Rainfall
   (see "Precipitation")

Range Expansion
   Animals
      Birds
      Butterflies
      Other
   Herbaceous Plants
   Marine Life
   Woody Plants
      Arctic
      Europe
      Miscellaneous
      North America
         USA Pacific Northwest
         USA Scattered
         USA South-Central
         USA Southwest

Rapid Climate Change
   Biological Systems
   History
   Temperature Effects
   Thermohaline Circulation

Reconstructions of Climate

Reactive Oxygen Species

Reefs
   (see "Coral Reefs")

Regime Shifts

Religion

Reptiles

Respiration
   General
   Herbaceous Plants
      Crops
      Other
   Human
   Oceans
   Response to Temperature
   Soils
   Woody Plants
      Coniferous Trees
      Deciduous Trees
      Multiple Tree Studies

Rivers

Roman Warm Period
   Asia
   Europe
      Central
      Mediterranean
      Northern
      Other
   Miscellaneous
   North America
   South America

Roots
   Crops
   Grasses
   Miscellaneous
   Shrubs
   Trees
      Conifers
      Deciduous

Rubisco
   Agricultural Species
   General
   Grassland Species
   Tree Species

Runoff