Storm warning: a new long-range tropical cyclone outlook is set to reduce disaster risk for Pacific Island communities

Andrew Magee, University of Newcastle; Andrew Lorrey, National Institute of Water and Atmospheric Research, and Anthony Kiem, University of Newcastle

Tropical cyclones are among the most destructive weather systems on Earth, and the Southwest Pacific region is very exposed and vulnerable to these extreme events.

Our latest research, published today in Scientific Reports, presents a new way of predicting the number of tropical cyclones up to four months ahead of the cyclone season, with outlooks tailored for individual island nations and territories.

A new model predicts tropical cyclone counts up to four months in advance.

Tropical cyclones produce extreme winds, large waves and storm surges, intense rainfall and flooding — and account for almost three in four natural disasters across the Southwest Pacific region.

Currently, Southwest Pacific forecasting agencies release a regional tropical cyclone outlook in October, one month ahead of the official start of the cyclone season in November. Our new model offers a long-range warning, issued monthly from July, to give local authorities more time to prepare.

Most importantly, this improvement on existing extreme weather warning systems may save more lives and mitigate damage by providing information up to four months ahead of the cyclone season.

This map shows the expected number of tropical cyclones for the 2020/21 Southwest Pacific cyclone season (November to April)., Author provided

Tropical cyclones and climate variability

An average of 11 tropical cyclones form in the Southwest Pacific region each season. Since 1950, tropical cyclones have claimed the lives of nearly 1500 and have affected more than 3 million people.

In 2016, Cyclone Winston, a record-breaking severe category 5 event, was the strongest cyclone to make landfall across Fiji. It killed 44 people, injured 130 and seriously damaged around 40,000 homes. Damages totalled US$1.4 billion — making it the costliest cyclone in Southwest Pacific history.

Read more:
Winston strikes Fiji: your guide to cyclone science

Tropical cyclones are erratic in their severity and the path they travel. Every cyclone season is different. Exactly where and when a tropical cyclone forms is driven by complex interactions between the ocean and the atmosphere, including the El Niño-Southern Oscillation, sea surface temperatures in the Indian Ocean, and many other climate influences.

Capturing changes in all of these climate influences simultaneously is key to producing more accurate tropical cyclone outlooks. Our new tool, the Long-Range Tropical Cyclone Outlook for the Southwest Pacific (TCO-SP), will assist forecasters and help local authorities to prepare for the coming season’s cyclone activity.

This map shows the probability of below or above-average tropical cyclones for the 2020/21 Southwest Pacific cyclone season., Author provided

According to the latest long-range sea surface temperature outlook, there is a 79% chance that La Niña conditions could develop before the start of the 2020-21 Southwest Pacific cyclone season. La Niña conditions typically mean the risk of tropical cyclone activity is elevated for island nations in the western part of the region (New Caledonia, Solomon Islands and Vanuatu) and reduced for nations in the east (French Polynesia and the Cook Islands). But there are exceptions, particularly when certain climate influences like the Indian Ocean Dipole occur with La Niña events.

Read more:
India’s cyclone Fani recovery offers the world lessons in disaster preparedness

Improving existing tropical cyclone guidance

Current guidance on tropical cyclones in the Southwest Pacific region is produced by the National Institute of Water and Atmospheric Research, the Australian Bureau of Meteorology and the Fiji Meteorological Service. Each of these organisations uses a different method and considers different indices to capture ocean-atmosphere variability associated with the El Niño-Southern Oscillation.

Our research adds to the existing methods used by those agencies, but also considers other climate drivers known to influence tropical cyclone activity. In total, 12 separate outlooks are produced for individual nations and territories including Fiji, Solomon Islands, New Caledonia, Vanuatu, Papua New Guinea and Tonga.

Other locations are grouped into sub-regional models, and we also provide outlooks for New Zealand because of the important impacts there from ex-tropical cyclones.

Our long-range outlook is a statistical model, trained on historical relationships between ocean-atmosphere processes and the number of tropical cyclones per season. For each target location, hundreds of unique model combinations are tested. The one that performs best in capturing historical tropical cyclone counts is selected to make the prediction for the coming season.

At the start of each monthly outlook, the model retrains itself, taking the most recent changes in ocean temperature and atmospheric variability and attributes of tropical cyclones from the previous season into account.

Both deterministic (tropical cyclone numbers) and probabilistic (the chance of below, normal or above average tropical cyclone activity) outlooks are updated every month between July and January and are freely available.The Conversation

Andrew Magee, Postdoctoral Researcher, University of Newcastle; Andrew Lorrey, Principal Scientist & Programme Leader of Climate Observations and Processes, National Institute of Water and Atmospheric Research, and Anthony Kiem, Associate Professor – Hydroclimatology, University of Newcastle

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


What makes people switch to reusable cups? It’s not discounts, it’s what others do


Sukhbir Sandhu, University of South Australia; Robert Crocker, University of South Australia, and Sumit Lodhia, University of South Australia

People are more likely to use re-usable coffee cups if they see others doing it, or if cafe owners charge extra for throwaway coffee cups, our research has found.

