Flashcards
Geog 1001 - Lectures 9-
Cards in this deck (140)
- 1What are the essential function of soils?1. Medium for plant growth
2. As a water resevior
3. Recycling of plant/animal material - 2What are the components of soils?1. MINERAL PARTICLES - 45%
2. SOIL ORGNAIC MATTER - 5%
3. SOIL WATER - 25%
4. SOIL AIR - 25% - 3What are primary and secondary minerals?Primary - Crystals that make up the rock
Secondary - V.v.v broken-down primary minerals. Primary minerals with reagreggated chemicals - 4What is the importance of organic soil matter?Contains litter/ humus/ biomass
Mineralisation is the break down by microorganisms
Peat is formed where decomposition is slowed
Important for binding/ water holding capacity/ nutrients - 5What are the different types of soil water?1. Gravitational water
2. Capillary water = suction pressure held between minerals
3. Hygroscopic water - closest to mineral = strongest chemical bond
4. Plant available water - 6What are the different soil states?1. Saturation
2. Field capacity
3. Wilting point - 7What is meant by soil air?- Pores not filled with water
- Provides ventilation for soil via aeration
- High CO2 - 8What is meant by eluviation?Minerals washed down into the soils
- 9What is meant by illuviation?Minerals washed into lower horizons
- 10What is the importance of solum regarding soil?Solum is the A, E and B horizons
- Place where soil forming processes are most active
- Plant/ animal life contained - 11What is pedogenesis? Explain inputs, outputs and mixesTHE PROCESS OF SOIL FORMATION
Inputs - Parent material weathered. Solutes and particles from precipitation/ wind energy
Losses - Wind/ water erosion and leaching
Mixes - Through soil animals/ microbes/ roots/ ploughing/ chemicals/ shrinking/swelling - 12What are luvisols?- Soils of fine particles that move down the profile
- Mineral heavy B horizon
- Rainfall > evapotranspiration
- Clay elevated and deposited in argillic horizons - 13What are the features of podzolization?- Areas of intense leaching/ translocation
- Organic acid compounds (Fe and Al)
- Freely drained
- Water moves quickly through soils = leaching - 14What are the features of gleying?- Where water logging leads to reduction/ mobilisation/ removal of Fe compounds
- Mottling apparent
- Oxygen orange in oxidised state
- Oxygen grey in reduced state - 15What are the characteristics of ferralisation?- Heavy leaching = depletion of cations. Secondary minerals destroyed
- V.v thin organic layer
- Deluded, so takes on weathering resistant mineral characteristics - iron=red
IN TROPICAL / SUBTROPICAL SOIL - 16What factors affect soil formation?1. Time
2. Organisms
3. Relief
4. Parent material
5. Time - 17What are the physical properties of soil?1. Colour - nature of soil properties/ horizons
2. Texture - proportion of sand/silt/clay
3. Structure - size/ distinctiveness of peds - 18What are surface water gleys?Where underground water accumalates
- 19What are the different structure types?1. Blocky - temperate areas
2. Spheroidal - Areas of high biomass
*GRANULAR - non-porous
*CRUMB - porous
3. Platy - Inhibits drainage and good for vegetation
4. Prismatic - In clayey soils. Arid/semi arid conditions - 20What is meant by isomorphous substitution in clays?A form of weathering
- Clay minerals become electrically negative
- The negative charge is balanced by cation absorption to the surface by electrostatic attraction - 21What is meant by cation exchange?- Interchange between a cation in solution and another on the surface of a soil colloid
- 22What is meant by cation exchange capacity?It's the net negative charge of a clay mineral per unit mass of soil
Base cations (Ca++) and acid cations (H+) - 23What is special about secondary minerals chemically?They are 'imperfect' and are chemically imbalanced
They then take on the dominant elements around them
Clays have a net negative charge around the edge, meaning minerals can be held and balance the charge - 24What is the pH range of most soils?3.5 - 9 pH
(Slightly acidic is the optimum) - 25What processes can lead to hydrogen and aluminium becoming the predominant cations in soil- increased acidity?- Leaching of base cations in wet conditions
- Acid rain
- CO2 dissolving into carbonic acids
- Nitrification releasing H+
- Crop harvesting removing base cations - 26Why is pH important for crop growth?- Influences the availability of 16 essential elements
Influences fate of toxins and pollutants - 27What are the key elements of the phosphorous cycle?- Comes from, apatite (within rocks) or guano
- Critical for life - energy for metabolism, DNA
- Water is key to distributions, as P is very insoluble. P is adsorbed onto other particles
- Used in fertilisers ect. - Peak p reached?
