New Zealand may initially get off relatively lightly as the world increasingly experiences the consequences of climate change, but will still face moral obligations to harder-hit vulnerable nations, warn scientists.
A UN report released on Friday in Uganda found that increasing human emissions had “likely” – defined as a 66-100 percent probability – caused more extreme heat waves and sea surges, but was less sure about the link between man-made climate change and worse floods.
Extreme weather events such as heat waves, heavy rainfall, floods, strong cyclones, landslides and intense droughts were also likely to become more common.
“New Zealand is likely to fare relatively well in terms of food production for the next few decades, but we may well be impacted by economic instability related to crop failures and food shortages in other parts of the world,” said Dr James Renwick, leader of the Climate Research programme at National Institute of Water and Atmospheric Research (NIWA):
“Moreover, New Zealand may come to be seen as a ‘safe haven’ as the climate changes more dramatically elsewhere. We have moral and ethical obligations to those who look to us for assistance, from the Pacific and elsewhere.”
The IPCC’sSpecial Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) was the culmination of over three years’ work by a team of over 80 experts from around the world and its writers included two New Zealand scientists: Professor Glenn McGregor of Auckland University and Associate Professor John Campbell of Waikato University.
The Science Media Centre gathered the following comments from New Zealand scientists. Feel free to use these quotes in your reports. Contact the SMC for further details or to speak to a climate change expert.
Dr James Renwick, Leader – Climate Research programme at National Institute of Water and Atmospheric Research (NIWA), comments:
“New Zealand will feel the effects of climate change in coming decades, although local impacts are bound to differ from those in other parts of the world. We have a temperate climate and we are insulated to some extent by the oceans surrounding us. Yet even this is a double-edged sword. Sea level rise is currently at about 3mm per year globally (double the 20th century rate, and increasing) and New Zealand sea levels are rising at close to the global rate.
“We are likely to see the best part of a metre of sea level rise by the end of the century – when combined with king tides and storm surge, this significantly increases the risk of inundation in many coastal areas. Places with small tidal ranges (e.g. Wellington) will see larger relative effects. The globe is already committed to many centuries of sea level rise, and a number of regional authorities are developing policies for a managed retreat from coastal areas.
“Changes in storminess may mean slightly fewer big storms overall, but they are likely to be more intense and damaging when they come, than those we experience at present. Temperatures are rising in New Zealand, associated most clearly with a significant decrease in frosts and cold nights in many places over the last 50 years. Frosts will likely become rare or unknown in most major population centres by the end of the century. Such changes will affect agriculture here, but there are likely to be much larger changes in food production in other countries.
“New Zealand is likely to fare relatively well in terms of food production for the next few decades, but we may well be impacted by economic instability related to crop failures and food shortages in other parts of the world. Moreover, New Zealand may come to be seen as a ‘safe haven’ as the climate changes more dramatically elsewhere – we have moral and ethical obligations to those who look to us for assistance, from the Pacific and elsewhere”.
New Zealander Dr Kevin Trenberth, head of the Climate Analysis Section at the USA National Center for Atmospheric Research, comments:
“I have the final (version) of chapter 3, which deals with the science aspects. Overall it is awfully waffley. FAQ 3.1 argues about semantics as to what an extreme means. It is pitiful. It passes entirely on answering the question ‘Is the climate becoming more extreme?’ Of course it is a silly question but it could have said something useful in response (or changed the question).
“FAQ 3.2 on “Has climate change affected individual events?” similarly is ineffective. The answer is quite wrong. It frequently asks the wrong question and then waffles. The framing is quite wrong. The changes in the environment in which all events occur are missed entirely. The shift in odds is missed. It simply argues that because events could have occurred one can not say anything. It mentions models (but not their flaws) and statistics but not physics. I would give it a failing grade.
“The chapter is quite confused… It makes a number of correct statements about natural variability leading to continued extremes. It correctly states that odds of extremes change. The statements are very conservative by always leaning toward a null hypothesis of no human influence. There is a lot on projections but it uses CMIP3 models and places undue weight on them: the models are not good at this stuff. There is no commonsense approach to all this”.
(Climate model output from simulations of the past, present and future climate was collected mostly during the years 2005 and 2006 to create phase 3 of the Coupled Model Intercomparison Project CMIP3 used by climate scientists preparing the IPCC Fourth Asssessment Report).
Dr David Wratt, Chief Scientist at NIWA’s National Climate Centre and Director of the New Zealand Climate Change Centre (a member of the NZ delegation at the Joint Session of the IPCC Working Groups I and II and the IPCC Plenary in Uganda) comments:
“Projecting local changes in extremes is often more challenging than making projections at broader regional to global scales. Local measures which provide benefits under a range of future climates, and help manage current disaster risks are a good starting point to adaptation.
