February 20, 2020

Accept Climate Change, or fight it? By Dr. Richard Smart

Even in the first few months of 2019 the global news coverage of climate change seems to have dramatically increased. Perhaps this was an effect of the global school childrens’ strike, and/or the Extinction Rebellion protest in London. There has also been more climate change attention in this period for the international grape and wine community. Firstly there was the Porto Summit in March focused directly on “Climate Change Leadership” and its likely impact; however the majority of presentations were about “impact” and “adaptation”, only a few considered “mitigation”. This was followed in May by VinExpo Bordeaux with climate change a key subject at the Symposium.

At the end of the year, there was the Australian  “bushfires” causing loss of life and property, and dramatic images shown around the world. Climate change on this large, flat and arid island continent was blamed, the warnings were many years old.

These events gradually contributed to a change in public perception about climate change. Initially the attitude was one of “awareness”, wondering was the recent weather a warning about climate change? The second reaction has been one of “adaptation”, as record temperatures, droughts, floods and hurricanes were documented, how can we live with them? These are generally, apart from droughts, short term phenomena. But what will be the effects of the well documented general rise in global temperature?

We note usually that wine grapes from cooler regions have a higher value than those grown in hotter regions,  generally over the world. The map of where wine is grown in the world, and which varieties are grown where, might change in coming decades. I often say in my public addresses, that “ the grape and wine industry is the canary in the coal mine for agriculture”.  That is, even relatively small changes in temperature (much less than the 3⁰C  that the climate scientists warn us about) will effectively rewrite regional reputations and varietal preferences.

For society in general there has also been a change of attitude, in regards to responsibility for climate change mitigation. Once seen solely as the role of Governments, this has devolved more to the individual, increasingly involving families, communities and industry sectors. The wine industry, which for so long has campaigned that it is particularly affected by climate change, may now be seen to have its opportunity to mitigate. Yet there is very little evidence of this, on a global scale. Will the wine industry accept some responsibility here? It should.

This article is written as a contribution to how and what members of the global wine industry might contemplate as their contribution, both as wine companies and vineyards, as employers and as employees.

The Carbon Footprint of Grapes and Wine

There have been many studies of the carbon footprint of the grape and wine industry, from ‘cradle to grave’, in all of its complexity. Many studies come to similar conclusions.

Export of wine in glass bottles, and their transport and limited recycling had the largest carbon footprint in Australian studies (68%). Grape growing, contributing 15% and wine making contributing 17% were similar and both minor components to the overall average figure.

For vineyards, the major greenhouse gas emissions were associated with electricity used on site, and for pumping irrigation water, and for diesel. In general, fertiliser, transport and agrochemicals were minor contributors, as were nitrous oxide emissions.

For wineries the situation is similar. Electricity is a major contributor and refrigeration requirements constitute a major proportion. Minor contributions were for LPG, citric acid, caustic, refrigerants, waste water and diesel.

The (transparent) elephant in the room; 750ml glass bottles.

I believe now is the time to reconsider the continued use of 750 ml round and tapered glass bottles for wine, especially for cheaper, ready-to-drink wine. Glass bottles are expensive in terms of energy to manufacture and few are recycled; their shape and weight make them expensive in terms of carbon for transport. Consider the fact that most wine is bought for immediate consumption: it is picked off the supermarket/liquor store shelf one day, consumed often that evening, and put in recycling bins within a week. So why do we use glass bottles, well designed for longer period storage? Design of this packaging format comes to us from the seventeent century!!!, and it is still being used!

It is interesting to contemplate how a change to universal use of round, tapered glass bottles may occur, what may be the drivers?  Might climate change mitigation be a driver? It should be! Certainly we now see the emergence of a new class of environmentally-driven consumers, who might choose wine based on its packaging? But how much choice, and information about carbon footprint are they given by wine producers who presently show little initiative. The same might be said of wine journalists. Figure 1 shows a 1L carton alternative, but there are many other alternative forms, including bag in box, pouches etc.

