Figure 19-2: Observed impacts of temperature-related regional climate change in the 20th century:

• Hydrology and Glaciers—Glacier retreat, decrease in snow-cover extent/earlier snowmelt, reduction in annual duration of lake and river ice
• Sea Ice—Decline in sea-ice extent and thickness
• Animals—Poleward and elevational shifts in range, alteration in species abundance, changes in phenology (including earlier reproduction and migration), physiological and morphological adaptation
• Plants—Change in abundance and diversity, change in phenology (including earlier flowering), change in growth.

Studies that cover large areas and use remote-sensing methods are indicated. About 50 studies were selected, according to the following criteria: (1) hydrology/sea-ice studies that report long-term trends in observed variables (time periods of studies range from ~20 to 150 years), and (2) terrestrial and marine ecosystem studies that associate trends in observed change(s) with trends in regional climate data for Ž20 years (time periods of studies range from ~20 to 50 years). Of the ~100 physical processes and ~450 biophysical species that exhibited change, more than 90% (~99% physical, ~80% biophysical) are consistent with well-known mechanisms of system responses to climate.

Sources: Hydrology and Glaciers, and Sea Ice—Ames and Hastenrath (1996), Cavalieri et al. (1997), Dettinger and Cayan (1995), Dowdeswell et al. (1997), Dyurgerov and Meier (1997), Greene et al. (1999), Groisman et al. (1994), Haeberli and Beniston (1998), Hastenrath (1995), Johannessen et al. (1999), Kaser (1999), Kratz et al. (2001), Magnuson et al. (2000), Maslanik et al. (1996), Rothrock et al. (1999), Schindler et al. (1990), and Vinnikov et al. (1999); Animals and Plants—Barber et al. (2000), Bergmann (1999), Bezzel and Jetz (1995), Bradley et al. (1999), Brown et al. (1999), Crick and Sparks (1999), Crick et al. (1997), Cunningham and Moors (1994), Dunn and Winkler (1999), Ellis (1997), Ellis et al. (1997), Fleming and Tatchell (1995), Forchhammer et al. (1998), Fraser et al. (1992), Gatter (1992), Grabherr et al. (1994), Hasenauer et al. (1999), Jarvinen (1994), Loeb et al. (1997), Ludwichowski (1997), Mason (1995), McCleery and Perrins (1998), Menzel and Fabian (1999), Pauli et al. (1996), Parmesan (1996, 2001), Parmesan et al. (1999), Post and Stenseth (1999), Post et al. (1997), Pounds et al. (1999), Ross et al. (1994), Sagarin et al. (1999), Slater (1999), Smith (1994), Smith et al. (1999), Sparks (1999), Thomas and Lennon (1999), Visser et al. (1998), Winkel and Hudde (1996, 1997), Zhou et al. (1995).