- Soil --> soil water --> plants --> organic molecules --> consumers - 28What are the key elements of the nitrogen cycle?* N2 abundant in atmosphere as its un reactive
*NH3 / NO/ NO2/ N2O are in trace amounts
* Lightening strike converts N (g) to NO3- - 29What is biological nitrogen fixation?Where NO3- is created through a series of oxidation reactions by nitrifying bacteria
(NH4+ --> NO2- --> NO3-)
It originally occurs as plants
- This fixes it, but other bacteria can convert it to nitrites and nitrates
- It originally occurs in plants but can be used later by consumers - 30What are the human impacts of the nitrogen cycle?- Haber - Bosch process fixation of N2 to ammonium and N-fertalisers
- Internal combustion engines (produce NOx emissions)
- Animal farming - ammonia in faeces - 31What are the main changes that are occurring with the increased N inputs through human use?- Enhanced rates of ammonium/ nitrate depositions in the water supply
- Nitrogen deposition = plants faster growth = increased biomass = increased carbon uptake
- Eutrophication and eventual functional decline of surface water - 32What are the key fluxes of carbon?Photosynthesis
Respiration
Weathering
CaCO3 in limestone letting
Volcanic eruptions
Fossil fuel combustion - 33What are carbon stocks?How much carbon is actually contained in a system
Atmosphere = small (naturally kept in balance by exchanges in land + oceans)
Soils = large
Ocean = the biggest - 34What is the extent of anthropogenic burden on carbon?-7.5-8.5gtCyr-1
(Fossil fuel combustion = 6.5gtCyr-1. Forest clearing = 1-2gtCyr-1)
Concentrations in the atmosphere only rising by 3gtCyr-1, as terrestrial and ocean uptake removes some - 35What are the limits looking like for C, N and P?C - Exceeds safe limit (350ppm)
N- Greatly exceeds safe limit
P - Nearing safe limit - 36What techniques are used to explore how changing climates have been affected and are affecting humans?- Reconstructing past climates
- Archeological digs
- Paleoecological techniques
- Ice cores (gas bubble analysis for air compositions to give indicators for temperature) - 37When was the Holocene?Over the past 11,000 years
Stable climates
Humanity flourishes - 38What are the key points of the 8200 BP event?- Temperatures around Greenland falling dramatically
- Melt of the Laurentide ice sheet caused the formation of Lake Agassiz
- A weak point in the lake caused 150,000km3 meltwater to flow in the Hudson bay and towards the Atlantic
- 1-2'C drop in temp and 1.4m rise in seas modelled
- Displaces European coastal communities - 39What are the key points of the Browning of the Sahara?- Amplified climate impacts on soils and vegetation caused by the weakening African monsoon
- Thresholds and feedbacks
- Green Sahara (full monsoon climate) to Brown Sahara
- Caused by a long term decrease in solar radiation to N. Hemisphere (from small change in Earth's orbit) = rainfall decrease = vegetation decrease = increase dust and crossing of thresholds - 40What are the main points of the medieval warm period?AD 950- 1250
- Benign conditions leading to boom in agriculture. Less famine = pop. explosion
- Black death meant a pop decline
- 0.5'c - 1'C change - 41What were the issues surrounding the collapse of the Maya?- 800AD Mayan population reached peak
- Carrying capacities tried to be increased by clearing forests (soil erosion)
- Period of water stress thought to also have been an issue...
