Rebuilding a Zero Carbon Christchurch

This post reproduces the essay 'Next Generation Infrastructure' by Generation Zero members Peter Cockrem and Clayton Prest, which was published in the book Once in a Lifetime: City Building after Disaster in Christchurch by Freerange Press. The book contains 55 written and 39 visual essays, and includes a foreword by Helen Clark. It can be purchased here.



‘Addressing climate change is the great challenge of our age. All nations are affected so we must all play our part.’
- Hon. Tim Groser, Minister for Climate Change Issues, December 2013.[1]

Post-earthquake Christchurch faces a multitude of issues that test our current resolve and question our future ambitions. Climate change may seem intangible next to the many immediate recovery issues, yet its environmental, social and economic impact will ultimately shape our city over the next 50 years. The current rebuilding of our city’s land use, transport, and energy infrastructure presents an opportunity to steer away from a fossil-fuel dependent pathway and avoid passing on the cost of solving these challenges to the next generation.

Two conclusive reports from the Intergovernmental Panel on Climate Change (IPCC) in early 2014 are an urgent reminder to evaluate how the Christchurch recovery is responding to climate change. This essay reviews why the recovery needs to respond to climate change, examines what is happening locally to reduce carbon emissions and addresses how can we better mitigate and adapt to its impacts. Christchurch’s potential transition from recovery to carbon-zero is not only a chance to be global leaders in clean energy, but to create a more prosperous city and better lives for current and future generations of Cantabrians.

Why does the recovery need to respond to climate change? 


As one of the biggest challenges facing our society in the twenty-first century, climate change will affect the way we live in Christchurch. There is global scientific consensus that increasing greenhouse gas emissions, particularly carbon dioxide from the burning of fossil fuels, is linked to changes in global climate.[2] Research shows the link to be as certain as that between smoking and lung cancer.[3] In early 2014 the IPCC released their comprehensive Fifth Assessment Report which analyses the causes, impacts, adaptive measures and mitigation solutions to climate change.[4] The report has prompted calls for urgent action to curb our accelerating emissions, which have already raised the average global temperature by 0.85 degrees and sea levels by 200 mm since 1880.[5]

The consequences of inaction will affect us in New Zealand and we’re not prepared. A 2013 report from the Ministry for the Environment (MFE) indicates that our agricultural industry is threatened by severe droughts that are predicted to become more frequent as the planet warms. A 0.8 metre sea level rise before the end of the century will increase our vulnerability to severe heavy rainfall events, particularly in Christchurch where land subsidence from the earthquakes has already resulted in flooding in March and April 2014.[6] New Zealand is part of an international agreement to limit global warming to a relatively tolerable two degrees, which will require large scale transition away from our fossil-fuel dependent cities and economies.

However we are doing poorly in response to climate change compared to other countries. The 2013 Climate Change Performance Index ranked New Zealand forty-first in the world, with a ‘very poor’ grade for its climate policy.[7] Climate Change Issues Minister Tim Groser claims we are doing ‘our fair share’ to reduce emissions, yet we have the fifth-highest per-capita emissions in the OECD, emitting more per person than countries like the UK and Japan.[8] Although our electricity generation is mostly from renewable sources, electricity makes up only 28 per cent of Christchurch’s energy use, with the remainder being predominantly petrol and diesel used for transport.[9] MFE sets unconditional targets of a 5 per cent reduction in greenhouse gas emissions from 1990 levels by 2020, and 50 per cent reduction by 2050.[10] With our carbon emissions having increased by 32 per cent since 1990, we are not on track to meet even these low targets and have few mitigation policies to transition to clean energy.[11] The Government states that this responsibility is being left to local governments, yet the Christchurch rebuild is an opportunity to collectively lead climate change mitigation and adaptation to reduce its harmful effects.[12]


What is Christchurch doing about climate change? 


‘People and communities actively work towards a climate smart Christchurch that reduces its greenhouse gas emissions and is resilient to the social, economic and environmental effects of climate change.’ 
- Christchurch City Council’s Climate Smart Strategy.[13]

Before the February 2011 earthquake, Christchurch’s CO2 emissions were rising, despite the inclusion of climate change in local government policies. In 2008, 80 per cent of the city’s energy came from fossil fuels, with only 20 per cent from renewable sources including hydroelectricity, wind, and wood fires.[14] Two-thirds of our total emissions came from transport, and 18 per cent from fossil fuels used to heat our homes and buildings.[15] The energy use for transport and buildings in Christchurch grew by 33 per cent per capita from 1990 to 2008.[16] In response the Christchurch City Council (CCC) released its Climate Smart Strategy in 2010, which looks at the necessary steps to mitigation and set emissions targets of 20 per cent reduction by 2020.[17] Although a step forward, it is small compared to targets set by cities such as Copenhagen (carbon neutral by 2025).[18] In 2008 CCC was far more ambitious with a vision for 2050 where ‘Christchurch’s energy supplies are provided solely from renewable sources, and the city’s energy systems are efficient and secure, ensuring sustainability and net zero impact on climate, local environment and public health.’[19]