“We have high confidence that extreme events will have greater impacts on sectors directly reliant on weather and climate. Our agriculture, horticulture and energy sectors clearly fall into that category. The high likelihood of increasingly severe extreme sea level events is also significant, given that 12 of New Zealand’s 15 largest towns and cities are located on the coast.”
“The challenge for policymakers the world over is to develop strategies to reduce vulnerability and exposure of people and assets to climate change extremes. That way, extreme weather and climate events won’t necessarily become disasters.”
Expert reaction collected by our colleagues at the SMCs in the UK, Australia and Canada follows:
Dr Kathleen McInnes from the Climate Change Research Group (Sea Level Rise and Coasts) at the Centre for Australian Weather and Climate Research, a lead author of the report, comments:
“Recognising that the effects of climate change will be felt most acutely through extreme events, this report is the first comprehensive assessment that focuses on extreme events as well as bringing together the experience of experts in climate change adaptation and disaster risk management to consider options for managing the risks associated with climate change.
“Some of the findings for Australia are that it is likely that there has been an overall decrease in the number of cold days and nights and an overall increase in the number of warm days and nights. While it is likely that the storm systems that affect southern Australia have moved poleward, changes in observing capabilities means there is low confidence in changes in tropical cyclone activity.
“It is likely that anthropogenic influences have led to warming of extreme daily minimum and maximum temperatures on the global scale and have led to increasing extreme coastal high water due to mean sea level contributions.
“Because of the nature of extremes (i.e. their rarity), changes in many extremes and their causes are assessed with lower levels of confidence due to such factors as length of observational record and the influence of natural variability. However, low confidence in an observed change neither implies nor excludes the possibility that a change has occurred.
“It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur through the 21st century and it is very likely that the length, frequency and/or intensity of warm spells, including heat waves, will continue to increase over most land areas. It is also likely that that the frequency of heavy precipitation or the proportion of total rainfall from heavy falls will increase in the 21st century over many areas of the globe. In Australia by the end of the 21st Century, a 1 in 20 year daily maximum temperature is projected to occur once every 1 to 10 years. It is very likely that mean sea level rise will contribute to upward trends in extreme coastal high water levels in the future.
“As well as addressing climate extremes, this report also integrates perspectives from research communities studying adaptation to climate change, and disaster risk management. The severity of the impacts of extreme and non-extreme weather and climate events depends strongly on the level of vulnerability and exposure of human, ecological and physical systems to these events.”
Prof Bill McGuire, Professor of Geophysical Climate Hazards at University College, London, comments:
“One of the key ways in which anthropogenic climate change will affect human society is through the increasing impact of extreme events such as floods and droughts. This landmark report uses the latest observations and models to forecast what we will be up against in the decades to come. It also highlights the complex and sometimes unexpected ways in which climate change may drive dangerous extreme events, including a response from the solid Earth in the form of increased landslide activity and other geological hazards.
Dr Simon Brown, Climate Extremes Research Manager at the Met Office Hadley Centre, comments:
“This focus of the IPCC on extremes is very welcome as less emphasis has traditionally been given to these phenomena which are very likely to be the means by which ordinary people first experience climate change. Human susceptibility to weather mainly arises through extreme weather events so it is appropriate that we focus on these which, should they change for the worse, would have wide ranging and significant consequences. This review will be very helpful in progressing the science by bringing together a wide range of studies – not just on the physical weather aspects of climate extremes but also on how we might adapt and respond to their changes in the future.”
Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science, comments:
“This expert review of the latest available scientific evidence clearly shows that climate change is already having an impact in many parts of the world on the frequency, severity and location of extreme weather events, such as heatwaves, droughts and flash floods. This is remarkable because extreme events are rare and it is difficult to detect statistically significant trends in such small sets of data. What is more, these trends have been identified over the last few decades when the rise in global average temperature has been just a few tenths of a centigrade degree. The report shows that if we do not stop the current steep rise in atmospheric levels of greenhouse gases, we will see much more warming and dramatic changes in extreme weather which are likely to overwhelm any attempts human populations might make to adapt to their impacts.
“This report should leave governments in no doubt, as they prepare for the next United Nations climate change summit in Durban, South Africa, at the end of November, that climate change is, through its impact on extreme weather, already harming the lives and livelihoods of millions of people around the world. Governments must focus clearly on reaching a strong international agreement to strengthen their efforts to reduce emissions and to prepare their populations for those impacts of climate change that cannot now be avoided.”
