2021-11-15 GC Agenda - Item 7 - Attachment 1 - Coastal Hazards Adaptation Plan

          Noosa Shire Council



  This section discusses Phase 2 to Phase 7 of the CHAP’s development, with each phase listed below.
  Each sub-section includes the methods used to complete each phase, as well as their respective outputs.
      • Phase 2 – 3: Identifying the hazards
      • Phase 4 – 5: Identifying assets of importance and their risks
      • Phase 6 – 7: Assessing potential adaptation actions for Noosa


  Understanding climate change & sea level rise
  The Earth’s atmosphere has warmed significantly over the past 200 years, and this is unequivocally
  due to human activities that have significantly increased the amount of greenhouse gases (GHG) in
  the atmosphere4. The rise in the concentration of greenhouse gases in the atmosphere is trapping
  more heat within the Earth’s climate system than would otherwise have occurred without the
  increases in these gases. This is, in turn, causing land and oceans to warm at a rate much faster than
  has occurred naturally in the past5.
  Based on the available science, the factor with the most influence on coastal hazards due to climate
  change is rising sea levels. Sea level rise is the elevation of global and local mean sea level caused
  by the expansion of the ocean as it warms, and the transfer of water currently stored on land to
  the ocean, particularly from melting glaciers and ice sheets. Global sea levels have risen at an
  increasingly higher rate than in the past 3000 years6. Sea levels started rising in the 1800s following
  the increase in use of fossil fuels associated with the Industrial Revolution. Between 1901 and 2018,
  global average sea level has increased by 0.20 metres7. The rate of global average sea level rise is
  accelerating, from 1.3 ± 7 mm annually between 1901 and 1971, to 3.7 ± 5 mm per year between
  2006 and 20188. In Australia, the rate of sea level rise has varied across the continent, with the north
  and southeast being significantly higher than the global average, and other locations being closer to
  the global average9.
  The result of this sea level rise is more land area exposed to coastal erosion and inundation over time.
  There is also high confidence amongst scientists that sea level rise (along with increases in heavy
  precipitation) increases the probability and magnitude of compound events10 such as compound
  flooding (storm surge, extreme rainfall and/or river flow) in coastal regions11.


  Phase 2 – 3: Identifying the hazards
  The first stage in developing a risk-based plan to respond to coastal hazards is to model and map the
  expected behaviour of each hazard. Modelling of a range of hazard events was performed by expert
  consultants, consistent with the QCoast2100 guidelines and Queensland Government technical
  guidelines. The future climate scenario underpinning the hazard modelling is based upon a high


  4
       Intergovernmental Panel on Climate Change (IPCC) (2021). Climate Change 2021: The Physical Science Basis.
        Contribution of Working Group I to the Sixth Assessment Report of the IPCC.
  5 
       National Aeronautics and Space Administration (NASA) (2021). Global Climate Change. Available Online:
       https://climate.nasa.gov/evidence/
  6
       IPCC (2021)
  7
       IPCC (2021)
  8
       IPCC (2021)
  9
       Bureau of Meteorology (BOM) & Commonwealth Scientific and Industrial Research Organisation (CSIRO)
  (2020). State of the Climate 2020.
  10 
         Compound events are situations where two or more weather events, which may or may not necessarily be
         extremes by themselves, occur together or in sequence, leading to more severe impacts
  11
         IPCC (2021)

Page 20