describe the changes in caron stored in ice, oceans +biosphere
In ice:
* permaforst contains a lot of carbon–> when it melts it releases carbon and methane from dead organic matter. contains nutrients.
In oceans
* oceans dissolve carbon dioxide to carbonic acid–> lowers pH(acid)
* carbonic acid weakens marine shells making them more vulnerable.
In the biosphere
In biosphere:
* sinks such as forests assimilate a lot of carbon dioxide. deforestation emits a lorge potion of that was in biomass.
Human impacts of climate change
- ocean transport*–> due to seas level rise which alters routes and ports
-
Migration—> extreme weather pattets destroy homes and forces people to migrate (eg in Kiribati and Maldives)–> sea level rise.
* Human health–> heat waves, crop yields, pests, diseases fewer water resources.