Introduction Flashcards
What are the primary driving forces of change
An increasing population
Climate change
Pollution
Many interlinked secondary changes
What did John Beddington say
He likened climate change to a perfect storm - he raised awareness of issues we are facing as a species in terms of our ability to manage energy demands, usually results in fossil fuel use. Amount of freshwater is decreasing.
What is the timeline of overpopulation
1315-1317- great famine where there was low light conditions due to volcanic clouds from volcanoes around the world.
1850s - time of industrial revolution, there’s been an increase in population.
1940s - potatoes were the dominant crop and the Irish potato famine caused a decrease in population through migration and death.
1950s - the green revolution.
Now - population is slowing down in some places but other places like Africa the population is still increasing
What is the green revolution
A series of technologies that allowed scientists and farmers to substantially increase food production
What do farmers expect back from every seed
7 seeds
How many seeds back per seed planted did farmers get during the great famine
Only 2
What does the computer model say about the world
It will level out at 5 billion and 2 billion of the people will be African
What causes overpopulation
Imbalance between demand for food and agricultural production
What caused the Irish potato famine
Partially caused by a single plant pathogenic fungus that destroyed crops before they could be dug up and eaten
What made the Irish potato famine even worse
There were still significant exports of potatoes to England - social issue
How would we have to sustain agricultural production
Agricultural production per unit would have to be substantially increased
How might one increase agricultural production per unit
Convert existing land to agricultural production
What is the issue of converting existing land to agricultural production
Extensive reach of deforestation as a result of trying to create the land, climate change feedback as deforestation released co2 and the agricultural land has low sequestration rates.
What are some lands limited by
Low rainfall
Low temperatures which can cause massive degradation as not suitable for global use
What is the concept of buffering food supply against population change
Shouldn’t be looking at opening new land but achieving the most from existing land by breeding plants to be more productive or manage them different to make most out of them
What are 3 buffers of food supply against climate change
Plant breeding solutions
GM technology
Crop Management solutions
What happened to the Aral Sea
It used to be one of the largest freshwater bodies on the planet now becsuse water is used in irrigation it is depleted. Also a climate change signature
What caused a loss of biodiversity
Intensification of agriculture and deforestation, desertification due to overpopulation
How did farmland birds in UK coincide with increased pesticide use
Farm spaces for bigger so less space for breeding birds
What percentage of UK GHG emissions come from agriculture
9%
Nitrous oxides 55%. Methane 36%. Co2 9%
Example of intensification causing local problems of pollution
Fertilisers stimulating algal growth
What do we need to consider with pollutants in landscapes
Their spatial distribution
What are local pollutants
Heavy metals like lead Radioisotopes Salinity Increased nutrients Acidification
What are continental pollutants
Acidic gases and acid rain
Tropospheric ozone
What are global pollutants
Persistent organics
Ozone depleting gases
Greenhouse gases
What is the enhanced greenhouse effect
Incident solar radiation is absorbed by the earths surface and re-emitted at longer wavelengths.
A proportion of re-emitted radiation is radiated back to space.
A proportion of reemitted radiation is absorbed by greenhouse gases, warming the atmosphere.
