Eastern China pinpointed as source of rogue ozone-depleting emissions



Sunset at Australia’s Cape Grim observatory, one of the key global background monitoring sites for CFC-11.
Paul Krummel/CSIRO, Author provided

Paul Krummel, CSIRO; Bronwyn Dunse, CSIRO; Nada Derek, CSIRO; Paul Fraser, CSIRO, and Paul Steele, CSIRO

A mysterious rebound in the emissions of ozone-depleting chemicals – despite a global ban stretching back almost a decade – has been traced to eastern China.

Research published by an international team today in Nature used a global network of monitoring stations to pinpoint the source of the rogue emissions. According to these data, 40-60% of the increase in emissions seen since 2013 is due to possibly illegal industrial activity in the Chinese provinces of Shandong and Hebei.




Read more:
After 30 years of the Montreal Protocol, the ozone layer is gradually healing


Chlorofluorocarbon-11 (CFC-11) is a powerful ozone-depleting chemical that plays a major role in the appearance, each spring, of the ozone “hole” over Antarctica.

In the past, CFC-11 had been used primarily as a propellant in aerosol products and as a foam plastic blowing agent. The production and consumption (use) of CFC-11 are controlled by the global Montreal Protocol. CFC-11 consumption has been banned in developed countries since 1996, and worldwide since 2010.

This has resulted in a significant decline of CFC-11 in the atmosphere. Long-term CFC-11 measurements at Cape Grim, Tasmania, show the amount in the atmosphere peaked in 1994, and fell 14% by 2018.

However, this decline has not been as rapid as expected under the global zero production and consumption mandated by the Montreal Protocol since 2010.

Background levels of CFC-11 measured at Australia’s Cape Grim Baseline Air Pollution Station, located at the north-west tip of Tasmania.
CSIRO/Bureau of Meteorology

A 2014 study was the first to deduce that global emissions of CFC-11 stopped declining in 2002. In 2015, CSIRO scientists advised the Australian government, based on measurements compiled by the Advanced Global Atmospheric Gases Experiment (AGAGE), which includes those from Cape Grim, that emissions had risen significantly since 2011. The cause of this rebound in CFC-11 emissions was a mystery.

Global CFC-11 emissions based on atmospheric measurements compared with the expected decline of this compound in the atmosphere if compliance with the Montreal Protocol was adhered to.
CSIRO/AGAGE

An initial explanation came in 2018, when researchers led by Stephen Montzka of the US National Oceanic and Atmospheric Administration analysed the CFC-11 data collected weekly at Mauna Loa, Hawaii. They deduced that the increased emissions originated largely from East Asia – likely as a result of new, illegal production.

Montzka’s team concluded that if these increased CFC-11 emissions continued, the closure of the Antarctic ozone hole could be delayed, possibly for decades. This was a remarkable piece of detective work, considering that Mauna Loa is more than 8,000km from East Asia.

Suspicions confirmed

A still more detailed explanation is published today in the journal Nature by an international research team led by Matt Rigby of the University of Bristol, UK, and Sunyoung Park of Kyungpook National University, South Korea, together with colleagues from Japan, the United States, Australia and Switzerland. The new study uses data collected every two hours by the AGAGE global monitoring network, including data from Gosan, South Korea, and from an AGAGE-affiliated station at Hateruma, Japan. Crucially, Gosan and Hateruma are just 1,000km and 2,000km, respectively, from the suspected epicentre of CFC-11 emissions in East Asia.

The Korean and Japanese data show that these new emissions of CFC-11 do indeed come from eastern China – in particular the provinces of Shandong and Hebei – and that they have increased by around 7,000 tonnes per year since 2013.

Meanwhile, the rest of the AGAGE network has detected no evidence of increasing CFC-11 emissions elsewhere around the world, including in North America, Europe, Japan, Korea or Australia.

Yet while this new study has accounted for roughly half of the recent global emissions rise, it is possible that smaller increases have also taken place in other countries, or even in other parts of China, not covered by the AGAGE network. There are large swathes of the globe for which we have very little detailed information on CFC emissions.

Map showing the region where the increased CFC-11 emissions came from, based on atmospheric measurements and modelling.
University of Bristol/CSIRO

Nevertheless, this study represents an important milestone in atmospheric scientists’ ability to tell which regions are emitting ozone-depleting substances and in what quantities. It is now vital we find out which industries are responsible for these new emissions.

If the emissions are due to the manufacture and use of products such as foams, it is possible that, so far, we have seen in the atmosphere only a fraction of the total amount of CFC-11 that was produced illegally. The remainder could be locked up in buildings and chillers, and will ultimately be released to the atmosphere over the coming decades.




Read more:
Explainer: what is the Antarctic ozone hole and how is it made?


While our new study cannot determine which industry or industries are responsible, it does provide strong evidence that substantial new emissions of CFC-11 have occurred from China. Chinese authorities have identified, and closed down, some illegal production facilities over the past several years.

