#81

Millions of fish have been dying in Australia’s major rivers
26 February 2019

By Ruby Prosser Scully

Fish have been struggling to breathe and dying by the millions on the banks of Australia’s largest river system. Experts say that without serious change, it will continue to happen.

Poor management, excess upstream irrigation and drought led to three mass deaths of endangered fish species during December and January in the Murray-Darling Basin. These deaths included Murray cod fish that were decades old, according to an investigation by the Australian Academy of Science that was published last week.

Craig Moritz at the Australian National University in Canberra, who chaired the investigation, says the sight of millions of dead fish should be a wake-up call. He described the mass fish deaths as a mainland equivalent of the coral bleaching events that have been hitting the Great Barrier Reef.

Much of Australia’s economy and food security depends on the Murray-Darling Basin, a complex river system with 2.6 million nearby residents, including more than 40 Aboriginal nations.

The Australian Academy of Science investigation was initiated by the opposition Labor party. The government has also launched its own separate investigation, but the panels from both have agreed on the immediate cause of the fish deaths.

Warm, still water created the perfect environment for blue-green algae to bloom. Algae are important for providing oxygen in the upper layers of water, but when they die, they fall to the bottom of the riverbed where microorganisms that deplete oxygen in the lower layers feed on them.
Read more: Fracking chemical leak kills threatened fish

A cold snap caused the oxygenated upper layer and the larger, unoxygenated, lower layer of water to mix. Fish that had been surviving in the shallow top layers quickly ran out of oxygen and suffocated.

The government-commissioned interim report highlighted role of “exceptional climactic conditions” in exacerbating the situation.

But Moritz’s report said the drought hadn’t been unprecedented, and that excess upstream irrigation led to a lack of water and a “catastrophic decline” of the system’s condition through dry periods.

Culum Brown at Macquarie University says focusing on extreme weather conditions is “nonsense” and that management of the Murray-Darling river system had ignored the predictable results of climate change.

“Sticking your head in the sand and pretending climate change does not exist is not an appropriate management action,” says Brown.

#82

https://www.newscientist.com/article/2194781-earth-could-warm-by-14c-as-growing-emissions-destroy-crucial-clouds/ posted:

Earth could warm by 14°C as growing emissions destroy crucial clouds

Environment 25 February 2019

By Michael Le Page

If we keep burning fossil fuels with reckless abandon, we could trigger a cloud feedback effect that will add 8°C on top of all the warming up to that point. That means the world could warm by more than 14°C above the pre-industrial level.

Needless to say, this would be cataclysmic. For instance, large parts of the tropics would become too hot for warm-blooded animals, including us, to survive.

The good news is that if countries step up their efforts to cut emissions we should avoid finding out if this idea is correct. “I don’t think we will get anywhere close to it,” says Tapio Schneider at the California Institute of Technology, Pasadena, who led the research.

Schneider’s team modelled stratocumulus clouds over subtropical oceans, which cover around 7 per cent of Earth’s surface and cool the planet by reflecting the sun’s heat back into space. They found there was a sudden transition when CO2 levels reached around 1200 parts per million (ppm) — the stratocumulus clouds broke up and disappeared.

The reason why this finding applies only to subtropical stratocumulus is that these clouds are unusual. The cloud layer is maintained by the cloudtops cooling as they emit infrared radiation — and very high CO2 levels block this process.

The loss of these bright white clouds would have a dramatic warming effect, adding 8°C to the global temperature, Schneider calculates. Since the world would warm around 6°C or more if CO2 levels passed 1200 ppm, this means the average global temperature could exceed 14°C or more.

No need to panic
CO2 levels will pass 410 ppm this year, up from 280 ppm in preindustrial times. If we burned all available fossil fuels, atmospheric CO2 levels could rise as high as 4000 ppm.

However, even in the standard worst case scenario used by climate scientists, which assumes nothing is done to curb emissions, CO2 levels would only pass 1200 ppm decades after 2100.

Other climate scientists say this cloud feedback is plausible. “Conceptually I think it’s sound,” says Helene Muri at the Norwegian University of Science and Technology. But there are some uncertainties about the numbers, so it will be important to try to narrow them down, she says.

The result might hold up, but we already have more than enough reasons to avoid reaching this point, says Kate Marvel at the NASA Goddard Institute for Space Studies.

Emissions are currently growing in line with the worst-case scenario, but the expectation is that countries will eventually do more. “This result isn’t cause for panic,” says Marvel.

