By Paul Homewood
Another of those "climate-driven" extreme weather events, again according to Christian Aid:
https://mediacentre.christianaid.org.uk/download?id=4170&pn=21e38f435ea050ce63ac6b7e52c58d72-pdf
The actual data from the Australian BOM tells a rather different story:
There is nothing at all unusual about the weather in the last few years, either in Eastern Australia as a whole, or the Murray-Darling Basin highlighted by Christian Aid. The black line is the 7-year running average, taking us back to 2012 when the drought started.
Their claim that rainfall in southeastern Australia has fallen 15-25% over recent decades, is a particular dishonest one, given that they are comparing with the unusually wet period in the 1950s to 70s. The climate was actually much drier than now prior to 1950.
And what about the claim that this is only the second time since 1900 that such dry conditions have persisted for two years across the Murray-Darling Basin.
Technically this correct, but why cherry pick two years? A totally different conclusion would have been made if three, or four, or five years had been used.
And while last year was exceptionally dry, the three driest years were 1902, 1944 and 1982. Clearly there is no trend towards a drier climate.
I know that some prefer to see actual graphs, rather than anomalies, so here is the actual rainfall for Eastern Australia:
As for the UK Met Office's long term projections for Australia, they find little evidence of any significant changes in precipitation trends, other than in SW Australia.
If anything they expect areas such as NSW to be slightly wetter.
Crucially, however, these projections are against the 1960-90 baseline, which we have already seen was an unusually wet period.
In short, the 21stC will likely be a bit wetter than the 20thC, if the Met Office are right.
https://www.metoffice.gov.uk/climate-guide/science/uk/obs-projections-impacts
PDO
There is one more piece to the jigsaw.
Many may have realised the significance of that wet 1950s to 70s period.
It matches, of course, the negative phase of the Pacific Decadal Oscillation (PDO).
https://en.wikipedia.org/wiki/Pacific_decadal_oscillation#/media/File:PDO.svg
And as the Met Office point out:
Positive phases of the PDO tend to be associated with periods of more rapid global warming whilst cold PDO events have been linked to severe droughts spanning many years in south western USA, as well as increased rainfall over eastern Australia.
https://www.metoffice.gov.uk/learning/ocean/pacific-decadal-oscillation
Are Christian Aid aware of these fundamental climate cycles? If they are not, they are not qualified to be making scientific judgments about them.
If they are, and ignore them, they are guilty of fraud.
As for the BBC, who happily promoted their junk science, I will let others judge their motivations.
from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2F6wwgi
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