Climate Projections for New Zealand by 2040 and 2090 according to NIWA

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Climate Projections for New Zealand by 2040 and 2090 according to NIWA

NZ Herald reports a 38.2 C temperature in Gisborne last 31st January 2020, the hottest since 1940 and the country’s fifth warmest January temperature that NIWA had ever recorded. Although Met Service station recorded it slightly cooler at 37.1C (Neilson, 2020).

NIWA or the National Institute of Water and Atmospheric Research is a research institute of New Zealand, which mission is to conduct leading environmental science to enable the sustainable management of natural resources for the country and the planet.

On 2 February 2020, Newshub also reported over 35°C temperature around the country, fearing it could go over 4°C in some eastern parts of New Zealand. NIWA says on its Facebook page that “sea temperatures around New Zealand have really warmed up” and adds that the hot sea temperatures in the Pacific could lead to more destructive weather patterns in the second half of February 2020 (Palmer, 2020).

What used to be the cool seas in the north of Australia has been replaced by warmer seas, and these cause a rising motion in the Atmosphere creating rain and thunderstorms, says NIWA meteorologist Ben Noll on Hub news (Palmer, 2020).

Climate change projections for NZ

Will these high temperatures become a trend every summer season in the future and will there be a steady increase in the temperature in the coming years?

The Ministry for the Environment (MFE) has published a report on New Zealand’s future climate projections based on the IPCC’s 5th assessment report.

The full report may be read through the link below

Climate Change Projections for New Zealand, Atmospheric projections based on simulations undertaken for the IPCC’s 5th Assessment 2nd edition

A summary of the report says that climate is changing and this is a result of increasing amounts of greenhouse gases in the atmosphere. In New Zealand changes in key climate parameters like temperature and rainfall are already felt.

Projections of climate change will not happen this year or the next couple of years but in 2040 and 2090.

However, there already signs that the climate is changing in the country according to NIWA’s scientists.

New Zealand’s climate varies naturally from year to year or even from decade to decade. But it is the human-induced (anthropogenic) long-term trends, particularly the concentration of greenhouse gas in the atmosphere and the response of the global climate system that will cause climate that the country will be exposed to.

In New Zealand, there has been a long-term increase in temperature at around .90°C in the last century, just a bit below the global average.

Climate change projections from the 2016 report say that temperature and rainfall patterns in the year 2040 and 2090 will depend on the various emission pathways or amounts emissions.

Projections of temperature in 2040 are as follows. In a low emission scenario, the temperature increase will be at 0.7°C. A high emission scenario will produce a 1.0C increase in temperature. In 2090, low emissions will result in a 0.7°C increase in temperature, while high emissions will cause a 3.0°C temperature increase.

Emissions scenarios in New Zealand is aligned with the IPCC’s Representative Concentration Pathways (RCP).  These four pathways are abbreviated as RCP2.6, RCP4.5, RCP6.0, and RCP8.5 and are ordered according to the amount of greenhouse gas concentrations in the atmosphere.

RCP2.6 represents a low emissions and mitigation scenario wherein emissions stop after 2080. RCP8.5 represents a high-emission scenario or business-as-usual, and RCP4.5 and RCP6.0 represent two futures with global emissions stabilise at different levels.

What the climate future looks like will depend on which pathway we are on and the amounts of greenhouse gas emissions we are putting into the atmosphere and the success or failure of mitigation efforts around the world.   

What will climate change look like in New Zealand according to the IPCC 5th Assessment Report?

  • The average temperature will rise further if greenhouse gas emission continues
  • Frost-free lands during spring and autumn will tripe by 2080.
  • An increase of up to 60 days of hot days or over 25°C temperatures for the northern areas by 2090
  • A shift in rainfall patterns and rise in extreme rainfall of up to 8 per cent per 1°C of warming that will vary in some regions
  • Droughts in the eastern and northern part of the country will double or triple by 2040
  • Global sea-level rise by 2100 of about .5 to 1 meter in high emissions scenario, or 0.3 to 0.6 if there is rapid decarbonisation.
  • Decline in peak snow accumulation by 30 to 80 per cent at 1000 meters and by about 5 to 50 per cent at 2000 metres by 2090.

How will New Zealand cope with climate change?

According to NIWA, New Zealand as a temperate maritime country may not face some of the worst effects of climate change this century unlike parts of Australia where peak temperatures of 40°C are projected to increase. New Zealand is also generally well-equipped in principle to adapt to climate change with some adaptation occurring already particularly for sea-level rise. However, despite the country’s adaptive capacity, there are still some major constraints that need to be addressed, for example, limited integration of climate change in different levels of governance, a different attitude towards risk associated with climate change, and a few others (Climate change IPCC Fifth, n.d.).

Key Risks of Climate Change in New Zealand

NIWA highlights three risks faced by New Zealand due to climate change. These risks were identified as a result of strong and reliable research and because of its potentially severe impact on the country which can make adaptation challenging (Climate change IPCC Fifth, n.d.).

  1. Coastal erosion from sea-level rise is already experienced by some communities. These put coastal infrastructure and low-lying ecosystems at risk.  If future sea-level rise projections continue which is predicted to happen by 2100, a coastal retreat is one of the possible solutions.
  2. Risk of wildfires. This risk is very high in Australia and a bit lower in New Zealand, according to NIWA.  Early warning systems, local planning mechanisms, and building designs along with public education can help with adaptation.
  3. Increasing frequency and intensity of flooding can damage to infrastructure and settlements. Planned adaptation measure includes land-use control and relocation, protection and accommodation of increased protection when feasible.

References:

Nielson, M. (2020, February 1). Your weather: More heat on the way after whopping 38C in Gisborne. NZ Herald. Retrieved from https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12305126

Palmer, S. (2020, February 2). Heatwave weather: New Zealand boils as sea temperatures surge over 20C. Newshub. Retrieved from https://www.newshub.co.nz/home/new-zealand/2020/02/heatwave-weather-new-zealand-boils-as-sea-temperatures-surge-over-20c.html

Climate Projections for New Zealand. Ministry for the Environment. Snapshot June 2016, Info 765. Retrieved from https://www.mfe.govt.nz/sites/default/files/media/Climate%20Change/climate-projections-snapshot.pdf

Hollis, M. et. al (n.d.) Climate Change IPCC Fifth Assessment Report New Zealand findings. New Zealand Climate Change Centre. Retrieved from https://niwa.co.nz/sites/niwa.co.nz/files/NZCCC%20Summary_IPCC%20AR5%20NZ%20Findings_April%202014%20WEB.pdf

Ministry for the Environment 2018. Climate Change Projections for New Zealand: Atmosphere Projections Based on Simulations from the IPCC Fifth Assessment, 2nd Edition. Wellington: Ministry for the Environment. Retrieved from https://www.mfe.govt.nz/sites/default/files/media/Climate%20Change/Climate-change-projections-2nd-edition-final.pdf

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