The climate assessment of fruits and vegetables transported by air or from heated greenhouses is highly negative, WWF estimates.
Twenty-five varieties of fruits and vegetables were evaluated to assess their climatic impact. WWF wanted to know if regional and seasonal foods had the best environmental record. The study in Switzerland shows that it is not so much the season or the regional provenance of the products that is decisive, but the mode of production and means of transport. The balance of greenhouses heated by gas or oil and by air transport is consistently poor.
Vegetables and fruits from highly efficient renewable energy plants, which require minimal use of water, fertilizers and pesticides, are much more climate-friendly. Often these products are not indigenous but imported from different countries. The environmental organization thus nuances the balance sheet. WWF points to retailers, as they only state with rare exceptions that vegetables and fruits have been transported by air or grown in greenhouses heated by fossil fuels. WWF therefore calls for clear labeling of the products concerned.
The WWF provides some comparisons. For example, one kilo of German or Swiss green asparagus (the country where the study was carried out) weighs just 1 kilo of CO2 on the climate. The same quantity of Spanish green asparagus, transported by truck, has a balance of 1.5 kilograms of CO2. And those imported by air from Peru weigh the climate balance of 15 kilograms of CO2. Greenhouses are also harmful to the climate: in winter, one kilo of tomatoes matured under the Spanish sun causes about 0.5 kilograms of CO2, ten times less than tomatoes grown in Europe under greenhouses heated by fossil fuels .