LEC.101 Global Environmental Challenges Flashcards
From the 2019 global report, how many species worldwide are threatened by extinction?
1 million
What % of people in the 2019 poll were ‘very worried’ about climate change?
59%
What is an example of a direct (largest) and indirect driver of biodiversity loss?
Direct: Land/sea use change
Indirect: Economic & technological
What does SDG stand for and which is one of the most important goals?
Sustainable Development Goals, 13. Climate action
What kind of problems are global environmental challenges?
Wicked problems - the problem isn’t easily defined
What are the 2 external risks to the planet?
- Sun becomes a red giant
- Impact with energy > gravity
What are the 2 external risks to the global biosphere/ecosphere?
- Meteorite impact
- Gamma-ray burst from star explosion
What are the 3 internal risks to the global biosphere/ecosphere?
- Core/mantle convection
- Rapid climate change
- Biosphere imbalance
What is an external and internal global risk to human society?
External: Planetary/biosphere threats
Internal: Ecosphere overshoot
What is ecosphere overshoot and how many people are there on the planet now?
Using up biosphere resources to meet increasing human demand, 8.1bn people
What occurs once carrying capacity is exceeded and where in the world is this happening?
Population die-off, most of Europe, North America and Asia
Who came up with the term ‘Anthropocene’ in 2000 and what does it refer to?
Paul Crutzen, a new epoch whose signature is human impacts
Why does the talk of ‘emergencies’ make social scientists nervous?
- Rights are often drastically curtailed in states of emergency
- Authoritarian rule favoured over democratic decision-making
- Problem can be turned into one of management or technological intervention
How many people does modern intensive agriculture produce more than enough calories for and what % of the world’s adult population are overweight?
7.7 billion, 39%
Food security definition
All people at all times have physical + economic access to sufficient, safe, and nutritious food that meets their dietary needs + food preferences for an active + healthy lifestyle
There is a strong association between hunger and ___?
Political unrest/war
Which individuals have a higher personal carbon footprint?
Wealthy (consume more meat)
Where in the UK is at high risk of water scarcity and which crops are particularly water-demanding?
South East, cotton, wheat + rice
Which crop technology reduces CH4 emissions?
AWD (Alternate Wetting and Drying)
What is now needed for the Anthropocene?
Post-normal science (doesn’t exclude non-experts)
For every 1 degree increase in temp., by what % do wheat yields decrease?
5%
What are 4 challenges to achieving increased food production?
- Increase in biofuels
- Urbanisation
- Climate change
- Soil degradation
What are the 3 benefits that improving the efficiency of CO2 assimilation will provide?
- More space for biodiversity
- Water use efficiency
- Lower fertiliser inputs so lower cost + promotes soil sustainability
What is a genetic approach to increasing crop performance?
Generating novel germplasm
What are the 2 threats to the world’s soil?
- Erosion (rates outstrip soil formation worldwide)
- Nutrient mining
What have scientists predicted to happen after 2050?
Population likely to decline due to food deficit unless there is radical societal transformation
What did Amartya Sen say is almost always the cause of famine?
Food allocation
What happened as a result of NAFTA (1994) and what was adopted by the UN in 2018 as a result?
Cheap corn flooded Mexican markets, putting Mexican farmers out of business, food sovereignty
What is food sovereignty?
People producing the food they want to eat rather than working as exploited labour in global system
What is causing people to disconnect from nature?
Increased urbanisation
What did stress reduction theory show about the relationship between nature and human health (Ulrich 1983)?
Less pain medication + hospital visits when able to see nature
How many people worldwide lack access to basic sanitation services (UN 2015-)?
2.4 billion
Which areas face particular WASH (Water, Sanitation + Hygiene) challenges relating to land/housing tenure insecurity?
Urban areas
What has there been a greater focus on in recent decades due to ‘secondary’ failures in sanitation?
Sanitation value chain
What do Dalits believe handling human waste is considered a form of and which campaign did Dalit activists take part in?
