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Penny Whetton and CSIRO on how 8 areas of Australia will fare under climate change

Penny Whetton

They called it Box 5.2. It sounds innocuous enough. But take a closer look at this section appearing in all eight regional impact assessments of climate change covered in the seminal report from CSIRO and the Bureau of Meteorology this week and you will find what the reality of living under the new climate regime could mean for your area.

According to Penny Whetton, lead author of the report and until October last year its senior principal research scientist, the CSIRO will soon expand on Box 5.2 with a set of tools that will be even more visually powerful.

The new tools will allow a resident of an area to look at various emissions projections and the kind of heat and lack of rainfall each projection is likely to cause.

Now like most scientists, Whetton, who is now an honorary research fellow at CSIRO, is a calm and measured interviewee on the topic of climate change.

On Wednesday she told The Fifth Estate the impact of climate change would vary for each person depending on their activity and level of responsibility.

For instance, if you are a local government authority in a low lying sandy area you might want to increase the size of your stormwater capacity. If you are a regular urban citizen your concerns might be more related to how to stay cool and reduce the impact on your health. Or making sure you can still afford some foods that climate change may wipe out or cause to be in short supply and therefore become more expensive.

Still Whetton was keen to point out that though a 2°C warming scenario is now inevitable, warming of 5°C or more was still in our hands and depended on the greenhouse gas emissions we pump into the atmosphere in the coming period.

We were keen to know what areas would survive better than others.

Whetton says what’s likely is an intensification of whatever climate patterns are already evident in a particular area.

So if you think Tasmania might be cooler in the future because it’s cooler now then you’d probably be right.

“If you think of all the climates we have in Australia at the moment, that it’s generally cooler as you go further south Tasmania has the coolest summers, so that it will probably still have the coolest summers in the future,” Whetton says.

Future rainfall pattern, however, is not as clear cut for Tasmania, however.

Elsewhere, “the hotter climates will push into really uncomfortable weather patterns”.

“For what Sydney’s climate will be like in 60-70 years you can look at the climate of Brisbane.”

But how relevant the patterns are depends on what you want to do.

If you are a farmer and you like to work with 600mm of rain a year you can use the analogue tool to work out where you can move to continue the same type of farming. Or you might change crops and produce to adapt to the new conditions.

“If you worry about how to adapt to a changing climate it’s not just the climate people will experience, it will also have an impact on a range of things, Whetton says.

“If you think about just cities, the risk is of extreme events of various sorts. If you are in a low lying coastal area you should have increasing concerns about storm surge events of a certain height that will become more frequent or that the risk of a one in 100 year event will increase.”

But the risk of erosion and the impact of rising sea levels is very “location specific”.

Whetton says there will be variations in sea level rises around the country but these will be small compared with the general rises.

“So if we hear 2090 sea levels will rise by 88cm that might vary between 70 and 90cm but not by a great deal more than that.

“But the impact of that rise will vary enormously depending on what that location’s coastline is like – is it low lying and sandy or has cliffs?

“Cities will need to deal with the intensity of heavy rainfall events that will increase in frequency. The capacity of drainage systems to deal with that is something that needs to be assessed.”

But Whetton points out that headlines this week saying Australia would be hotter than other places in the world was a “slight misunderstanding”.

“Australia will warm at the global average, but temperatures in inland areas will be higher than global average impacts.”

What is true is that Australia will be one of the more severely affected because parts of it are so close to the equator.

Another areas of impact is on the natural ecosystem. Some of Australia’s unique flora and fauna will be at risk of extinction.

Box 5.2

Here is a sample of what you will find on the Box 5.2 segments in the analysis from the recent climate report. The segments use analogues to illustrate various scenarios of climate warming and rainfall changes.

Central slopes

Say you live in Dubbo. If the scenario is simply warmer, that is 0.5 to 1.5 °C warmer, and the rainfall doesn’t change much, just -5 to +5 per cent by 2030, Dubbo’s future climate would be more like the current climate of Muswellbrook or Scone in NSW.

If it is going to get hotter (1.5 to 3.0 °C warming), but drier (5 to 15 per cent reduction) then the climate at Dubbo will be more like Coonamble or St George in Queensland.

If it’s much hotter (greater than 3.0 °C warming), and much drier (greater than 15 per cent reduction) think Walgett or Lightning Ridge in NSW.

East Coast

A warmer scenario (with indicators as named above) in Brisbane would see the weather look and feel more like Hervey Bay in Queensland.

And Sydney’s would be more like Newcastle.

If Brisbane is hotter (1.5 to 3.0 °C warmer), and drier (5 to 15 per cent reduction, possible by 2050 under one of the scenarios, then Brisbane would feel more like Bundaberg and Sydney would feel like Brisbane.

At the much hotter rate (greater than 3.0 °C warmer), and much drier (greater than 15 per cent reduction) then Brisbane will feel more like Ayr near Townsville and Sydney becomes like Bundaberg.

Monsoonal North

If you’re in Darwin and the weather succumbs to the warmer scenario (0.5 to 1.5 °C warmer) with little change in rainfall (-5 to +5 per cent) the climate would feel like Nguiu (Bathurst Island in the Northern Territory).

But if it’s hotter (1.5 to 3.0 °C warmer) with little change in rainfall (-5 to +5 per cent) which could occur by 2090, there’s no analogue in Australia.

Murray Basin

At Mildura, if the climate reaches much hotter (greater than 3.0 °C warmer) and much drier (greater than 15 per cent reduction) by late in the 21st century under one of the scenarios then think Carnarvon in Western Australia. Or if it’s just warmer think Broken Hill in NSW or Port Augusta in SA.

Rangelands

Under a warmer scenarios (0.5 to 1.5 °C warmer) and wetter (5 to 15 per cent increase), by early in the century under any emission scenario Alice Springs’ future climate would be more like that of Quilpie in Queensland.

Southern Slopes

In Melbourne a warmer scenario (0.5 to 1.5 °C warming) with little change in rainfall (-5 to +5 per cent) possible by 2030 would see Melbourne’s climate become more like that of Wangaratta in Victoria and Hobart’s like Geelong in Victoria.

Under the hotter scenario possible by mid-century Melbourne’s analogue would be Cowra in NSW and Hobart’s future climate would be more like the current climate of Victor Harbor in South Australia.

If it gets much hotter (greater than 3.0 °C warming), but drier (5 to 15 per cent reduction), possible by late in the 21st century under one emissions scenario, Melbourne’s future climate would be more like that of Dubbo and Hobart would feel like Adelaide.

Southern and South-Western Flatlands

Under a hotter scenario (1.5 to 3.0 °C warming), but much drier (greater than 15 per cent reduction) by 2050 Perth’s future climate would be more like the current climate of Jurien 222km north of Perth and Adelaide would feel more like Griffith in NSW.

Wet Tropics

A hotter climate scenarios (1.5 to 3.0 °C warmer), but drier (5 to 15 reduction) possibly by 2050 under certain emissions scenarios would see Cairns’ future climate be more like the current climate of Weipa.

Comments

One Response to “Penny Whetton and CSIRO on how 8 areas of Australia will fare under climate change”

  • jack says:

    All the ‘journalists’ at The Daily Telegraph newspaper don’t believe in climate change. Obviously they have some information the CSIRO don’t have.

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