Fuerteventura could approach hyperarid conditions by century’s end, study finds
University of La Laguna researchers project increasing aridity across the Canary Islands, with implications for water management and irrigated crops.
Fuerteventura could approach the threshold of hyperaridity by the end of the century under a high-emissions climate scenario, a University of La Laguna study has found. The researchers project increasing aridity across the Canary Islands, with potential consequences for water resources and agriculture.
The study uses an aridity index that compares rainfall with the atmosphere’s demand for water. The lower the value, the drier the conditions. During the reference period of 1985–2014, Fuerteventura and Lanzarote both had an average index of 0.10 and were classified as arid.
Under the high-emissions scenario, the islands would remain in that category but approach the hyperarid threshold by the end of the century, with values of 0.06 for Fuerteventura and 0.05 for Lanzarote. Although the changes amount to only a few hundredths on the index, they represent reductions of 40–50% from already low values. The paper warns of particularly serious implications for water management and irrigated crops.
How the projections were made
Published in Theoretical and Applied Climatology, the study compares 1985–2014 with three periods: 2021–2050, 2041–2070 and 2071–2100. The first two future periods overlap by a decade so that each covers the 30 years commonly used as a reference interval in climatology.
The researchers used ten global climate models and two scenarios from the Intergovernmental Panel on Climate Change: an intermediate scenario and a more adverse, high-emissions scenario. They applied the FICLIMA methodology to produce local projections at a resolution of 100 by 100 metres.
Aridity is influenced by rainfall, temperature, evaporation and water released by vegetation, as well as soil and vegetation characteristics. The university notes that rising temperatures and reduced rainfall associated with climate change can intensify water shortages and contribute to soil degradation and desertification.
Differences between the islands
The projections suggest that La Gomera would move from the dry subhumid category to semi-arid under both scenarios. Gran Canaria would move from semi-arid to arid by the end of the century only under the high-emissions scenario, while Tenerife would remain on the boundary of the semi-arid category.
The study agrees with earlier research that aridity is likely to increase during the century and that changes would be smaller in the eastern islands. Its projections differ, however, on where the largest absolute increases would occur: they place them in La Gomera, the east coast of La Palma and the wetter northern areas of Tenerife and Gran Canaria.
The paper reviews adaptation measures proposed in previous research, including collecting rainwater, improving irrigation efficiency, sustainable farming practices and drought-resistant crops. It cautions that their use depends on local conditions, available funding and support for agriculture.
The research was coordinated by University of La Laguna professor Juan Carlos Santamarta Cerezal. Its authors say small-scale climate projections are needed to develop strategies suited to each territory.