Carbons source and contribution to anthropogenic greenhouse effect
Fossil fuels and deforestation
56%
Methanes source and contribution to anthropogenic greenhouse effect
Biomass burning, fossil fuels and agriculture
16%
Cfcs source and contribution to anthropogenic greenhouse effect
Refrigerants
11%
Tropospheric ozone source and contribution to anthropogenic greenhouse effect
Hydrocarbons and biomass burning
5%
What is the global warming potential of methane
32 GWP
What is the global warming potential of nitrous oxide
282 GWP
What is preindustrial co2 levels
270ppm
What is co2 levels likely to rise to by the end of this century
700ppm
What has happened to co2 levels in the space of 30 years
Seen an increase of about 50ppm
Where are co2 readings taken
At Mauna Loa observatory in Hawaii
What has mean global temperature risen by in 50 years
0.75*C
What are the predictions of increase in temperature
1.5-6*C. Uncertainty bc of uncertainty of how ju am emissions will be
What may mean change in temp disguise
Spatial and temporal variations such as more extreme local weather events
What will broader changes in climate disrupt
Both natural and cultivated ecosystems
What will increase in sea level result in
Loss of cultivar able land thus hastening agricultural intensification
What may the speed of change be too great for
Either agricultural systems to change or organisms to evolve
What may migration of ecosystems and organisms result in
Increased disease incidence
As temps increase what may happen to areas immune to human disease
They become stricken with them as a result of host being able to migrate into regions
What is the good news about the greenhouse effect
Post-Kyoto limitation of greenhouse gas emissions
Kigali agreement limited HFCs
More co2 is good for plants
We’ll be able to have more vinyards in south of England
Bad news of greenhouse effect
Patchy implementation of post-Kyoto emissions limit
Effects of increased incidence of extreme weather events
Impact of change agricultural practices on native organisms and ecosystems
What happens for each 1% decrease in stratospheric ozone
There is a 2% increase in UV-B radiation reaching the biosphere, which has biological effects
Where is the stratosphere
15-35km up
What does ozone in the stratosphere do
Selectively filters out the shortest, most energetic and potentially most damaging UV from sunlight
What is the wavelength of UV-C
200-280nm (removed by O3 and O2)
What is the wavelength of UV-B
280-315nm (reduced by O3)
What is the wavelength of UV-A
315-400nm (not absorbed by O3)
What does ozone filter out
Impacts of ultra-violet radiation
What does stratospheric o3 depletion lead. To
Increased Uv-B
What does upper tropheric O3 increase lead to
Trapped heat and acts as a greenhouse gas itself
What does mid-level tropheric o3 doe
Breaks down pollutants
What does ground level o3 affect
Plants and makes smog
What is ozone measured in
Dobson Units
When did atmospheric ozone decline
In 1980s over the Antarctic
What was the main cause of the ozone hole
CFCs
Why did ozone depletion also occur in the Arctic and Tibet
Due to air circulation patterns
When was there a substantial ozone depletion over the Uk
1996
What is the good news about ozone depletion and UV radiation
The Montreal Protocol (1989£ successfully limited CFCs
The atmospheric concentrations of CFCs is falling and ozone is beginning to recover
What is the bad news about ozone depletion and UV radiation
Ozone recovery is slow and recovery is delayed by global warming and pollution
Ozone unlikely to return to pre-1980s ozone before 2050
This may have long term impacts at the poles
How is ozone production
Combined action of NOx, hydrocarbons (exhaust) and UV radiation
What are the two components of the atmosphere
Stratosphere
Troposphere (near earth)
How does ozone reduce crop yield
Stomatal closure and synthesis of anti-oxidants and reduced photosynthesis. Leads to reduced leaf growth and reduced root growth so reduced crop yield.
How are some crops grown now to combat ozone levels
In open topped containers that ensures crops get exposed to charcoal filter air and not ozone
What is the good news about tropospheric ozone
The use of catalytic converters in new cars in substantial reducing emissions of hydrocarbons that lead to o3
What are the bad parts of tropospheric ozone
Lots more cars as economic Developement continues its pace
What are the gases causing acid rain
Sulphur dioxide
Nitrogen oxides
What is the source of sulphur dioxide
Burning fossil fuel
Industry. 85% of global budget
Forest fires 8%
What is the source of nitrogen oxides
Automobiles
Burning fossil fuels. 40% of global budget
Incinerating organic wastes
Forest fires 20%
What causes the UK Vlean Air Act in 1952
In London there has been a serious epidemic of sulphur gases.4,000 fatalities to the effects of coal smoke, acid gases and particulates
How does acidic gases and rain effect human health
Lung disease like bronchitis and asthma
What ecological effects is acid rain linked to
Long term health of forests in Northern Europe and major concerns in scandalous even tho not wide spread pollutant emissions a lot of the U.K. Pollutants got transported to it
Good news about acidic gases and acid rain
Controls on industry and power stations in developed countries are reducing emissions of sulphur and nitrous
Acid precipitation is much less common
Bad news about acid rain
Industrialisation in developing countries means emissions are not being reduced everywhere
NOx emissions from cars remain a problem
