Study investigates effect of global warming on grape harvesting

Unlike other industries, wine production is still dominated by manual work, in particular picking grapes during summer or autumn months. In Cyprus the mean maximum temperature in August – the main part of the harvest season – is around 36°c.

In an article in the journal Temperature​, researchers studied the effect of high temperatures on the labor output and productivity of grape pickers in Cyprus.

Researchers found that higher temperatures in working conditions during the summer correlated with “a significant labor loss of up to 27%, ​due to the environmental heat causing increased perceived exertion on worker's metabolic and cardiovascular systems and resulting in reduced output.”​

Tasks rely on manual work​

While climate change has opened up new areas suitable for growing vines, it may also affect the subtropical areas where the majority of wine is currently produced.

The wine industry makes up 0.2% of world GDP, and researchers warn that the increased temperatures from global warning may negatively impact the industry and potentially result in large losses worldwide.

“In the agriculture sector, occupational heat stress is very relevant because many tasks rely on manual work as the prevailing and, sometimes, only feasible method for gentle handling of vulnerable plants,”​ write the authors in the study.

“Workplace heat is difficult to mitigate in agriculture, as artificial cooling or shadowing toward the sun would be detrimental to growth or directly harmful for the plants.” ​

Researchers note that, to date, there is very limited detailed and evidence based knowledge on the effects of workplace heat on agriculture workers, with no relevant studies in Europe.

Researchers used a time-motion analysis which includes analysing movement and time spent on each movement through video analysis; alongside physiological measurements and environmental data (including air temperature, relative humidity, wine speed and solar radiation).  

Higher temperatures in working conditions during the summer correlated with a labor loss of up to 27%, while there was also a 15% decrease in the amount of time workers were able to carry out duties (due to the increased need for breaks).

“These research findings demonstrate that workplace heat, specifically in European agricultural workers, is accompanied by significant labor and productivity losses,” ​says researchers.

Wider impacts of climate change on the wine industry​

A wine index study led by the Karlsruhe Institute of Technology (KIT) earlier this year noted that many northern and southern hemisphere wine regions may benefit from climate change, while regions closer to the equator may be lost over time.​​

Wine regions can learn to manage climate changes by changing grape varieties or harvest times, and researchers suggest using new grape strains and innovative technologies to optimize wine production.

Countries such as the UK are in the spotlight as future wine growing areas. The growing season temperature in south east and south central UK is increasingly similar to that of the Champagne region in 1961-1990; and the UK has set targets to increase the area of planted vineyards from 2,000 hectares to 3,000 hectares by 2020, doubling wine production to 10m bottles a year.

However, a 2016 study from the University of East Anglia warned that climate variability – such as cold snaps and sharp frosts – could threaten productivity.​​ Researchers said that wine makers in the UK will need the right management strategies and ability to cope with lower yielding years, while further investigation into future climate conditions will help assess risk.

Source:

Temperature; ​published online July 12, 2017.

Leonidas G. Ioannou, Lydia Tsoutsoubi, George Samoutis, Lucka Kajfez Bogataj, Glen P. Kenny, Lars Nybo, Tord Kjellstrom & Andreas D. Flouris.

Published by Taylor & Francis; full article online: http://www.tandfonline.com/doi/full/10.1080/23328940.2017.1338210​