....Sediments observed in the Carinoco Basin in Mexico were made of gypsum and layers of chemical deposits - 42What are the main points of the little ice age?* Periods of cooling around 1150 -1460
*Severity of storms have increased
*Cold summers meant growing season decreased by 15-20%
*1788 bread riots in France thought to have sparked French revolution
*Malnutrition led to weakness to disease (bubonic plague/ malaria)
*Upland areas abandoned
*>1'C change - 43What are sunspots?*Flares on the suns surface
*They mean earth receives more energy in these periods - 11 year spikes
*Maunder/ Dalton and 1900 minimum periods saw drops in sunspot activity - 44How are the isotopes Be- 10 and C-14 used as proxies for reduced solar outputs?They're more predominant where there are lower numbers of sunspots
- 45How does volcanic activity affect sunspots?(short lived) cold periods occur in time with large eruptions
- Tambora 1815
- Krakatoa 1883
- Pinatubo 1991
Clouding effects can block the suns irradiation
Tree rings show poor growth when this occurs so can be used as proxies - 46What are considered natural forcings?- Solar
- Tectonic
- Climate
- Oceans - 47What are human forcings?- Population
- Technology
- Culture
- Orgnaisation - 48What is meant by climatic determinism?Natural forcings having an effect on human society and ecosystems
- 49What is the anthropocene?- Changes in the Earth's climate is down to human influence
- CO2/ N2O and CH4 all rise from 1750
- 2015 the first time CO2 over 400ppm
- 80% world's total energy from fossil fuels
- Stratascopic ozone/ ocean acidification and shrimp aquaculture all up
- - 50What does the carbon dioxide record show?- Measured in Mauna Loa (every hour every day)
- Yearly fluctuations, but general rise
- South Pole data shows upward rise too
- Glacial = low CO2
- Interglacial = high CO2 - 51What are facts for recent global warming?Since 1880, unquestionable rise in temperature (around 0.85'C)
Each of last 3 decades warmer than the last - 52What have been the effects on the cryosphere and sea level through global warming?- Decrease in Northern hemisphere spring snow cover since 1960s
- Greenland/ Antarctic ice sheets continually loosing mass
- Global sea levels rapidly rising from thermal expansion and addition of meltwater (150mm over past 100 years)
- 30% of temperature rise has been attributed to pre- industrial people - 53What do global climate models set out to achieve?The degree to what extent changes are natural or anthropogenic
- Anthropogenic seem more in line with changes
- Natural forcings more constant and flat - 54What are the theories for early hypothesis of anthropogenic induced warming?Over the holocene, CH4 and CO2 high at the start, then fall then come back up
In other interglacials there has seen a downward trend because of downward trend of solar radiation - 55What are the links with forest clearing 8000 years ago and greenhouse gases?- As agriculture spread from E.med, evidence from 10000 years ago there was much deforestation
- CO2 up after a trough at 8000 years ago and CH4 5000 years ago - 56How has CO2 changed in the last 2,500 years?* Dips around 1500BP and 500BP correlate with epdemics = natural reforestation after people die and move off the land
- 57Why do CO2 levels fluctuate seasonally?Seasonal minima in areas of higher vegetation see CO2 drawdowns
- 58What are the theories for the difference in tertiary global cooling?1. STRONG MONSOONS - encouraging phytoplankton
2. INCREASES OF CHEMICAL WEATHERING - More modern flowering plants = faster cation production = faster chemical weathering
3. MOUNTAIN BUILDING - Creating land at higher altitude
4. FORMATION OF ANTARCTICA - Albedo of ice reinforced global cooling - 59What does to Vostok record show during the tertiary period?* Large fluxes in global temps
* Ipswichian period slightly warmer than todays interglacial
*Many layers of unconsolidated materials on top of cretaceous chalks - 60Where does evidence come from for the 50+ glacial- interglacial cycles?1. Ice sheet
2. Sediments in ocean basins
3. Quaternary marine records
4. Oxygen isotopes - O-16, O-17 and O-18 all in different ratios so used as proxy for global ice volumes
5. Crater lakes
Trees = warm, Grass= cool
6. Pollen
7. Diatoms - x-rays can show summer or winter conditions - 61When are cycles considered statistically significant in time series analysis?On 100,000 year cycles (like glacial/ interglacial cycles) and when the sets contain at least 7-10 different cycles
- Time series analysis data sets use the environmental variable and plot it against time - 62What are the three main hypotheses for long term climate change?1. Geographical changes in the Earth's surface ( mountain building)
2. Changes in the atmosphere
3. Changes in solar radiation receipt - 63What astronomical factors cause day and night?24 hour cycles