John Clague, Shrum Research Professor, CRC Chair in Natural Hazard Research, Department of Earth Sciences, Simon Fraser University, comments:
“Sea level is currently rising at a rate of about 3 mm/yr and the rate is likely to increase through the remainder of the century. Low-lying coastal areas on all three of Canada’s coasts will experience increased erosion and inundation during extreme storms as the century progresses. Erosion and inundation occur during extreme storms, which as noted below, may increase along the Pacific and Atlantic coasts in the future. Greater erosion of some coasts in the Arctic will be exacerbated by reduced Arctic ice cover.
“The recent devastating flooding in Bangkok is a harbinger of things to come for that city. Bangkok lies only about 2 m above sea level. The slow rise in sea level reduces the gradient of the Chao Phraya River, which flows through the city to the Gulf of Thailand. During extreme river floods, as occurred this year, the lower ‘freeboard’ to the tops of the protective dykes at high tides increases the likelihood of flooding”.
Hans Schreier, Professor, Aquatic Ecosystem Research Laboratory, Institute for Resources, Environment and Sustainability, University of British Columbia, comments:
“As a result of the critiques of previous IPCC reports this SREX report is very cautious. Most of the IPCC efforts and projections are using climate data as a basis and land use information is usually not incorporated into the modelling. I would argue that land use changes alone have likely a greater influence on water processes than climate but they both are changing at the same time. It is therefore impossible to state which is more important. However, what is critical is that the combined effect of extreme event and land use change will have an accelerated impact leading to greater disasters and risks particularly at local levels.
“The lack of good historic data is the main reason why many of the experts are cautious in how much confidence they have in the current trends. However, most of the modelled projections to 2100 clearly show an increase in many aspects of extreme events. This means we need to focus on using adaptation and prevention methods to reduce risks. The report mentions that post disaster recovery provides an opportunity to reduce the effect of extreme event. A more appropriate statement would be to use the precautionary principle and start taking steps to reduce the risk of extreme events and prevent or reduce future impacts.
“The experts are virtually certain that the frequency and magnitude of daily warm temperature extremes are increasing. The implications of this for food production and energy demands are significant. A much higher risk of flooding — when land use changes are taking into consideration — is of particular concern in urban areas where storm water systems are inadequate. The flooding problem is even more critical in coastal areas because of anticipated sea level rise.”
Patrick M. Condon, Professor & James Taylor Chair in Landscape and Liveable Environments, School of Architecture and Landscape Architecture, University of British Columbia, comments:
“Even if we stopped spewing carbon into the atmosphere tomorrow, global temperatures will rise by 2degC. In this unprecedented circumstance our cities must do two things. First and foremost we must slowly rebuild them so they don’t demand so much carbon to operate. Our cities now demand at least five times more carbon per capita than they did prior to World War 2 largely due to our reliance on the car, and the low density sprawl which the car spawned. Doing our part to slow or stop global warming is not simply a practical imperative; its a moral one.. Changing our carbon greedy cities is the place to start.
“In rebuilding our cities for an altered world, we must work with our rapidly changing natural systems, not against them. One very simple example: “Green streets”, streets with ample shade trees and natural verges to infiltrate storm water, can both mitigate the threat of floods while naturally cooling our homes. The shade and protection thy provide can also make walking and cycling a more reasonable option than the car.”
John Stone, Adjunct Research Professor, Carleton University, (Canada) Department of Geography, comments:
“I’m not particularly surprised with the findings. It’s pretty much what I expected to see – and it’s a reflection of what’s been known for quite a while. Some of the things (like heat-waves) we have been pretty sure of have not change and some of the things (like hurricanes) still have question-marks. Many of the findings are not much different from those in the IPCC’s 4th report.
“The report has addressed how we might respond – including such matters as disaster management. This should be quite useful to governments at all levels. There is still a lot of controversy with respect to what we know about tropical cyclones – hurricanes in the North Atlantic. There are still some questions about whether there will be increases in hurricanes or not in the future. From what we know, it’s likely that we will see more category 4 or 5 hurricanes – the most intense. The overall number might drop but we may see increases in the number of the stronger ones”
“From simple statistics and basic physics, we can say that there will be an increase in the frequency and severity of extreme events. What we’ve seen today doesn’t surprise us. It doesn’t mean we can attribute every extreme event to anthropogenic climate change, but it does support the idea that we’ve ‘loaded the dice’, so to speak. That these extreme events are more likely to happen now than they have been in the past”.