D4.3 Climate Change Flashcards
Climate
a long term average of the weather over 20-30 years
climate change
a long term change in global or regional climate patterns, caused by natural or human factors
Eg of climate change
increased levels of atmospheric CO2
The greenhouse effect
the heating caused by the atmosphere on earths surface because certain atmospheric gases absorb and emit infrared radiation
why is the greenhouse effect very important for life
without it the earths temperature would be too cold
green house gas
a gas the contributes to the greenhouse effect by absorbing infrared radiation
types of green house gases
carbon dioxide
water vapour
methane
nitrogen oxide
what is green house gas largely a product of
gas and how abundant it is
eg of the abundance of gas
methane is more powerful than CO2 but CO2 is present in higher concentrations than methane
what are long term records of changing levels of greenhouse gases based on
evidence from ice cores
ice was formed by accumulation layer upon layer
trapped green house gas from atmosphere
what does ice core provide
a record of how CO2 and methane concentrations have varied over a period of 400,000 years
what does CO2 increase due to
respiration
combustion
decay by micro organisms
burning of fossil fuels
deforestation
agricultural emissions
what due CO2 decrease due to
fixation of gas during photosynthesis
what does photosynthesis do in terms of Co2
withdraws almost as much CO2 during the day as released by other processes but not quite as much
what does keeling curve show
atmospheric CO2 rising
keeling curve
a daily measure of global atmospheric CO2 concentration
global warming
an increase in the global average temperature of the earths surface and atmosphere
carbon dioxide
due to build up of human activity
double impact of deforestation
increases atmospheric CO2
removes trees that convert CO2 to glucose
what does trees account for in terms of CO2
removing 12-15% of CO2 caused from burning fossil fuels
Methane symbol chemical
CH4
Methane
- 2nd largest contributor to global warming
- increasing rapidly 0.5-2% every year
- cattle releases 85 mil tonnes annually
- natural wet lands release 150 mil tonnes
positive feedback
increasing temperatures, thawing permafrost and the release of methane
methane feedback
1/4 of the earths surface is affected by continuous or sporadic permafrost
covers 23 mil square km
formed during past cold glacial periods, persisting through warmer periods
rising of temp - methane
permafrost melting rapidly
temperatures have risen by 4-10 degrees since 1960
climate related drying of wetlands
increases emissions of methane and CO2 in peatlands
would increase the potential for peat fires
elements of the model for water vapour
temperature rises
permafrost thawing to release methane
reduction in oceans ability to absorb CO2
begins to release CO2 instead
what happens to CO2 in oceans
sink to colder parts
carried in the bodies of creatures
phytoplankton absorb some
transfered to food chains
organic carbon eventually sink to ocean floor with death
albedo
the fraction of solar radiation reflected b a surface or object, often expressed as a percentage
increase global temp means
Greater chance that droughts will occur, and the chance of fires increases
Boreal forest
store more carbon than tropical forest
are distributed across the greater area
frozen soil contain large reserves of carbon
SIRS full form
Siberia integrated regional studies
what does SIRS aim to investigate
Environmental change in Siberia due to global changes
what has happened in Siberia
Temperatures have increased and number of frost days and growing season length have also increased
decreased winter snowfall means
Increased incident of drought and reductions in primary production in tiaga
first main regional challenge
Permafrost degradation forms a significant carbon and methane source to atmosphere
Climate related drying would alter methane emissions in peatlands and would increase the potential for fires
second main regional challenge
Temperatures and rain increases forest browning and increases the frequency of fires thus changing carbon cycle
third main regional challenge
Shifting ecosystem borders words reducing 40% of present area
arctic features
Highly sensitive region
Decline in arctic sea is 12.6% per decade
Maybe no ice by 2060
Greenland similar
loss of sea ice impact
Impacts animals that use the ice to feed and breed
example of a walrus in loss of sea ice
Can’t swim so uses ice as a place for rest between dives to the sea floor
how much ice is Antarctica losing approximately per year?
150 billion tons of ice mass due to melting
landfast ice
See ice that is fastened to the coastline to the sea floor around shows or grounded icebergs
What happens as temperature increases in terms of ice?
Sea ice breaks away from the attachment
Happening earlier in the year due to global warming
Good impact species ongoing survival
what do oceanic conveyor belt do
Transfer energy around the world and links the greatest oceans
Equator and high latitudes temperature
Equator is warm
latitudes are cold
What is happening with increasing temperature at the poles?
More melting ice decreases ocean salinity, and slows currents
what do ocean currents convey?
Heat energy from warmer to colder regions through the pattern of convection
what happens as the Gulfstream slows down?
More heat is retained in the Gulf of Mexico
Hurricanes get their energy from warmer waters, and are becoming more frequent
upwelling
Process with deep cold water rises towards the surface of the ocean
impact of upwelling
Draws nutrients to surface, causing an increase in phytoplankton and zooplankton
Some animals, such as whales migrate to these areas
what happens if ocean primary production decreases in areas?
Knock on effect for marine food chains
what can warmer surface water prevent in nutrient upwelling
Can prevent nutrient upwelling to the surface
Decreases ocean, primary production and energy flow
increase in main global temperature has an effect on
Distribution of habitats communities and ecosystems
where species move as a result of warming conditions
Upward in mountain ranges, causing habitats to shift higher
response of terrestrial organisms to climate change
Distribution of organisms are currently shifting in latitude or elevation
why do species need to shift to colder areas?
They have zones of tolerance
Distribution changes
upslope range shift
Process where mountain species move up higher in the mountains in response to recent temperature increases
distribution of biomes depend on
Climate
what do corals form and some features?
They form underwater structures called coral reefs
Are formed in warm, shallow waters where sunlight penetrates
Home to 25% of all marine species
What does increase in CO2 do to oceans
Cause more absorbing of heat
Changing of ocean currents
Rise in ocean temperatures
why do the rise in temperatures affect corals?
Have a very sensitive range of tolerance
algae is expelled which causes bleaching and kills the coral
calcification due to CO2
Coral skeleton male from calcification
Increased CO2 causes a certification and suppression of calcification
Once the coral has been lost, other species lose the niches, and the coral reef loses its biodiversity
afforestation
The establishment of forest in an area where there was no previous tree covers
what the nutrients act as and help with
Help with climate change and mitigation
what is the UNREDD program?
Provides incentives for developing countries to conserve their rainforest by placing a monetary value on forest conservation
Stresses the role of conservation
agroforestry
Combines agriculture with forestry, allowing the farmer to continue cropping while using trees for animal, food fuel, and building timber
carbon sequestration
The capture and storage of CO2 from the atmosphere by physical or biological processes, such as photosynthesis
Forest regeneration
New trees and forest species become established after forest trees have been harvested or have died from fire, insect or disease
how is peat formed
In certain conditions in waterlogged soils, dead organic matter is not fully decomposed, but accumulates as peat
how does peat increase carbon in the atmosphere?
peats shrank decomposed and became eroded by the wind
what does restoring wetlands do
Increases land carbon store, and decreases the atmospheric store
