Describe two factors that may be used to determine a species’ Red List status and how each may be affected by human activity.

Explain how developments in technology may increase or decrease the ecological footprint of a human population.

The long term effects of global warming may influence the carrying capacity for human populations.

Discuss whether global warming is likely to increase or decrease carrying capacity for human populations around the world. Support your conclusion with valid reasons or evidence.

Award [2 max] for factors affecting Red List status:
population size;
reduction in population;
numbers of mature individuals;
geographic range/fragmentation;
quality of habitat;
area of occupancy;
location prone to natural disaster;
species characteristics (eg life-history, reproductive behaviour etc);
probability of extinction;   [2 max]

Award [2 max] for the following human activities appropriately linked to factors given above (eg deforestation may lead to fragmentation of larger forest populations):
deforestation;
harvesting/hunting;
urbanisation/infrastructure;
pollution;
trade in rare species;
introduction of non-native species;
unfavourable climate change due to anthropogenic global warming;
conservation/protection management;
poor land management/fracking (leading to earthquakes/landslides);

Do not credit human impacts that not linked to specific Red List factors.
Same human activity can be used for two factors if appropriate   [2 max]

[4 max]

The ecological footprint is essentially the area of land required to sustainably provide all the resources required and assimilate the wastes produced (by a population);

Technological development may decrease the EF/area of land required through…
…agricultural technologies for irrigation/fertilisers/pesticides increasing productivity (per unit area);
…increased productivity of genetically engineered crops;
…technology for hydroponic agriculture requiring less resources;
…increased energy efficiency reducing CO₂ waste;
…alternative energy sources (eg wind/solar/ etc) reducing CO₂ waste;
...hybrid/H-fuel vehicles reducing CO₂ waste;
…technology to harvest energy/recycle materials from waste;
…technology to capture/store C waste;

Technological development may increase the EF/area of land required through…
…fossil fuel dependent technology increasing CO₂ waste in use/production;
…increasing demands for resources used in manufacture of technology;
…pollution produced by use/manufacture of technology requiring more waste assimilation;
...reducing limits to population growth thereby increasing demand for resources/waste assimilation;
…promoting rapid turnover of technologies/consumer market that increase rate of resource consumption/waste production;

N.B. Award credit only for those factors for which it is explicitly indicated in the context of the response whether it will lead to either an increase or a decrease of EF.

[6 max]

N.B. Question addresses effect of Global Warming on carrying capacity, so do not credit responses that focus on direct effects of CO₂ (eg ocean acidification) or other causes of GW.

Global Warming may increase carrying capacities due to:
increasing crop yields through higher temps/increased precipitation;
melting of permafrost releasing more arable land;
increasing available freshwater supplies through increased precipitation/ice melts;
creating more favourable/healthy climate for some human populations;
technological developments that mitigate its negative impacts while exploiting its benefits;
human ingenuity has reversed major threats in the past / turned them to human advantage;
impacts of global warming may promote environmental concern/values that lead to more sustainable lifestyles;

Global Warming may decrease carrying capacities due to:
increasing spread of tropical diseases/pests to new regions;
destroying coastal habitats/settlements/available land through sea rise;
changing oceanic currents reducing productivity of fisheries;
reducing crop yields through higher temps/reduced precipitation;
reducing available water supplies through increased evaporation/reduced precipitation;
loss of habitats/biodiversity may deplete natural capital available to human populations;
increasing natural hazards through extreme weather patterns/hurricanes/flooding;
speed at which change is happening will not allow time for human populations to adapt;
phenomenon involves positive feedback mechanisms that will increase impacts further;

Award [1 max] for an explicit and valid conclusion.
Note to examiners: An isolated statement e.g. “global warming will increase carrying capacity” or an unjustified opinion e.g. “I think carrying capacity will decrease” should not be considered as a valid conclusion. The conclusion must be supported/justified by points raised that must have at least addressed both sides of argument. A valid conclusion may, however, be stated within the body of the response rather than at the end, and may be tenuous, involving a balance of factors and provisos, or distinguish between local and global capacities:

eg Global warming may lead to increase in local carrying capacities in some parts of the world, but is likely to lead to an overall decrease in global capacity; [1 max]

Alternative points of equivalent validity, significance and relevance to those given, should be credited.

Award [5 max] for responses that only explore one side of argument.
Otherwise, award [7 max] for marking points above, and [1 max] for a clear conclusion that is justified by points raised.

[8 max]

Expression of ideas: [2 max]

Generally good. Most could identify two examples of factors used for Red List status and human impacts on these.

Most had a sound grasp of the concept of ecological footprint and could identify one way in which technology increases, and decreases, this value. Few gained any further credit.

Generally good, but often responses addressed an insufficient variety of potential impacts, or only looked at negative impacts. Discussions often lacked valid conclusions derived from balanced argument.