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Certainly larger and more frequent storms are one of the consequences that the climate models and climate scientists predict from global warming. But you cannot attribute any particular storm to global warming, so let’s be quite clear about that. – Prime Minister Malcolm Turnbull, speaking to reporters in Tasmania on June 9, 2016.

In the aftermath of the deadly East Coast Low that swamped eastern Australia, dumping massive amounts of rain in early June, the prime minister toured flood-affected Launceston and announced emergency relief funding.

Turnbull told reporters that larger and more frequent storms were forecast by climate scientists but cautioned that no individual storm could be attributed to global warming.

Is he right?

Checking the source

The Conversation asked the prime minister’s office for sources to support his statement but did not hear back before publication deadline. Nevertheless, we can test his statement against recent published and peer-reviewed research on this question.

The science shows that, just like real estate, climate change is all about location. Different parts of Australia will be affected in different ways by climate change.

And global warming will have different effects on different types of weather systems.

Let’s break Turnbull’s statement into two parts: is it true that we can expect larger and more frequent storms as a consequence of global warming? And is it possible to attribute a specific storm to global warming?

Can we expect larger and more frequent storms as a result of global warming?

Yes – but not for all regions or types of storms.

There are many types of storms that affect different parts of Australia, among them East Coast Lows, mid-latitude cyclones (a category that includes cyclones that happen in the latitudes between Australia and Antarctica), tropical cyclones, and associated extreme rainfall events. Each will be affected in a different way by climate change, and the effect will vary by region and by season.

On East Coast Lows: Acacia Pepler, who is studying extreme rainfall and East Coast Lows in relation to climate change, recently wrote in The Conversation that her research showed that:

… 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.

For all low-pressure systems near the coast, “most of the models we looked at had no significant change projected in the intensity of the most severe East Coast Low each year,” Pepler wrote.

On mid-latitude cyclones: Another study predicted that the overall wind hazard from mid-latitude cyclones in Australia will decrease – except in winter over Tasmania.

On tropical cyclones: Northern Australia is expected to get fewer cyclones in future – but their maximum wind speeds are expected to become stronger.

On rainfall: Scientists tend to be quite confident that climate change will be accompanied by an increase in extreme rainfall for most storms in future. One of the main reasons for this is that increased temperatures will cause increased evaporation. While the total amount of water held in the atmosphere will also increase slightly in future, the total amount of rain has to go up too.

Is it true you can’t attribute any particular storm to global warming?

Turnbull is correct. We cannot say for sure that a particular flooding rainfall event was solely “caused” by climate change, any more than we can say for certain that a particular car accident was solely caused by speeding (even if excessive speed was a likely or even major contributing factor).

Evidence for the effects of global warming on extreme rainfall events that have already occurred is currently equivocal for most regions.

According to a collection of studies published in 2015:

A number of this year’s studies indicate that human-caused climate change greatly increased the likelihood and intensity for extreme heat waves in 2014 over various regions. For other types of extreme events, such as droughts, heavy rains, and winter storms, a climate change influence was found in some instances and not in others.

One recent study in that report found:

evidence for a human-induced increase in extreme winter rainfall in the United Kingdom.

Verdict

Malcolm Turnbull was essentially correct on both points.

It’s true that scientists predict more frequent and intense storms for some parts of Australia as the climate changes. The evidence appears to be strong that extreme rainfall will increase. Some increases in extreme wind speeds are possible – but not in all regions or all seasons.

Turnbull was right to say you cannot attribute any particular storm to global warming. –Kevin Walsh

Review

This is a good FactCheck that summarises the broad conclusions from a range of studies examining the nature of current and likely future storms across Australia.

As the author points out, Australian storms range from tropical cyclones in the northern tropical regions to temperate east coast lows and mid-latitude cyclones.

The consensus regarding tropical cyclones is that they will generally decrease in frequency in the Australian region. In northeast Australia, they are forecast to experience the most dramatic decrease in frequency of any ocean basin globally. Some northern hemisphere ocean basins will see an increase in their frequency.