Such a dramatic change as to continued use of round and tapered glass bottles might also be initiated by a national wine industry, might it be from Australia, as for screw caps? It should certainly involve substantial research effort into different packaging and carbon footprints, and also their impacts on product quality and consumer acceptance.  This is what happened for screw caps replacing cork; studies at the Australian Wine Research Institute were pivotal in fostering this global trend. Might it happen for alternate packaging of commodity wines?

Garçon Wines award-winning bottle, made of 100% recycled plastic and 87% lighter

Other Carbon Footprint Reductions which can be made

  1. Use of solar panels, for large and small wineries, and vineyards

Many global viticultural regions are sunny, and the use of roof- or land-mounted solar panels are increasingly common. Solar electricity production is of course periodic, as for wind energy, but technology advances are overcoming this issue.

  1. Biomass supplies, prunings, pomace, stalks

Many of the worlds’ vineyards are in discrete regions. This regionality facilitates the collection of vineyard and winery waste for processing over shorter distances. A common situation is a winery surrounded by its own vineyards. Vineyards and wineries produce waste biomass which can be a valuable renewable resource to reduce the carbon footprint of purchased energy from the grid; foremost among these are pomace (or grape marc), collected after pressing for both red and white wine, and also vine prunings and grape stalks. Pomace and stalks are already aggregated at the winery; recent machinery developments in Europe allow vineyard prunings to be readily and economically collected from the field as smaller or larger bales, to be stored under cover for air drying and subsequently chipped before ensilage and combustion, see Figure 2.

A CAEB baler at work in a vineyard. The pruings need to be stacked in a rain proof shelter for drying before shredding. See http://www.caebinternational.it/

Combustion using fitted ovens at the winery can involve thermal only, thermal plus electricity generation and or thermal plus diathermic oil and absorption chiller to also produce chilled water to -10⁰C.

Vineyard and winey biomass can also be used in pyrolysis, the thermal decomposition of materials at elevated temperatures in an inert atmosphere. It involves a change of chemical composition and is irreversible. Products can include bio-oil, syn-gas, wood alcohol and and bio-char. These products can be used to produce electricity and heat, and even hydrogen with attachments. A significant recent advance has been to  develop smaller portable units (pictured in Figure 3) suitable for location at wineries, thus bringing pyrolysis to the biomass, not bringing biomass to pyrolysis units, which is more expensive.

3.  Avoidance of fermentation emissions.

Wineries should capture fermentation emissions, one of the most concentrated sources of CO2 produced by man’s activity, according to Prof. Roger Boulton of UCD. The technology exists to capture, clean and compress CO2 arising from alcoholic fermentation, and this can make a sizeable contribution to reducing CO2 emissions to the atmosphere, and is a direct contribution which winemakers can make to lowering atmospheric CO2.


A portable pyrolysis unit which can be used to produce ectrtricity from vineyard biomass. See https://pyrotechenergy.com/

Such emissions have until now escaped public attention; however, as concerns over atmospheric CO2 levels and climate change escalate in the future, public reactions are likely to become more strident. Why should wineries continue to use the earths atmosphere as a sewer?


While the author recognises that climate change is a political issue, and may not have (presently) a universal following, his hope is that this article may be seen as a “call to action” for those who are concerned about the issue. This will require some major changes in attitude, especially in regard to continuing use of glass bottles, to

solar energy deployment, to greater utilisation of “waste” biomass, and to capture of fermentation CO2 among other solutions.

The challenge exists to be taken up by researchers, funding bodies and especially by producers, and might well dominate research for the next few decades.

Figure 4. Let us hope that we may see a logo like this one day, on some sort of wine package, indicating that no CO2 was lost to the atmosphere during fermentation. (Design by Richard Smart and Rachel Cooper)

Dr Richard Smart is an experienced and well qualified viticultural scientist, and consultant. He lives in Melbourne, Australia. Once known as “the flying vine doctor”, he now prefers the label “the carbon conscious vine doctor”, by offering consultation in the office or the vineyard via the internet, to avoid air travel and expense to the clients. His specialities are canopy management, improving wine q

uality by vineyard management, managing trunk diseases and climate change mitigation. Contact Dr Smart by email vinedoctor@smartvit.com.au, or telephone +61 4 80188269.

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