Andrew Bolt liked the trick of pointing to the one part of a document that doesn’t mention floods and pretending that there is no mention of floods in the whole document so much that he did it again in his column:
The mantra was that global warming meant drought for us, and the 2007 Synthesis Report of the Intergovernmental Panel on Climate Change – the Vatican of the warming faith – made no mention of more floods in Australia from rain.
I hope you spotted Bolt’s scam. The Synthesis Report summarises the WG1, WG2, and WG3 reports and only has four bullet points about Australia and NZ. It does say this:
Available research suggests a significant future increase in heavy rainfall events in many regions, including some in which the mean rainfall is projected to decrease.
Is Australia one of those regions? If we look at the WG1 report we find:
A range of GCM and regional modelling studies in recent years have identified a tendency for daily rainfall extremes to increase under enhanced greenhouse conditions in the Australian region (e.g., Hennessy et al., 1997; Whetton et al., 2002; McInnes et al., 2003; Watterson and Dix, 2003; Hennessy et al., 2004b; Suppiah et al., 2004; Kharin and Zwiers, 2005). Commonly, return periods of extreme rainfall events halve in late 21st-century simulations. This tendency can apply even when average rainfall is simulated to decrease, but not necessarily when this decrease is marked (see Timbal, 2004). Recently, Abbs (2004) dynamically downscaled to a resolution of 7 km current and enhanced greenhouse cases of extreme daily rainfall occurrence in northern New South Wales and southern Queensland as simulated by the CSIRO GCM. The downscaled extreme events for a range of return periods compared well with observations and the enhanced greenhouse simulations for 2040 showed increases of around 30% in magnitude, with the 1-in-40 year event becoming the 1-in-15 year event.
Increases in extreme
daily rainfall are likely where average rainfall either increases or
decreases slightly. For example, the intensity of the 1-in-20 year
daily rainfall event is likely to increase by up to 10% in parts of
South Australia by the year 2030 (McInnes et al., 2002), by 5 to
70% by the year 2050 in Victoria (Whetton et al., 2002), by up
to 25% in northern Queensland by 2050 (Walsh et al., 2001) and
by up to 30% by 2040 in south-east Queensland (Abbs, 2004).
In NSW, the intensity of the 1-in-40 year event increases by 5 to
15% by 2070 (Hennessy et al., 2004).
For the Albert-Logan
Rivers system near the Gold Coast in Queensland, each 1%
increase in rainfall intensity is likely to produce a 1.4% increase
in peak runoff (Abbs et al., 2000). However, increases in runoff
and flooding are partially offset by a reduction in average rainfall,
which reduces soil wetness prior to storms. A high-resolution
atmospheric model of storm events coupled with a non-linear
flood event model has been applied to flooding around the Gold
Coast caused by tropical cyclone Wanda in 1974. If the same event
occurred in 2050 with a 10 to 40 cm rise in mean sea level, the
number of dwellings and people affected is likely to increase by
3 to 18% (Abbs et al., 2000).
The Rudd government was also sucked in, and told Murray-Darling farmers they’d have their water rights cut to “save” our rivers. Here’s then-Climate Change Minister Penny Wong in 2008:
“We know the IPCC, the Intergovernmental Panel on Climate Change, said by 2050 that Australia should expect around about a 25 per cent reduction in rainfall in the southern part of the Australia.”
And the very next paragraph in WG2 predicted that increases in extreme daily rainfall were likely.
Bolt is so pleased with his trick that he repeats it again and again:
As Garnaut himself told the National Press Club about his influential report:
“It almost had an exciting title. When our team in Melbourne finished the draft of the draft a few weeks ago we held a naming competition and the winner by acclamation was No Pain, No Rain. [Laughter]”
What the Garnaut report said about impacts in Queensland:
Queensland’s coastal settlements are
anticipated to suffer extreme
infrastructure impacts from increased
storm surge and localised flash flooding.