Climate change impacts on human health were the focus of an Auckland academic's contribution to the latest report from the Intergovernmental Panel on Climate Change (IPCC).
The second part of the Fifth assessment report has just been released by the IPCC and considers how the changing climate impacts people and the natural world.
A University of Auckland expert in epidemiology and biostatistics, Professor Alistair Woodward led the chapter on human health and an accompanying paper which is published today by prestigious medical journal, the Lancet.
The full IPCC Fifth Report was released this week and was the culmination of three years of work by 300 authors, amounting to almost 2000 pages.
Professor Woodward says the effects of high temperatures on workers' health and labour productivity were highlighted in this report.
"The Fifth Report also gives greater attention to the so-called high-end climate scenarios, reflecting recent research and the persistent failure of international negotiations to make credible progress toward substantial reduction in emissions", he says.
"Some scenarios project warming of 4–7°C (on average) over much of the global landmass by the end of the 21st century," he says. "If this change happens, then the hottest days will exceed present temperatures by a wide margin and increase the number of people who live in conditions that are so extreme that the ability of the human body to maintain heat balance during physical activity is compromised for parts of the year and unprotected outdoor labour is no longer possible."
The new assessment concluded, as did the Fourth Report, that there might be some health gains from climate change (such as reduced cold-related morbidity and mortality), but showed that the evidence is now stronger for positive effects to be outweighed, worldwide, by negative effects.
"The effect of climate-sensitive health outcomes (such as hunger and vector-borne diseases) is moderated by many factors other than climate (for example, living conditions and health care)", says Professor Woodward.
"The key message is that climate change is a huge risk. It is a risk to health, and every other aspect of human activity. The problem is that our present trajectory of consumption is taking us further into the danger zone," he says. "But there are also significant opportunities. There are many ways to reduce future risk and at the same time promote present-day health and well-being."
"These include energy policies that move away from polluting fuels, coal especially and making our cities places for people to move comfortably on foot and bicycle and public transport."
"Boosting public health services in vulnerable, low-income countries is necessary to cope with climate change impacts; we know this will also bring many benefits in the short-term," he says.
Explore further: UN panel issues corrections for climate report