First let me clarify my position on the Queensland floods: climate change is not solely to blame.
Attribution is a tricky business. However, what is happening in Queensland is line with predictions made by scientists.
Don’t believe me?
Then read on.
At least the media are drawing the connection, as today’s The Age editorial notes:
A disturbing aspect of the floods is that they are consistent with (although not proof of) climate change predictions for northern Australia. Meteorologists accurately forecast that intense monsoonal rains would hit Queensland this season, under the influence of a strong La Nina event in the Pacific Ocean. They also warned that up to six cyclones could hit the state (the most ever to cross the coast in a season is three)
Which is my personal view: the floods are not “proof” per se, but are consistent with predictions about the impact of climate change on Northern Australia.
Flooding and increased precipitation events predicted
A 2010 publication released by the Queensland government titled “Climate change in Queensland: what the science is telling us” notes:
Extreme rainfall is defined as the amount of rain falling in the top one per cent of rainfall days.
Projections based on 15 climate models and a medium emissions (A1B) scenario indicated that Cape York can expect up to a four per cent increase in extreme rainfall across all seasons, and that western Queensland and the Gulf Region can expect up to a four per cent increase in summer and autumn (CSIRO & BoM 2007).
Climate change is also likely to affect extreme rainfall in south-east Queensland (Abbs et al.2007). Projections indicate an increase in two-hour, 24-hour and 72-hour extreme rainfall events for large areas of south-east Queensland, especially in the McPherson and Great Dividing ranges, west of Brisbane and the Gold Coast. For example, Abbs et al. (2007) found that under the A2 emissions scenario, extreme rainfall intensity averaged over the Gold Coast sub-region is projected to increase by 48 per cent for a two-hour event, 16 per cent for a 24-hour event and 14 per cent for a 72-hour event by 2070. Therefore despite a projected decrease in rainfall across most of Queensland, the projected increase in rainfall intensity could result in more flooding events.
The report notes the greatest risks to the state:
In Queensland the major risks to communities and their supporting infrastrature are cyclines and flooding. In addition, poor building design will place an increasing load on mechanical cooling to manage the effects of higher temperatures, increasing the need for fossil-fuelled electricity generation and thereby increasing greenhouse gas emissions.
Climate change will affect settlements through direct and indirect impacts resulting in damage to buildings and other infrastructure. These climate changes include:
> increased intensity of rainfall events
> increased temperatures
> more frequent extreme weather events
> increased extent and frequency of coastal flooding due to sea level rise and storm surges.
The science is well understood, and so are the impacts.