Biodiversity Strategy - Gosford City Council - NSW Government

Increased needs for active recreation areas such as playing fields also places pressure on
natural areas, particularly as these are often located on low-lying flat land that may support
remnant endangered ecological communities. Commercial and recreational fishing have the
potential to also impact on native fish as well as habitats, particularly when the methods used
are highly damaging such as prawn trawling. Many of these impacts can however be addressed
through appropriate controls, innovative technological solutions and increase community
awareness.
A - 7.13 Climate Change
The world’s climate is changing as a result of greenhouse gas emissions and this issue is
emerging as the most serious global threat facing biodiversity. Despite past argument and
scientific uncertainties, there is now scientific consensus that climate change is a reality and is
caused by human activity, as demonstrated by the Joint Science Academies’ statement signed
by twelve national scientific academies and presented to the G8 Summit in July 2005
(http://www.g8.gov.uk).
On average, global temperatures rose 0.6° Celsius in the 20th Century. The ten warmest years
on record worldwide occurred from 1990. In Australia, there is also compelling evidence of
climate change impacts. 2005 was the hottest year on record for Australia. In a study of snow
depth at Spencer’s Creek near Mt Kosciusko, a decrease of 40% since 1962 was recorded
which was attributed to temperature rise (Nicolls et al. 2003).
Over the 21st Century, global temperatures are predicted to rise by between 1.4 and 5.8°
Celsius (Intergovernmental Panel on Climate Change ref). In Australia, predictions are for an
increase of between 0.4 to more than 2° Celsius by 2030 and possibly up to 6° Celsius increase
(Whetton 2003). For south east Australia, predictions are for lower overall rainfall with more
frequent hot days and droughts. There is a predicted increase in the frequency and intensity of
bushfire. Increased incidence of bushfires will have associated impacts such as increased soil
erosion and loss soil nutrients.
Sea level rise is predicted to be between 0.1 and 0.9 metres between 1990 and 2100 (Walsh
2003). This is likely to impact on low relief areas in Gosford City such as the Woy Woy
Peninsular, Bensville, Saratoga and St Hubert’s Island. Also increased strong winds and higher
storm tides are predicted that will result in more coastal inundation, with serious impacts for
coastal areas of the LGA. Although important habitat such as saltmarsh is now listed as
Endangered Ecological Community, legislation will not protect them from climate change.
Saltmarsh in Gosford generally abut urban developments or steep escarpments. As sea levels
rise these habitats may be squeezed out of existence. Climate change, and associated smallscale
changes in tidal range, may also be responsible for the encroachment of mangroves into
saltmarsh.
Some species will increase their current distribution but others will contract their distribution, for
example cane toads are expected to be favoured by warmer temperatures and this will enable
them to expand their range even further south than the current Port Macquarie limit and are
expected to reach the Central Coast. Some change will be directly as a result of climate change,
while others will be due to predation, impacts on breeding cycles, flow regimes. As a result of
climate change more algal blooms are also predicted. Increased incidence and spread of
disease, such as mosquito borne viruses, is also likely.
A conference in 2003 sponsored by the Commonwealth Standing Committee on Natural
Resource Management examined the impacts on natural resources as a result of climate
impacts. In examining how species will respond to accelerating biological changes associated
with warming, Hughes (2003) predicted that there would be the following changes in the
relatively short term:
Biodiversity - Technical Report Page 166