The Explainer - What Is Climate Change?

What Is Climate Change?

- Alex Franklin-Cheung

IS CLIMATE CHANGE THE SAME AS GLOBAL WARMING?

People often use the terms ‘climate change’ and ‘global warming’ to describe the same phenomenon: an increase in average global temperatures, caused by humans adding heat-trapping greenhouse gases into our planet’s atmosphere.

But while some places are getting warmer, as a result, other parts of the globe might sometimes be cooler. Ocean and atmospheric temperatures aren’t the only things that are changing: weather patterns and sea levels are, too. Some people, therefore, prefer to use the term ‘climate change’ as it covers the full range of predicted impacts. ‘Climate crisis’ is another term you might hear.

WHAT’S THE EVIDENCE FOR CLIMATE CHANGE?

Temperature records show that our planet’s average surface temperature has risen by about 1°C since 1850. Most of this warming has taken place in the past 35 years, and the five warmest years on record have all occurred since 2015.

There’s a growing body of evidence for rising temperatures and their effects. As ocean water warms, it expands, causing global sea levels to inch higher. A 2018 study showed that sea levels had risen by an average of seven centimetres over the previous 25 years. Around 40 per cent of this was due to thermal expansion, with the rest due to melting ice sheets in Antarctica and Greenland, and melting glaciers. The Greenland ice sheet, for example, lost an average of 280 billion tonnes of ice per year between 2002 and 2016.