This week’s heatwave in Perth prompted me to look more deeply into the interaction of climate and health in Australia. An article published in Environmental Health Perspectives Journal in November last year entitled ‘Between extremes: health effects of heat and cold’ provides a very good review investigating the effects higher and lower temperatures have on the human body. In particular, author Nate Seltenrich discusses the impacts of increasing heat waves, which could worsen as global average temperatures continue to trend upward.
High body temperatures are linked to higher heart and breathing rates, and in extreme cases can cause damage to the brain, heart, lungs, kidneys and liver. Heat stroke contributes to a number of physical and mental effects, and is initiated at a body temperature of 40°C. Below 40°C, heat exhaustion can also occur – which is similar to heat stroke in terms of its symptoms but is less severe. The people most at risk of sickness or death from high or low temperatures include those who are unable to regulate their body temperature as effectively due to age, those with pre-existing conditions or chronic diseases, and heavy users of drugs or alcohol. Infants and children are also at risk.
Heat-related death rates have been shown to be higher in urbanised areas than in less urbanised areas. In urbanised areas, the ‘urban heat island’ effect plays a significant role in urbanised areas. These areas tend to be densely packed with buildings which absorb heat from roads, other buildings and refrigeration and air conditioning systems during the day. The densely packed nature of these areas means that there is little air flow to reduce the temperatures. As a result, the temperatures in these urbanised areas tends to be higher than areas with trees and plants. Trees and plants absorb heat and release water vapour which lowers the temperature in the vicinity. The urban heat island effect is most noticeable at night when densely built up areas slowly release the absorbed heat.
The Australian Government Bureau of Meteorology (BoM) Annual Climate Statement 2015, released on January 6 this year, revealed that 2015 was Australia’s fifth warmest year on record – with eight of Australia’s top ten warmest years occurring since 2002.
There were a number of significant heatwaves in Australia last year and the BoM highlighted three in particular:
There were a number of significant heatwaves in Australia last year
- The first occurred in March 2015 across northern and central Australia. Higher temperatures were reported in the north region of the Northern Territory, the Gulf region and in North West Queensland. In the latter half of March, higher temperatures were reported across the rest of the Northern Territory and Queensland, outback South Australia and northern New South Wales
- The second occurred in October 2015, affecting most of southern Australia. Commencing in southwestern Australia on October 1, the heatwave spread across southeast Australia, resulting in record temperatures. Extreme temperatures were reported in southern parts of South Australia (including Adelaide) and Western Victoria (including Warrnambool and Ballarat) on October 3. Temperatures reported from October 4 to 6 set records over southern South Australia, most of Victoria, the Australian Capital Territory, southern New South Wales and Tasmania. According to the BoM, October 2015 was the hottest October on record
- A third heatwave in December 2015 saw extreme heat across southeast Australia. In the first week and a half of December, temperatures were warmer than usual across the region. From December 13 a very intense period of warm weather commenced in South Australia, peaking in South and Western Australia on December 19
According to the 2015 BoM climate statement, an El Niño declared in May contributed to the higher temperatures in Australia during 2015. The 2015 El Niño was one of the strongest on record and influenced both Australian and global temperatures. Global sea surface temperatures from January to November 2015 were the highest since records began in 1854. The BoM anticipates that the effects of this 2015 El Niño will continue in 2016.
I have had a keen interest in climatic data for my entire career. I believe it is of growing importance that we focus more attention on the health burden associated with such events and what protective protocols can be put into place – both in terms of dealing with the symptoms of heatwaves and their causes. As part of this focus, Governments and policy makers need to allocate sufficient resources to identify and assist those citizens with existing health conditions making them more vulnerable to heatwave events. It is only once this is done that appropriate mitigation measures can be implemented at Federal, State and Local Government levels. Measures implemented at these levels are the only real way for a Government to demonstrate that they have appropriately focused on the health burden of climate change and are dedicated to treating the cause and effects of heatwaves, and tackling the challenges of climate change. Governments must accept the challenge, implementing emission reduction measures and changing their urban planning and public health practices to better address the health impacts of climate change.