Slavery, ‘Stop Killing Us’ campaign
What are 3 challenges for sanitation workers?
- Injuries/death
- Fear job loss due to mechanisation
- Can’t access ‘improved’ jobs in sanitation
What are the units of radioactivity and radiation dose?
Radioactivity: Becquerels (Bq)
Radiation dose: Sievets (Sv)
What is a lethal dose of radiation?
10,000 mSv
Explain nuclear fission
Neutron collides with nucleus of 235U to form unstable 236U –> explosion releases energy, fission products that cause contamination, and more neutrons that trigger more nuclear fission
What do the moderator, control rods, and pressure vessel do in a nuclear reactor?
Moderator: Slows down neutrons so more likely to react with 235U
Control rods: Change rate of nuclear fission reaction
Pressure vessel: Contains reaction safely, pressurised fluids more likely to get to higher temp. before boiling
What caused Chernobyl 1986 (level 7 nuclear accident)?
Operators conducted tests that deliberately overrode safety systems 6 times + in-built design faults –> Reactor 4 exploded + caught fire for 10 days
How many people did of acute radiation sickness as a result of Chernobyl?
28
What caused Fukushima 2011?
Earthquake triggered >10m tsunami which shut down nuclear power plants + flooded backup generators –> H started building up –> series of explosions
What 3 things does the ozone layer do?
- Absorbs UV radiation
- Heats stratosphere
- Protects life on Earth
What has caused an increase in tropospheric ozone?
Pollution
What 4 modern techniques are used to measure ozone concentration?
- Satellites
- Ozonesondes (lightweight, balloon-borne instruments)
- High/low altitude aircraft
- Laser beams
What is ‘column ozone’ and what is total column ozone measured in?
All ozone over a certain area compressed down to 0°C and 1 atm pressure, Dobsern Units (DU)
At what latitude is there less ozone?
Mid-latitude/tropics
What were 2 causes of ozone depletion in the 1980s?
- NO emissions from aircraft
- Cl. from CFC refrigerants (banned by Montreal Protocol)
What year was the ozone hole discovered over Antarctica and why does ozone deplete more over this region?
1985, extremely cold temps. allow polar stratospheric clouds to form which increase ozone depletion via Cl. from CFCs
What was the 1st, 2nd, and 3rd generation of CFCs and what were the problems with each?
1st gen: CFCs (ozone depleting)
2nd gen: HCFCs (less ozone depleting but not completely)
3rd gen: HFCs (no ozone depletion but GHG)
When is the ozone hole expected to close?
Between 2050-2100
Define pollution
Presence of substances in atmosphere that cause adverse effects to man and the environment
How is acid deposited in remote areas such as Scandinavia?
Acid rain from UK transported via prevailing winds
What are 2 examples of primary polluting gases?
- CO2
- SO2
What are 2 examples of secondary polluting gases?
- Ground level ozone (formed from VOCs, NOx + sunlight)
- HNO3
What are 4 examples of primary polluting particles?
- PM 10
- PM 2.5 (more harmful because easier to enter lungs)
- Dust
- Soot
What is an example of secondary polluting particles?
Organics
What are the 5 major pollutants?
- NO2 (combustion, –> O3, acid rain)
- Ozone (strong oxidant)
- CO (poisonous, –> O3)
- SO2 (fossil fuels, –> acid rain)
- PM (Particulate Matter)
Define grounding line
Point at which ice sheet isn’t thick enough to be grounded and starts to float
Define circumpolar deep water
Region of relatively warm water around Antarctica which can increase melting and calving if drawn closer to an ice sheet
Define calving
Iceberg breaking off from an ice shelf
Define reverse slope
Bedrock sloping downwards due to erosion and weight of the ice sheet
What are 3 examples of geohazards and their tropographic change?
- Tectonic processes (strain accumulation + release)
- Volcanic processes (lava flows + domes)
- Landslides/rockfalls
What are 2 examples of expensive monitoring geohazards equipment?
