Are Rising Sea Levels a Real Risk?

With El Nino on its way, climatologists are voicing increased concerns over rising sea levels. Some experts have even warned that by the end of the century, sea levels could have spiked by several metres. The high profile study was published in the Atmospheric Chemistry and Physics journal, and sparked further climate change controversy.  

Should the world be worried?

So is the prediction valid? Or is it simply yet another fanciful warning from eco-advocates? Debate rages, yet one thing is for certain – sea levels are now rising at a rate that doesn’t align with several millennia of comparative stability. Since 1880, sea levels have risen by over 20cm, which has had a global impact on coastlines. Even faster levels have been recorded since 1993, with scientists logging 3mm per year, or 30cm a century.

Climatic pattern or artificial event?

Climatologists are concerned, however rising sea levels aren’t necessarily a new concept. Prehistoric records clearly indicate that around 100,000 years ago (during the Earth’s most recent interglacial period) temperatures were around 2 degrees warmer, and sea levels were up to 10 metres higher than they are today.

In the past, the thermal expansion of oceans and melting ice glaciers have been cited as key factors causing sea levels to rise. Yet over the past decade greenhouse emissions have emerged as another major driver, with the Intergovernmental Panel on Climate Change (IPCC) projecting that sea levels will jump by up to 98cm by 2100 if output isn’t curbed. If it is, sea levels are still expected to rise by 28-61 cm. Increased ocean expansion and glacier melt remain two major sources, with surface melting from the Greenland ice sheet also pinned as a threat. If emissions continue to flow at their current rate, climate analysts are predicting that sea level rise rates could hit 1 metre per century by 2100, and a total of 7 metres by 2500.

Melting from the ground, up

The rapid destabilisation of the Antarctic ice sheet is a fundamental cause of concern, with the IPCC estimating that melting along could contribute to a 20 cm of sea-level increase this century alone. As well as thawing from the surface, warm ocean water could also fast-track melting at the ice sheet’s base, triggering a rapid flow into the ocean. While some specialists maintain that parts of the West Antarctic sheet are already beyond repair, others assert that slashing emissions could prevent the rapid onset of marine ice destabilisation.  

Ultimately, a host of factors are at play, all of which will determine whether or not a multi-meter sea-level rise could materialise within the century.

Not only do ice shelves stabilise sea levels, but they also preserve organisms for centuries. ‘Moss Brought Back to Life After 1,500 Years Frozen in Ice’ explores a recent feat achieved by researchers from Reading University and the British Antarctic Survey, and the exciting new insight it offered into the survival of life on Earth.