IB ESS HL 6.2.11 Global climate models Question Bank

Explanation of models:
models are simplified representations of natural systems that enable predictions for change based on pre-existing data;
climate models are mathematical formulae/computer programmes that scientists/IPCC use to predict future changes in climate based on historic climatic data; [1 max]

Strengths:
provides information/range of scenarios to policy/decision makers;
allows predictions/extrapolations to be made based on wide input of historic data;
large quantities of data (from a variety of sources) can provide statistical certainty to predictions;
can provide relatively objective information to political/emotional/contentious issues;
can lead to greater understanding of complex relationships between environmental factors;
visualizes projected effects / eg images of projected changes in global average temperatures; shows that some regions are more vulnerable than others / eg poles might undergo higher temperature increase than the Tropics;

Limitations:
conflicting results from different models can lead to uncertainty/confusion for policy/decision makers;
...and enable politicians to pick those that are most supportive to their cause; approximations/simplifications are necessary and lead to uncertainties; only a few experts/not all policy/decision-makers will fully understand the statistical limitations/reliability/application of models;
data used may be inaccurate as in-depth recordings have only been made recently;
data comes from many sources and instrumentation/methodologies may not be consistent/compatible;
models generally rely on assumptions that factors will operate in the way they have historically which may not always be valid;

Appraisal: Award [1 max] for a clear appraisal that is consistent with argument of response. eg while models have significant limitations they are the best available means of planning appropriately for the future; eg there is so much political manipulation in the current use of models that they are of very limited value;

Marking guidance:

[5 max] if no clear appraisal regarding relative strengths or weaknesses:
[3 max] if only strengths or only limitations are discussed.
[6 max]