Global warming

In the syllabus and the exam

Global warming refers specifically to the long-term rise in the Earth's average surface temperature, and the syllabus links it directly to the enhanced greenhouse effect as its principal cause, so candidates should be able to trace the causal chain from a named human activity (deforestation, burning fossil fuels, open burning) through increased greenhouse gas concentration, to the enhanced greenhouse effect, and finally to global warming, rather than jumping straight from 'pollution' to 'warming' without the intermediate steps. Candidates are also expected to describe consequences examined at SPM level, such as melting of polar ice and glaciers, rising sea levels that threaten low-lying coastal areas, shifts in rainfall patterns affecting agriculture, and disruption to ecosystems such as coral bleaching from warmer ocean temperatures. A common error is treating global warming and the greenhouse effect as the same term, when in fact the greenhouse effect is the mechanism (a natural process made more intense by human activity) while global warming is the resulting outcome (the measured rise in temperature). Candidates should frame every consequence of global warming as tied to a specific, explainable mechanism rather than a vague statement that 'climate will get worse', since higher-order questions specifically credit answers that connect a described effect back to the temperature rise or its downstream consequences, such as thermal expansion of seawater contributing to sea-level rise. Candidates should also be able to suggest specific mitigation measures, such as reforestation, switching to renewable energy, and international agreements to cut emissions, distinguishing these forward-looking solutions from measures that merely describe the observed consequences of warming already under way.

Example

Average sea surface temperatures rising over several decades, together with more frequent coral bleaching events, are evidence cited for global warming linked to increased greenhouse gas concentrations.

Related terms

Greenhouse effectSustainabilityEutrophication

Source:SRC-DSKP-EN