Life on Earth has experienced dramatic alterations of diversity and distribution as conditions of environment have changed over millennia of evolutionary history. The Earth’s climate has cooled during the past 100 million years, and events such as volcanic activity and meteorite strikes have resulted in extinctions and collapses of ecosystems. There is now overwhelming evidence that the Earth’s temperatures are warming and that human activities are driving this aspect of climatic change. Global average temperatures have increased by ~ 0.2°C per decade during the past 30 years due to increasing atmospheric concentrations of greenhouse gases (Hansen et al., 2006). Much of the added energy contributing to global warming is absorbed by the world’s oceans, in which the upper layers have increased in temperature by 0.6°C during the past 100 years (IPCC, 2007). Further warming will produce thermal expansion which could result in an 18–30 cm rise in sea level by 2100 (Meehl et al., 2005). Warming is larger in the Western Equatorial Pacific than in the Eastern Equatorial Pacific over the past century, probably due to strong El Niños, and comparisons with paleoclimatic data suggest that this critical region and possibly the planet as a whole is as warm as the Holocene maximum and the maximum temperature during the past million years (Hansen et al., 2006).

Accepting the reality of climatic change in its current status, non-avian reptiles are an important and informative group of vertebrates to examine in related contexts. The utility of reptilian data for assessing the effects of climatic changes on organisms and communities relates to characteristic features of this group, including ectothermy, geographic distributions, reproductive modes (especially oviparity), breadth of diversity, biogeographical histories, local abundance, keystone status in some communities, dispersal capabilities, trophic relationships, and energetics. With regard to global warming, it is significant to note that two-thirds of the global variation in the species richness of reptiles can be explained by temperature alone (Qian, 2010). The diversity of reptiles is greater in the tropics and decreases with increasing latitude.