2015), exceptions to them became a focus of study. For example, in northern regions of the Northern Hemisphere, the spring flowering of some plants was delayed instead of being advanced as to be expected with warming . These turned out to be species requiring vernalisation  to speed their development in spring . For these plants, phenological changes result from the combined effects of advancement caused by spring warming and retardation caused by winter warming. Incorporating this level of complexity into analyses revealed that a greater proportion of species was responding to climate change than estimated according to the simple expectation that warming would always cause advancement  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report