Cai Songwu works for the Guangdong Centre for Disease Control and Prevention, studying disease outbreaks. In the past, communication between Cai and other officials about outbreaks was slow, hampering their ability to anticipate and respond. Since 2005, districts and counties across the province have been able to connect to a real-time online monitoring system. ‘With real-time data, we are able to understand the breeding speed, growth and decline of vectors and pest density,’ he says. This kind of monitoring is becoming increasingly important as climate change alters the environmental conditions – temperatures, humidity, rainfall and carbon dioxide concentrations – that allow different kinds and numbers of pests to survive and thrive. ‘In the future, regions previously without vector organisms might become more suitable for vectors to breed, and this is likely to give rise to infectious diseases.’ The links between climate variability, seasons, human behaviour and health have been areas of concern for researchers and public health officials globally, as described by Cai Songwu; climate change must now be factored into health programmes. Shifts in the frequency and intensity of heat waves, increasing incidences of floods and droughts, and sea level rise are just some of the many examples of a visibly changing climate. Death, injuries and illness due to extreme weather and slow-onset events have unfolded at unprecedented scales in the turn of the millennium; these have finally begun to attract attention to the critical challenge the impacts climate change poses to human health (Field et al., 2014; Huang, C. et al., 2011; Parry et al., 2007). Vector-borne and zoonotic disease transmission rates are also likely to be altered by climate change and are being investigated by research organisations. The Fifth Assessment Report from the United Nations Intergovernmental Panel on Climate Change (IPCC) states with very high confidence that the health

of human populations is sensitive to shifts in weather patterns and other aspects of climate change.1 For example, in many parts of the world, including China, heat waves and other extreme temperature events have led to increased morbidity and mortality. Climate change, in conjunction with rapid urbanisation and development, is altering the distribution of infectious diseases. Climate shifts are contributing to livelihood losses and food insecurity due to reductions in agricultural productivity associated with floods, droughts and storms. These can in turn increase risk of malnutrition or illness from contaminated food and water (WHO, 2010; Kan et al., 2012). If the climatic changes continue as projected, the health of a large number of populations, particularly those who are poor and vulnerable, will be at risk and their existing problems will be exacerbated (Field et al., 2014). Current research suggests that climate change will primarily exacerbate existing health problems, although unanticipated health consequences cannot be excluded. Compared to sectors like agriculture, forestry, ecology and water resources, climate change related health impacts have received little attention from decision makers. The need for many countries to develop response strategies to protect health continues to go unnoticed. Until recently, health impacts were not assessed or well-quantified, nor have the findings been communicated effectively beyond the scientific community. This lack of information may have contributed to the perception in China that the burden of ill health from climate change is minimal and will continue to be so.