Could Four Billion People Die at 3°C?

A 2025 UK actuarial report has circulated claims that four billion people could die at 3°C of warming, but the author argues these figures lack scientific rigor and are presented without clear timeframes or modeling methodology. The estimates of 2-4 billion deaths are implausible given current warming rates and appear to be worst-case speculations rather than robust scientific projections, with mortality from climate impacts being too complex to predict precisely due to varying exposure, vulnerability, and adaptive capacity across populations.