From Fred White, Nottingham, UK
Given the more than 70 per cent reduction in foraminifera shell thickness since 1872 due to ocean acidification, the idea that global temperatures will stop rising in the short term if we manage to get to net zero seems optimistic. These shells are an oceanic carbon sequestration engine that will need alkalinity levels to return to historical norms, which might take over a century, if not a millennium (18 November, p 11).
