12 Apr 2017

It’s hard to deny climate change has a human footprint.

1:55 pm on 12 April 2017

With increasingly extreme floods, droughts, fires and storms lashing the country, it’s hard to deny climate change has a human footprint. Can we stop it? 

A flooded home in Edgecumbe

A flooded home in Edgecumbe Photo: supplied / Tautini Hahipene

Tomorrow in parliament, MPs will debate a report which offers scenarios that could shape the way New Zealand responds to climate change. 

The Net Zero New Zealand report looks at how the country can reach a goal of zero greenhouse gas emissions by 2050. 

It’s futuristic, and may seem extreme. But climate scientists argue zero emissions by 2050 will be necessary to stop global warming. 


Last week, the swollen Rangitaiki River burst its banks and flooded the small Bay of Plenty town of Edgecumbe, population 1600, in what the area’s mayor called “a one in 500 year event." 

About 900 homes were evacuated. Some will remain unoccupied because of extensive damage. 

As of today, a state of emergency has been extended to the entire Bay of Plenty, with up to 250mm of rain forecast for the sodden region over the next 48 hours.  

In March, parts of Auckland, Waikato and the Bay of Plenty had rainfall at more than 300 percent higher than normal. In West Auckland, 176 homes flooded leaving many residents in emergency accommodation with nothing but the clothes they were wearing. 

Both the storm that caused Auckland’s flooding, dubbed the Tasman Tempest, and ex-tropical Cyclone Debbie, which wreaked havoc in Edgecumbe, can be attributed to climate change, according to Victoria University climate scientist Professor James Renwick. 

And we should expect to see more of the same intense storms in the coming years.

But it’s not just storms and foods that have a human footprint. Climate change will contribute to heightened fire risk in the future, similar to the size and scale of Christchurch's Port Hills fires in February, as drought risk for prone areas will likely increase. 

NIWA predicts that sea level rise will continue for several centuries even if greenhouse gas emissions are reduced (the prediction for New Zealand is an increase of 18 to 59cm between 1990 and 2100). Snowlines will rise, the duration of the snow season will decrease and glaciers will continue to recede. 

The Mueller Glacier, Hooker Glacier and Tasman Glacier in January 1990.

The Mueller Glacier, Hooker Glacier and Tasman Glacier in January 1990. Photo: NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team

The Mueller Glacier, Hooker Glacier and Tasman Glacier in January 2017.

The Mueller Glacier, Hooker Glacier and Tasman Glacier in January 2017. Photo: NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team

According to NASA, 2015 was the warmest year on record, and the 10 warmest years in the 136-year record all have occurred since 2000, with the exception of 1998. The global temperature has increased about one degree celsius since 1880. 

In Australia, more than 700km of the Great Barrier Reef saw an unprecedented coral bleaching event in 2016. Arctic sea ice had a record melt last year, and the UN High Commissioner for Refugees (UNHCR) estimated that, on average, 21.5 million people have been displaced by climate, or weather-related events each year since 2008. 

A 2010 heatwave in Russia that killed more than 50,000 people and destroyed the country’s wheat crops was made more likely by climate change, and flooding that year in Pakistan killed 2000 and directly affected millions. 

Extreme weather events, failure of climate change mitigation and adaptation, as well as water crises as a result of climate change were identified as global risks interconnected with conflict and migration in the World Economic Forum’s 2017 Global Risk Report

Professor Renwick says if climate change is ignored, and emissions continue, the future will be bleak. 

“If we continue to allow emissions to go up and up, all of the ice on the Antarctic and Greenland will melt, the sea level will go up 80 odd metres and the climate will become unrecognisable.

“It will be gradual. The storms will get wetter and the sea level rises by a few millimetres a year. We’re already feeling the effects - we have been for decades.”

Eventually, populations in coastal cities - including Auckland, Wellington, Christchurch and Dunedin - will have to move further inland. Places where crops are grown and cattle graze will change, and global food production willd go down to a fraction of what it is now. 

“Several billion people will starve to death or get washed away. It sounds terribly doomsday-ish, but if we leave things that’s what will happen eventually,” Professor Renwick said.


On October 4, 2016 New Zealand ratified the Paris Agreement. It commits the world to holding the rise in global temperature to below 2C above pre-industrial levels, and to pursuing the goal of limiting the increase to 1.5C. The agreement also commits the world to the peaking of emissions as soon as possible. 

New Zealand’s emissions reduction target is five per cent below our 1990 greenhouse gas emissions levels by 2020, 30 percent below 2005 levels by 2030, and 50 per cent below our by 2050. 

But Professor Renwick says 50 percent by 2050 is not good enough. 

“Actually the latest science is saying we need to do that by 2030, and again by 2040, and again by 2050 so we’re down to less than 10 percent of the present by the middle of the century. That’s much more the timetable that we should be looking at.

