Sunday, September 16, 2007

Evil Co2 and the terrible Australian drought

As reader George commented:

I am wondering if you are still sticking to your belief that the drought is over and we have returned to normal rainfall patterns.
Because it seems that what the BOM said, of a bleak picture, has actually come to fruition.

I replied:

as shown here rainfall in australia over the last 6 months have been low i the south west - north of perth. High in the north and especailly north west Australia.

No sign of drought there.

The last 12 months has seen low rainfall in the far seaboard west and low in the mid south, and south east. Higher has been recorded in central north and north west.

No sign of a drought there either, with some up some down.

Seems to me that Australia's rainfall is not decreasing in total (as is shown here), (which also shows if anything increasing Australian rainfall), but rather the places that are getting less rainfall are in the south east highly farmed land, and the places are are not are in the northern non farmed land.

Is Australia getting less rainfall? No, the graph above shows this. Its just been unfortunate that the rainfall of late has fallen on the places that don't use the land for agriculture.

Maybe Co2 causes the rain to only fall where we don't need it. Nasty thing Co2

Oh, and by the way, I never said that the current or previous rainfall patterns were not normal.


chemikazi said...

There have been numerous studies in recent years showing far greater cloud formation over native forrest than over agricultural land. A lot of work has been done in the WA wheat belt.

I might also add that over the past 30 years living in an inner Brisbane suburb, I have come to expect that storm fronts moving down off the Great Divide between Toowoomba and Warwick very frequently seem to split and cells pass north and south of the city area, rarely passing through the CBD area. I presume this is some type of heat island effect.

In short, I believe the shifts in rainfall geographic patterns have more to do with micro-climatic effects than any world climate shift.

philip said...

xigkbtjThe cloud formation over natural bushland and not over farmland produces dramatic straight lines of cloud and one side and clear skys on the other. I see it on a regular basis here in WA.

A general trend of clearing bush could well impact rainfall.

Compare Merredin (in the wheatbelt) to Southern Cross (100ks further east in natural bushland).

Rainfall decreases west to east in WA yet Southern Cross has significantly higher rainfall. If these 2 sites are a guide we are looking at a rainfall decrease of perhaps 10% to 20% over cleared land versus native bush.