HL responses should turn a personal perspective into a defensible comparison. Establish what ‘greater threat’ means, weigh global warming against biodiversity loss using the same frame, and support the conclusion with connected evidence and counter-considerations.
State whether you believe global warming or biodiversity loss represents the bigger threat in the future. Justify your viewpoint.
Expression of ideas
Credit different interpretations of what is meant by "bigger" in this context e.g. bigger can refer to the scale/number of effects, or to how immediate/frightening/concrete the threat may seem, or in terms of whether the threat is to humans or to living systems in general.
Marking guidance:
Award [1] for a explicit statement of their view on which is the bigger threat. global warming is a bigger threat than biodiversity;
biodiversity is a bigger threat than global warming;
Do not credit if the viewpoint is only implied in the response.
Award [8 max] for relevant arguments for why one issue is a bigger threat than the other.
Award [4 max] if response is simply a description of the threat/effects not a comparison with the other threat. e.g. global warming is the bigger threat because:
it will have big effects e.g. melting ice caps/shifting biomes/changing the world's weather/flooding land;
its effects will be more widespread than biodiversity/every country will be affected;
whereas the loss of diversity in, e.g. a tropical rainforest, may have little direct impact on people elsewhere;
larger numbers of people will be affected e.g. Bangladeshi delta region low-lying and densely populated affected by sea level rises;
it will affect a bigger range of human activity, such as food supply/living space, health/disease;
it will lead to biodiversity loss as well (whereas loss of diversity will not cause global warming);
many biodiversity hotspots are particularly vulnerable e.g. coral reefs;
it has a higher public/global profile;
it can lead to significant social consequences e.g. wars / mass migrations;
is harder to solve than biodiversity loss which can be helped by e.g. seedbanks;
current rate of warming is unprecedented, whereas there have been mass extinctions in the past and the biodiversity has recovered;
it may lead to positive feedback loops/potentially devastating tipping points/exponential change;
> e.g. biodiversity is the bigger threat because:
> biodiversity provides/ensures key essential ecological services;
e.g. a balance of atmospheric O2 and CO2 /soil preservation/mineral cycles;
without these there would be no life-supporting conditions on the planet;
once biodiversity is lost it is gone forever;
and whereas global warming may be mitigated by negative feedback mechanisms there are no feedback mechanisms to maintain diversity;
to restore biodiversity it can take very long periods of time;
whereas climatic variations are reversible/happen in cycles (and have occurred in the past);
> from a human point of view, loss of biodiversity may mean loss of critical resources;
> biodiversity provides many forms of natural income, e.g. aesthetic, economic, ecological services;
> at a point in human population growth where resources are possibly limiting;
it is biodiversity that gives living systems the ability to adapt to change;
and the more it is reduced, the lower the chances of adapting to change;
biodiversity is being lost now/threats seem more immediate to people;
there are some positive benefits of global warming but no benefits to biodiversity loss;