James Lovelock, a gentleman scientist

James Lovelock, who has died on, remarkably, his 103rd birthday, seemed to relish his status as a scientific outsider, but he probably never considered himself to be a maverick. Whether discussing his ideas about the Gaia hypothesis, climate change, nuclear power or the biological effects of radiation, he considered that he was merely voicing the rational view. Indeed, one sensed he imagined his stance on such matters to be that of the practical-minded engineer rather than the visionary guru. For much of his career he presented himself more as inventor than thinker, and it was his skill and deep intuition as a maker of scientific instruments that allowed him to exist as that anachronistic entity, the gentleman-scientist of independent means.

And a gentleman he surely was. He could be fiercely trenchant when defending his views, but he was never less than kindly, thoughtful and convivial, even in the face of some bitter attacks on his ideas. The Gaia hypothesis, which argued that our planet is a homeostatic, self-regulating system involving interactions and feedbacks between the oceans and atmosphere, geosphere and biosphere, raised many hackles when first proposed in the 1970s, not least because some considered it to conflict with Darwinian evolution. (It was not, necessarily, but the reconciliation was not immediately obvious.) Some felt it bordered on mysticism, hinting at notions of teleology and higher purpose – all the more so when Lovelock suggested that the Gaian Earth system had genuine characteristics of a living organism. But the core idea has since been thoroughly validated by the sciences of earth, environment and ecosystems: the biosphere does indeed play an active and even an adaptive role in shaping the planetary environment and climate through the operation of biogeochemical cycles.