Amphibian and Reptile Conservation 6(1):1-24. POINT OF VIEW Can humans share spaceship earth?

—Earth was a pretty durable spaceship, but we have managed to trash its life support systems, the atmosphere, and the oceans. Humans have also destroyed vast areas of habitats and !"#$%&'(&)*%#'+*,(-&"./*0&*-#1&*%,)23&)* (-&*#(%,.4-&"&*#')* 2'*),2'$*.,*-#1&* 2'5"&#.&)* (-&* greenhouse effect, which has changed the climate to produce ever increasing maximum temperatures. Increased temperatures threaten some lizard species in highly biodiverse tropical and subtropical regions. Many lizards are also threatened by habitat loss and over-harvesting. Although lizards are ectotherms and might therefore be expected to be resilient to global warming, evidence strongly suggests that many species could be threatened by warming. Some, such as fossorial or nocturnal species or those in cold temperate regions, may be little affected by climate warming but many others such as thermoconformer species in tropical forests and live bearers appear to be particularly vulnerable. The 2011 IUCN Red List of Threatened Species lists 12 lizard species as extinct and another 462 species as Critically Endangered, Endangered, or Vulnerable. Together, these constitute at least 8.4%, probably more, of all described lizard species. The highly biodiverse lizard fauna of Madagascar is especially threatened mostly due to habitat loss from extensive deforestation by humans. Three of the IUCN listed species are monitor lizards. Most varanids are top predators, generally have large territories, and have low population densities, which make them particularly vulnerable to habitat loss, habitat fragmentation, and over-harvesting. All monitor lizards are 62.(&)*7+*89:;<*#.*;')#'$&"&)=*#')*31&*.4&52&.*#"&*,!352#66+*62.(&)*#.*>(-"&#(&'&)*?2(-*&@(2'5(2,'/A* Others, including the sister taxon to varanids, the Earless monitor Lanthanotus from Borneo, and several island endemic Varanus species from biodiversity hot spots in SE Asia should be added to these lists. The future survival of all lizards including varanids will depend on our ability to manage the global environment. Sustainable management will require controlling the runaway population growth of humans, as well as major changes in our use of resources. To maintain lizard biodiversity, anthropogenic climate change and habitat destruction must be addressed.