Carbon footprint as a function of inter-annual climate variability in Uruguayan viticulture production systems

Abstract

Climate change, driven by greenhouse gas (GHG) emissions, is one of humanity’s most significant environmental challenges. To mitigate this, all GHG-contributing human activities including viticulture, require careful assessment to understand and reduce their environmental impact. The objective of this work was to evaluate, for the first time in Uruguay, the carbon footprint (CF) of one hectare of Tannat and Albariño vineyards over four growing seasons (GS) and to analyze its interannual variation. The analysis followed guidelines from the Life project Adviclim (Adoir, 2020), and was conducted using OpenLCA® software and the Agribalyse® database, incorporating direct GHG emissions from nitrogen fertilization. We analyzed both direct (DE) and indirect emissions (IE) associated with 10 production activities, including fertilizer application, canopy management, harvesting, pest and disease management, plot maintenance, soil management, trellis maintenance, plant maintenance, winter pruning, and transport in an evaluation plot from a commercial vineyard under Uruguay’s Sustainable Viticulture Program.  Across the 2020-21 to 2023-24 GS, the average CF in Tannat was 1705 kg CO₂ eq. ha⁻¹ yr⁻¹, with DE and IE accounting for 70% and 30% of emissions, respectively. Albariño had a CF 14 % lower than Tannat, with the same distribution between DE and IE.  The total coefficient of variation across the GS was 18% and 25%, with DE fluctuating by 22% and 15% and IE by 23% and 50 % in Tannat and Albariño, respectively. Among production activities, pest and disease management emerged as the main CF contributor (39% in Tannat and 41% in Albariño), followed by fertilizer application (30%) in Tannat and Soil management in Albariño (24%). Notably, CF from disease management decreased by up to 39% under drier conditions (e. g., 2023 GS) in Tannat, whereas CF from fertilizer application was unaffected by climate variability. Identifying and quantifying GHG emissions is the first step in climate change mitigation, providing a foundation for adjusting production systems toward environmental sustainability. Uruguay is advancing environmental and social awareness of viticulture through its sustainable viticulture program and certification. This study’s findings establish a baseline for future climate change mitigation efforts in viticulture.