(AU) Troubling Detail In Aussie Weather Data

NEWS.com.au - Benedict Brook

Australia has gone through its coolest and wettest summer for years, but a graph released by the weather bureau has revealed a concerning detail.

This summer was our wettest for five years and the coolest in a decade, due mostly to La Nina shaking up Australia’s climate.

Scientific evidence and popular opinion on climate change are at odds. Sorting fact from fiction.

That’s according to the Bureau of Meteorology (BOM) which released it’s summer climate review today.

It’s undoubtedly good news for a country that has been ravaged by drought and bushfires.

But a small detail in the flurry of data released by the BOM is sobering, climate watchers, have said.

After the dry and scorching summer weather of 2019/20, the hallmark of which was huge bushfires, this year’s season was remarkable for how wet and non-scorching it was.

Since 1900, there have only been three years that have seen a wetter December than the one last year. Overall, rainfall across the continent during this summer was the highest since 2016-17.

In New South Wales, that rain was 29 per cent above the long term average (measured between 1961 and 1990) and the wettest since 2011/12, making it the soggiest state.

Queensland saw 8 per cent more rainfall but, rarely across Australia this summer, it also saw below average moisture in some areas around the Capricornia, Wide Bay and Burnett regions.

All this rain has largely been fuelled by the La Nina climate driver which bubbled up in the Pacific and pushed warmer water towards eastern Australia.

The mercury also took a dive. This summer was the coolest since 2011/12.

Melbourne had its chilliest summer since 2004/05 with Brisbane, Sydney and Canberra seeing the coldest such season for a decade.

Chart shows troubling trend

The BOM has helpfully published a chart that details how each summer’s overall temperatures performed against the average, as measured from 1961-1990. You can have a look at this below.

BOM analysis of summer temperatures anomalies above and below the long term average. Picture: BOM

Red bars are summers where the difference between the actual temperature and the average temperature, known as the anomaly, is higher. Essentially, hotter than average summers.

The blue bars are the opposite: summers where it was cooler than average.

If you look at the updated chart, which included this current summer, you’ll see a huge drop in that temperature anomaly from 2019 when the mercury was approaching 2C above average. In 2018, the anomaly was even higher, above 2C.

In 2020, that anomaly was far smaller. Temperatures were just 0.06C above the average. You can see that little spike below.

Our cool, cool summer was still warmer than usual. Picture: BOM

And that’s the big issue: on the coldest summer for a decade, aided by a strong La Nina, and with one of the coolest Decembers for more a century, the average summer temperature in Australia was still above the baseline.

If any summer was to finally see temperatures dip below average, it was the summer we’ve just had.

It didn’t happen. It was still warmer than it should be.

La Ninas drag up cold water in the western Pacific and push warmer water towards Australia. Picture: NOAA

La Ninas getting hotter

Associate Professor David Holmes from the Monash University Climate Change Communication Research Hub (MCCCRH) said it was a clear and troubling sign that even Australia’s cold summers were now actually quite warmer.

“La Nina summers are, on average, 0.36C cooler than average for all summers.

“But like all summers, La Nina summers have been warming,” he said.

“As the observations show, they have warmed by 1.1C since 1949 while all summers have warmed by 1.4C.”

Back in December, Monash University climate scientist Dr Ailie Gallant told news.com.au she was “in shock” at how hot Australia’s run up to summer was, despite it being a La Nina year.

November 2020 was the hottest Australia had ever seen.

“Typically late spring and early summer is when we have the strongest signal for La Nina episodes. They typically should be cooler than the years around them so to have the hottest November on the record, well I’m blown away by the whole situation. I’m actually in shock.”

Temperatures did indeed drop going into December. However, not by enough to stop the season being warmer than average.

This autumn is unlikely to be record breaking in terms of heat, but over the last few decades the season has been hotting up. Picture: Monash University

In Western Australia, there is another worrying sign about where our climate is headed.

A rare and potentially damaging climate phenomenon has caused temperatures to soar in the waters off the WA coast.

A type of maritime heatwave, dubbed a “Ningaloo Nino,” has been increasing in frequency.

The heating occurs during La Nina years when warmer water from the Pacific travels between northern Australia and the Indonesian archipelago and ends up joining with a current, called the Leeuwin Current. The warm water then travels down the entire coast of WA.

