Understanding Climate Risk

Science, policy and decision-making

Hunt lies as the reef dies

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Twitter is going off after Australia’s Minister for the Environment Greg Hunt posted this:

Hunt-reef-claim

Reef scientist Professor Terry Hughes was quick to respond.

Just 12 hours earlier, he had posted this:

Reef-coral-mort

Last year, I visited Ove Hoegh-Guldberg at the University of Queensland to update him on our rapid shift hypothesis and what it might mean for the reef. He and his fellow reef scientists were concerned about the coming summer, saying that things were looking worse now than he had projected in his famous 1999 paper. There was an El Niño in place and reefs were already bleaching in the northern hemisphere, so the coming summer looked bad. Their fears have been realised.

After the severe bleaching in the 1998 summer it seemed that things were going to get progressively worse, but perhaps the plateau in sea surface temperatures from then had kept a lid on things – what if there was going to be another shift, not just a spike?

These is the March anomaly for the GBR, the month where all the damage was done. That is 0.5 °C above the previous warmest March.

sst.GBR.03.45174

And this is what it looked like spatially, sea level on the left and heat anomaly on the right.

20160315
In 2003 in a collaboration between CSIRO and AIMS, we built a bleaching model called ReefClim (see report – pdf). I just had a look at a coral bleaching and mortality model based on that model combined with the 1998 and 2002 events (pdf) to estimate potential spatial damage. This model projects that a 3 °C anomaly above the bleaching threshold would affect over 90% of the GBR (97%). This current event has almost that level of severity, and is causing a level of mortality that will decade decades to recover (see paper based on mortality and recovery models). More from Peter Hannam in the SMH.

These events are on a scale or even worse than projected by detailed studies conducted over the past decade or so. Below is a map showing anomalies 1 to 3 °C above the 1993-2003 average.

ssta14dayleg-n-20160331

This sort of data was not available in the last bad event of 2002 but sadly, it is writing an epitaph that will continue to document worsening conditions.

For Hunt to tweet that sort of rubbish while this is still playing out is a total obscenity. It demonstrates that neither he, nor his party are fit for government. The Labor Party are also schizophrenic over coral reef protection and the development of new coal mines, so need to be held to account.

Whatever is done now will not help the reef for a couple of decades, but it is still possible to stabilise temperatures this century and possibly even bring them down in tropical waters (research in progress). It is critical to reduce nutrients coming from land to increase coral resilience in the meantime. That will buy the corals some time, but the warming story is as bad as it could be.

 

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Written by Roger Jones

May 30, 2016 at 10:14 pm

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