Analyses indicated that responses in range shifts and timing were lagging behind the changes expected from regional warming. This type of lag, where biological response is less than expected from known underlying physiology or general climatic limits, is called 'climate debt'. Examples of climate debt, measured from community composition changes, come from birds and butterflies in Europe  and lowland forest herbaceous plants in France . The French study found that larger debts occurred in communities with warmer baseline conditions and that some of the apparent debt stemmed from the ability of species to tolerate warming in situ, so no range shift was observed.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report