Northland is bracing for another bout of heavy rain, while barely recovering from the weekend's storm.
The downpour was labelled a "one in 500 year event" by MetService, and the region's Civil Defence is predicting an
expensive clean-up.
The SMC asked experts to comment.
Professor James Renwick, Head of School of Geography, Environment and Earth Sciences, Victoria University of Wellington,
comments:
"The recent flooding in Northland has been devastating for many communities. Having your home, your farm, or your
business flooded must be a terrible experience, let alone damage to infrastructure. The economic costs of such events
can be huge.
"The bad news is that such deluges are becoming more frequent and more intense as the climate warms. The reason is that
a warmer atmosphere can contain more moisture (water vapour), so when a storm comes along, there is more water to wring
out of the sky, leading to a greater likelihood of heavy rain and flooding. We already see this trend in heavy rainfall
statistics from around the world.
"The rainfalls experienced recently in Northland have been estimated as a '1-in-500-year' event. This doesn’t mean we
have to wait another 499 years to see the next one, more that there’s a 1-in-500 chance of experiencing such a heavy
rainfall in any given year. Putting an exact likelihood on such a rare event is hard to do precisely, but what we do
know is that as the climate warms, those odds are shortening. The only way to stop this happening to reduce greenhouse
gas emission as fast as we can."
No conflict of interest declared.