Caused by rotations in the Earth's axis
The equinox is where there is equal night and day - 64What astronomical factors cause the seasons?- The tilt of the Earth's axis
- Midwinter is slightly warmer, as we are closer to the sun - 65What is perihelion?Where the earth is closest to the sun
- 66What is Aphelion?Where the earth is furthest from the sun
- 67Where does the Earth's axis point in the Northern hemisphere summer?Towards the sun
(It points away in the winter) - 68What are the long term changes in the Earth's orbit?1. ECCENTRICITY (weak) - 100,000 years
Shape of the orbit changes from circular to elliptical. Makes for summer/winter
2. OBLIQUITY (strong) - 42,000 year cycle. Tilt of Earth's axis change between 21.5' + 24.5'
3. PRECESSION OF THE EQUINOXES (strong) - 21,00 year cycle. Wobble in the axis. Caused by celestial bodies pulling the Earth around (also causes tidal forcing) - 69What palaeo- evidence is there for support of the orbital theory?1. PRETORIA SALTPAN RAINFALL - time series analysis for the past 200Ka
2. OCEAN CORES - Contains over 50 climatic cycles and shows eccentricity of the orbit and obliquity of the ecliptic
3. OXYGEN ISOTOPE RECORDS-
Frequencies match with cycles - 70What are the problems with the astronomical theory of climate change?1. Can't explain long term tertiary cooling
2. Stage 11 problem - at 400Ka, an interglacial with v. pronounced glacial that doesn't fit Milankovitch
3. Main pacing of ice age shifted from 41Ka and 100Ka
4. 900,000 years ago, there was a shift from 41,000 - 100,000 year cycles - 71What is meant by the 100,000 year problem?The forcing at 100,000 years is weak, yet it seems to be the pacing of the ice ages
Ice sheet growth enforced by +ve feedback - 72What are the main 5 positive feedback mechanisms?1. Albedo
2. Reduced sea level - larger land area for ice
3. Smaller sea area - can't store as much energy
4. Ice sheet height
5. CO2 reduced in the atmosphere - lower CO2 = slow down of ocean ventilations - 73What factors drive sub-milankovitch climate change?1. Volcanism
2. Solar irradiance
3. Ice sheet and ocean
4. Changes to ocean
5. Human impacts - 74How can volcanism drive sub-milankovtich climate change?- Ash and debris goes high into jet stream
- Sulphur detected in ice cores and it adds to cloud formation and cooling
- Particles can act to block solar radiation
- Volcanism thought to contribute 22% of temperature variability of last 1,000 years
- Deglaciation can cause water loading = flexing of crust = more eruptions - 75How can solar irradiance drive sub-milankovitch climate change?*11/200/ 1500 year cycles shows higher sunspots
*Reduced sunspot activity = less solar output = weaker solar winds
*Solar winds intercept high energy particles from deep space
(C-14 and Be-10 created when not blocked) - 76How can ice sheets and oceans drive sub- milankovitch climate change?- Some changes in the great ice sheets occur independently to milankovitch
- Glacial/ interglacial cycles are higher frequencies than milankovitch cycles
- Ice sheets = ice streams + stagnant ice
- Can increase global sea level rise and add to global cooling - 77What showed the end of the Ipswichian interglacial- Two short lived cold stages (oxygen isotope stages 5b + 5d) at end
- 95Ka BP saw surge in Antarctic ice streams and caused cooling
- Antarctic ice sheet saw fluctuations though oxygen isotope stage 5
- Ice sheet may have collapsed chaotically
- Surge could've raised sea levels - 78What is meant by surging?- Caused by distribution of basal till, lubricated the flow of the ice sheet
- Enhanced global temperatures could potentially trigger Antarctic ice sheet collapse
- This could disrupt thermohaline circulation - 79What are IRD layers?ICE RAFTED DEBRIS LAYERS
- Climate changes coincide with IRD layers in the ocean core record
- Normal, fossil rich ocean sediment show ward ocean conditions
- Clast - rich IRD layers (few/no fossils) show it would've dropped out of ice - 80What and where in time is the Younger Dryas?- Earth slowly cooled during Younger dryas after the false start to the Holocene in the Bolling/Allerod lategacial interstadial
- Tundra forming through periglaciation - 81What is the evidence for the 8200 event?- An Atlantic- wide cooling event
- 1/3 magnitude of the late glacial climatic fluctuations
- Associated with the release of major icebergs - 82What is the evidence for holocene wet shifts?(Holocene wetshifts at pacing of 1,100 yrs)
- Holocene warm period sees 10+ major oscillations with 1,100 year pacing
- Probably caused by changes in N.Atlantic circulation
- Plants and amoebas show cooling/warming cycles - 83What is THC?(Thermohaline circulation system) Acts to transfer heat around the Earth
