Order matters: Autocorrelation of temperatures dictates extinction risk in populations with nonlinear thermal performance

Forecasting the risks caused by climate change often relies upon combining species' thermal performance curves with expected statistical distributions of experienced temperatures, without considering the order in which those temperatures occur. Such averaging approaches may obscure the disproportionate impacts that extreme events like heatwaves have on fitness and survival. In this study, we instead incorporate thermal performance curves with population dynamical modeling to elucidate the relationship between the sequence of temperature events -- driven by temporal autocorrelation -- and extinction risk. We show that the permutation of temperatures determines the extent of risk; as thermal regimes grow warmer, more variable, and more autocorrelated, the risk of extinction grows non-linearly and is driven by interactions between the thermal distribution and its temporal autocorrelation. Given that the mean, variance, and autocorrelation of temperatures are changing in nuanced ways across..., Included datasets (1) input data required to simulate extinction for 38 species with known thermal tolerances (arising from datasets compiled and used by Deutsch et al. 2008, Duffy et al. 2022, and Frazier et al. 2006) under two decades of observed climatic conditions at their collection locations (provided by Visual Crossings Corporation 2024); and (2) simulation outputs for several models which test extinction risk for species with different thermal tolerances, given variable thermal distributions and levels of autocorrelation, processed in Mathematica V.13.0.1 and as reported in the associated manuscript.
, , # Effects of temporal autocorrelation on extinction risk

[https://doi.org/10.5061/dryad.w0vt4b91q](https://doi.org/10.5061/dryad.w0vt4b91q)

This project utilized several models to test the impacts of varying the temporal autocorrelation of temperature time series on extinction risk, given a known organismal thermal tolerance. The first model (Model 1, 1.2) tests how varying different aspects of a thermal regime (mean, standard deviation, and autocorrelation of temperatures) alter different metrics of extinction risk for species with two idealized thermal performance curves (one generalist/temperate species and one specialist/tropical species); Model 1 examines how extinction risk and time to extinction vary across the full parameter space, while Model 1.2 examines the effects on population size across a narrower parameter set. Model 2 tests how varying the level of autocorrelation impacts more realistic scenarios by incorporating 38 empirical thermal performance curves with observed t...,