“…The focus of this work is on systems that are particularly sensitive to how fast the external input changes [53]. Such systems may not even have any critical levels, but they may have critical rates of change: they suddenly and unexpectedly move to a different state if the external input changes too fast [79,100,116,10,104,5,113,80,55,108,66,7,87,20,75,83]. Although critical rates are less understood than critical levels, they are equally relevant and ubiquitous.…”