Shape of Future Health Risks and Responses from Step Changes in Global and Regional Temperatures

Lessons and opportunities for climate change adaptation can be drawn from research and debate regarding temporal variation in the rate of global mean surface temperature increases (aka the global warming “hiatus” or warming slowdown).  Jones (2012) shows that recent warming is less a smooth linear trend than a series of step changes with periods of relative stability alternating with periods when the rates of increase in global and regional surface temperatures exceed the long-term trend.  This uneven pattern has profound implications for the health risks of climate change and for adaptation.  Current assumptions of linear or monotonic increases in global or regional temperatures can lead to inefficient planning processes that underestimate the magnitude, pattern, and timing of the risks faced by health systems and infrastructure, which could exaggerate future impacts and the costs of managing them.  Projections of the possible consequences of non-linear changes in temperature and precipitation for health systems and infrastructure, along with non-linear human and natural system responses to such changes, would more accurately describe the possible evolution of hazards over coming decades and would likely increase the effectiveness of adaptation, reducing future impacts to the extent possible.  Incorporating how possible development (e.g. human) choices could affect exposure and vulnerability into these projections would increase understanding of the range of possible future impacts and would increase the effectiveness of adaptive research (research into adaptive management and research that learns from and adapts to new knowledge) and planning.  Adaptation planning based on such projections could consider the implications of non-linear climate change on the level of adaptation effort, as well as the benefits, economic costs, and residual impacts that will have to be prepared for and coped with.