Dailan Pugh, Byron Bay
It never ceases to amaze me how many people remain in denial about climate heating and the effects it is having on sea levels and thus coastal erosion.
The CSIRO’s recently released ‘State of the Climate 2020’ once again confirms that seas have been rising over the past century and the rate is rapidly increasing.
The CSIRO identify that ‘Global mean sea level has risen by around 25cm since 1880; half of this rise has occurred since 1970’. Further identifying ‘the rate of global mean sea level rise increased from 1.5 ± 0.2 cm per decade (1901–2000) to 3.5 ± 0.4 cm per decade (1993–2019)’.
The CSIRO also identify that ‘Rising sea levels pose a significant threat to coastal communities by amplifying the risks of coastal inundation, storm surge, and erosion. Coastal communities in Australia are already experiencing some of these changes’.
Sea levels are rising because our rapidly warming seas are expanding and land based glaciers and ice sheets are melting and flowing into the sea. This is an indisputable fact.
CSIRO identify that sea level rises could be as ‘high as 0.61 to 1.10m global average by the end of the century for a high emissions pathway’.
Many published scientific papers support the predictions that sea level rises are likely to be a metre or more by the end of this century, and that no matter what we do, sea levels will go on rising for centuries.
We can now only affect the rate, and ultimate level before they stabilise, by quickly moving to zero emissions.
Similarly the 1:50–150m relationship between sea levels and retreat of sandy coastlines is a well established fact, though the distance it will retreat in Byron is contested.
So if we let nature take its course, the coastline will retreat as sea levels rise. And the rises so far are undoubtedly a contributor to Byron’s erosion problems.
We can intervene in this process by building rock walls, though the cost is that sooner or later the beach will erode away and at some stage the rock walls will be undermined and then overtopped.
The question now is whether we want rock walls or beaches?
Also as sea levels rise so too does the height of water in tidal estuaries, so the problem extends up the Belongil to the town centre.
Enough of the denials, obfuscation, and expensive knee-jerk reactions. We need a plan.