Changes in N.Atlantic Ocean circulation are considered important in driving sub-milankivtch climate change - 84What are the 2 main factors in driving THC?1) SEA WATER TEMPERATURE - colder=denser
2) SEA WATER SALINITY - saltier = denser
Cold/ saline water will sink and form DEEP WATER - surface waters rush in to replace the sinking column - 85Where does upwelling occur?N. Pacific and Indian Oceans
- 86Where does the gulf stream deflect off?Cape Hatteras
- 87What happens during THC?1. Warm water heading N looses energy
2. Storms going W --> E bring in evaporated water from the Atlantic
3. Water lost from the Atlantic goes N and lost into Arctic watersheds
4. Evaporation losses then make the water more saline
5. As water freezes to make sea ice, salt is left in the water below the ice
6. Saline water sinks as density is high
7. Brine exclusion excludes the salt - 88What is NADW North Atlantic Deep Water- A major site of deepwater formation
- Can then cause major impacts on the THC when altered
- Situated near Canada and Iceland - 89What can cause disruption to THC?- Salinity/ temperature differences
- Iceberg calving
- Meltwater discharge
- Warming of surface waters - 90How can iceberg calving cause disruption to THC?- Ice sheet collapse and surface water makes it less saline
- Cap of freshwater on the ocean prevents and slows deepwater formation
- Heat transfers to N.lattitudes reduce - 91How does NADW change during late glacial?- Laurentide ice sheet in America size change massive
- Created lake agassiz
- 11,500 BP, the St. Lawrence river valley opened allowing water to flow into the oceans
- Lateglacial stadial proceeded the outflow from Lake agassiz
- 9,500km freshwater flowed into most sensitive area of NADW formation - 92What are the proposed causes of the late glacial stadial?1. Drainage of cold meltwater from glacial lake Agassiz
2. Collapse of Barents sea ice sheet
3. Changes in insolation caused by volcanic ash
4. Changes in jet stream
5. Changes in solar radiation
6. Strong winds = increased high pressure over Greenland
7. Surge in Canadian ice sheet
8. Fluctuations in atmospheric CO2
9. Meteorite impact - 93What is the problem with the lake Agassiz idea?- The late glacial event = full glacial/ interglacial change from 9,300km3 discharge
- 8,200 BP event = climate cooling only a 1/3 of late glacial stadial, but 163,00km3 discharge - 94What theories are there as to why there such differences in late glacial stadial and 8200 BP event could occur?1. THC itself has a weak glacial circulation and a strong interglacial circulation
- 8,200 event occurred when THC was still in strong interglacial mode
2. Lateglacial outburst went straight to more sensitive part of N.Atlantic - 95What are the IPCC sea level change predictions for 2100?60-70 cm or 1.8m for worst case scenarios
- 96What is the main concern for coastal areas with rising sea levels?Storm surges
- 97What types of geomorphological evidence provides evidence for past sea level change?1. RAISED WAVE CUT PLATFORMS - above present mean high waters
2. RAISED BEACH DEPOSITS
3. Be-10 IN QUATX CRYSTAL LATTICE - how long the rocks have been exposed to the sun - 98How do submerged terrestrial features provide evidence for past sea level change?SHOWS RSL LOWER
- Freshwater remains at sea level
- Increased river valleys and submerged forests
- Submerged peat beds (freshwater --> saltwater) - 99What sedimentary evidence is there for sea level change?1 - SEDIMENT CORES
Saltmarsh clays --> freshwater peat = -ve sea level tendency
Freshwater peat --> marine clay = +ve sea level tendency
2 - ISOLATION BASINS
Use sediment coring and come from where the glacier has melted
3. EVIDENCE IN THE MED
Received large influx of meltwater at the end of the last ice age. Cave deposits have shell remains - 100What are sea level index points comprised of?1. Date
2. Altitude
3. Tendency change - 101What is eustacy?GLOBAL changes in the ocean volume
- 102What is isostasy?Tectonic change in the level of land LOCALLY to the sea
- 103What forms are the of eustatic change?-Hydro
- Sedimentario... Gradual infilling of ocean basins with sediment
- Glaico... Build ups of ice. Last ice age saw a 100 - 120m drop
- Thermal expansion/ contraction of sea
- New water added from volcanoes
- Tectono... change through continental scale activity - 104What is the geoidial effect?- The sea isn't evenly distributed
- Sea level is affected by Earth's rotation and density
- Changes in ice sheet sizes can cause gravity changes
- Sea is attracted to gravitational pull of the ice sheet - 105What are the key features of glacio- isostacy in Europe/ GB?Ice sheets push on crust and create a forebuldge
25,000 BP = ice sheets over Scandinavia and Scotland
Beach ridges provide evidence for this
Scotland rebounding, south sinking
Hinge line correlates with global ocean basin filling - 106What other isostatic processes are there?Loading of the crust from...