Yet the reality is that emissions have only increased further since the earthquakes. Land use has changed significantly in the east and around the periphery of the city, increasing average trip distances and reducing the efficiency of public transport and attractiveness of walking and cycling.[20] The dip in overall energy use caused by the earthquakes has more than rebounded and is now 3.7 per cent higher than pre-quake levels.[21] Our current business-as-usual construction of housing and infrastructure locks in these increases for the long term, and risks leaving these assets stranded if travel behaviour is forced to change due to land use and the rising cost of oil.

The Christchurch Central Recovery Plan (CCRP) considers this in its vision for ‘a greener, more attractive central Christchurch, which includes measures against climate change’.[22] The CCRP sets out a compact central city of special-use precincts, constrained by a frame of green space and residential development. The Land Use Recovery Plan affects the rest of Christchurch and Canterbury, allowing limited intensification in some areas, but also releasing large amounts of greenfield land outside the existing city. The planned central-city living has been too slow to absorb the post-earthquake housing demand, which has been displaced to greenfield sites. The District Plan is being urgently reviewed, yet its land-use policies make few changes from present. Mixed-use development is limited to existing neighbourhood centres with little expansion of their extents, though increased residential density in existing centres is a positive step.

There are several major transport plans that will determine the city’s development and future emissions profile. The CCRP urgently designated land uses long before the transport chapter, ‘An Accessible City’, put in place objectives to support a mode shift away from driving with a people-orientated core that is walking and cycle friendly. Separating land-use and transport planning makes it difficult for effective and efficient urban development to occur. The CCC has allocated funding for the construction of thirteen major cycleways, for completion in eight years. Its District Plan Review aims ‘to reduce dependency on private motor vehicles and promote the use of public and active transport’ and ‘minimise the adverse effects on the environment from the transport network,’ but continues to mandate the provision of car parking spaces with most developments.[23] The exclusion of neighbourhood centres from these parking requirements, and the reduction from two to one spaces for residential units are steps in the right direction. However, mandating any parking increases the cost of development and reduces the perceived cost of owning and operating a car, thus inducing greater demand for emissions-intensive car travel.

The CCRP acknowledges that ‘Greater Christchurch has an opportunity to build green, healthy and resilient buildings that have a lasting, positive legacy’. It suggests Green Star building ratings for the recognition of sustainable buildings, but makes no commitment to assessment.[24] It does lay out possible plans for a District Energy Scheme, which would increase energy efficiency and could be powered by renewable sources. The IPCC recognises that ‘Building codes have been among the cost-effective instruments for emissions reduction’, yet NZ building standards set no mandatory targets on energy use or embodied emissions.[25] The NZ Green Building Council, in conjunction with CCC, have developed BASE (Building a Sustainable Environment) as a simple assessment for new buildings in Christchurch to achieve 20 per cent more energy and water efficiency than the building code.[26] Sustainable energy initiatives, like trialling energy performance improvements in the repair of earthquake damaged homes and the Build Back Smarter Project, indicate a shift towards an energy efficient built environment, but this is not enough in terms of meeting climate targets.[27]


How can we better mitigate and adapt to climate change?


The recovery presents the opportunity to build a mitigation pathway towards a carbon-zero Christchurch by 2050. If Christchurch is going to even achieve its emissions targets then pre- and post-earthquake trends need to be turned around. To do so, rebuild plans need to include specific and measurable policies to address land use, transport and building energy use and emissions.

Land-use patterns that reduce the distances people need to travel are the key to major reductions in carbon emissions. The IPCC recommends ‘co-locating high residential with high employment densities, achieving high diversity and integration of land uses’.[28]
Exemplar ‘density done well’ competitions such as the Breathe Urban Village and community-driven developments such as the Viva Project could lead the way for this in Christchurch.[29] This is important in attracting and retaining skilled and mobile young workers and entrepreneurs, who value vibrant urban life and choose to live predominantly in central areas.[30]

