By the time of AR5, >4000 species with long-term observational data had been studied in the context of climate change . Since then, thousands of new studies and additional species have been added, leading to higher confidence in climate change attribution  . Freshwater habitats have been under-represented in prior reports, but new long-term datasets, coupled with laboratory and field experiments, are improving our understanding. This assessment stresses observations from lakes and streams. As numbers of studies increase and data is increasingly extracted from areas with high LULCC, attribution is more difficult as habitat loss and fragmentation are known major drivers of changes in terrestrial and freshwater species . Due to the overwhelming volume of literature, the assessments for chapter 2 concentrates on results from large continental or global-scale reviews and meta-analyses. Most of the assessment of studies conducted in individual countries can be found in Regional chapters, but this chapter does include studies across very large countries or political entities that occupy much of a continent , or studies that provide rare or uniquely-relevant information.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report