The intensity of these types of storms is expected to increase. This will not only involve higher wind speeds but also higher storm surges and floods. That will mean greater coastal impacts and damage to coastal developments and infrastructure.

So the prime minister’s statement about more frequent storms resulting from climate change does not apply to tropical cyclones – however, he was right to say that larger and more frequent storms are one of the predicted consequences of climate change. This consequence is predicted to apply to other storm categories, but not tropical cyclones.

And yes, climate scientists are hesitant to attribute the occurrence of any single storm to global warming. – Jonathan Nott

Have you ever seen a “fact” worth checking? The Conversation’s FactCheck asks academic experts to test claims and see how true they are. We then ask a second academic to review an anonymous copy of the article. You can request a check at checkit@theconversation.edu.au. Please include the statement you would like us to check, the date it was made, and a link if possible.

Kevin Walsh receives funding from the ARC, Australian government grants and various overseas organisations.

Jonathan Nott receives funding from the ARC.

I, too, used to walk up Piggies Lonnen (Letters, 13 June) with my sisters on our way from Lemington to Walbottle, to see my Grandpa, Johnny McSwine. We were allowed to help feed his pigs and clean out their pigsties. Though the lonnen was near the “piggery”, it had nothing to do with Grandpa’s pigs, who never left their sties. On a memorable visit he took us to see the sow and her piglets cosseted under a heat lamp in the biggest of the three sties. The pigs were fed on scraps and meal which was weighed out in the “flower house”, – so called because that was where mounds of freshly cut blue scabious would be bunched and boxed ready for market. Around the tea table at his house, I would hear about the Bull family who lived in the village, but I don’t think had bulls. My grandfather died in 1963 but his name, or his father’s, lives on – “Johnny’s Bank” is the road that ran past the market garden up to Walbottle Stores. The market garden continued until my Uncle Fred retired.
Judith McSwaine
Newcastle upon Tyne

• The street names of south-west Scotland are evidence of a culture shared with north-east England, at least in their alleyways. For example, Jenny’s Loaning in Castle Douglas clearly matches the lonnens of Northumberland, while Friars Vennel in Dumfries would fit in well in Durham.
Steven Edgar
Bristol

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Scientists announce the detection at Earth of another burst of gravitational waves coming from a black hole merger.

Experts identify areas where coral reefs are flourishing against the odds despite overfishing and environmental pressure

Surprising “bright spots” where coral reefs are flourishing against the odds despite overfishing and environmental pressure have given new hope to conservationists.

Experts believe they could shine a light on better ways to protect embattled coral reefs affected by climate change, overfishing and pollution.

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Jack Conway was working in a bog cutting turf when he came across a massive chunk of butter.

Millions of diamondback moths have migrated from their eastern European breeding grounds to descend on English crops. But are they really a ‘biblical plague’?

As if Brexit and football violence weren’t enough to make us miserable about Europe, it seems that the UK is now experiencing an invasion of “Euro-moths”. Tens of millions of small but potentially lethal diamondback moths are crossing the North Sea, come to devastate our cabbages and cauliflowers.

The first signs of the invasion came last Saturday night, when observers reported a two-mile long cloud of moths near the Herefordshire market town of Leominster. As one witness reported: “It was like driving through rain.”

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Figures show the numbers of licenced diesels rose by 29% from 2012-15, despite warnings over their contribution to illegal levels of air pollution

Diesel vehicles have taken a record share of the market on London roads in recent years, despite warnings blaming them for contributing to the capital’s illegal levels of air pollution.

Sadiq Khan, the new mayor of London, has been lobbying for a diesel scrappage scheme, a policy that was backed by his predecessor, Boris Johnson, as a way of tackling the illegal high nitrogen dioxide (NO2) levels caused by diesels.

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President François Hollande calls on other European countries to follow France’s lead by the end of the year

President François Hollande on Wednesday finalised ratification of the Paris climate accord reached in December 2015, making France the first industrialised country to do so.

“Signing is good, ratifying is better,” Hollande quipped at the Élysée Palace ceremony, flanked by environment minister Ségolène Royal, foreign minister Jean-Marc Ayrault and other top officials.