1. Sediment
2. Flooding of the continental shelf (it's thin and flexible) - 107What is meant by the energy balance?Incoming and outgoing radiation differences
- 108Where does heat transfer occur?In the stratosphere - where incoming radiation changes to outgoing
Through convection it changes to clouds - 109What is the importance of CO2?- CO2 and temperature strongly correlated
- It freely mixes in the atmosphere and coordinates Northern/ Southern glaciations
- Triggers of glaciation are often orbital, but NADW and volcanism play roles
- Glaciation starts in the North, reducing CO2 and enforces global cooling and glaciation in the South - 110Why does atmospheric CO2 decline during glaciation?1. CHEMICAL WEATHERING - Greater land mass = solution of rock by carbonic acid locks up CO2 (50-100ppmv drop in Ipswichian)
2. CHANGES IN THE OCEAN
*TEMPERATURE - CO2 more soluble in colder water (However, colder oceans = more salinity = CO2 release)
*PRODUCTIVITY - In glacials, Northern sea ice pushes phytoplankton south = stronger productivity. Low productivity areas of the oceans where there's been nutrient leaching (iron) - 111What are the key points to the iron hypothesis?- Lots of dust in perglacials as organic matter low
- Lack of water in continental interiors
- Braided stream channels disgorged by ice add to dust
- Sinking air onto ice sheet = windier conditions - 112What is the effect of dust?- Greater oceanic productivity
- Greater cloudiness and increased albedo
- A source of condensation nuclei for cloud development - 113What are the effects of methane?- Lower in glacials (350 ppbv)
- Higher in interglacials (650 ppbv)
- Changes in wetland composition main driver for changing CH4 - Thaw lakes = darker = heating = expanding lake
- Methane producing bacteria can also then eat the decaying organic matter - 114What is the effect of water vapour?- Normally super abundant in interglacial periods
- Cold air holds less vapour (in glacials)
- Colder oceans = restricted evaporation
- Precipitation can start to reduce at beginning of glacials, this tipping the balance for meltwater and ever increasing starvation of water (oceans are warm at the beginning and moisture starvation then affects ice sheet growth) - 115What is the outcome of recent global warming?- Mean global temperature is up 0.65' - 1.06' since 1880
- 2011-15 warmest 5 year period
- CO2 over 400ppm - highest in 800,000 yrs
- Solar irradiation (sunspots) the only glare it may not be humanly influenced - 116Where has warmed the most?Higher latitudes
- 117What have precipitation changes showed?Some areas have become wetter, but others much drier (N.China/ Sahara)
- 118What other issues have become apparent through recent global warming?- Number of cold days and night decreased on global scale due to night temperature changes (warm days and nights increased)
- Frequency of heat waves has increased
- Frequency and intensity of heavy precipitation events has increased - 119What are global climate models?- Mathematical representations of physics and chemistry laws
- 3D systems of cells showing the interactions
- Simulate movements of energy and matter in all directions and flows between spheres
- Complexity and spatial resolution has increased
- What ifs now analysed - 120What is TRF?- SREs (social/ economic pathways) were the basis of emission scenarios previously
- Now based on total radiative forcing data (for 2100 relative to 1750)
- Focuses not only on CO2, but all extra forces on climate
- TRF is +ve, so led to uptake of energy in the climate system
- 2MW2 of radiative forcing increase since 1750
- Solar inputs very small compared to GHG - 121What are the global climate projections?- RCPs (representation concentration pathways) show forward projections
- Mean annual/ monthly precipitation and temperature taken from a pre-determined base line
-IPCC made 4 RCP predictions - 122What is the RCP predictions for 2.6?If carbon stopped now
Lag time makes for a 1'C rise by 2100
