Rising temperatures will lead to a rising tide of aggression
THE WEIGHT OF NATURE How a changing climate changes our minds, brains and bodies
CLAYTON ALDERN 336pp. Allen Lane. £25.
Climate change doesn’t just affect the external world: it changes how we think and feel. As Clayton Aldern puts it in The Weight of Nature, “the climate change is inside us” – and we have consistently underestimated its impact on cognitive performance. Trauma from extreme weather events changes the structure of the brain, even in foetuses. The acidification of water from carbon dioxide affects sound transmission and confuses the navigation of fish. Cyanobacteria, now appearing in freakish blooms worldwide as a result of higher tempera-tures and nutrient run-off, generate neurotoxins that have been linked to neurodegenerative disease. And, spreading through freshwater lakes, there is a “braineating amoeba” that has a 95 per cent fatality rate.
Aldern is an excellent storyteller, drawing on interviews and personal experience, with an elegant prose style that only occasionally takes a folksy (“critters”, “our noggins”) turn. He does a fine job navigating the dense technical research where acronyms proliferate like algal blooms, and his background in neuroscience puts him on a strong footing to explore the mechanistic impacts of climate change on brain function and chemistry.
But he finds it harder to account for the socialpsychological responses to climate change or, in his words, “the intricate interplay between our neurolandscapes and the social, cultural, and environmental ecologies we inhabit”. Climate change may well affect brain function, but its actual impacts will always be mediated by culture. In the past human societies have proven to be extremely adaptive: the Bedouin thrived under temperatures that Aldern claims can lead parts of the brain to “irreversibly stop working”. Nonetheless, there are biological limits and he is right to highlight findings that a third of humanity is living in areas that, by the middle of the century, will be “nearly unliveable”.
The impacts of climate change become even more complex when applied to behaviours. Aldern presents strong evidence that rising temperatures will lead to increased anger and inter-personal aggression. For example, annual data shows a correlation between the rise in violent crime and temperature in Finland. But the link