This study highlights the importance of undertaking long-term measurements of trace gases like CFC-11 to verify that international treaties and protocols are working. It also identifies shortcomings in the global networks for detecting regional emissions of ozone depleting substances. This should encourage expansion of these vital measurement networks which would lead to a capability of more rapid identification of future emission transgressions.The Conversation

Paul Krummel, Research Group Leader, CSIRO; Bronwyn Dunse, Climate Science Centre, CSIRO Oceans and Atmosphere, CSIRO; Nada Derek, Centre for Australian Weather and Climate Research, CSIRO; Paul Fraser, Honorary Fellow, CSIRO, and Paul Steele, Centre for Australian Weather and Climate Research, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The role of climate change in eastern Australia’s wild storms


Acacia Pepler, UNSW Australia

Australia’s east coast is recovering from a weekend of wild winds, waves and flooding, caused by a weather pattern known as an East Coast Low. Tragically, several people have died in flooding.

Parts of New South Wales have received more than 400mm of rain since Friday morning. Some places such as Canberra and Forster recorded their wettest June day on record. Waves have also caused severe coastal erosion and damaged property.

East Coast Lows are a type of low-pressure system or cyclone that occur on the Australian east coast. They are not uncommon, with about seven to eight lows a year causing widespread rainfall along the east coast, particularly during late autumn and winter. An East Coast Low in April last year caused similar damage.

But whenever they happen they raise the question: did climate change play a role?

Good news?

Climate models suggest that the cyclones that move through the global mid-latitudes, around 30° to 50°S, are moving south. This is contributing to long-term declines in winter rainfall in southwestern Australia and parts of southeast Australia.

These models also suggest that the atmospheric conditions that help East Coast Lows form could decline by between 25% and 40% by the end of the century.

In recent work, my colleagues and I looked even more closely at how climate change will affect individual East Coast Lows.

Our results also found East Coast Lows are expected to become less frequent during the cool months May-October, which is when they currently happen most often.

But there is no clear picture of what will happen during the warm season. Some models even suggest East Coast Lows may become more frequent in the warmer months.

And increases are most likely for lows right next to the east coast – just the ones that have the biggest impacts where people live.

This chart shows how the frequency of East Coast Lows could change by 2080 across May-October (left) and November-April (right). Red indicates fewer storms, while blue indicates more. Crosses show high agreement between climate models.

What about the big ones?

The results in the studies I talked about above are for all low-pressure systems near the coast – about 22 per year, on average.

But it’s the really severe ones that people want to know about, like the current event, or the storm that grounded tanker Pasha Bulker in Newcastle in June 2007.

These storms are much rarer, which makes it harder to figure out what will happen in the future. Most of the models we looked at had no significant change projected in the intensity of the most severe East Coast Low each year.

Warming oceans provide more moisture, so intense rainfall is expected to increase by about 7% for each degree of global warming. East Coast Lows are no different – even during the winter, when East Coast Lows are expected to become less frequent, the frequency of East Coast Lows with heavy rain is likely to increase.

Finally, even though there may be fewer East Coast Lows, they are occurring in an environment with higher sea levels. This means that many more properties are vulnerable to storm surges and the impact of a given storm surge is that much worse.

Was it climate change?

While the frequency of cool-season East Coast Lows looks likely to decrease in the future, changes in the big ones are a lot less certain.

However, East Coast Lows are very variable in frequency and hard to predict. So far, there hasn’t been any clear trend in the last 50 years, although East Coast Lows may have been more frequent in the past.

As for extreme rainfall, studies have found little influence of climate change on Australian extreme rainfall so far. Climate variability, such as El Niño, currently plays a much larger role. This doesn’t mean climate change is having no effect; it just means it’s hard to tell what impact a warming world is having at this stage.

So did climate change cause this weekend’s storms? No: these events, including intense ones, often occur at this time of year.

But it is harder to rule out climate change having any influence at all. For instance, what is the impact of higher sea levels on storm surges? And how much have record-warm sea temperatures contributed to rainfall and storm intensity?

We know that these factors will become more important as the climate system warms further – so as the clean-up begins, we should keep an eye on the future.

The Conversation

Acacia Pepler, PhD student, UNSW Australia

This article was originally published on The Conversation. Read the original article.

Australia: Koalas Now Recognized as a Threatened Species


Koalas in eastern Australia have now been listed as a threatened species. However, the Koala population is growing rapidly in both Victoria and South Australia.

For more, visit:
http://www.bbc.co.uk/news/world-asia-17893014

Australia: Wagga Wagga – Spiders Trying to Escape Massive Flooding


The link below is to an article reporting on the massive flooding currently impacting eastern Australia. This report is all about the spiders (Wolf and Orb) trying to escape the flood waters.

For more, visit:
http://io9.com/5891091/massive-spiderwebs-engulf-australian-town-as-arachnids-escape-floods

Shark Numbers Growing off Eastern Australia


Shark numbers appear to be growing off the east coast of Australia. In recent days large numbers of sharks, including Tiger Sharks have been spotted of the southeastern coast of Queensland at Teewah, feasting on large schools of baitfish and tuna.

For more information on sharks visit:

http://www.removesharknets.com/

http://www.sharksinternational.org/