Two new pieces of climate research underscore the inevitablity of more frequent and intense storms for Hawke’s Bay.
A study conducted by researchers from NZ, France, Germany, the Netherlands, the UK and the US – scientists and meteorologists in the World Weather Attribution group – found that very heavy rain has become four times more common in our region. And that such events produce around 30% more rain than previously.
These conclusions are based upon historic observed trends as opposed to climate models, the latter hampered by the small size of our region as a study sample.
The researchers view climate change was the cause of the increase.
“They reached this conclusion because well-established weather science and climate models both indicate that further greenhouse gas emissions, leading to more warming, will make heavy rainfall more intense and more frequent. The scientists also could find no plausible explanation, other than human-caused warming, for the observed increase in heavy rainfall,” the study said.
This conclusion is consistent with the findings of a much larger global study just published in the journal Nature Water by NASA scientists in the US.
Their study looked at 20 years of satellite data to identify extreme wet and dry events and chart those against global temperatures. They found that major droughts and ‘pluvials’ – periods of excessive precipitation and water storage on land – have indeed been occurring more often and are closely linked to global warming.
From 2015-2021 – seven of the nine warmest years in the modern record – the frequency of extreme wet and dry events was four per year, compared with three per year in the previous 13 years.
The study applied an “intensity” metric that accounts for the severity, duration, and spatial extent of droughts and extreme wet events, identifying 1,056 such events. Researchers found the global total intensity of extreme events increased from 2002 to 2021, mirroring Earth’s rising temperatures over the same period.
Meantime, the UN-sponsored Intergovernmental Panel on Climate Change (IPCC) is about to issue a major synthesis report on climate change impacts and mitigation requirements in preparation for the next global negotiating conference, COP28, in December.
In a message IPCC members, UN Secretary-General António Guterres’ commented: “Our world is at a crossroads — and our planet is in the crosshairs. We are nearing the point of no return; of overshooting the internationally agreed limit of 1.5°C of global warming. We are at the tip of a tipping point.”
When it comes to global warming, Guterres is the bluntest of politicians. Earlier this year he commented:
“We must end the merciless, relentless, and senseless war on nature …
2023 is a year of reckoning. It must be a year of game-changing climate action.
We need disruption to end the destruction.
No more baby steps.
No more excuses.
No more greenwashing.
No more bottomless greed of the fossil fuel industry and its enablers.”
Guterres warns:
“Humanity is waging war on nature. This is suicidal. Nature always strikes back – and it is already doing so with growing force and fury.”
Here in Hawke’s Bay, don’t we know it!
The future is looking grim. Stop banks will not protect low lying areas. One immediate answer is to declare the area between the two rivers an overflow buffer zone, consequently a ‘no build zone’. OK for farming and horticulture (at the owners risk) but all building to be ‘outside’ this flood zone. Similarly the river flats of Esk Valley. As you suggest, long term sea level rise will eventually necessitate either a ferry or an elevated road or bridge to connect the Bluff and Hospital hills to the mainland.
“Re-connect” the Bluff and Hospital Hills; it was not that long ago that they were islands…
A recent scientist summed it up in 3 protective strategies.
1/ Managed retreats in vulnerable areas.
2/ The investment of billions of $$$ nation wide, of water infrastructure to cope with increasing water volumes that are dumped from above.
3/ Paying heed to protecting/ developing wetland areas, green spaces and tree planting to absorb excess water.
Ultimately rivers will find their own course. Best to allow this to happen. This means removing large amounts of development from flood plains. We are collectively responsible for this huge cost because we collectively allowed what exists to happen.
Perhaps, but please publish the peer – reviewed science. How wide was the data spread, difference from tue mean, standard deviation and the coefficient of correlation? Trusting scientific spokespersons is very short sighted.