Pass the shiraz, please: how Australia’s wine industry can adapt to climate change



Victor Fraile/Reuters

Gabi Mocatta, University of Tasmania; Rebecca Harris, University of Tasmania, and Tomas Remenyi, University of Tasmania

Many Australians enjoy a glass of homegrown wine, and A$2.78 billion worth is exported each year. But hotter, drier conditions under climate change means there are big changes ahead for our wine producers.

As climate scientists and science communicators, we’ve been working closely with the wine industry to understand the changing conditions for producing quality wine in Australia.




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We created a world-first atlas to help secure Australia’s wine future. Released today, Australia’s Wine Future: A Climate Atlas shows that all 71 wine regions in Australia must adapt to hotter conditions.

Cool wine regions such as Tasmania, for example, will become warmer. This means growers in that state now producing pinot noir and chardonnay may have to transition to varieties suited to warmer conditions, such as shiraz.

Australian wine regions will become hotter under climate change.
AAP

Hotter, drier conditions

Our research, commissioned by Wine Australia, is the culmination of four years of work. We used CSIRO’s regional climate model to give very localised information on heat and cold extremes, temperature, rainfall and evaporation over the next 80 years.

The research assumed a high carbon emissions scenario to 2100, in line with Earth’s current trajectory.

From 2020, the changes projected by the climate models are more influenced by climate change than natural variability.

Temperatures across all wine regions of Australia will increase by about 3℃ by 2100. Aridity, which takes into account rainfall and evaporation, is also projected to increase in most Australian wine regions. Less frost and more intense heatwaves are expected in many areas.




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By 2100, growing conditions on Tasmania’s east coast, for example, will look like those currently found in the Coonawarra region of South Australia – a hotter and drier region where very different wines are produced.

That means it may get harder to grow cool-climate styles of varieties such as chardonnay and pinot noir.

Some regions will experience more change than others. For example, the Alpine Valleys region on the western slopes of the Victorian Alps, and Pemberton in southwest Western Australia, will both become much drier and hotter, influencing the varietals that are most successfully grown.

A map showing current average growing season temperature across Australia’s 71 wine regions.
Authors provided

Other regions, such as the Hunter Valley in New South Wales, will not dry out as much. But a combination of humidity and higher temperatures will expose vineyard workers in those regions to heat risk on 40-60 days a year – most of summer – by 2100. That figure is currently about 10 days a year, up from 5 days historically.

Grape vines are very adaptable and can be grown in a variety of conditions, such as arid parts of southern Europe. So while adaptations will be needed, our projections indicate all of Australia’s current wine regions will be suitable for producing wine out to 2100.

Lessons for change

Australia’s natural climate variability means wine growers are already adept at responding to change. And there is much scope to adapt to future climate change.

In some areas, this will mean planting vines at higher altitudes, or on south facing slopes, to avoid excessive heat. In future, many wine regions will also shift to growing different grape varieties. Viticultural practices may change, such as training vines so leaves shade grapes from heat. Growers may increase mulching to retain soil moisture, and areas that currently practice dryland farming may need to start irrigating.

The atlas enables climate information and adaptation decisions to be shared across regions. Growers can look to their peers in regions currently experiencing the conditions they will see in future, both in Australia and overseas, to learn how wines are produced there.

If our wine industry adapts to climate change, Australians can continue to enjoy homegrown wine.
James Gourley/AAP

Industries need not die on the vine

Agriculture industries such as wine growing are not the only ones that need fine-scale climate information to manage their climate risk. Forestry, water management, electricity generation, insurance, tourism, emergency management authorities and Defence also need such climate modelling, specific to their operations, to better prepare for the future.

The world has already heated 1℃ above the pre-industrial average. Global temperatures will continue to rise for decades, even if goals under the Paris climate agreement are met.

If Earth’s temperature rise is kept below 1.5℃ or even 2℃ this century, many of the changes projected in the atlas could be minimised, or avoided altogether.

Australia’s wine industry contributes A$45 billion to our economy and supports about 163,000 jobs. Decisions taken now on climate resilience will dictate the future of this critical sector.




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The Conversation


Gabi Mocatta, Research Fellow in Climate Change Communication, Climate Futures Programme, University of Tasmania; Rebecca Harris, Senior lecturer, Manager, Climate Futures Program, University of Tasmania, and Tomas Remenyi, Climate Research Fellow, Climate Futures Programme, University of Tasmania

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

Research Check: do we need to worry about glyphosate in our beer and wine?



