Global warming, because of excess greenhouse gases we have been putting into the air, is going into warming the oceans, even more than it is going into warming the atmosphere. This makes the water expand and rise, even before we start accounting for icecaps and glaciers.
Average sea levels rose by around 200mm last century, and sea level rise is accelerating - it is already twice as fast as last century.
Unfortunately we don’t yet have OzCoasts maps for some areas, including the Illawarra and NSW south coast to verify whether some coastal grounds would be within or beyond the reach of a sea level rise such as 1.1 metres, which has been modelled by OzCoasts for other areas. Among grounds used by cricket and other sports:
- Fred Finch in Berkeley has 4 grounds, which show as only 1 metre above current average sea level on Google Earth
- For JJ Kelly Park, Wollongong, some of the ground is shown as only 2 metres
- Wollongong Golf Club shows as having some areas between 2 and 3 metres above current average sea level.
- Darcy Wentworth in Warrawong has 2 grounds which Google Earth shows as only 2 metres above current average sea level
- The football field at Kully Bay Park also shows as having some of its area only 2 metres above current average sea level
- Thomas Dalton Park at Fairy Meadow has 4 grounds on the coast, shown as 3-4 metres above current average sea level on Google Earth. Some grounds at similar altitudes in areas where risks have been modelled by OzCoasts show up as at risk of inundation from 1.1 metres sea level rise - due to tides and king tides, even before storm surges are considered
- Wetherell Park in Port Kembla shows as 3 metres above current average sea level
- Port Kembla Golf Course has much of its area showing as between 1 and 2 metres above current average sea level, and some parts under 1 metre high.
- Keith Bond Oval in Albion Park shows as between 3 and 4 metres above current average sea level.
- King Mickey Park in Warilla shows as 2 metres above current average sea level
- Oakleigh Park shows as 2 metres above current average sea level
- Beverley Whitfield Park shows as 3 metres above current average sea level
- Ron Costello Oval in Shellharbour shows as 3 metres above current average sea level.
Obviously it's not good enough to have to rely on Google Earth for such important issues. We need professional assessments, such as have been done for other areas by OzCoasts.
Local governments around Australia have been updating flood assessment and mapping to take account of climate change. But of course they are giving priority to effects on housing and infrastructure. Sports fields by definition are often in lower lying areas where there was already too much flood risk to approve housing or commercial and industrial development.
Expert information is needed on risks to grounds which at first sight may seem relatively safe because they are a few metres above current average sea levels, but which are adjacent to rivers and near the coast, and so may be exposed to increased flood risks from tides and from floodwaters being less able to escape to sea with higher high tides.
- For example, further south, Bomaderry Oval shows on Google Earth as 4 metres above current average sea level, but is also immediately adjacent to the Shoalhaven River.
Further south, and, like Bomaderry, among the grounds used for NSW Country Cricket competitions:
- Eden oval shows on Google Earth as 4 metres above the average level of the nearby ocean
- The Hanging Rock and Mackay grounds in Batemans Bay both show on Google Earth as 4 to 5 metres above current average sea level
How much sea level rise before these grounds are under threat? Until the Federal Government extends OzCoasts mapping to cover the Illawarra and South Coast regions of NSW we don't really know.