Our study also found people would be more likely to properly dispose of compostable cups if councils provided dedicated organic waste bins. Alternatively, councils could provide facilities allowing people to rinse compostable cups before putting them in a recycling bin.

The need to find ways to encourage Australians to quit throwaway coffee cups has never been more urgent. About 1 billion disposable coffee cups are thrown into landfill sites across Australia annually, because the polyethylene lining that makes them leak-proof also makes them unrecyclable.

The COVID-19 pandemic has reportedly driven a surge in throwaway cup use as many cafes refused reusable cups at the height of the pandemic.

In places where reusable cups are allowed, however, coffee drinkers, cafe owners and local governments can use insights from behavioural science to discourage use of throwaway cups.

Read more:
The ‘recycling crisis’ may be here to stay

Coffee drinkers: show off your reusable cup

We interviewed consumers, café owners and policy makers in South Australia, and unobtrusively observed customer behaviour in cafes for around 50 hours.

One finding became very clear: people mimic each other. Customers we interviewed told us over and over that watching their colleagues bring in their reusable coffee cups (such as a KeepCup) made them change their habits. As one coffee drinker told us:

I started using a KeepCup because one of my other staff members was using a KeepCup and I was like, hmm, that’s very environmentally conscious of her.

As more consumers start using reusable coffee cups, the practice becomes ever more socially acceptable.

If others start seeing you use your reusable cup, they’re more likely to follow suit.

One of our interviewees told us she initially felt “scabby” bringing her reusable cup but as more consumers did so, she felt more confident:

At first, I would not walk across the road from work holding a cup coming here [to the cafe]. I’d just feel scabby. Because I would have been the minority. It probably was a bit less socially acceptable, but it’s probably more socially acceptable now because when I’m there I do see people walk in with their cups.

The best part is that you do not even have to nudge and preach to others (although you can if you like!).

So, coffee drinkers: if you want to make a difference, one of the easiest and best things you can do is to take your reusable coffee cup to the cafe.

You may not be aware of it, but the signalling effects are strong. Your colleagues will gradually notice and start bringing in their own reusable cups.

Cafe owners: discounts for reusable cup use don’t work

Many cafe owners offer discounts ranging from 10c – A$1 to customers who bring in their own reusable cups.

But our findings reveal these discounts are ineffective in changing consumer behaviour.

Billions of single use coffee cups end up in landfill every year.

A cafe owner we interviewed described how, despite providing a 20c discount for reusable cups, she didn’t think saving money motivated her customers:

The regulars were people who’d happily drop in a dollar tip into the jar kept on the counter. They were therefore not that concerned about 20c discount.

We know from previous behavioural psychology literature consumers are more likely to be what’s called “loss averse” as opposed to “gain seekers”. In other words, people hate paying extra for takeaway coffee cups more than they like getting a discount for bringing their reusable cups.

So, if you own a cafe, focus on making consumers pay extra for choosing takeaway coffee cups rather than offering discounts for reusable cup use. It’s more likely to motivate customers.

Policy makers: make proper disposal of compostable cups easy

Compostable cups can, in theory, be recycled. But they also end up in landfill because of a lack of appropriate bins and public waste infrastructure.

Customers often feel uncertain about how and where to dispose them. A council officer we interviewed stressed:

In the case of compostable cups, it is not solely a matter of ensuring that the cups end up in any bin, they must end up in the correct bin […] in order for compostable cups to be recycled, they must be placed in a bin dedicated to organic waste or, alternatively, rinsed and placed in a recycling bin.

Currently, however, most cities don’t have enough organic bins or facilities to allow people to rinse compostable cups before putting them in recycling bins.

Councils and city governments can address this by introducing organic waste bins as a part of the street waste infrastructure to reduce the number of compostable cups ending up in landfill.

Customers often feel uncertain about how and where to dispose of compostable cups.

Changing habits is hard but collectively, we can rewrite the waste story.

Three easy ways to do that are to bring your own reusable cup, charge extra for throwaway coffee cups and make it easy for people to recycle compostable cups.

Read more:
Avoiding single-use plastic was becoming normal, until coronavirus. Here’s how we can return to good habits

The Conversation

Sukhbir Sandhu, Senior Lecturer in Sustainability and Ethics, University of South Australia; Robert Crocker, Senior Lecturer, Sustainable Design Theory, University of South Australia, and Sumit Lodhia, Professor of Accounting, University of South Australia

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