Dealing with the effects of climate change will arguably be the biggest challenge coastal managers will face in the future. The effects of climate change are already becoming apparent, and will increase over time. There are four key climate-change related impacts that will affect the coastal environment:

The Intergovernmental Panel on Climate Change (IPCC) is the international scientific body that compiles and evaluates global studies on climate change. The fourth assessment by the IPCC was released in 2007 and gave information on global warming related to emissions scenarios, and particularly relevant is the advice and guidance on projected sea-level rise. The IPCC projected sea-level rise of between 0.18-0.59 m by 2090-2099 in this assessment. However, the upper values of sea-level rise (e.g. 0.59 m) projected by the models were not considered to be upper bounds of possible sea-level rise by 2099. The fifth assessment by IPCC was released late in 2013. This gives a range of values for each Representative Concentration Pathways (RCP) scenario that relates to estimated global temperature increases. Estimates for the low RCP scenario are 0.26 - 0.54 m by 2100, whilst the highest RCP scenario estimates a rise in sea-level of between 0.53 - 0.97 m by 2100.

With the majority of the Australian population living within close proximity to the shoreline, the implications of sea-level rise are numerous and varied. The first pass national assessment of climate change risks (DoCC, 2009) identified assets to a value of approximately $63 billion at risk with a static water-level increase of 1.1 m. The second-pass Future Coast assessment (Lacey & Mount, 2011) used a static inundation modelling method to determine potential inundation extents under various sea-level rise scenarios. Static inundation modelling uses known water-levels and topographic elevations to determine potential maximum inundation extents. This is a relatively simple method and provides an indication of inundation, but includes significant uncertainty.

Work done recently by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) has furthered the knowledge of climate change and sea-level rise risk in Australia. In Victoria, relevant reports include two CSIRO reports that detail the effects of climate change on extreme sea-levels for the Victorian Coast and Port Phillip Bay (McInnes et. al., 2009 a,b).

At present, research into wave height increases in response to climate change has been inconclusive; therefore no increase in the magnitude of future storms has been incorporated in this study.