Research shows fall in greenhouse gases over two decades but a worrying rise in transport emissions

  • Published Date 09 Jun 2020

A just-released report from infrastructure consulting firm AECOM commissioned by the region's nine councils shows that the Wellington Region's gross greenhouse gas emissions fell by 5 per cent between 2001 and 2019, from a gross of 4,427,849 tonnes of carbon dioxide equivalent to 4,190,050 tCO2e.

However, transport emissions rose by 14 per cent across the region. Main causes were road petrol and diesel (cars and trucks, up 8%), aviation (up 37%) and shipping (up 22%). Within this, fuel use/emissions associated with shipping logs overseas has increased by a factor of 13 compared to 2000-01, and all other international shipping has doubled. 

Transport emissions around the region vary. For example in 2018-19 Upper Hutt's transport emissions were 6% lower than 2000-01, Wellington City's have increased 4 per cent and emissions from Kāpiti and Wairarapa have increased by 40 per cent and 41 per cent respectively (the rise in part due to the transport of logs overseas, as emissions are allocated to the district where the logs originate).

"Our transport emissions have gone up 14% so far this century. They need to start falling now and fast. If we want to bring climate pollution down we have to transform the way we get around. 

"The data shows an eight percent rise coming straight from the exhausts of petrol and diesel vehicles," says Greater Wellington Climate Committee chair Cr Thomas Nash.

"Cars are convenient, but our outdated car-dominated transport system is totally incompatible with the zero carbon future that we absolutely must achieve.

"Communities, businesses and organisations can all use imaginative policies to bring down transport emissions. Let's make it possible for people to reduce car use, to replace car journeys with bus, train, ferry and cycle journeys and make sure the cars that do need to drive are electric.

"Our response to COVID-19 shows that many people can work productively from home and also stagger our journey times by travelling to and from work outside peak times. These measures are being embraced enthusiastically by many employees and employers.

"For people who need to commute, we are accelerating procurement of electric buses, getting bus priority done and, further out, putting in mass rapid transit.

"Clean, safe, healthy transport is the biggest climate action lever we can pull and the good news is that doing so will bring a whole host of other benefits to our wellbeing and the quality of life for everyone in our region.

"Alongside transport, the other big lever we need to pull is our economy. The data reveals the high climate costs of shipping raw logs overseas. This highlights both a core problem with New Zealand's wider economic settings of low value, high volume exports and an opportunity for the post-covid world.

"We have an opportunity to move towards producing high quality processed wood and timber products for use in NZ. This wood-first policy would have massive benefits both for our economy and our climate and support local industry."

The good news from the inventory is that waste, stationary energy and agricultural energy emissions reduced between 2001 and 2019, by 36, 18 and 17 per cent respectively. Key reasons for the fall include use of landfill gas capture, which has driven down waste emissions more than any sector, greater use of renewable energy to provide electricity, and a reduction in the number livestock e.g. cattle, sheep, pigs, deer farmed within the region.

Greater Wellington has already committed to net zero emissions by 2030 for its corporate emissions and is working with its partners to reduce wider regional emissions. As part of this, Greater Wellington and the eight other councils in the Wellington Region commissioned an update to the regional greenhouse gas inventory for activities occurring up to 2019 from consultants AECOM. Methodology changes were applied to past inventories to make a comparable series of results from 2001.

The inventory relates to all emissions occurring within the region, as well as emissions from waste generation (regardless of where it is disposed of) and electricity used in the region (regardless of where it is generated). Half of the emissions from air and sea travel beginning and ending at the region's ports was also included.

Net emissions (that include forestry) rose by 34% over the period. This is mainly due to the timing of forestry harvests, rather than a reduction in land used for forest, which has in fact increased.

Separate inventories for Wellington City, Lower Hutt District, Upper Hutt District, Porirua City, Kāpiti Coast District and the combined Wairarapa Districts (Masterton, Carterton and South Wairarapa) were also produced.

Wairarapa has the highest gross emissions of all the cities and districts due to its comparatively large agricultural sector. However the large amount of forestry located in the Wairarapa - which absorbs carbon dioxide from the atmosphere - means its net emissions are only third highest.

Kāpiti Coast Greenhouse Gas Inventory (PDF 3.5 MB)

Lower Hutt Greenhouse Gas Inventory (PDF 3.5 MB)

Porirua City Greenhouse Gas Inventory (PDF 3.5 MB)

Upper Hutt City Greenhouse Gas Inventory (PDF 3.4 MB)

Wairarapa Combined District Greenhouse Gas Inventory (PDF 3.6 MB)

Wellington City Greenhouse Gas Inventory (PDF 3.5 MB)

Wellington Region Greenhouse Gas Inventory (PDF 2.4 MB)

Updated October 19, 2021 at 12:16 PM

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