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
