27 Mar 2014

Climate Change Impacts

From Our Changing World, 9:04 pm on 27 March 2014

IPCC

After lengthy discussions, scientists and government representatives meeting in Yokohama approved the Intergovernmental Panel on Climate Change Working Group 2 report on climate change impacts, adaptation and vulnerability. (image: Earth Negotiations Bulletin)

Wildfires, more frequent and severe floods, and higher risks to coastal infrastructure due to rising seas are just some of the impacts New Zealanders can expect from climate change in the coming decades.

The Intergovernmental Panel on Climate Change (IPCC) released its report, Climate Change 2014: Impacts, Adaptation and Vulnerability (pdf), which details the impacts of climate change to date, the future risks from a changing climate and the opportunities for effective action to reduce risks.

It confirms that the effects of climate change are occurring on all continents and across the oceans, and that the world “in many cases, is ill-prepared for the risks from a changing climate”.

“We live in an era of man-made climate change,” says Vicente Barros, co-chair of the IPCC’s Working Group II. “In many cases, we are not prepared for the climate-related risks that we already face. Investments in better preparation can pay dividends both for the present and for the future.”

The Australasia chapters (Chapter 25) identifies eight key risks that will affect New Zealand and Australia as temperatures continue to rise in step with increased greenhouse gas emissions. It warns that adapting to future impacts in this region could mean having to translocate industries and giving up on protecting certain areas from sea level rise and excessive heat.

Wildfires are expected to cause damage to settlements and ecosystems, economic losses and risks to human life in many parts of New Zealand as a consequence of drier and warmer conditions.

One of the lead authors for this chapter, NIWA climate scientist Andrew Tait, says wildfire is already a major issue in Australia, but New Zealand now also faces a higher risk. The chapter’s coordinating lead author, Agricultural Greenhouse Gas Research Centre deputy director Andy Reisinger, says wildfires could be more destructive in New Zealand’s as our native forests are not adapted to it.

Rainfall predictions for New Zealand are for more rain in the south and west, and drier conditions in the north and east. Andrew Tait says the main pattern is associated with a likely change in westerlies over the country, which are projected to increase mostly in the spring and in winter. Sea level rise is expected to reach about half a metre by the end of the century under low-emission scenarios, but Andy Reisinger says even that will be a challenge for New Zealand, with most of our cities and infrastructure built on flood plains and near river mouths.

However, there will be some benefits from climate change for New Zealand. Warmer winters will mean lower heating bills and might reduce winter illnesses, forest growth is expected to increase, and some parts of New Zealand can expect stronger spring pasture growth. 

An increase in heat waves, constraints on water resources and loss of agricultural production represent three risk areas that apply to both countries, but will have a more immediate and more damaging impact in Australia. Two other key risks – the loss of montane ecosystems and changes to the structure of coral reefs – apply largely to Australia.

Meanwhile, the World Meteorological Organization has released its Status of the Climate report last week, highlighting the key climate events of 2013, and the fact that temperatures in many parts of the Southern Hemisphere were especially warm, with Australia having its hottest year on record.

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