This is the current situation in regard to climate change. There has been a 1C rise in global temperatures in the past 200 years matched by a move from 250ppm of greenhouse Carbon Dioxide to 401ppm. (SEE Q & A on the menu bar.) Adding another 1C rise, forecast in the next thirty or so years, will see the following adverse local consequences for Marlborough. (The national implications will be considerably more severe and the international consequences will see huge flows of refugees and probably an increase in wars over dwindling access to food, water and other assets.)


• Loss of the main road/rail link south to Christchurch.
• Loss of the Blenheim sewage ponds and treatment facilities.
• Loss of and/or major disruption to coastal communities including Blenheim township, Grovetown, Spring Creek, Tuamarina, Rarangi, Riverlands etc.
• Increased coastal erosion and changes to the shape of the coastline due to sea level rise and storm surges.
• A hotter, drier climate with more regular droughts and increased fire risks.
• Higher demands for irrigation water placing pressure on the region’s aquifers.
• Salt water intrusion into aquifers especially the essential Wairau aquifer.
• Aquaculture threatened by ocean acidification, higher sea temperatures and increased algal blooms.
• Agriculture and food production and human health affected by new pests and diseases.

wairau lagoons

Not far to the oxidation ponds and then onto State Highway 1!

Weld Pass fire

Weld Pass 2015. Whole of Marlborough 2050?


Psychological and Sociological Impacts of Climate Change.

Climate change is as much a psychological and social phenomenon as a matter of biodiversity and geophysics. These impacts occur on multiple and simultaneous levels and will to a varying extent be evident in Marlborough.

Aspects of these include:

• An increase in violence and crime as a result of competition for resources.
• An increase in interpersonal aggression including assault and domestic abuse.
• A decrease in community cohesion.
• Impacts on psychological and mental health such as trauma, post traumatic stress disorder and ongoing stress and worry stemming from disasters such as floods, injuries, wild fire, deaths, sudden and gradual change and insurance issues. There will be, loss of personal and environmental identity and social cohesion and livelihood, suicide, and an increasing sense of unpredictability.
• The affect of increased heat is that it arouses a focus on heat and detracts from the ability to focus on other people and long term issues.
• Children will be hearing and witnessing bad news about climate change but having little power and autonomy will exhibit symptoms such as depression, social withdrawal, clinging and developmental problems.

These are just some of the known psychological and social impacts of climate change. What is equally important to know is that with willingness and determination we, as individuals and a society, may now and in the future be in a position to adapt to and mitigate some of these impacts. This is especially true if we have a government that recognises the problem and accepts its responsibility to be proactive in helping society adapt.

What is required to achieve this is that both government and people become informed and are able to make predictions about these and other impacts of climate change. As individuals and a community, we need to acquire the knowledge that will enable us to be proactive and effective in dealing with these psycho-social issues. This can be done by promoting emotional resilience and empowerment and by acting at systems and policy levels to address the impacts. As the paper by Doherty and Clayton referenced in the ‘Links Libary,’ says, ‘The challenge calls for increased ecological literacy, a widened ethical responsibility, development of psychological and social adaptations and an allocation of resources to relevant training.’


Here is a more detailed analysis of the physical consequences for our province:


Emissions of greenhouse gases have so far added a 1C rise to average global temperatures in the past 200 years and an increase from 250ppm to 400ppm of greenhouse CO2 (SEE Q & A on the menu bar.) Another 1C rise, forecast in the next thirty or so years, will see considerable adverse local consequences for Marlborough. (The national implications will be more severe and the international consequences will see huge flows of refugees and probably an increase in wars fought over dwindling access to food, water and other resources.)

Loss of the main road/rail link south to Christchurch – This has the potential to have severe effects on road and rail transport options from the ferry terminal at Picton south to Christchurch. The guidance given in the 2008 “Ministry for the Environment Guidance Manual” is expressed in terms of four general principles that councils should incorporate into their decision-making. These are – progressive reduction of risk over time, a precautionary approach, the importance of coastal margins, and an integrated, sustainable approach. The Ministry for the Environment (MfE) recommends planning for future sea-level rise of at least 0.5 metre, along with consideration of the consequences of a mean sea-level rise of at least 0.8 metre (relative to the 1980–1999 average) by the 2090s. Some climate scientists see these projections as conservative, as the IPCC reports and the computer models that they are based on do not take into account feedback loops in the climate system. This is because of the lack of reliable information available on how these feedback loops might evolve. We are in new uncharted territory. The dynamics of ice sheet reduction due to climate change are complex and new research is regularly discovering alarming evidence of destabilisation occurring in Greenland and West Antarctica. Suffice is to say that there is growing evidence to suggest that sea level rise may be considerably more by 2100, maybe up to 4 metres.

