DEAR News Of The Area

WARREN Tindall (‘Conaghan’s contrary opinions on climate change’, p28, NOTA 22 October Edition) suggests flooding in Coffs Harbour is the result of climate change and sea level rise will see the town under water within decades.

The more plausible reason for flooding in Coffs Harbour is that the town lies on low land in a basin surrounded by very steep hills.

Consequently runoff is quick to develop in heavy rain.

Over the years with more development occurring in the catchment the amount of runoff is increased.

The only drainage system for the area is Coffs Creek.

Sometime in the past the natural estuary of the creek was reduced from hundreds of metres wide to approximately twenty metres wide.

Thus restricting the rate of outflow that the creek naturally required. If the tide is high the problem is compounded.

Humans have contributed to the problem but not through climate change.

As for the sea level, it has been rising for the past twenty thousand years.

It is difficult to tell what is natural and what is human caused.

It was rising at the rate of 120 mm per decade until 7,000 years ago when it slowed dramatically. For the past three decades the rate has been 3mm per year.

At that rate it will take 100 years to rise 30cm.

A problem it may be but no need for alarmism.

Regards,
W DUESBURY,
Boambee.