Rachel returns with an important post on local impacts
So what if the world is getting a little warmer – what’s the harm in that? After all as scientists have told us its been warmer in the past. Around 6,000 to 8,000 years ago in the mid Holocene period it was probably 0.5 to 1.5 degrees warmer than today and sea levels were around 1 – 1.5 metres higher than current levels. Fortunately, we have enjoyed a relatively stable climate for all of human civilisation and the changes that are now projected will have devastating effects for all of us.
The impacts of climate change have been modelled in a recent publication titled ‘NSW Climate Impact Profile’ prepared by the State Government
The modelling finds that summer average temperatures are likely to be 2.0 to 3.0 degrees warmer by 2050 and 1.5 to 3.0 degrees warmer in winter. Rainfall is expected to increase in spring and summer:- in summer particularly a 20 – 50% increase is predicted however a 10 – 20 % decrease is expected in winter. More evaporation is likely to occur, particularly in spring months. Overall, water supply inflows to water storages are predicted to decrease by around 10%.
Short term droughts are projected to become more severe but medium to long term droughts are thought to become less severe.
Flood frequency, height and extent in the lower coastal floodplains is likely to increase. Urban streams are likely to flood more frequently. Areas for potential significant overland flooding include Gosford.
For bushfires intensification of fire danger levels is predicted with a longer fire season and very high to extreme fire danger days are projected to increase by 10 – 50%.
For sea level rise the report finds that residential and commercial beachfront development in the region are virtually certain to be threatened by either ocean inundation or coastline recession. Dwellings, tower blocks, commercial premises, caravan parks, surf clubs, beachfront roads and associated infrastructure will be potentially at risk by 2050.
By considering these risks we can better understand the local impacts and better plan for them now. The climate projections in this study have been based on the upper range of climate scenarios prepared by the Intergovernmental Panel of Climate Change (IPCC) but the rate of global emissions since 2000 has been much greater than for the most fossil-fuel intensive of the IPCC’s emission scenarios. Therefore, these models should be viewed as a more conservative estimate of climate change impacts over the next 40 or so years.
The report considers Sydney and the Central Coast as one region and is based on selected climate models that were shown to most closely predict climate variability in the past when compared to known climate data.
Source: NSW Environment, Climate Change and Water (2010) NSW Climate Impact Profile The impacts of climate change on the biophysical environment of New South Wales.