Many animals won’t cope with climate change without access to ample drinking water

12 08 2020

Climate change implies change in temperature and water, and both factors shape species’ tolerances to thermal stress. In our latest article, we show that lack of drinking water maximises differences in tolerance to high temperatures among populations of Iberian lizard species.


Climate change is a multidimensional phenomenon comprising temporal and spatial shifts in both temperature and precipitation (1). How we perceive climate change depends on whether we measure it as shift in (i) mean conditions (e.g., the mean air temperature or rainfall over a decade within a given territory), (ii) magnitude or frequency of extreme conditions (e.g., the frequency of floods or tornados or the number of days with temperatures or rainfall above or below a given threshold), or (iii) speed at which mean or extreme conditions change in space and/or time.

In aquatic ecosystems, climate change further alters water acidity, oxygen dissolution and melting of ice. However, many people, including some scientists, tend to equate climate change erroneously with increased mean temperatures. Psychologists have made the semantic point that the use of the expressions climate change and global warming as synonyms can give mixed messages to politicians, and society in general, about how serious and complex the climate emergency we are facing really is (2, 3) — see NASA’s simple-worded account on the subject here.

In our latest article (4), we reviewed the ecological literature to determine to what extent ecologists investigating the tolerance of terrestrial animals to high temperatures have looked at thermal effects over water effects. It turns out, they were five times more likely to examine temperature over water.


Frequency of correlations between climate (air temperature versus precipitation) and tolerance to high temperature of terrestrial fauna in 64 papers published in the ecological literature (thickest link = 36, thinnest link = 2) following a systematic literature review in Scopus (4).

This is counterintuitive. Just imagine you have been walking under the sun for several hours on one of those dog days of summer, and you are offered to choose between a sunshade or a bottle of water. I’d bet you’d choose the bottle of water.

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