New Zealand needs to start taking extreme heat seriously

Dr Luke Harrington hopes in the next few years we might see a heatwave warning index alongside the UV index for sunburn risk on the nightly weather forecast.

As the mercury climbed to dangerously high levels on Tuesday 26 January, the collective response to forecast temperatures in the mid-30s was one of joy: a great day to get out and enjoy the sunshine.

In reality, we should be increasingly concerned about the potential impacts of these hot days on the most vulnerable people in our communities, and how much higher these temperatures will climb in response to climate change over the coming decades.

Extreme heat has not been given the time of day in Aotearoa New Zealand: the health risks of extreme heat didn’t even rate a mention in the Ministry for the Environment’s first Climate Change Risk Assessment, despite heatwaves being widely recognised as the climate hazard showing the most rapid changes due to rising greenhouse gas emissions.

Our indifference to the potential impacts of extreme heat in Aotearoa is likely thanks to the sweltering heatwaves we see experienced by our neighbours in Australia. Unfortunately, ample research has shown that people who live in different climates are adapted to different experiences: the types of temperatures which will lead to the premature deaths of the elderly in Christchurch will be much lower than temperatures which are equally deadly in Barcelona.

And make no mistake, extreme heat can kill. Severe heatwaves during the European summer of 2003 led to the loss of some 70,000 lives, while heatwaves have also killed thousands in Russia, Pakistan, India and Japan in recent years. And while these countries all sound like they have generally hotter temperatures than what we associate with a classic Kiwi summer, there are also examples of excess deaths from relatively extreme heat in much milder climates like Finland or the UK.

Unfortunately, such numbers are not readily available for the main centres in New Zealand, despite the fact that the growing number of extreme hot days seen in New Zealand over the past decade would have almost certainly resulted in premature deaths among those who are most vulnerable in our communities.

Evidence from many countries also shows the benefits of having robust early warning systems in place: this means not just forecasting the high temperatures, but also communicating the clear health risks of the forecasted heat to the public, and supporting local councils to offer practical solutions. Despite evidence from France, India and the UK of the life-saving benefits of introducing these early warning systems, the Ministry of Health has yet to develop a comprehensive nationwide strategy.

We now have enough evidence and scientific understanding to know that if the same weather system that brought the extreme heat on Tuesday were to have occurred in the 1850s without the effects of human-induced climate change, the roasting temperatures along the eastern side of the country would have likely been several degrees cooler. And as the severity and frequency of these exceptionally hot summer days will continue to worsen over the coming decades, we need to think carefully about whether we have the strategies in place to cope with the resulting impacts, and what still needs to be done.

As a very first step, we need to develop a heatwave definition tailored to the climate of New Zealand: one that meaningfully captures the health impacts of heat experienced by New Zealanders, and particularly our ageing population.

I hope in the next few years we might see a heatwave warning index alongside the UV index for sunburn risk on the nightly weather forecast. These small changes are precisely what climate adaptation looks like in Aotearoa.

Dr Luke Harrington is a senior research fellow in the New Zealand Climate Change Research Institute at Te Herenga WakaVictoria University of Wellington.

Read the original article on Stuff.