Lethal Heating: 11/21/19

21/11/2019

(AU) Climate Change The Biggest Threat To Great Barrier Reef: Ley

Sydney Morning Herald - Tony Moore

Federal Environment Minister Sussan Ley and Queensland's Environment Minister Leeanne Enoch released a statement on Tuesday afternoon acknowledging climate change as the biggest threat to the health of the Great Barrier Reef.
The United Nations scientific body, UNESCO, will in 2020 make a decision on whether or not to list the Queensland's Great Barrier Reef as a world-heritage site that is in danger.

Federal Environment Minister Sussan Ley. Credit: Lukas Coch/AAP

The Great Barrier Reef has been a UNESCO world-heritage listed site since 1981.The two environment ministers - part of the Great Barrier Reef Ministerial Forum - met in Townsville on Tuesday to discuss the progress of policies set over the past five years to protect the Great Barrier Reef.
They will on December 1 release the report that will be provided to UNESCO's world heritage committee, which will ultimately make the ruling on the future listing of the Great Barrier Reef.
Ms Ley said she was confident the policies of both governments would protect the Great Barrier Reef of the impacts of climate change.
"There is clear acceptance of the science and it is also telling us that we are taking important steps to strengthen the Reef’s resilience," Mr Ley said in a statement.
"This year’s reef Outlook Report highlighted the challenges we face but it was also clear about the steps we can and are taking to protect its future and its World Heritage status."
The Great Barrier Reef Management Authority's August 2019 Outlook Report downgraded the future health of the Great Barrier Reef from "poor to very poor".
In September 2019, the Queensland government moved away from voluntary measures by agricultural groups to control sediment run-off into coastal reef areas to a new system where minimum standards for nutrient run-off are set and enforced by the Queensland government.
Ms Enoch said that decision was one of a number which showed governments were taking concerted steps to protect the Great Barrier Reef.
A project to slowly reduce eroded soil flowing down the Burdekin River onto the Great Barrier Reef has also received recognition by Premier Annastacia Palaszczuk.
"These regulations, along with other efforts including tree-clearing laws and action on climate change, are all steps that are being taken by the Queensland Government to support the health of the Reef and prevent it from being listed by the World Heritage Committee as in-danger next year," Ms Enoch said.
"The partnerships being developed with traditional owners are driving key recommendations under the Reef 2050 plan, and the work of Indigenous rangers on the land and sea are also proving vital to protect precious ecosystems."
The two levels of government "endorsed" the existing range of policies, despite conservationists arguing for a faster shift from carbon-intensive energy sources and agriculture sources.
Conservation groups argue a faster shift towards renewable energy is needed because the the world's atmospheric temperature has risen by more than one degree centigrade, an issue highlighted by the Federal Government's own Great Barrier Reef Management Authority's in it's 2019 Outlook Report.
Australia is a signatory to international efforts to keep atmospheric warming below two degrees.
"The rapid increase in greenhouse gas emissions has caused an estimated one-degree centigrade increase in global average temperature since pre-industrial times," the report says.
"The rising global temperature is causing an increase in sea temperature, which has a multitude of impacts, including destructive marine heatwaves."
The Great Barrier Reef Marine Park Authority released this blunt statement in July 2019: "Only the strongest and fastest possible actions to decrease global greenhouse gas emissions will reduce the risks and limit the impacts of climate change on the reef. "

Queensland's Great Barrier Reef

No commitment was made by either environment minister to increase the pace of a shift towards renewable energy.
Queensland promises to provide 20 per cent of it energy by 2020 from renewable energy sources and 50 per cent by 2030.
The Australian government has a commitment to provide 23.5 per cent of its energy from renewable energy by 2020.

