Climate change: cause and effect

• The Quaternary is the last 2.6 million years, when the climate swung between cold glacial periods and warmer interglacials.
• Evidence for past climate includes ice cores, tree rings and pollen records. Recent evidence includes thermometer records and retreating glaciers.
• The greenhouse effect: greenhouse gases absorb heat leaving the Earth's surface and send some back, which warms the air. Burning fossil fuels adds carbon dioxide. Cattle farming adds methane.
• Consequences include rising sea level, changes for farming and wildlife, pressure on water supplies, and changes for tourism.
• People and governments hold different views on climate change. Global agreements such as the Paris Agreement of 2015 try to limit warming.
• Mitigation tackles the causes, such as wind power or planting trees. Adaptation deals with the effects, such as building flood barriers.

Greenhouse effect

Gases in the air trap heat that would escape to space and warm the Earth.

Greenhouse gas

A gas, such as carbon dioxide or methane, that absorbs heat in the atmosphere.

Ice core

A tube of ice whose air bubbles show what the atmosphere was like in the past.

Mitigation

Reducing the causes of climate change.

Adaptation

Adjusting to the effects of climate change.

Carbon capture and storage

Trapping carbon dioxide from power stations and storing it underground.

• Saying burning fossil fuels harms the ozone layer. The problem is extra carbon dioxide strengthening the greenhouse effect.
• Writing 'homes get flooded' as a full consequence. Say who is affected and what follows.
• Mixing up mitigation and adaptation. A flood barrier is adaptation. Switching to solar power is mitigation.
• Listing what governments and individuals can do when the question says 'how far do you agree'. Weigh both sides and give a view.

7 questions, 14 marks. Answer, then press Check. The marking guide explains how the marks are worked out. Nothing is saved.