NZ warned to brace for climate refugees

Prime Minister John Key and his entourage walk along a beach on Stewart Island (Getty)

Climate refugees will pour into New Zealand whether we like it or not if global warming continues unabated, one expert is warning.

A new report by the Royal Society of New Zealand (RSNZ) has outlined what New Zealand stands to lose from climate change, which could see the oceans rise by a metre this century if we don't stop emitting huge amounts of carbon and methane.

"Even if we were able to turn them all off globally tomorrow, we would still get at least another 30cm of sea level rise and other changes in the climate," Prof James Renwick, who chaired the expert panel which produced the report.

"If we keep going we have the last few years, we could be seeing 4 or 5degC of global warming this century, well over a metre of sea level rise -- with a commitment to 10m or more over the next few hundred years. So take your pick."

While other effects of climate change are likely to be felt more strongly elsewhere, with conflict over increasingly scarce resources thanks to crop failures and freshwater shortages, Prof Renwick says New Zealand shouldn't be complacent.

"Think about Syria and the Mediterranean today -- that could be a picture of the future in a lot of parts of the world if we don't get on top of the problem… A lot of people may want to come here, whether we want them to come or not."

The sea level in New Zealand is predicted to rise by 10 percent more than most other places.

"There are gravitational effects, the way the winds blow over the ocean affects where the water piles up and where it's a bit lower," says Prof Renwick.

"As the weight of water changes on the surface of the Earth, tectonic plates adjust, and so on. It's all a very dynamic situation and what it adds up to for New Zealand and the western Pacific, we're expecting on the order of 10 percent more sea level rise in the west than we'd see around the rest of the globe."

Sea levels rose in New Zealand about 17cm through the 20th century. While 30cm over the next eight decades doesn't sound like much, Prof Renwick says it makes adverse events much more likely.

"Because beaches are basically pretty flat, it's surprising how little you need to change the sea level to change the risk of a king tide or a coastal inundation event. Ten centimetres triples that risk."

Yesterday it was claimed New Zealand has been "cheating" on its carbon emissions by buying fraudulent credits from Ukraine and Russia.