File 20190307 100787 1qzaux0.jpg?ixlib=rb 1.1
Research out of the US tested different varieties of beer and wine for the presence of glyphosate – but there’s lots to consider when interpreting the findings.
From shutterstock.com

Ian Musgrave, University of Adelaide

Glyphosate is back in the news again. The common weed killer, which has previously attracted controversy for its possible link to cancer, has been found in beer and wine.

Researchers in the US tested 15 different types of beer and five different types of wine, finding traces of the pesticide in 19 out of the 20 beverages.

So how much should we be worried? Hint: not at all. The amount detected was well below a level which could cause harm. And there are insufficient details in the methods section to feel confident about the results.




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How was this study conducted?

One of the first things I do when evaluating a piece of research is to check the methods – so how the researchers went about collecting the data. What I found didn’t fill me with confidence.

The authors say they set up their experiment based on a technique called a mass spectroscopy method. This methodology has been used to measure the quantities of glyphosate in milk (but not alcoholic drinks). Mass spectroscopy is a very sensitive and specific method, and the authors quote the concentrations that can be reliably detected in milk with this approach.

But the method they actually used is called enzyme linked immunosorbent assay (ELISA). Importantly, you can’t use the concentrations that can be reliably detected with the mass spectroscopy to describe ELISA sensitivity. They’re not compatible.

Glyphosate is the pesticide which makes up many weed killers.
From shutterstock.com

ELISA is sensitive, but typically not as sensitive as mass spectroscopy, which uses an entirely different physical method to measure glyphosate.

ELISA also has issues of cross contamination. Biological samples for glyphosate measurement, whether ELISA or mass spectroscopy, need careful sample preparation to avoid cross-reaction with any other materials in the sample such as the common amino acid glycine, which looks quite similar to glyphosate and is present in much higher quantities. But the authors didn’t give any detail about the sample preparation used.

These issues make it difficult to be confident in the results.

We’ve seen this before with claims of detection of glyphosate in breast milk, which could not be duplicated. So given the lack of detail around the methodologies used, we should be cautious about taking these figures at face value.

What did they find?

For the sake of argument, let’s accept the researchers’ values and take a look at what they mean.

The highest level of glyphosate they measured was 51.4 parts per billion in one wine (in most of the beverages they found much less). That’s equivalent to 0.0514 miligrams per litre (mg/L).

The authors cite California’s Office of Environmental Health Hazard’s proposed “No Significant Risk Level” for glyphosate consumption of 0.02 mg/kg body weight/day. The limits are based on body weight, so a heavier person can be exposed to more than a person who weighs less, taking into account body volume and metabolism.

This is much lower than the EU Food Safety Authorities’ and Australia’s regulatory allowable daily intake of 0.3 mg/kg body weight/day.

But again, for argument’s sake, let’s use the Californian proposed limits and look at the wine in which the researchers measured the highest amount of glyphosate. With those limits, an average Australian male weighing 86kg would need to drink 33 litres of this wine every day to reach the risk threshold. A 60kg person would need to drink 23 litres of this wine each day.




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If you’re drinking 33 litres of wine a day you have much, much bigger problems than glyphosate.

Alcohol is a class 1 carcinogen. Those levels of alcohol consumption would give you a five times greater risk of head, neck and oesophageal cancer (and an increased risk of other cancers). The risk of glyphosate causing cancer is nowhere near these levels. The irony is palpable.

This isn’t even taking into account the likelihood of dying of alcohol poisoning by drinking at this level – which will get you well before any cancer.

And that’s using the highly conservative Californian limits. Using the internationally accepted limits, an average adult male would have to drink over 1,000 litres of wine a day to reach any level of risk.

So how should we interpret the results?

The report does not contain a balanced representation of the risks of glyphosate.

They cite the International Agency for Research on Cancer’s finding of glyphosate as class 2 (probably) carcinogenic (alcohol is class 1, a known carcinogen).

But they don’t mention the European Food Safety authority finding that glyphosate posed no risk of cancer, or the WHO Joint Meeting on Pesticide Residues report showing no significant cancer risk to consumers under normal exposure.

They cite a paper on glyphosate supposedly increasing the rate of breast cancer cell growth, but not the papers that find no such thing.

They don’t cite the most important study of human exposure, the Agricultural Health Study which is the largest and longest study of the effect of glyphosate use. This study found no significant increase in cancer in highly exposed users.




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The “report” claiming that there is glyphosate in wine and beer provides inadequate information to judge the accuracy of the claimed detection, and does not put the findings in context of exposure and risk.

Even taking their reported levels at face value, the risk from alcohol consumption vastly outweighs any theoretical risk from glyphosate. Their discussion does not fairly consider the evidence and is weighted towards casting doubt over the safety of glyphosate.