Transport options that provide an alternative to car travel could substantially reduce carbon emissions in Christchurch, while providing economic and social co-benefits including reduced travel costs, travel times, and road deaths and injuries.[31] The Congestion Free Network plan for Auckland developed by Generation Zero and Transport Blog offers inspiration for the potential of a multimodal transport network to provide people with the choice of travelling without traffic congestion. In Christchurch, high-frequency public transport on key routes with priority to increase speed and reliability would make a big difference to the attractiveness of the system. The energy efficiency of public transport can be further improved by changing from diesel buses to hybrid or battery electric buses, or electric light rail, though shifting trips from private vehicles is more important for the system as a whole.[32] Commuter rail service to satellite towns on the railway lines north and south of Christchurch would reduce carbon emissions substantially compared to private car travel, though risks increasing the attractiveness of low-density lifestyle blocks dependent on car use for non-work trips.[33]

Buildings are a focus of the rebuild and could be much warmer, healthier and more efficient in the use of energy and emission of greenhouse gases. The IPCC suggests that a well-designed, insulated, and passively-heated building cuts energy use by 50–90 per cent.[34] There are also emissions associated with producing and assembling new building materials, which is typically a quarter of the emissions over a 60-year lifetime. Constructing a new steel or concrete building releases almost half a tonne of CO2 per square metre, while timber buildings are less carbon-intensive to construct.[35] However, it should not be overlooked that the buildings that require the least energy and emissions to construct are those already standing. Christchurch can retrofit existing buildings for greater performance and set the standard with new buildings tested for mandatory Green Star and Home Star assessments, including monitoring energy use and emissions. In addition to energy cost savings, mitigating emissions in buildings creates considerable co-benefits including higher productivity and healthier occupants.[36]

If we cannot successfully mitigate climate change globally we will have to adapt to its impacts locally. We can reduce our exposure to sea-level rise threatening coastal areas such as New Brighton, Sumner and the Avon and Heathcote rivers through higher floor levels, relocatable buildings, and developing areas that will not require expensive flood protection.[37] With the severity of flooding predicted to increase, and ‘if communities cannot achieve a managed retreat, then the risk is likely to increase until a forced retreat is unavoidable.’[38]



Taking action in the Christchurch recovery to reduce and prepare for the impacts of climate change is economically and socially beneficial today and leaves a much less expensive legacy for future generations. Christchurch is especially vulnerable to the effects of climate change, and is not doing its share in reducing its effects. Our emissions were increasing before the earthquakes and continue to grow. Recovery plans for the central city are a chance to align with good climate outcomes, but the wider regional land use and transport plans need to address the critical challenge of reversing current trends in emissions and energy use.

Recovery agencies have a responsibility to ensure efficient land-use; provide attractive public transport, walking and cycling options; and build sustainable, energy efficient homes and workplaces. The IPCC report emphasises that the benefits of mitigation include a stronger, resilient ‘green economy’, thus creating skilled jobs; building a healthy, accessible city; and attracting global talent to our doorstep. These are all aspects that are integral to the future success of Christchurch - rebuilding the city as it was will not be enough.[39]

Christchurch has been named as one of the Rockefeller Foundation’s global network of one hundred Resilient Cities - a chance to lead by example in adaptation and resilience measures which lower risk and substantially reduce disaster costs in the long term.[40] Not only can we be an exemplar to other post-disaster scenarios, but through mitigation become a leading international carbon-zero city.


About the authors


Peter Cockrem studied engineering and is part of Generation Zero’s policy team having worked as a transportation engineer in Christchurch and Sydney. Clayton studied architecture and is Generation Zero Christchurch’s external relations coordinator, while working on the WikiHouse project. 


1. Ministry for the Environment, New Zealand's Sixth National Communication to the United Nations Framework Convention on Climate Change, (Wellington: MFE, 2013), 2.

2. ‘97% of published climate papers with a position on global warming agree global warming is happening and we are the cause,’ “The Consensus Project,” accessed March 31, 2014,

3. AAAS Climate Science Panel, What We Know: The Reality, Risks and Response to Climate Change, (American Association for the Advancement of Science), accessed April 14, 2014,

4. The IPCC report builds on previous research published in 1990, 1995, 2001,and 2007; IPCC, Summary for Policymakers, Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, 2014.

5. IPCC, Summary for Policymakers, Climate Change 2014: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, 2013; ‘According to economists’ estimates climate-related damage is already costing us more than 1.2 trillion dollars worldwide in global GDP,’ from Fiona Harvey’s ‘Climate Change is Already Damaging the Economy,’ The Guardian, 26 September 2012, accessed May 2, 2014,

6. MFE, New Zealand's Sixth National Communication, 149; “Global warming warning after ChCh floods,” 3News, accessed May 12, 2014,

7. Jan Burck et al., Climate Change Performance Index, (Germanwatch, 2013), 18-19.

8. “Climate Change Minister welcomes IPCC report,” New Zealand Government, accessed May 3, 2014,; “Greenhouse gas emissions and removals,” Ministry for the Environment, accessed April 23, 2014,

9. 73 per cent in 2012, according to MFE in Sixth National Communication on Climate Change; “ChCh Energy Use,” Christchurch Agency for Energy, accessed May 11, 2014, database.

