climate change - natural hazards Flashcards
causes, adaptations, mitigation
climate change definition
a long-term shift in the average weather patterns of the Earth, such as changes in temperature, precipitation, wind, and ocean currents
global warming definition
the gradual increase in the average surface temperature of the Earth
Ice cores
-geological, long-term
-drill into ice sheets, analyse gases trapped within, oxygen isotopes are used to estimate temperature: higher ratio of O-18 to O-16 when warmer
-800,000 years back
sediment core/pollen analysis
-long-term, geological
-core trap information: organisms, sediment, pollen
-types give data on past temperatures, oxygen levels + nutrients
historical records
-medium-term, imprecise
-paintings, diaries, newspaper, culture can tell us climate in the past e.g. painting of the Thames frozen over
tree rings
-medium-term, indirect
-dendrochronology
-thicker ring = warm, wet
-thin ring = cold, dry
-ring per year of growth
retreating glaciers
-medium-term
-warming, melting glaciers
-measure how fast ice melts, provide visible changes
weather records
-short-term, instrumental
-measured data from weather stations provides lots of information: wind, rain, temp etc
-only goes back to 1850s
polar ice melt
-short-term
-can take data from satellites
ecosystem changes
-short/long-term
-extinctions/migrations/
adaptations of organisms due to climate
3 natural causes of climate change
orbital changes (Milankovitch Cycle), solar output, volcanic activity
what is solar output + how does it contribute to CC
-sunspots are magnetic storms on the sun’s surface
-no. + size of sunspots show cyclical patterns
-minimal change over last 50yrs
-during low amplitude, sun’s output of radiation is reduced, cold earth
what is eccentricity + how does it contribute to CC
-change in shape of orbit (circular to elliptical) over 100,000 yrs
-elliptical = ice age
what is precession + how does it contribute to CC
-as the earth rotates it wobbles over 26,000 yrs
-impacts the seasonal contrasts between hemispheres + timing of seasons.
what is obliquity + how does it contribute to CC
-variation in earth’s tilt (22.5°-24.5°)
-When the angle increases the summers become warmer and the winters become colder
how do volcanic eruptions contribute to CC
-eruptions eject sulfur dioxide, can stay in atmosphere for 3yrs
-reacts w/water vapor, forming volcanic aerosol that’s optically dense layer that reflects sunlight + reduces sun’s heat energy entering earth’s atmosphere
3 human causes of climate change
fossil fuels, agriculture, deforestation
what is the greenhouse effect
CO2, methane + water vapour trap infrared heat from the sun. this is natural + without it, it would be 33°C colder
how do fossil fuels contribute to CC
-accounts for >1/2 of gg emissions
-burning releases CO2 enhancing gh effect
how does agriculture contribute to CC
-accounts for 20% of gg emissions
-methane produced by cattle, microbes in paddy fields
how does deforestation contribute to CC
-accounts for 10% of gg emissions
-during photosynthesis trees sequester carbon
-when trees are slash + burnt CO2 is released + there are less trees to absorb it
impacts of climate change in UK
-sea levels could rise, flood low lying areas, e.g. east England
-droughts + floods are more likely as extreme weather increases
-increased need for water in hot summers pressures water supplies
-Industry impacted e.g. Scottish ski resorts have to close due to no snow
Impacts of climate change globally
-sea level rise will affect 80mil people
-tropical storms will increase in magnitude
-species in affected areas (Arctic) become extinct
-diseases such as malaria increase, an additional 280 mil people may be affected
mitigation definition
actions to limit the magnitude/rate of global warming + its effects
4 mitigation strategies
-alternative energy resources
-afforestation
-carbon capture + storage
-international agreements
examples of renewable energy sources (4)
wind, solar, nuclear, hydroelectricity
how do renewable energy sources reduce CO2 emissions (2)
they produce little to no CO2 and replace fossil fuels (which contribute 87% of human emissions)
5 advantages of alternative energy sources
✔reduced carbon footprint
✔improved public health
✔more jobs
✔secure energy supply
✔economic benefits
5 disadvantages of alternative energy sources
✘expensive
✘potentially dangerous
✘disrupt wildlife
✘intermittent
✘NIMBYism
what is afforestation
planting trees
how does afforestation reduce CO2 emissions
plant photosynthesise + sequester CO2 - 1 trillion new trees could absorb 1/3 of emissions made by humans
5 advantages of afforestation
✓accessible
✓easy
✓reduces habitat loss
✓flood control
✓CO2 sequestration
5 disadvantages of afforestation
✘loss of agricultural land
✘increased fire risk
✘land degradation
✘loss of biodiversity
✘hard to maintain
what is CCS
Carbon Capture + Storage is compressing + transporting CO2 underground
how does CCS reduce CO2 emissions
CCS machines can be placed near factories to limit the effects on the atmosphere and environment of the CO2 they release
4 advantages of CCS
✓reduces emissions
✓once captured can be used productively
✓buys time to change
✓creates job
5 disadvantages of CCS
✘expensive
✘political tensions
✘temporary
✘environmental risks
✘requires a lot of energy
example of an international agreement
Paris Climate Change Agreement
how do international agreements reduce CO2 emissions
multiple countries make a joint effort to implement aims + rules regarding gg emissions
5 advantages of international agreements
✓effective
✓awareness
✓higher chance of finding solutions
✓framework for action
✓support from private companies
5 disadvantages of international agreements
✘political differences
✘unequal burden
✘hard to enforce repercussions
✘insufficient ambition
✘mistrust
adaptation definition
process of adjusting to current/expected climate change + effects
3 methods of adaptation
changes to agricultural systems, managing water supply, reducing risk from rising sea levels
how do changes to agricultural systems respond to climate change (4)
-move production to another location due to changing temp + extreme weather
-increase irrigation
-change crops grown (GM) + time of the year planted
-prevents famine + health problems
3 advantages of changes to agricultural systems
✓keeps food cost down
✓reduces potential effects
✓more carbon friendly
3 disadvantages of changes to agricultural systems
✘expensive
✘loss of biodiversity
✘increase global divide
how does managing water supply respond to climate change (2)
-reduce demand, increase supply
-due to rising temperatures precipitation in many regions has decreased causing drought
3 advantages of managing water supply
✓prevents drought
✓less water wasted - increased security
✓easy to implement at low level
3 disadvantages of managing water supply
✘needs funds
✘takes time
✘lots of energy required
how does reducing risk from rising sea levels respond to climate change (2)
-build coastal barriers to prevent tidal surge-induced floods
-migrate further inland/to more mountainous regions ( build away from shore )
3 advantages of reducing risk from rising sea levels
✓decrease risk of floods
✓protects ecosystems
✓prevents social + economic damage
3 disadvantages of reducing risk from rising sea levels
✘defences could be overcome
✘unrealistic/expensive
✘political unrest