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(AU) Global Heating Supercharging Indian Ocean Climate System

The Guardian - Peter Beaumont | Graham Readfearn

Indian Ocean dipole events, linked to bushfires and floods,

are becoming stronger and more frequent, scientists say

Smoke haze blanketing Sydney as bushfires burn in New South Wales, Australia. Photograph: Neil Bennett/AAP

Global heating is “supercharging” an increasingly dangerous climate mechanism in the Indian Ocean that has played a role in disasters this year including bushfires in Australia and floods in Africa.
Scientists and humanitarian officials say this year’s record Indian Ocean dipole, as the phenomenon is known, threatens to reappear more regularly and in a more extreme form as sea surface temperatures rise.
Of most concern are years in which the sea surface off the coast of Africa warms up, provoking increased rains, while temperatures off Australia fall, leading to drier weather.
It is similar to El Niño and La Niña in the Pacific, which cause sharp changes in weather patterns on both sides of the ocean.

Temperature changes in the Indian Ocean lead
to extreme weather events in Australia and east Africa

Guardian graphic. Source: The Commonwealth Scientific and Industrial Research Organisation

Caroline Ummenhofer, a scientist at Woods Hole Oceanographic Institution in Massachusetts who has been a key figure in efforts to understand the importance of the dipole, said unique factors were at play in the Indian Ocean compared with other tropical regions.
While ocean currents and winds in the Atlantic and Pacific can disperse heating water, the large Asian landmass to the north of the Indian Ocean makes it particularly susceptible to retaining heat. “It’s quite different to the tropical Atlantic and tropical Pacific events. There you have you have steady easterly trade winds. In the Indian Ocean that’s not the case,” Ummenhofer said.
“There is a certain season where you have easterly winds. Otherwise you have seasonally reversing monsoon winds, which makes for very different dynamics.”
Recent research suggests ocean heat has risen dramatically over the past decade, leading to the potential for warming water in the Indian Ocean to affect the Indian monsoon, one of the most important climate patterns in the world.
“There has been research suggesting that Indian Ocean dipole events have become more common with the warming in the last 50 years, with climate models suggesting a tendency for such events to become more frequent and becoming stronger,” Ummenhofer said.
She said warming appeared to be “supercharging” mechanisms already existing in the background. “The Indian Ocean is particularly sensitive to a warming world. It is the canary in the coalmine seeing big changes before others come to other tropical ocean areas.”
Australian climatologists have pointed to this year’s dipole as at least one of the contributing factors in the bushfires. Jonathan Pollock, of Australia’s Bureau of Meteorology, said this dipole was “up there as one of the strongest” on record.

Flooding has affected more than
2.5 million people in eastern Africa since July

Guardian graphic. Source: OCHA

Gemma Connell, of the UN’s Office for the Coordination of Humanitarian Affairs, raised concern over the impact of stronger and more regular Indian Ocean dipole events on Africa.
“What we are seeing from the current record events is large-scale flooding across the region. Entire swathes are under water, affecting 2.5 million people,” she said.
“And putting it in the broader picture of the climate crisis, this flooding is coming on the back of two droughts. What we are seeing, and what we are going to see more of, is more frequent climatic shocks coming. And all that is on top of the violence and conflict that has already displaced many of the people involved.
“In Kenya, for example, the region hardest hit has been around Lake Turkana, where there are already global malnutrition rates above 30% following drought. People are trying to cope with back-to-back shocks and their resilience has been eroded.”
Another concern for Connell and other humanitarian officials is that although climate scientists are racing to try to develop predictive modelling, there is disagreement over whether stronger Indian Ocean dipole events will lead to a wetter climate for Africa or a drier one.
“As non-meteorologists trying to plan ahead, we’re being faced with complex and changing scenarios. We’re just running to keep up. Looking now at southern and eastern Africa, with failed rainy seasons and then flooding, none of it looks normal,” she said.
“The new normal is a severe weather events. Looking at the Indian Ocean dipole’s effects, you have to see this is as a preview of what can be expected in other parts of world. And while I’m not surprised that attention of the world is elsewhere, that is still unforgivable given how many are suffering from a phenomenon the rest of the world helped create.”

