Climate Change

Geography: AQA GCSE, topic 1.4.1

There are 3 cycles of climate change. The Quaternary period is the period from today to 2.588 million years ago.

The Earth was warmer than it is now in the period before the Quaternary period (called the Neogene period).
The Quaternary period has lasted for the last 2.588 million years.
The Neogene period lasted 21.4 million years.

Over the last 300,000 years, there is a cycle between glacial periods and interglacial periods.
Glacial periods are cold and last for roughly 100,000 years.
Interglacial periods are about 7 degrees warmer on average and last about 8,000-12,000 years.

Interglacial periods usually last 8,000-12,000 years.
200 years is very small on this timescale.
NASA scientists find that the Earth has warmed by 0.8 degrees Celsius since 1880. Most of this warming has happened since 1970.
Without changes to our current behaviour, some studies expect the Earth's temperature to be 4.1°C – 4.8°C higher than in 1880 by 2100, which is 4°C more of warming by 2100.
The behaviour of the last 150 years is what we call climate change.

The scientific consensus is that human activities are responsible for the recent increase in global temperatures because they are strengthening the greenhouse effect.
The greenhouse effect happens when greenhouse gases (e.g. carbon dioxide, methane) absorb heat that has been reflected off the Earth and re-radiate this heat back towards Earth.

Test yourself on Climate Change

What is the name of the most recent geological period that spans from 2.6 million years ago to the present day?