Soft options for hard climate change decisions

Impact: Cheaper, more environmentally sensitive solutions for mitigating climate change impacts on coastal communities

Climate change will invoke a new set of challenges for coastal living in the 21st Century, the most significant of which are the effects of sea-level rise and altered storm frequency, and intensity on flooding in the coastal zone and the position of shorelines.

There are solutions available for limiting the effects of climate change on coastal dwelling; seawalls can buffer the erosive effects of waves, levees can restrain floodwaters, barriers can control tidal incursion.

These approaches are collectively termed ‘hard engineering’ as they largely use hard surfaces to buffer any impacts. Engineering actions that harness the inherent capacity of coastal ecosystems to adapt to environmental change are collectively termed ‘soft engineering’, and harness the inherent adaptive capacity that coastal ecosystems provide.

The capacity of coastal ecosystems to adapt to sea-level rise and buffer the effects of storms on coastlines is the focus of research by Dr Kerrylee Rogers.

Unlike hard adaptation options, coastal ecosystems provide ongoing additional benefits to society, such as carbon sequestration and fish habitat, which have a real and measurable economic value.

By understanding the intrinsic relationship between sea level and the benefits provided by coastal ecosystems, Dr Rogers and her research team are finding that in some situations where coastal ecosystems, such as mangroves, are allowed to adapt naturally to sea-level rise by increasing extent across coastal floodplains, the additional benefits provided by these ecosystems will be compounded (for example, increased carbon sequestration and fish habitat).

Harnessing the economic value of these additional benefits may contribute to offsetting financial costs associated with facilitating natural adaptation, while also incurring little to no ongoing maintenance costs, unlike hard engineering options.