Since 1880, the average global sea level has risen around 21 to 24 centimetres, and it’s currently rising at a rate of 3.6 millilitres per year. Scientists have estimated that by 2100 the average sea level will increase by as much as 0.8 metres. Drastic fluctuations in the world’s sea levels have been a natural part of Earth’s history. Around 20,000 years ago, the average sea level was around 120 metres lower than it is today. After a 10,000-yearlong period of naturally occurring global warming, the world’s sea levels rose to modern levels at a rate of around 1.2 centimetres per year. However, the rapid rise seen in recent history coincides with an increase in human activities that involve the burning of fossil fuels and release of enormous amounts of greenhouse gases, which contribute to global warming and climate change. The melting of polar ice and the expansion of the world’s water as a result of increasing global temperatures are the primary causes of the acceleration in sea level rise. Antarctica, for example, is currently losing 146 billion tonnes of ice each year on average, while Greenland’s ice sheet is shedding around 270 billion tonnes of ice annually.
Did you know?
There’s around 3,210,003,271 cubic miles of water in the oceans