# Multiplicity of time scales in climate, matter, life, and economy

## TL;DR

This paper reviews the importance of multiple time scales across various scientific fields, highlighting recent advances and ongoing uncertainties in multiscale modeling and their implications for environmental research.

## Contribution

It provides a comprehensive analysis of multiscale processes in climate, materials, biology, and economics, emphasizing the significance of time scale interactions and their impact on modeling and interpretation.

## Key findings

- Advances in broad-band temporal sampling and multiscale modeling.
- Identification of properties dependent on measurement time scales.
- Highlighting the risks of neglecting multiple characteristic times.

## Abstract

This topic review communicates working experiences regarding interaction of a multiplicity of processes. Our experiences come from climate change modelling, materials science, cell physiology and public health, and macroeconomic modelling. We look at the astonishing advances of recent years in broad-band temporal frequency sampling, multiscale modelling and fast large-scale numerical simulation of complex systems, but also the continuing uncertainty of many science-based results. We describe and analyse properties that depend on the time scale of the measurement; structural instability; tipping points; thresholds; hysteresis; feedback mechanisms with runaways or stabilizations or delays. We point to grave disorientation in statistical sampling, the interpretation of observations and the design of control when neglecting the presence or emergence of multiple characteristic times. We explain what these working experiences can demonstrate for environmental research.