Planning for Sea Level Rise High on Agenda in Australia
Governments in Australia are at the forefront in recognizing that Sea Level Rise (SLR) will become a significant issue for coastal communities as this century progresses. Presently they are using 90 cm (3 feet) as the planning assumption for the end of the century. For 2050 they set the benchmark at 40 cm (16 inches). A sea level rise of this magnitude will have significant impacts. For each foot of rise, shorelines can move hundreds of feet inland, in some places more than a thousand feet.
Today, August 13, the State of New South Wales (NSW) passed a “Sea Level Rise Policy Statement” recognizing these assumptions, and amended their Coastal Protection Act accordingly. It has implications for future land use planning and for defensive measures that property owners may take such as building up their coastal property using sandbags, seawalls and other means.
Australia is not the only area to have formally put SLR on the planning agenda. In the United States communities from California to Florida to Delaware are also coming to realize the seriousness of the issue. From my monitoring of the situation, it simply appears that the problem has a higher recognition factor at the federal and state level in Australia than elsewhere. But that is changing rather quickly.
The projections for SLR this century continue to be advanced as the melt rates in Greenland accelerate. 2007 was the last time that the definitive body, the Intergovernmental Panel on Climate Change (UN-IPCC) issued their Assessment Report which is prepared every 5-6 years. At that time, their summary table on projected SLR this century forecast a range of 18 – 59 CM (7 -23 inches), ALTHOUGH most readers totally missed the explanatory note, that stated that this projection EXCLUDED large changes in the melt rate of Greenland and the Antarctic, because there was insufficient data.
What is lost in this heavily negotiated wording is that the reason they could not put a figure on the Greenland melt rate is that it’s melting faster and faster — in 2007 the scientists simply could not plot the curve. They could not put a number on how much the melting of Greenland would raise sea level by the end of the century. Thus that component was NOT INCLUDED in the estimated increase range of 18 -59 cm. When you realize that scientists project that that the melting of Greenland and Antarctica will account for about 90% of sea level rise by the later part of this century, you see the absurdity of the situation. We have been ignoring or underestimating the impact that will change the shape of all continents this century.
Recently some very credible scientific experts have stated that sea level rise by the end of this century could be as much as 2 meters (6+ feet). That is huge. This subject will be continued in future blog posts. Please sign up for email updates.