We’ve all heard a tonne of different reasons for rising sea levels – climate change, a delayed reaction to the last ice age, a natural change in our surrounds and climate (because, after all, the world changes). But what’s the scientific evidence to back this up? Do we really know the reason behind rising sea levels? Is it a little bit our fault, but a little bit inevitable? It’s a constant debate in the media, and I’m sure as ocean lovers (like myself), it is a question that you also ponder. Are rising sea levels my fault, or is it something else?
Well, a recent study has found that it wasn’t our fault pre-1970. CSIRO researchers found that from the 1950s to the 1970s, rising sea levels were mostly caused by a delayed reaction to the warming that followed the ‘Little Ice Age’ (1300 – 1870 AD). This accounted for approximately 70% of the increase in sea levels across the world. However, after 1970, less than 10% of measured rises were due to this delayed reaction. So what, I hear you ask, has caused an increase in sea levels in the past 45 years?
Yes, you guessed it, it turns out that we are, in fact to blame for such a drastic change in sea levels. The effect of humans, via global warming, on sea level rises for the period of about 1870 – 1970 is actually quite low, accounting for only 15% of the problem. But since 1970 this has become over 70% of the driving force behind rising sea levels, and the subsequent loss of homes, infrastructure and coastal stability.
There are a number of reasons why the sudden increase in greenhouse gases and aerosols have increased sea levels but primarily this is because of the increase in temperature. Not only does it lead to the melting of the ice caps in the Arctic and Antarctic, and glaciers around the world, but it also, quite literally, expands the water. You know how your drink bottle will expand (and sometimes even explode) if you leave it in a hot car all day? Well, the same principle applies here – heat means expansion, and in the case of the ocean, expansion means rising sea levels.
So, it’s because of us that sea levels are rising so drastically. But, as always, it’s not all doom and gloom. You can do your part to help – you may not think that one person’s actions can change the world, but it can. And being one of millions to take a few minor steps in cutting your greenhouse emissions and carbon footprint will make a HUGE difference to our planet – and to the safety of our beloved, Australian coast.
Original research link.