Jan 2, 2003

A globally coherent fingerprint of climate change impacts across natural systems

Camille Parmesan, Gary Yohe
  • States that causal attribution of recent biological trends to climate change is complicated because non-climatic influences dominate local, short-term biological changes
  • States that any underlying signal from climate change is likely to be revealed by analyses that seek systematic trends across diverse species and geographic regions; however, debates within the Intergovernmental Panel on Climate Change (IPCC) reveal several definitions of a ‘systematic trend’
  • Explores these differences, applying diverse analyses to more than 1,700 species, and shows that recent biological trends match climate change predictions
  • Global meta-analyses documented significant range shifts averaging 6.1 km per decade towards the poles (or metres per decade upward), and significant mean advancement of spring events by 2.3 days per decade
  • Defines a diagnostic fingerprint of temporal and spatial ‘sign-switching’ responses uniquely predicted by twentieth century climate trends 
  • Finds this diagnostic fingerprint for 279 species among appropriate long-term/large-scale/multi-species data sets
  • This suite of analyses generates ‘very high confidence’ (as laid down by the IPCC) that climate change is already affecting living systems.