Assessing an indirect health implication of a changing climate: Ross River Virus in a temperate island state

摘要

Highlights ? We examine an indirect health implication of a changing temperate climate. ? We assess regional human vulnerability to Ross River virus via systems thinking. ? Even subtle climatic changes can amplify, or assist emergence of, health issues. ? Social adaptive capacity is essential in assessing health vulnerability and risk. ? Tasmanian is likely to become more vulnerable to Ross River virus by mid Century. Abstract In Tasmania, a temperate island state of Australia, there is little understood about the human health implications of a changing climate. Here, we investigate the hypothesis that human populations in Tasmania might become more vulnerable to Ross River virus (RRV) under climate change, Australia’s most significant vector-borne disease. Importantly, our study considers the complex social-ecological systems based setting that this virus represents, with our approach being underpinned by systems thinking. Specifically, we undertake an integrated and participatory assessment of potential human vulnerability to RRV in a changing climate, and taking account of other parallel, non-climate regional-scale change considerations. We show that projected moderate changes in Tasmania’s climate will have implications for the State’s human health, whereby Tasmania is likely to become more vulnerable to RRV as the 21st Century progresses, shifting this health issue from a relatively low public health risk to one that will become more concerning and costly. The study assists us to contemplate how we frame human health questions as we move into a climatically changing world and reminds us that health impacts will not always be linear or obvious. It demonstrates an approach for scoping indirect and potentially insidious implications of climate change, even in the face of uncertainty, imperfect systems understanding, and limited resources, to inform a range of decision makers. prs.rt("abs_end"); Keywords Vulnerability assessment ; Ross River virus ; Climate change and human health ; Vector borne disease ; Adaptation planning ; Tasmania Introduction In Tasmania, a temperate island state and the most southern and smallest state of Australia, the impacts of climate change on human health and wellbeing remain largely unstudied. Consequently there have been few developments in climate change adaptation research and praxis for the human health sector in Tasmania ( Lyth et al., 2015 ). Climate change assessments suggest that Tasmania will experience relatively modest climatic changes through the 21st Century compared with other parts of Australia ( Hughes and McMichael, 2011 ). In particular projected extreme heat indicators point to Hobart’s much lower projected increase in extreme heat days compared to other Australian capital cities in turn tending to imply low or moderate impacts of climate change on human health for Tasmania overall ( Hughes and McMichael, 2011 and Steffen and Hughes, 2012 ). While physically-based climate indicators, such as the number of hot days per year, may help guide research and decision making on the possible intensity and/or frequency of climatic stressors, they tell us little about the broader spectrum of indirect human health responses associated with climate change through regional socio-ecological system change. Human health vulnerability to exposure from climatic stress is also influenced or exacerbated by established poor socio-health ( Bell, 2011 ), socio-economic adaptive capacity, and/or sensitivity and tolerance of differing populations to changing regional environmental conditions. These mediating factors are particularly pertinent to issues of disease, such as vector-borne diseases, which are influenced by changes in ecological environments in which communities are located ( McMichael et al., 2006 ). Ross River virus (RRV) represents a relevant example of a significant health concern that is influenced by complex ecological, environmental, and socio-economic interactions. It is the most common vector-borne disease affecting Australia ( Russell, 1998 ), accounting for some 63% of all reported mosquito-borne disease notifications in 2011 ( DoHA, 2012 and Yu et al., 2014 ). While a number of significant RRV outbreaks have been reported in Tasmania, and the factors enabling outbreaks of this disease are indeed prevalent, RRV occurrences in this State are historically lower than for northern Australian states. In the climate change context, however, there is consensus within the scientific community that climate change will affect the incidence and extent of vector-borne diseases globally ( IPCC, 2014 ), though there is relatively poor regional understanding of the complexity that tends to underpin future impacts of climate change on vector-borne diseases. In its most recent Fifth Assessment Report, Working Group II of the Intergovernmental Panel on Climate Change (IPCC) concludes, with medium confidence, that the effects of climate change combined with other factors, such a