Scott Alexander examines theories for disease seasonality, proposing a dynamic model where seasonal factors entrain waning immunity cycles. Longer summary

Scott Alexander explores the seasonality of diseases, particularly focusing on flu and COVID-19. He discusses various theories for why diseases peak in winter, including cold temperatures, low humidity, indoor crowding, and vitamin D deficiency. He finds these explanations unsatisfactory and proposes that ultraviolet light might play a role. Scott then considers a dynamic model where disease immunity wanes over time, and seasonal factors entrain this cycle to create annual epidemics. He suggests that COVID-19 is currently in a 'half-seasonal' phase and may become fully seasonal once it has infected most of the population and exhausted easy mutations. Shorter summary

Scott investigates the claim that cold-related deaths account for 10% of global mortality, exploring various factors and potential impacts of global warming on death rates. Longer summary

Scott Alexander explores the surprising claim that cold-related deaths account for nearly 10% of all deaths globally. He investigates various studies and data sources to understand this phenomenon, discussing the differences between cold-related and winter-related deaths, regional variations in mortality rates, and potential mechanisms behind these deaths. The post delves into the complexities of adapting to different climates, the role of influenza in winter mortality, and cardiovascular effects of cold weather. Finally, Scott examines the potential impact of global warming on mortality rates, finding that most scientific analyses predict a net increase in deaths despite the reduction in cold-related mortality. Shorter summary