• Loss of the Blenheim sewage ponds and treatment facilities – The Marlborough District Council is using the MfE recommendations to inform it’s planning process and make decisions on what the impacts of sea level rise may be on local infrastructure. By using 0.5m to 0.8m by 2090 as the guideline we are taking the risk of being under-prepared for the consequences of a faster rate of sea level rise. It would be prudent to at least go through the exercise of assessing what options might be available if the current sewerage ponds and treatment facilities have to be abandoned. Even though the ponds have bunds that are 2 – 3 metres above sea level the surrounding ground is all less than 1 metre above sea level. This approach would be consistent with the principles outlined in the MfE report mentioned above.

• Loss of and/or major disruption to coastal communities – This includes low lying areas of Blenheim township, Grovetown, Spring Creek, Tuamarina, Rarangi, and Riverlands. Seymour Square in the centre of Blenheim township is about 6 metres above current sea level with the other settlements all closer to sea level. A 4 metre rise would have serious implications for the low lying parts of Blenheim and all these other settlements. The CBD of Blenheim could be seriously threatened indirectly and important industrial areas such as Riverlands would be under water, unless protective dikes are built. Groundwater levels will also rise making some areas unsuitable for housing and grape growing. In the “Preparing NZ for Rising Seas”, November 2015 report from the Parliamentary Commissioner for the Environment, high tide levels that are currently expected to occur only once every hundred years will occur more and more often. For a rise in sea level of 30 centimetres, such extreme high tide levels with accompanying coastal flooding effects, would be expected to occur every 1 – 4 years depending on location around NZ. She also notes that many of the cities and towns on New Zealand’s coasts are located at river mouths. In such cases, sea level rise will exacerbate river floods and compromise existing flood protection works by reducing the fall to the sea.

• Increased coastal erosion and changes to the shape of the coastline due to sea level rise and storm surges – The threat to the main trunk line and SH1 have already been mentioned. There are sections of the railway line and the highway on the coast between Ward and Kaikoura where there would be extreme difficulty in rerouting either or both of them in the case of sea level rise exacerbated by erosion during king tide and storm surge events.

• A hotter, drier climate with more regular droughts and increased fire risks – Only time will tell if the record dry year for Blenheim and the three large and expensive wildfires in the Wairau Valley in 2015 are an anomaly or a sign of what to expect in the future.

• Higher demands for irrigation water for grape growing and water for the wine making industry placing pressure on the region’s water resources – These resources will have considerable pressure placed on them if we do experience hotter, drier summers. A large proportion of the regions economy relies on the grape growing and wine making industries and it is imperative that the water resources are managed wisely and conservatively while we learn what changes we are going to be faced with as climate change effects take hold.

• Salt water intrusion into aquifers – A new water supply source is currently being sought for the township of Havelock due to issues including salt water intrusion during the dry summer of 2014 – 15. This is not something that can be directly linked to climate change but is an indicator of one possible effect of drier summers and sea level rise. The MDC operates a coastal monitoring network between Riverlands and Rarangi because of the potential for seawater intrusion, but none has been observed since measurements were started in 2001. Current monitoring indicates that balancing the rate at which groundwater is abstracted with natural rates of through-flow is the best means of avoiding seawater intrusion in the Coastal Sector of the Wairau Aquifer. Any sea level rise could alter this balance and affect the aquifer. The Riverlands Aquifer is a water resource that could be affected earlier than others with even a small rise in sea level. A coastal aquifer does not have to be directly connected to the sea to be influenced by sea level rise. Where an aquifer extends out under the sea, changes in the weight of the water above it can increase the pressure on the aquifer, forcing the water table closer to the surface.

