Adaptation on the Great Barrier Reef

They may seem far fetched, but geoengineering projects have already been proposed for areas in Australia's backyard.

One of the markers of global climate change is the health of the world's coral reefs, which are particularly sensitive to changing temperatures.

Following two consecutive years of mass coral bleaching, a team of researchers at the Sydney Institute of Marine Science last year proposed altering the clouds above the reef in a bid to save the delicate coral communities below.

They advocated "marine cloud brightening", making larger and more reflective clouds over the ocean to cool the water underneath.

Great Barrier Reef Marine Park Authority (GBRMPA) chief scientist David Wachenfeld said the authority has already undertaken local action to improve the resilience of the reef to climate change, which he said was "far and away the greatest threat" to its survival.

Although they are much smaller in scope than those proposed by geoengineering advocates like Dr Hunt, Dr Wachenfeld said the GBRMPA had already looked at adaptation and marine park management to reduce human impact on the reef, include altering turtle nesting habitats to ensure greater numbers survive each year.

"These areas can certainly still recover if we do the right thing in terms of global mitigation of climate change and local actions to improve resilience," he said.

"We need to try harder, do more and act now."

Continued

'What happens if we screw it all up?'

Summer ice in the Arctic is now so thin that researchers last year sailed in small yachts rather than large ice breaking ships.

Scientists say as much as 50 gigatons of methane trapped under the Arctic could be released into the atmosphere if — or when — the protective permafrost completely melts, rapidly speeding up global climate change.

The upshot of this and other climatic developments, according to Dr Hunt, is the need to urgently look at solutions that would otherwise seem unthinkable.

But he is not closed to the very real risk of catastrophe that geoengineering poses, pointing out that there are "hundreds" of potential adverse impacts. Most importantly, there is no "Planet B" if we get it wrong.

"The obvious ones are pumping something up high into the atmosphere and we know so little about the upper atmosphere - whatever we put up there has got to be safe," he said.

"What happens if we screw it all up? What happens if we accidentally switch off the Indian monsoon?"

Besides this, there is the risk the projects do not work at all, or are not as effective as advertised.

But Dr Hunt said this required more research and thought applied to the topic.

"I don't know which is worse - a seven metre sea level rise or geoengineering.

"That's putting it in a very pointed way, but we've got to think hard about this.

"It could be that there should be absolutely no way we ever do this. But that's why we've got to do the research."

Dr Hunt and Dr Wachenfeld spoke at the Climate Adaptation 2018 conference in Melbourne, recorded and broadcast by RN's Big Ideas.

Those alchemist’s apprentices have me quite worried, I wish Dr. Faust and old Paracelsus, Nicolas Flamel, Thomas Norton, etc  would come and check them out.

Yeah, that "we don't know what it will do, maybe kill the planet, but we've got to research it anyway" kinda worries me too.  There's nothing said that leads me to believe planet-wide or even local geoengineering testing can be done in the exact conditions in which it would be deployed, i.e. our upper atmosphere.  A lot of room for failure - gulp!  Who was it that said "best intentions often go awry"?

Climate Change Has Run Its Course

Its descent into social-justice identity politics is the last gasp of a cause that has lost its vitality.

Climate change is over. No, I’m not saying the climate will not change in the future, or that human influence on the climate is negligible. I mean simply that climate change is no longer a pre-eminent policy issue. All that remains is boilerplate rhetoric from the political class, frivolous nuisance lawsuits, and bureaucratic mandates on behalf of special-interest renewable-energy rent seekers.

I have to admit to having no confidence that efforts to "control" or "modify" our global climate would be beneficial.

This week is the first time this year that our local temperatures exceeded 40 degrees C.  In the 15 years since I moved to this part of the California desert, usually that happens in late March to early April.  So this year's weather patterns over out section of the desert are different than has been the recent normal.

And there's the important part - - it's this year's WEATHER, not necessarily a large-area climate change.  Most people don't seem to understand the vast difference.

Believe me, I know!

It’s getting warmer, no debate, it just is

The rate of Antarctic melting has nearly tripled in the past five years

The Antarctic ice sheet has lost more than 2,500 billion tonnes of ice in the past 25 years and nearly half of that has happened since 2012.

An international team of polar scientists found that melting in Antarctica has jumped sharply from an average of 76 billion tonnes per year prior to 2012, to around 219 billion tonnes each year between 2012 and 2017.

That's adding 0.6 of a millimetre to sea levels each year. Antarctica stores enough water to raise global sea levels by 58 metres, and has contributed 7.6 millimetres since 1992, according to the research published in Nature today.

The latest data is a continuation of previous assessments known as the Ice sheet Mass Balance Inter-comparison Exercise (IMBIE), which began in 2011 and tracks ice-sheet loss from 1992 onwards.

IMBIE was established with the support of NASA and the European Space Agency, to monitor the changes in ice-sheet cover around the world.

It uses combined satellite data to measure the Antarctic ice sheet's changing flow and volume.

The increase in melting should act as a wake-up call, according to project leader Professor Andrew Shepherd from the University of Leeds.

"These events and the sea-level rise they've triggered are an indicator of climate change and should be of concern for the governments we trust to protect our coastal cities and communities."

Continued

Emerging Antarctic sea-level rise research points to 'worst case scenarios'

Researchers say floating ice-shelf loss has triggered the faster loss of West Antarctic ice. 

(IMBIE: Planetary Visions)

West Antarctica contributed the most ice loss from the continent, shedding nearly 160 billion tonnes each year since 2012.

Although the general trend was of reduction, there was some increase in ice cover in East Antarctica.

This region has grown by an average of around 5 billion tonnes per year over the 25-year period, although margins of error could put that figure into the negative.

The researchers attribute the increased losses in West Antarctica and the Antarctic Peninsula to changes in regional floating-ice shelves, which can provide a buffer to continental-ice sheets.

In a separate analysis piece in Nature today, climate scientist and Antarctic policy expert Professor Rob DeConto warned that Antarctica may contribute more to sea-level rise than previously thought.

"But the good news is that a reduction in emissions in line with the aspirations of the Paris Climate Agreement dramatically reduces the risk of flooding our coastlines in future decades and centuries."

But there is also room for caution in how this latest data is interpreted.

It's too early to say whether this melting trend will continue or slow down, according to CSIRO physical oceanographer Dr Steve Rintoul, who wasn't involved in the study.

"It's a difficult one for us to answer because the time series is still pretty short," he said.

"There's still a wide range in projections between what is going to happen in Antarctica in the future."

However, he said that there is growing evidence that projections of Antarctica's influence on sea-level rise may have been underestimated.

"What we have seen as the climate has warmed is that more warm water is reaching the Antarctic ice sheet and that's what is melting the sea ice," he said.

Continued