The UNESCO world heritage listed Ningaloo Reef, off the coast near Exmouth, can experience significant coral bleaching during these heatwaves. Some fisheries can wane and seagrasses often die.

A brief by the MCCCRH stated there was a “growing risk” of more marine heatwaves due to the rising overall temperature trend.

While bleaching had not been as bad this year as in 2011, the increase in temperatures means it’s becoming more of a common event.

“The observations show us that, over the past 40 years, waters around the Ningaloo Reef have warmed much faster than most other surrounding Australian waters in summer”, MCCCRH’s Prof Holmes.

“Climate projections suggest that more frequent and intense marine heatwaves can be expected in the future.”

Meteorologists say that it’s likely La Nina has now reached its peak and we could be back into the neutral phase of the El Nino Southern Oscillation (ENSO) by May.

Until then, increased rain is still likely. But the long term forecast will see the mercury rise as we go trough March and April. The rain gauge will also only get emptier as we head into a neutral ENSO, possibly swinging to El Nino.

Links

• (AU) 2020 Annual Climate Statement - Bureau of Meteorology
• Bureau of Meteorology: Australia in summer 2020–21
• Bureau of Meteorology: La Niña weakens, but influence likely to continue into autumn
• Bureau of Meteorology: Australian Climate Influences
• Councils across NSW and Queensland join forces to demand climate action from Morrison Government
• Qld cops $18bn bill due to extreme weather disaster loss
• La Niña drives cooler temperatures, high rainfall during Australian summer
• Climate outlook for March to June 2021

(AU) Australia Marine Hotspots Found To Store 2bn Tonnes Of 'Blue Carbon'

EURONEWS - Maeve Campbell

The Great Barrier Reef has been found to be a 'blue carbon' hotspot. Copyright  Getty via Canva

Three World Heritage-listed marine sites in Australia store billions of tonnes of carbon dioxide, reports UNESCO.

The UN organisation has released its first global scientific assessment of ‘blue carbon’ ecosystems, which double as World Heritage sites. The research shows that preserving these environmental habitats could be “crucial” to fighting climate change due to the amount of carbon stored there.

The three sites mentioned are the Great Barrier Reef in Queensland, Shark Bay and the Ningaloo Coast in Western Australia.

Although the sites make up less than 1 per cent of the planet’s oceans, they house 15 per cent of blue carbon assets in their seagrass meadows, tidal marshes and mangroves.

Two billion tonnes of carbon dioxide are locked away in these marine ecosystems.

The areas are called ‘carbon sinks’, a term used to describe reservoirs of either vegetation or water which store carbon for an indefinite period of time. The Amazon rainforest is one of the largest carbon sinks, absorbing a quarter of the carbon taken up by forests around the world every year.

Carbon sinks help mitigate climate change by sequestering carbon which lowers the concentration of CO2 in the atmosphere.

"Found on the fringes of the world’s coastlines, blue carbon ecosystems play an important ecological role in nutrient and carbon cycling, as nurseries and habitats for a broad range of marine and terrestrial species, in shoreline protection, and in sustaining the livelihoods and well-being of local communities,” said Ernesto Ottone R., UNESCO Assistant Director-General for Culture in a statement.

Seagrass meadows, tidal marshes and mangroves are all part of marine ecosystems. Getty via Canva

Why is conserving UNESCO sites so important?

There are hundreds of World Heritage-listed sites all over the world, in almost every country. Some examples you may have heard of are the Vatican City, the Taj Mahal, Yellowstone National Park and Stone Henge.

They are regarded as needing to be safeguarded for future generations, due to their ‘Outstanding Universal Value’, either for education or science purposes or as part of a specific cultural history.

UNESCO World Heritage marine sites are particularly important as they act as the custodians of the largest blue carbon ecosystems in the world. They face challenges to their survival, including pollution, littering, and rising sea levels due to climate change.

"Because they store so much carbon, blue carbon ecosystems become sources of CO2 emissions when they are degraded or destroyed. Protection and restoration of these ecosystems present a unique opportunity to mitigate climate change,” says Professor and marine ecologist Carlos Manuel Duarte.

“By conserving blue carbon ecosystems, the large carbon stocks they have accumulated over millennia can be protected. As they are restored, they can regain their function as carbon sinks."