• Aquaculture threatened by ocean acidification, higher sea temperatures and increased algal blooms – Indications are that rising sea temperatures are affecting the mussel industry in the Marlborough Sounds with research showing that production in Pelorus Sound has been falling for the past 20 years. Sea water temperatures are only expected to increase, and with the added consequences of acidification from higher CO2 levels and more algal blooms, the effects on the mussel and salmon farming industries are likely to have a significant negative impact on Marlborough’s economy. The development and proliferation of algal blooms are likely to result from a combination of environmental factors including available nutrients, temperature, sunlight, ecosystem disturbance (stable/mixing conditions, turbidity), and the water chemistry (pH, conductivity, salinity, carbon availability…). However, the combination of factors that trigger and sustain an algal bloom is not well understood at present and it is not possible to attribute algal blooms to any specific factor.

• Agriculture and food production and human health affected by new pests and diseases – Globally, there is concern that many diseases may increase as a result of climate change. These include dengue fever, malaria, West Nile virus, chikungunya fever, salmonellosis, cryptosporidiosis, Lyme disease, and cholera. NZ’s comparative isolation, temperate climate, and low population density make it relatively protected from many of these diseases. However, NZ’s incidence of climate sensitive diseases may start to increase. This could occur if disease incidence increases in neighbouring countries, or if our climate changes enough that host species (like mosquitoes that carry dengue fever) are able to survive in NZ. Dengue fever and chikungunya fever are examples of climate sensitive diseases that are a threat in the Pacific (including Australia), but that cannot be acquired in NZ. MfE states that warmer weather would favour conditions for increased competition from exotic species as well as the spread of disease and pests, affecting the biodiversity of both fauna and flora.
The consequences for Marlborough beyond 2100 are even harder to quantify. What we do know is that there is huge inertia in the world’s oceans and ice sheets and that as the oceans warm up and the ice sheets destabilise the effects will be unstoppable and experienced for centuries affecting not only our grandchildren, but their grandchildren etc.


And this is what the NZ Royal Society has to say about the effects on NZ as a whole:

A report on “Climate Change Implications for New Zealand” was released on April 18th, 2016 by the Royal Society of New Zealand. Some of the startling facts in their report are that the high tide level now will be the low tide level in 50 – 80 years. And that with a 0.5 metre sea level rise a 100 year king tide or storm surge event will become an annual event. They also make the point that if we stopped all greenhouse gas emissions tomorrow the sea level would continue to rise for at least 2 centuries. Here is a link to their press release and a copy of the full report.

Their key findings on New Zealand’s sensitivities to climate change are:

Coastal Change: New Zealanders live mainly near coasts

Shoreline ecology, public infrastructure, residential and commercial assets, community values and the future use of coastal-marine resources will be severely affected by changes to coasts due to sea level rise, and storm surge, and secondary effects such as erosion and flooding.

Flooding: many New Zealanders live on floodplains

Damaging flood events will occur more often and will affect rural and urban areas differently. At and near the coast, floods will interact with rising sea levels and storm surges. Increasing frequency and severity of high intensity rainfall events will increase these risks.

Freshwater resources: New Zealanders rely on the availability of freshwater

Increased pressure on water resources is almost certain in future. Decreasing annual average rainfall in eastern and northern regions of both main islands, plus higher temperatures, are projected to increase the frequency and intensity of droughts and the risk of wild fire. At the same time, urban expansion and increased demand for water from agriculture will result in increased competition for freshwater resources.

The Ocean: New Zealand is surrounded by sea

Changes in ocean temperature, chemistry, and currents due to climate change will have impacts on New Zealand’s marine life, fishing, aquaculture and recreation use.

Ecosystem change: New Zealand has unique ecosystems

Over half of New Zealand’s more than 50,000 species are found nowhere else in the world; over three quarters of the vascular plants, raising to 93% for alpine plants, and over 80% for the more than 20,000 invertebrates. Existing environmental stresses will interact with, and in many cases be exacerbated by, shifts in mean climatic conditions and associated change in the frequency or intensity of extreme events, especially fire, drought, and floods.

International Impacts: New Zealand is affected by impacts and responses to climate change occurring overseas

The ways in which other countries are affected by and will respond to climate change, plus commitments New Zealand makes to international climate treaties, will influence New Zealand’s international trade relationships, migration patterns and specific domestic responses.

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