So you may enjoy your beer and wine (in moderation), without fear of glyphosate.

Blind peer review

This is a fair and accurate assessment of the study and its findings. That said, it is prudent for the scientific community to remain attentive to changes within the food supply and issues of potential risk to public health. Considering the increasing use of glyphosate by the food industry, we need continued diligence in this area. – Ben Desbrow


Research Checks interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.The Conversation

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

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

A warning for wine-lovers: climate change is messing with your favourite tipple’s timing



File 20190313 86707 1fmr5a6.jpg?ixlib=rb 1.1
Record-breaking maximum temperatures are changing ripening times in Australia’s wine regions.
Shutterstock

Christopher Davies, CSIRO and Christine Bottcher, CSIRO

While the much-derided “latte set” are stereotyped as the biggest worriers about climate change, it’s the chardonnay crowd who are acutely feeling its effects.

Australia’s wine industry is both world-renowned and economically significant, with around A$5.6 billion in sales in 2016–17, and winemaking and associated tourism responsible for more than 170,000 full and part-time jobs. Statistics also show that wine consumption is now accepted as being just as dinky-di as beer drinking for the average Australian.




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However, record-breaking daily maximum temperatures, warmer than average overnight temperatures, and increasingly erratic weather patterns are playing havoc with the way wine grapes grow and ripen. This has knock-on effects for Australian grape growers, wine producers and consumers.

Climate in the vineyard hits the cellar and the store shelf

Most of Australia’s wine regions have experienced rising average daily temperatures. One effect is changes to ripening times, which has compressed the harvesting season and given wine-makers a crucial logistical headache.

Traditionally, white grape varieties would generally reach optimum ripeness before red ones. While all grapes tend to ripen faster as temperatures rise, this effect is more pronounced for later-ripening varieties (for example Shiraz and Cabernet Sauvignon) than earlier ripening varieties (for example Chardonnay and Riesling).

Australian winegrape varieties are becoming ready for harvest simultaneously.
Shutterstock

The old process of staggered harvesting times for red and white grape varieties was efficient, allowing the winery’s capacity to be used in sequence for different varieties. Now that different varieties are ripening at the same time, vineyards and wineries will have to make tough choices about which grapes to prioritise, and which ones to leave until later, resulting in inferior wine. Alternatively, they could take the expensive decision to increase production capacity by investing in more infrastructure such as fermenters and stainless steel tanks.




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Perhaps you’re thinking that you, the savvy wine drinker, are unaffected by the difficulties faced by winemakers in the vineyards and wineries far away. Unfortunately this isn’t so. Harvesting grapes when they are not at optimal ripeness to solve the logistical problems of processing can lead to lower-value wine.

The fact is that this new reality is costing everyone – grape-growers, winemakers and consumers alike.

And just in case you think that the simple answer is changing Australia’s cultured palates back to beer, think again. Hop production is being hit just as hard by climate change.

Help is at hand

Fortunately, these are problems we hope to tackle. CSIRO recently announced a five-year research partnership with Wine Australia, and one of the projects aims to adjust wine grape ripening to suit a changing climate.

We hope to do it by studying plant growth regulators (PGRs) – molecules that are used by the plant to control and coordinate development. We are using a class of PGRs called auxins, first studied in grass seedlings by Charles Darwin in the 1880s, that have important roles in vine growth, and the timing of grape growth and ripening.

Plant growth regulators can help control ripening times.
Shutterstock

By spraying these compounds onto vines and grapes shortly before ripening, auxins can potentially be used to influence the timing of this process and therefore harvest date. They are already used in other horticultural crops, such as to control fruit drop in apples and pears.

Applying very small amounts of auxin can delay grape ripening, and therefore harvest timing, by up to four weeks (Davies et al., 2015, J Ag Food Chem 63: 2137-2144). This treatment works for red and white varieties in hot or cool climates, and is safe, cheap and easy to apply.

The flavour and aroma of wines made from ripening-delayed grapes is largely indistinguishable from wines made from untreated fruit harvested at the same sugar level, up to a month earlier. An exciting exception is that, in Shiraz, auxin-induced ripening delay can be used to increase the concentration of rotundone, the compound responsible for this variety’s popular peppery notes.




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Work is currently under way to fine-tune spray formulations and application times. The aim is to release a commercially available product within the next five years.

This kind of solution will be vital for the sustainable, economical production of high-quality wines from existing grape varieties in established wine growing regions. We hope it will ensure you can enjoy your favourite drop for many years to come.The Conversation

Christopher Davies, Team Leader, CSIRO and Christine Bottcher, Research scientist, CSIRO

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