0.6'C rise in top 100m of sea surface - 123What is the RCP predictions for 8.5?Business as usual
4'C rise in world average (5-7 in high latitudes). Would normally change glacial- interglacial (but already in interglacial)
Mid latitude would see a change in preoccupation drop
1.5'C rise by 2040
2'C rise for sea surface temperatures - 124What has the UK climatic impacts programme (UKCIP) found?- Shows low/ medium and high emission scenarios
- Latest projection was in 2009
- At a higher resolution to GCMs. Regional within the UK
- Weather forecasting models
- Summers to be warmer by up to 5'C
- Winters warmer by up to 3-4'C
- Precipitation more seasonal - drier summers (-60%), wetter winters (+30%) - 125What are examples of positive feedbacks?1. Melting Arctic ice = dark coloured sea
2. Warm climate = permafrost melt = methane release
3. Warm climate + more forest = reduction in albedo + increased surface warming - 126What are the examples of negative feedbacks?- Warmer atmosphere = melting ice caps = disruption in N.Atlantic THC = colder EU
- 127What has been acknowledged for future impacts?- IPPC RCP predictions = future only gets worse
- Significant notable issues for human/ecological systems = impacts (-ve or +ve)
- Fisheries have been most effected
- Management procedures widely discussed and many LEDCs not as willing to participate as hypocritical - 128What would happen with a 2'C rise?-1 bn people effected
- Corals bleached
- Higher risk of coastal flooding
- Higher mortality from vector disease increases - 129What are the future impacts for water?1. Rarer event have higher magnitude and frequency, as heating makes climate more energetic
2. Streamflow change of 2'C above present causes water losses in areas of high ecosystem and tourism
3. Water can increase in other areas causing floods
4. Seasonal changes downstream where glacial retreat is causing less ice caps - 130What are the future impacts for corals?- Even a 1'C rise can change coral metabolism and bleach them
- Strongest ocean warming is projected for surfaces where corals exist
- Higher CO2 = higher ocean acidity = reduction in ability to produce calcareous skeletons - 131What are the future impacts for ecosystems?- Many ecosystems specifically threatened
1. MID-LATITUDE/ SUB-TROPICAL glaciers cause water flow retreat
2. ENDORHEIC LAKES where water will continually evaporate
3. THOSE WITH MITIGATION BARRIERS - isolated areas miss out on tracking changes in temp/precipitation
4. CORALS
5. MANGROVES/ SUNDABANS
6. ENDANGERED SPECIES - 132What are the future impacts for food and agriculture?- Rising issues over food security
- In temperate latitudes Increase temps = increase yields as increased CO2 is utilised by plants
- In low latitudes, increase temps = decrease moisture = lower yields
- MARINE FISHERIES - see strong changes in catch potential. Massive drops in Asia as people depend on fish - 133What are the future impacts for sea level?- Likely to rise 0.26 - 0.98m by 2100
- Thermal expansion 30-55% of global sea level increase
- 15-35% glacial input - 134What are the future impacts for UK sea level?*South rise predicted at 26-86cm above present day by 2080
*More frequent winter storms predicted
- Thames flood barrier being increasingly used (119 times since opening)
- As the mean averages change, extremities are becoming more common - 135What are the future impacts for health?1. Malaria thought to extend north - changes in the transmission season
2. Increase in malnutrition
3. Rare events (2003 heatwave) becoming more common - many deaths - 136What are impacts?1. MULTIPLE
2. CASCADING
3. UNPREDICTABLE - 137What is hue?The dominant colour
- 138What is chroma?purity/ strength of the colour
- 139What is value?The lightness/ darkness
- 140—
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- Flashcards on Geog 1001 - Lectures 9-, created by Pippa Holman on 06/01/2016.
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