- Airborne laser scanning (laser deployed and reflects back to aircraft - measures distance, large spatial scale)
- Ground-based laser scanning (good for rockslides, small spatial scale)
What are the 3 steps to close-range photogrammetry and computer vision research (cheap, multiple phone cameras due to distortion)?
- ‘Structure from motion’ photogrammetry (gives general model)
- Multi-view stereo (fills in holes)
- Geo-referencing (links 3D model to coordinates system we know)
What is the loop from unsustainable use of natural resources?
–> poor environmental health –> poor human health + well-being –> socio-technical innovation –> unsustainable use of natural resources
In 2018 what temperature did the IPCC say that global warming must be limited to?
1.5 degrees
What % of global emissions does China’s net zero target cover compared to the net zero targets of all countries involved?
28% compared to 89%
What are 2 strategies implemented to try and reach net zero?
- Planting forests which are cut down and burnt (releases energy), carbon is captured before being released from factory and stored
- Carbon offset (company pays another company to reduce carbon emissions whilst keeping their own the same - balances out)
What % of medicine is from tropical forests?
25%
What fraction of the global terrestrial carbon sink do tropical rainforests represent?
1/2
What % of a tropical rainforest’s own rain does it produce (important in water recycling)?
30-50%
What are 2 reasons that tropical rainforests have strong climate control?
- Strong carbon storage
- Strong evaporative cooling
What % of deforestation is due to pasture expansion for beef and which country is the largest exporter of beef?
41%, Brazil
What % of mining in Brazil is illegal (forests can’t be replaced there)?
80%
What is a local climatic effect of deforestation?
Clouds forming over pastures between forests instead of over forests (less ppt.)
What is the edge effect caused by pasture expansion?
Trees on the edge of a pasture are more exposed to wind/fire from burning pastures to regrow grass
Which drought meant that there was 57% less rain than usual and affected 50% of forest?
2010 Amazonian drought
In which year did the world’s largest anti-deforestation policy begin in Brazil (national policy)?
2004
What is an example of a global commitment to tackling deforestation?
Paris Agreement 2015
Why does CO2 concentration naturally fluctuate?
Seasonal changes in photosynthesis (more in summer)
What are 3 ways carbon can be captured?
- Pre-combustion capture
- Post-combustion capture
- Oxy-fuel combustion capture
What are 2 ways carbon can be transported?
- Pipeline
- Ship/lorry
What are 3 ways carbon can be stored?
- Industrial fixation
- Ocean storage
- Geological storage
What are 3 options for geological storage of carbon?
- Depleted oil/gas reservoirs
- Use of CO2 in enhanced oil recovery (reduces oil viscosity so oil flows out more easily)
- Deep unused saline water-saturated reservoir rocks
What are 4 ways CO2 can be trapped?
- Structural/stratigraphic trapping
- Solubility trapping
- Mineral trapping
- Residual CO2 trapping
By how many metres did the IPCC predict global sea level to rise by 2100 in 2019?
Between 0.43 and 0.84m
What 4 underlying processes cause local sea level changes to deviate substantially from the global mean value?
- Dynamical ocean response + currents
- Static gravitational effects from glacier/land ice mass changes
- Terrestrial water storage changes
- Global isostatic readjustment
What 4 things can extreme sea levels arise from combinations of?
- Storm surges
- Wind waves and swell
- Astronomical tides
- Interannual variability in sea level
What is the prediction of future storm surges related to?
Wind (lots of uncertainties)
By how many cm is wave height predicted to increase in the British Channel by 2100?
20-30 cm
What are 3 factors affecting coastal flooding?
- Increased water levels + wave activity
- Drainage + GW levels (both affected by ppt. and increased water levels)
- Subsidence
What are 4 factors affecting coastal erosion?
- Increased water levels + wave activity
- Currents
- Precipitation
- Sediment delivery + sediment budget
How many properties are expected to be at significant risk of flood damage in the UK by 2050?
1.5m properties (1.2m homes)