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(AU) Firestorms And Flaming Tornadoes: How Bushfires Create Their Own Ferocious Weather Systems

The Conversation - Rachel Badlan

A firestorm on Mirror Plateaun Yellowstone Park, 1988. Jim Peaco/US National Park Service

As the east coast bushfire crisis unfolds, New South Wales Premier Gladys Berejiklian and Rural Fire Service operational officer Brett Taylor have each warned residents bushfires can create their own weather systems.
This is not just a figure of speech or a general warning about the unpredictability of intense fires. Bushfires genuinely can create their own weather systems: a phenomenon known variously as firestorms, pyroclouds or, in meteorology-speak, pyrocumulonimbus.
The occurrence of firestorms is increasing in Australia; there have been more than 50 in the period 2001-18. During a six-week period earlier this year, 18 confirmed pyrocumulonimbus formed, mainly over the Victorian High Country.

A pyrocumulonimbus cloud generated by a bushfire in Licola,Victoria, on March 2, 2019. Elliot Leventhal, Author provided

It's not clear whether the current bushfires will spawn any firestorms. But with the frequency of extreme fires set to increase due to hotter and drier conditions, it’s worth taking a closer look at how firestorms happen, and what effects they produce.

What is a firestorm?
The term “firestorm” is a contraction of “fire thunderstorm”. In simple terms, they are thunderstorms generated by the heat from a bushfire.
In stark contrast to typical bushfires, which are relatively easy to predict and are driven by the prevailing wind, firestorms tend to form above unusually large and intense fires.
If a fire encompasses a large enough area (called “deep flaming”), the upward movement of hot air can cause the fire to interact with the atmosphere above it, potentially forming a pyrocloud. This consists of smoke and ash in the smoke plume, and water vapour in the cloud above.
If the conditions are not too severe, the fire may produce a cloud called a pyrocumulus, which is simply a cloud that forms over the fire. These are typically benign and do not affect conditions on the ground.
But if the fire is particularly large or intense, or if the atmosphere above it is unstable, this process can give birth to a pyrocumulonimbus – and that is an entirely more malevolent beast.

What effects do firestorms produce?
A pyrocumulonibus cloud is much like a normal thunderstorm that forms on a hot summer’s day. The crucial difference here is that this upward movement is caused by the heat from the fire, rather than simply heat radiating from the ground.
Conventional thunderclouds and pyrocumulonimbus share similar characteristics. Both form an anvil-shaped cloud that extends high into the troposphere (the lower 10-15km of the atmosphere) and may even reach into the stratosphere beyond.

NASA image of pyrocumulonimbus formation in Argentina, January 2018. NASA

The weather underneath these clouds can be fierce. As the cloud forms, the circulating air creates strong winds with dangerous, erratic “downbursts” – vertical blasts of air that hit the ground and scatter in all directions.
In the case of a pyrocumulonimbus, these downbursts have the added effect of bringing dry air down to the surface beneath the fire. The swirling winds can also carry embers over huge distances. Ember attack has been identified as the main cause of property loss in bushfires, and the unpredictable downbursts make it impossible to determine which direction the wind will blow across the ground. The wind direction may suddenly change, catching people off guard.
Firestorms also produce dry lightning, potentially sparking new fires, which may then merge or coalesce into a larger flaming zone.
In rare cases, a firestorm can even morph into a “fire tornado”. This is formed from the rotating winds in the convective column of a pyrocumulonimbus. They are attached to the firestorm and can therefore lift off the ground.
This happened during the infamous January 2003 Canberra bushfires, when a pyrotornado tore a path near Mount Arawang in the suburb of Kambah.

A fire tornado in Kambah, Canberra, 2003 (contains strong language).

Understandably, firestorms are the most dangerous and unpredictable manifestations of a bushfire, and are impossible to suppress or control. As such, it is vital to evacuate these areas early, to avoid sending fire personnel into extremely dangerous areas.
The challenge is to identify the triggers that cause fires to develop into firestorms. Our research at UNSW, in collaboration with fire agencies, has made considerable progress in identifying these factors. They include “eruptive fire behaviour”, where instead of a steady rate of fire spread, once a fire interacts with a slope, the plume may attach to the ground and rapidly accelerate up the hill.
Another process, called “vorticity-driven lateral spread”, has also been recognised as a good indicator of potential fire blow-up. This occurs when a fire spreads laterally along a ridge line instead of following the direction of the wind.
Although further refinement is still needed, this kind of knowledge could greatly improve decision-making processes on when and where to deploy on-ground fire crews, and when to evacuate before the situation turns deadly.

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