The finding could also help solve a longstanding mystery — how the planet got so hot around 50 million years ago that crocodiles thrived in the Arctic. We know that CO2 levels were generally much higher at the time, but they were not high enough to explain the extreme warmth during this period.

The reason why the cloud feedback effect had not been discovered before is that general climate models of the planet have to greatly simplify cloud physics to make the computations manageable.

Schneider’s team instead modelled only a small part of the subtropical atmosphere in great detail.

And if the models are missing major effects like this, there could be more nasty surprises in store as the world warms. “Yes, for sure,” says Muri. “We will certainly see more surprises.”

Journal reference: Nature Geoscience, DOI: 10.1038/s41561-019-0310-1


#83

https://phys.org/news/2019-02-world-catastrophic-collapse-insects.html posted:

World seeing 'catastrophic collapse' of insects: study
February 11, 2019 by Marlowe Hood

Nearly half of all insect species worldwide are in rapid decline and a third could disappear altogether, according to a study warning of dire consequences for crop pollination and natural food chains. "Unless we change our way of producing food, insects as a whole will go down the path of extinction in a few decades," concluded the peer-reviewed study, which is set for publication in April.

The recent decline in bugs that fly, crawl, burrow and skitter across still water is part of a gathering "mass extinction," only the sixth in the last half-billion years. "We are witnessing the largest extinction event on Earth since the late Permian and Cretaceous periods," the authors noted.

The Permian end-game 252 million years ago snuffed out more than 90 percent of the planet's life forms, while the abrupt finale of the Cretaceous 66 million years ago saw the demise of land dinosaurs.

"We estimate the current proportion of insect species in decline—41 percent—to be twice as high as that of vertebrates," or animals with a backbone, Francisco Sanchez-Bayo of the University of Sydney and Kris Wyckhuys of the University of Queensland in Australia reported.

"At present, a third of all insect species are threatened with extinction."An additional one percent join their ranks every year, they estimated. Insect biomass—sheer collective weight—is declining annually by about 2.5 percent worldwide. "Only decisive action can avert a catastrophic collapse of nature's ecosystems," the authors cautioned. Restoring wilderness areas and a drastic reduction in the use of pesticides and chemical fertiliser are likely the best way to slow the insect loss, they said.

'Hardly any insects left'
The study, to be published in the journal Biological Conservation, pulled together data from more than 70 datasets from across the globe, some dating back more than a century. By a large margin, habitat change—deforestation, urbanisation, conversion to farmland—emerged as the biggest cause of insect decline and extinction threat. Next was pollution and the widespread use of pesticides in commercial agriculture. The recent collapse, for example, of many bird species in France was traced to the use insecticides on industrial crops such as wheat, barley, corn and wine grapes.

"There are hardly any insects left—that's the number one problem," said Vincent Bretagnolle, an ecologist at Centre for Biological Studies. Experts estimate that flying insects across Europe have declined 80 percent on average, causing bird populations to drop by more than 400 million in three decades. Only a few species of insects—mainly in the tropics—are thought to have suffered due to climate change, while some in northern climes have expanded their range as temperatures warm.

In the long run, however, scientists fear that global warming could become another major driver of insect demise. Up to now, rising concern about biodiversity loss has mostly focused on big mammals, birds and amphibians. But insects comprise about two-thirds of all terrestrial species, and have been the foundation of key ecosystems since emerging almost 400 million years ago. "The essential role that insects play as food items of many vertebrates is often forgotten," the researchers said. Moles, hedgehogs, anteaters, lizards, amphibians, most bats, many birds and fish all feed on insects or depend on them for rearing their offspring.

Other insects filling the void left by declining species probably cannot compensate for the sharp drop in biomass, the study said. Insects are also the world's top pollinators—75 percent of 115 top global food crops depend on animal pollination, including cocoa, coffee, almonds and cherries. One-in-six species of bees have gone regionally extinct somewhere in the world. Dung beetles in the Mediterranean basin have also been hit particularly hard, with more than 60 percent of species fading in numbers. The pace of insect decline appears to be the same in tropical and temperate climates, though there is far more data from North America and Europe than the rest of the world.Britain has seen a measurable decline across 60 percent of its large insect groups, or taxa, followed by North America (51 percent) and Europe as a whole (44 percent).