“We all have to make some pretty big changes, but we’re talking about a really big issue,” he said.  

“It’s daunting, but if we really took it seriously we’d amaze ourselves with how much progress we could make in a short time. 

“Zero emissions is not just an idea, we have to do it. We have to get our heads around that the fact that we do have to do this and the sooner the better.” 


The seriousness of New Zealand’s greenhouse gas emissions depends on which way you look at it. 

Compared to other developed nations our emissions are small. But we have the second-highest level of emissions per GDP unit in the OECD and the fifth-highest emissions per capita. 

Agriculture accounts for 49 per cent of New Zealand’s emissions, the highest share in the OECD, but more than 38 percent of New Zealand's exported goods come from the sector. Currently 80 percent of the country’s electricity comes from renewable sources - mainly geothermal and hydro, and the goal is 90 per cent by 2025.

Road transport and industry have pushed up gross emissions by 23 percent since 1990. Car ownership in cities is high and many vehicles are old and inefficient. The OECD’s environmental performance review of New Zealand says “current vehicle standards and taxes do not sufficiently encourage a shift towards cleaner, more efficient technologies.”

Road transport and industry have pushed up gross emissions by 23 percent since 1990.

Road transport and industry have pushed up gross emissions by 23 percent since 1990. Photo: RNZ


Tomorrow from 3pm to 6pm, the House will debate the Net Zero New Zealand report. 

The report was commissioned by Globe-New Zealand - a cross-party group of 35 members of the New Zealand Parliament (it’s chaired by the Greens’ Dr Kennedy Graham, and the executive committee includes Peter Dunne, Marama Fox, Tracey Martin, Scott Simpson, and Dr Megan Woods.)

It covers three main scenarios to mitigate the effects of climate change. 

Scenario one sees a slight increase in stocking rates (that’s more cows per paddock per grazing season, which frees up land), afforestation (planting more trees in said freed up land to absorb more carbon dioxide) and a changed use of forestation biomass. But in this scenario, by 2050 emisisions will only have dropped by 10 to 25 percent. 

In scenario two, technology improvements will allow electricity to be used for one-third of high-grade heating, will double the rate of medium-grade heating, and almost all low-grade heating will be electrified. Freight will moved from road to rail, and renewable electricity production will increase to 95 to 98 percent. In agriculture, stocking rates will be increased and beef cattle and sheep numbers will drop, freeing more land for forestry, horticulture and native forest. Technological advances will mean vaccines and breeding can reduce methane emissions in cattle. Dairy will be de-intensified, waste levels will drop, but industrial emissions will remain largely unchanged. The scenario is enough to place the economy on a path to net zero emissions by 2100.

Scenario three places the economy on a path to net zero emissions before 2100 with a combination of the above changes with additional tree planting of 2.3 million hectares by 2050.

But one scenario remains: Net zero in 2050. 

This scenario combines the forestry growth, agricultural productivity and stocking rate assumptions from scenario three with the technology penetration assumptions and livestock numbers of scenario two. In addition, industrial closure in the aluminium, steel and refinery sectors is necessary. 


“In the current political environment, I don’t see a move away from dairy happening,” Professor Renwick says. “But I don’t think it’s sustainable in the long term and we’ll move away in due course - the sooner the better.”

He says large increase in dairy farms occurred in the last 20 years. Farmers are adaptable, and the agriculture sector could change dramatically in the next 10 or 20 years towards something more sustainable.


As an individual, it might seem hard to know what to do about all this. But there is plenty, it would seem. 

In the United Kingdom, the government has been sued for its poor plan to tackle air pollution, and the same group of activist lawyers, Client Earth, may take legal action over the country’s Emissions Reduction Plan. In the United States, a group of teens are taking legal action against the government, alleging its “actions and inactions have so profoundly damaged our home planet that they threaten plaintiffs’ fundamental constitutional rights to life and liberty.”  In 2015, the dutch government was ordered by court to reduce emissions, and Greenpeace is suing Norway for drilling in the arctic. 

In New Zealand this week, Russel Norman swam in front of an oil exploration ship. And Waikato law student Sarah Thomson has filed papers in the High Court in Wellington, requesting a judicial review of aspects of the government's climate change policy (the hearing is set for June 26 to 28 this year). 

Professor Renwick says Kiwis should be working for change at the highest levels by encouraging governments to introduce policies to spend money on public transport and electric vehicles, new technology and renewable energy.  

“My advice to people is - if you want to do something as an individual, get in touch with your MP and tell them that you’re concerned about this and that you’d like to see more action.

“There’s no joy in running around shouting, and trying to frighten people about what might happen in the future. Let’s imagine a really great future where we’re not polluting the rivers and we’re not putting crap in the atmosphere. Let’s imagine the world we want to be in in 50 years time and let’s get there."