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Cimate change scientist James Renwick on the beach at Raumati South where the dunes are eroding away. (File photo)
Louise Perzigian is the communications manager for the Nelson Tasman Climate Forum
Slow political will and action have put the 1.5 degree climate goal out of reach, Victoria University Professor James Renwick has told an audience in Nelson.
Renwick, who is a professor of physical geography specialising in large scale climate variations, painted a picture of accelerating ecological change that was alarming on a global scale, but had not been met by urgent action from New Zealand politicians.
“We’re collectively pulling the rug out from beneath ourselves,” he said.
Humans had released more carbon dioxide into the air over the past 100 years than natural processes would do in 100,000 years. There was no question that humans were the main cause of the “warming blanket” of carbon dioxide in our atmosphere, he said.
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Renwick says a 1.8 degree temperature rise would cause 50-centimetres of sea-level rise in Nelson-Tasman.
“We’re the ones putting the spike of carbon dioxide in the air. This decade has to be the decade of action because if it isn’t, we’re definitely through 1.5 degrees (of temperature rise). We’re probably into the territory that would be pretty hard to deal with,” he said.
Earth would pass a 1.5 degree average rise in temperature over pre-industrial times within 10 years, if we continued to burn fossil fuels at current rates.
It would pass two degrees in 20 years, and three degrees in 30 years, unless substantial changes were made in our energy system. Renwick said we might be be able to stay within a 1.5 degree rise if we managed a 50 percent reduction in carbon dioxide emissions by 2030, and a 100 percent reduction by 2050.
In the Nelson and Tasman region a 1.8 degree rise would cause two times the number of hot days, fewer frosts and 50 cm of sea-level rise, Renwick said. The decline in frosts would affect the ability to grow apples and apricots which need setting in the winter, he said.
“If you live near the coast you probably want to retreat. We need to move with the coast. If you live near a river or are in a flood plain you can build stop banks, but that might lull you into a greater sense of security. You probably need to think about moving away.”
Renwick urged the audience to join protests and call politicians to convey the urgency of the situation.
New Zealand was at a point where the Government needed to prepare national policy for future scenarios, such as policies for people arriving on boats in large numbers as “climate refugees”.
GNS Scientist Paul White spoke to the audience about potential scenarios for replacing fossil fuels with renewable sources in the country’s energy and electricity systems. He acknowledged fossil fuels would be needed to build renewable power stations quickly.
Renwick said this was not an ideal scenario because we were trying to reduce the use of fossil fuels. “The big pusher is to do it in such a way that we can keep it below 2 degrees. 1.5 degrees is already in play. We have to try as hard as we can, basically.”
There was a long list of individual actions that covered every sector from transport to energy use that could reduce carbon emissions. National and global players had a big responsibility to take urgent action on climate and acknowledge that economic growth needed to become stable and sustainable.
Renwick was invited by the Nelson Tasman Climate Forum for a State of the Climate talk, held at Pūtangitangi Greenmeadows Centre in Stoke.