2021-11-15 GC Agenda - Item 7 - Attachment 2 - Coastal Hazards Adaptation Plan with tracked changes

         Developing this plan
This section discusses PhasesPhase 2 to Phase 7 of the CHAP’s development, includingwith 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
largelyunequivocally 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 are
risinghave risen at an increasingly higher rate than in the past 20003000 years6. Sea levels started
rising atin the 1800s following the industrial revolution and as a resultincrease in use of increased
dependency on fossil fuels. associated with the Industrial Revolution. Between 1901 and 1990 the
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

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)




Noosa Council – Coastal Hazards Adaptation Plan                                                Page 18