Comment: 55 pages, 34 figures, 4 tables, 117 items in bibliography. Difference to v1: More details on credibility and lack of credibility when treating complex systems with a multiplicity of different characteristic time lengths: sampling problems, feedback loops, scientification of environmental politics and the pitfalls of the related politicisation of sciences. See also https://events.ruc.dk/timescales/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.