More information: Francisco Sánchez-Bayo et al. Worldwide decline of the entomofauna: A review of its drivers, Biological Conservation (2019). DOI: 10.1016/j.biocon.2019.01.020 , www.sciencedirect.com/science/ … i/S0006320718313636#!

#84
No need to panic
CO2 levels will pass 410 ppm this year, up from 280 ppm in preindustrial times. If we burned all available fossil fuels, atmospheric CO2 levels could rise as high as 4000 ppm.

However, even in the standard worst case scenario used by climate scientists, which assumes nothing is done to curb emissions, CO2 levels would only pass 1200 ppm decades after 2100.
#85
I retaught myself the dark art of getting something onto the front page so this could go there. cool thread, i like reading it in between hyperventilating in fear
#86
a materialist analysis would suggest that you're actually hyperventilating in order to consume as much air as possible while its still relatively oxygen-rich, since you have grown accustomed to a bourgeois lifestyle that includes limitless breathable air
#87

https://www.austinmonitor.com/stories/2019/02/permanent-zebra-mussel-solution-still-18-months-out/ posted:

Permanent zebra mussel solution still 18 months out

Following the odorous indication that a zebra mussel infestation had arrived in Austin waterways earlier this month, Austin Water has been working to come up with a solution to prevent a similar instance from recurring.

Austin Water is already working to slow the population of zebra mussels by using chemical retardants in its piping systems and raw water tunnels. However, due to the speed with which these bivalves reproduce, it is not enough, according to Mehrdad Morabbi, an operations manager for Austin Water, who addressed the Environmental Commission at their Feb. 20 meeting.

After first appearing in 2017 in Austin’s jurisdiction of the Highland Lakes system, the mussels have spawned at such a rate that Austin Water reported a ½- to 2-inch-thick layer of mussels at every water treatment facility intake this past January. This already critical situation is compounded by the fact that “we could essentially look at a year-round spawning season,” said Morabbi.

With the possibility of tens of millions of nickel-sized mussels covering every hard surface within Austin lakes, the water utility is quickly searching for a solution. Unfortunately, the least expensive and most effective option of copper ionization is not readily available. According to Morabbi, the implementation of the electrolytic process that adds a very low dose of copper to the water and that is toxic to the mussels is still 18 months out. The water company is working with an outside consultant, the engineering firm Black and Veach, to develop the copper-ion system.

In the interim, Austin Water is planning on using a combination of manual removal of the mussels along with a sodium permanganate solution. Although effective, the sodium permanganate solution is significantly pricier than using copper.

To combat the mussels with a copper solution it will cost roughly $200,000 per annum. Meanwhile, to use sodium permanganate, it “would be roughly $1 million for an annual contract,” explained Morabbi. “But we need it, and we’re going to use it.” This will come on top of the $212,000-per-year diving contract that Council approved last June.

According to the Watershed Protection Department, there is no way to eradicate these mussels without damaging the natural ecosystems of the lake. Nor is there an environmentally friendly solution akin to grass carp that would function as a natural predator to this invasive species.

Commissioner Mary Ann Neely did ask if the mussels were edible in hopes that the city could consume their way out of this problem. However, Morabbi noted, “I haven’t seen garlic butter as a mitigation technique.”

Still, there is still some consolation to be had from the fact that the first spawning season is generally the worst. After the initial bloom, generally limiting natural factors keep populations at a steady state.

That’s not to say that things won’t get worse before they get better. As Austin Water works to keep populations under control, Liz Johnston, a program coordinator at the Watershed Protection Department, brought the commissioners’ attention to the fact that as filter feeders, these mussels will not only clog water intakes but they will allow the blue-green algae in the lakes to flourish more easily and their population will continue to spread downstream which will pose a risk to swimmers and recreational water users because of their sharp shells.

Morabbi admitted that the water utility “really won’t be able to do anything with the lake,” but he did assure the commissioners that Austin Water is working to ensure clean, safe drinking water for Austinites despite the infestation.



#88
“I turned on the water and it's just this over powering odor of what I would consider raw meat,” South Austin resident Kathryn Araguz told Austin's Fox 7. She said after her shower Thursday morning, her skin "smelled for quite a while."

Residents told KXAN the water smelled like "toilet water" or "rotten trash."

Even though the water smells rotten, it's safe to drink, according to Austin Water officials
#89
all the bugs are dead. the water smells like rotting meat. worms consume all plants. heat waves inexorably eradicate all life in the tropics.

cool, nice