Blue carbon strategies are currently underway in countries all over the world, to conserve seagrass, saltmarsh and mangroves, as well as expanding on seaweed aquaculture.

The UN report suggests that a system of carbon credits could mean countries earn credits for restoration and conservation of damaged areas, thereby incentivising them to better protect their marine ecosystems.

Links

• Blue carbon - Wikipedia
• The Blue Carbon Initiative
• What is Blue Carbon? - National Ocean Service
• Blue carbon: how three Australian marine sites lock away 2bn tonnes of CO2
• The future of Blue Carbon science
• Blue carbon is not the silver bullet the Coalition wants it to be
• Blue carbon - University of Wollongong
• Could the cure for COVID-19 lie at the bottom of the ocean?
• Underwater museum is protecting marine life in the Mediterranean Sea
• This floating 'continent' is self-sustainable and cleans the ocean

Watch This Giant Iceberg Break Off From Antarctica

SPACE.com - Chelsea Gohd

The iceberg broke off from Antarctica's Brunt Ice Shelf on Feb. 26.

This giant iceberg broke off from Antarctica's Brunt Ice Shelf on Feb. 26, 2021.  (Image credit: contains modified Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO)

New radar images captured from space reveal a giant iceberg breaking off in Antarctica. 

The iceberg, called A-74, covers about 490 square miles (1,270 square kilometers), making it 1.5 times bigger than Greater Paris. It broke off from the northern region of Antarctica's Brunt Ice Shelf on Feb. 26, just a few months after a large crack formed in November 2020. 

The new images of the iceberg's big break were captured by the European Space Agency's (ESA) Copernicus Sentinel-1 mission, an Earth-observing project made up of two orbiting satellites: Sentinel-1A and Sentinel-1B. 

"Although the calving of the new berg was expected and forecasted some weeks ago, watching such remote events unfold is still captivating," ESA scientist Mark Drinkwater said in an ESA statement about the event and how incredible it is to watch it all happen from space.

A map shows the Halley VI research station in relation to the north rift crack. (Image credit: British Antarctic Survey)

For years, glaciologists have monitored the cracks that have formed in the Brunt Ice Shelf, a large floating slab of ice 492 feet (150 meters) thick located on Antarctica's northern rim and the site of the British Antarctic Survey's (BAS) Halley Research Station. 

These scientists have been expecting a large "calving event" for at least a decade, according to the BAS. Ice calving, or iceberg or glacier calving, occurs when large pieces of ice break off of a glacier. The team working at the BAS Halley Research Station say that the station is unlikely to be affected by the recent calving event, according to the same BAS statement.

The Brunt Ice Shelf, which typically flows west at about 1.2 miles (2 kilometers) per year, routinely experiences calving events. According to the BAS in the same statement, there is "no evidence that climate change has played a significant role" in this specific event. 


Pine Island Glacier in Antarctica gives birth to an iceberg the size of Malta.

In November 2020, a new chasm (or deep fissure) named the North Rift started quickly cutting across the ice shelf, moving about 16 feet (5 meters) per day, according to the same ESA statement. Finally, on Feb. 26, the crack spread apart, widening before the iceberg was completely free from the ice shelf. 

"Over the following weeks and months, the iceberg could be entrained in the swift south-westerly flowing coastal current, run aground or cause further damage by bumping into the southern Brunt Ice Shelf. So we will be carefully monitoring the situation using data provided by the Copernicus Sentinel-1 mission," Drinkwater added.
 
Links

• A Huge Iceberg That's Bigger Than New York City Broke Off Near A UK Base In Antarctica
• Huge Antarctic Iceberg Headed Towards South Georgia Breaks In Two
• World's Biggest Iceberg Captured By RAF Cameras
• Why Scientists Are So Worried About Antarctica's Doomsday Glacier
• Melting Antarctic Ice Will Raise Sea Level By 2.5 Metres – Even If Paris Climate Goals Are Met, Study Finds
• The Tipping Points At The Heart Of The Climate Crisis
• Antarctica’s ‘Doomsday Glacier’ Is Starting To Crack
• 28 Trillion Ton Ice Melt Spells Danger For Sea Level Rise, Climate Change
• Antarctica: 60% Of Ice Shelves At Risk Of Fracture, Research Suggests