Preparing New Zealand for climate change

Preparing New Zealand’s water stores for a warmer climate is a major focus of new research projects just awarded more than $2 million.

The funding, for five studies, is part of the Deep South National Science Challenge, which aims to help Kiwis adapt to the effects that climate change will bring, among them extreme weather events, drought, changes in typical weather patterns and sea level rise.

One of the new projects will improve future projections of glacier and snow melt from alpine regions.

While warming would lead to loss of frozen water resources, scientists say the magnitude, timing and distribution of changes in the meltwater remained unclear.

Yet mountain rivers in both islands feed our largest hydro-electric power schemes, providing critical water for irrigation, especially during drought.

Melting snow and ice may also cause increased flooding risk.

Researchers will develop and apply new computer modelling tools to simulate snow and ice responses to different climate change scenarios, and make projections of future snow and ice cover, and resultant run-off from alpine catchments.

Another project will attempt to map out the potential effects of climate change on New Zealand’s entire hydrological cycle, across a time scale stretching to the end of the century.

Hydrological states and fluxes will be analysed to forecast major potential changes and implications they’ll have for agricultural water resources, hydropower potential and flooding.

A third study, beginning next month, draws on climate change data to better inform future investments around water storage, with an initial focus on Canterbury.

Like the Government’s other 10 National Science Challenges, the effort combines the firepower of the country’s top scientists, bringing together researchers from Victoria University, Niwa, Scion, Landcare Research, University of Otago, Plant and Food Research, AgResearch and GNS Science.

“We are at an exciting point in the development of the challenge and are looking forward to seeing these projects start,” challenge director Dr Mike Williams said.

“This work will look at some of the climate-related impacts on essential resources and are key components in setting future priorities.”

A core part of the challenge will be boosting the use of the New Zealand Earth System Model, a world-class numerical tool to simulate current climate and make projections of future climates with different scenarios of future global greenhouse gas emissions.

In recent years, scientists have reported more defined projections around what climate change will mean for New Zealand.

One study, published last year, found there was already a 50 per cent greater chance of exceptionally high pressure systems occurring over New Zealand in summer than was the case a century ago.

The same paper showed that, due to changes in climate in the past 130 years, in response to greenhouse gas emissions and ozone depletion, weather patterns such as those seen in 2013’s $1.3 billion drought were 20 per cent more likely to occur in the present day than in the late 1800s.

New Zealand and climate change

• Under present projections, the sea level around New Zealand is expected to rise between 50cm and 100cm this century, while temperatures could also increase by several degrees by 2100.
• Climate change would bring more floods (about two-thirds of Kiwis live in areas prone to flooding); make our freshwater problems worse and put more pressure on rivers and lakes; acidify our oceans; put even more species at risk and bring problems from the rest of the world.
• Climate change is also expected to result in more large storms compounding the effects of sea level rise.
• New Zealand, which reported a 23 per cent increase in greenhouse gas emissions between 1990 and 2014, has pledged to slash its greenhouse gas emissions by 30 per cent from 2005 levels and 11 per cent from 1990 levels by 2030.

Read the related Deep South Challenge press release

Read the original NZ Herald story

Jamie Morton – NZ Herald