A study from the University of La Laguna predicts a widespread increase in aridity in the Canary Islands by the end of the century due to climate change. This development could significantly impact water resources and sectors like agriculture, with notable variations across the islands.
Aridity refers to the degree of water deficiency in an area, influenced by factors such as rainfall, temperature, evaporation, soil characteristics, and vegetation. Climate change is expected to raise temperatures and reduce rainfall, exacerbating aridity, decreasing water availability, and promoting desertification, particularly critical in island regions with limited water resources.
Research indicates that the Canary Islands have experienced declining rainfall and rising temperatures over the past few decades. The study, titled “Climate projections and the increasing aridity in the Canary Islands,” published in Theoretical and Applied Climatology, compares climate projections from 1985–2014 with three future periods in the 21st century: 2021-2050, 2041-2070, and 2071-2100. The authors, Noelia Cruz Pérez, Susana Clavijo Núñez, and Professor Juan Carlos Santamarta Cerezal from the university’s Department of Agricultural Engineering and Natural Environment, collaborated with Katjusa Potocnik from the University of Ljubljana and César Paradina from FICLIMA.
The study analyses ten global climate models and two scenarios from the Intergovernmental Panel on Climate Change (IPCC), one intermediate (SSP2-4.5) and one high-emission scenario (SSP5-8.5), which are adjusted to local scale using FICLIMA methodology to achieve a 100 x 100 metre resolution.
Aridity is measured using an index that compares precipitation to atmospheric water demand; lower values indicate greater aridity. From 1985 to 2014, average values ranged from 0.10 in Lanzarote and Fuerteventura, classified as arid, to 0.52 in La Gomera, the only island in the subhumid dry category. La Palma, Tenerife, and Gran Canaria are semi-arid, while El Hierro is also arid.
Projections suggest category shifts for several islands. La Gomera would change from subhumid dry to semi-arid under both scenarios, while Gran Canaria could shift from semi-arid to arid (0.17) only under high emissions by century’s end. Tenerife would remain on the borderline of the semi-arid category (0.21). Under high emissions, Lanzarote and Fuerteventura would stay arid but approach hyper-arid conditions (0.05 and 0.06). Although the absolute index change is slight, the study warns of significant implications for water management and irrigated agriculture due to a projected 40-50% reduction in already low values.
This work aligns with previous studies predicting increased aridity throughout the century, although it identifies new areas for the largest increases, focusing on La Gomera, the eastern coast of La Palma, and the wetter regions of northern Tenerife and Gran Canaria.
To address the anticipated rise in aridity, the authors review proposed adaptation measures for water management and agriculture. Suggestions include rainwater harvesting, efficient irrigation systems, sustainable farming practices, and drought-resistant crops. They caution that the success of these measures will depend on local conditions, available funding, and support for the agricultural sector.
The researchers stress the need for small-scale climate projections to formulate strategies tailored to each territory. “With a 100-metre resolution, we can see what happens in each slope and farming area, which is the detail needed by water planners in the islands,” Santamarta explains.
The study’s data and projections are accessible through SICMA Canarias, a platform created by the University of La Laguna in collaboration with FICLIMA and Meteogrid. The research received partial funding from the European project NATALIE (Horizon Europe) and is published as open access.