10. MFE acknowledges that New Zealand is committed to playing its part in a global response and sets conditional reduction targets of 10-20% in its Sixth National Communication on Climate Change.

11. New Zealand's emissions of greenhouse gases are accelerating from 2.2% in 2012, from 1.4% in 2011. MFE, Sixth National Communication on Climate Change, 49.

12. ‘The effects will fall capriciously and unevenly, and local bodies cannot be expected to meet them’ from “Climate change everyone's issue,” The Dominion Post, accessed May 9, 2014,

13. Christchurch City Council, Climate Smart Strategy 2010-2025, (Christchurch: CCC, 2010).

14. MFE, Sixth National Communication on Climate Change, 11.

15. CCC, Climate Smart Strategy 2010-2025.

16. Total energy use in Christchurch has increased 66 percent since 1990; Ibid.

17. CCC also established a ‘Target Sustainability’ initiative. CCC, Climate Smart Strategy 2010-2025.

18. Copenhagen Clean Tech, Copenhagen 2025 Climate Plan, (Copenhagen Clean Tech, 2012).

19. Christchurch City Council, Sustainable Energy Strategy for Christchurch 2008 - 2018, (Christchurch: CCC, 2008), 11.

20. Between the 2006 and 2013 census population growth by 32.6% in Selwyn and 16.7% in Waimakariri while Christchurch City decreased by 2%. “Quick stats about Greater Christchurch, ” Statistics New Zealand, accessed May 4, 2014,; Public transport use dropped 44% from 2010 to 2012 with the loss of 50,000 jobs in the central city and the central bus exchange. Energy Efficiency and Conservation Authority, Powering Public Transport in New Zealand, (EECA, 2012), accessed May 3, 2014,

21. Energy use has risen predominantly due to a 26% rise in diesel use from heavy demolition vehicles, “Christchurch Agency for Energy,” CAfE, accessed May 2, 2014,

22. Christchurch Earthquake Recovery Authority (CERA), Christchurch Central Recovery Plan, (Christchurch: CERA, 2012), 23.

23. Christchurch City Council, Christchurch District Plan Review: Draft Transport Chapter, (Christchurch City Council, 2014).

24. CERA, Christchurch Central Recovery Plan; Green Star assessments are currently used by 50% of all new commercial buildings in NZ.

25. IPCC, AR5 SPM WG-III, 21; ‘Building codes...if well designed and implemented, have been among the most environmentally and cost-effective instruments for emissions reduction’. IPCC AR5 SPM WG-III, 26.

26. “BASE: A Green Building Assessment Tool for Christchurch,” NZGBC, accessed May 2, 2014,

27. The Christchurch Agency for Energy has established a $1.8 million fund in a bid to reduce carbon emissions by encouraging sustainable energy initiatives in the city rebuild. “New Energy Grant’s for the Christchurch Rebuild,” CCC, accessed May 1, 2014,; ‘Energy performance improvements should be included in the ‘standard’ repair of earthquake damaged homes;’ “What is the Build Back Smarter Project,” Beacon Pathway, accessed May 4, 2014,

28. IPCC, AR5 SPM WG-III, 28.

29. Brent Toderian,“Density Done Well, and Not Just Downtown,” Planetizen, accessed April 28, 2014; “Christchurch Sustainable Urban Villages,” The Viva Project, accessed March 21, 2014,

30. Richard Florida, “What Cities Really Need to Attract Entrepreneurs, According to Entrepreneurs,” The Atlantic CityLab, February 11, 2014, accessed April 17, 2014,

31. IPCC, AR5 SPM WG-III, 25; Ibid. 24.

32. MRCagney Ltd, Powering Public Transport in New Zealand, (Auckland: EECA, 2012), accessed May 3, 2014,

33. David Killick, “Commuter Rail Needed for Rebuilt City,” The Press, October 16, 2013, accessed May 6, 2014,

34. IPCC, AR5 SPM WG-III, 26.

35. 0.45 tonnes/square metre; John, Stephen et al., The Carbon Footprint of Multi-storey Buildings Using Different Construction Materials, (Christchurch: University of Canterbury, 2010), accessed May 5, 2014,

36. IPCC, AR5 SPM WG-III, 26.

37. Tonkin & Taylor, Effects of Sea Level Rise for Christchurch City, (Christchurch: Christchurch City Council, 2013), 63.

38. Tonkin & Taylor, Effects of Sea Level Rise.

39. Georgina Stylianou, “Can Christchurch be Saved?” The Press, May 4, 2014, accessed May 5 2014,

40. CCC, accessed May 3, 2014,

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