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Ineos company emails reveal huge amounts of treated wastewater are likely to be disposed of in the sea

A UK shale gas company is considering dumping waste water from fracking in the sea, emails from the company show.

Ineos, which owns the Grangemouth refinery and holds 21 shale licences, many in the north-west, North Yorkshire and the east Midlands, has said it wants to become the biggest player in the UK’s nascent shale gas industry.

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New sediment data suggests the dinosaurs were rapidly done in, strengthening asteroid impact theory

Boring is beautiful when you’re studying a calamity, especially one as spectacular as the mass extinction that wiped out the dinosaurs. That’s because exciting sediments, full of variations and gaps, make it hard to disentangle the extinction signal from the noise of natural variability.

So you could say that James Witts, of the University of Leeds in the UK, lucked-out with an especially boring batch of sediments in Seymour Island on the Antarctic Peninsula (the part on the map that points up to South America). His study, recently published in the journal Nature Communications, catches the extinction of marine life in one of the most detailed records ever published for the end-Cretaceous. As Witts describes it:

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Green groups warn of UK’s opposition to EU bans on harmful pesticides and promises by the Leave campaign to cut nature protection laws

Brexit would be bad for Britain’s bees, according to campaigners, who point to the UK government’s opposition to EU bans on harmful pesticides and the desire of figures in the Leave camp to cut nature protections.

Bees and other pollinators are vital to producing food but have been harmed by loss of habitat, disease and pesticides. The EU banned three neonicotinoid pesticides in 2013 in the face of strong opposition from UK ministers.

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Parliament approves radical proposal of accelerated emissions cuts and carbon offsetting to achieve climate goal 20 years earlier than planned

Norway’s parliament has approved a radical goal of achieving climate neutrality by 2030, two decades earlier than planned.

On Tuesday night MPs voted for an accelerated programme of CO2 cuts and carbon trading to offset emissions from sectors such as Norway’s oil and gas industries, which are unlikely to be phased out in the near future.

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Deception is everywhere in nature, as plants and animals turn trickster in the hope of eating or avoiding being eaten. The evolutionary biologist Martin Stevens introduces some subtle strategies in the game of life

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Exceptionally high numbers of the diamondback moth, that attacks crops such as cabbages and cauliflowers, have been recorded arriving in the UK

Experts have warned of a potential explosion in numbers of an invasive “super-pest” moth that attacks crops such as cabbages and cauliflowers.

Rothamsted Research, in Hertfordshire, issued a warning that exceptionally high numbers of the diamondback moth are arriving in the UK, after reports from a network of moth traps around the country.

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Renowned biologist E.O. Wilson wants to set aside half of the planet as protected areas for nature. But is this possible? And, if so, how would it work?

As of today, the only place in the universe where we are certain life exists is on our little home, the third planet from the sun. But also as of today, species on Earth are winking out at rates likely not seen since the demise of the dinosaurs. If we don’t change our ways, we will witness a mass extinction event that will not only leave our world a far more boring and lonely place, but will undercut the very survival of our species .

So, what do we do?

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The 2016 Great British Bee Count has reached the halfway point with more than 189,000 bees recorded so far. The annual count, which runs until 30 June, aims to help people learn more about bees, a key pollinator species that faces multiple threats. Here are some of the species spotted so far

• Download the free app to help monitor the British bee population and get tips for bee-friendly planting.
  

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Redflow battery lab tour next Monday, Australian Technologies Competition open for entries

The Bombay night frog favours a mating position previously unseen in frogs, making a total of seven in the Kama Sutra for Frogs.

Research has identified what is believed to be the world's oldest live yeast from a beer bottle.

Modelling shows Australian RET of 50% by 2030, rather than current trajectory of 34%, would almost double number of jobs created

Boosting renewable energy in Australia from the current trajectory of 34% of total energy by 2030 to 50% would double the number of new jobs created, according to modelling by Ernst & Young and the Climate Council.

The results come following a similar report from The Australia Institute this week comparing the employment implications of renewable energy policies of the three main parties, showing Labor and Greens policies would cause job growth in the sector, while Coalition policies would see a decline.

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