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Climate scientists have played a significant role in investigating global climate change. In the USA, a debate has swirled about whether a consensus on climate change exists among reputable scientists and this has entered the policy process. In order to better understand the views of US climate scientists, we conducted an empirical survey of US climate scientists (N = 468) in 2005, and compared the results with the 2007 Intergovernmental Panel on Climate Change (IPCC) physical science report and policy summaries. Our results reveal that survey respondents generally agree about the nature, causes, and consequences of climate change, and are in agreement with IPCC findings. We also found that there is strong support for a variety of policy initiatives to reduce greenhouse gas emissions.

On 14 May 1994, tadpoles were collected from Lateral Pond and Municipal Lake in Bryan, Texas. These waters are immediately downstream from Finfeather Lake which was directly contaminated during 53 years of industrial production of arsenic (As)-based cotton defoliants. The tadpoles contained elevated levels of arsenic, chromium (Cr) and zinc (Zn). As far as it is known, the mean concentrations of As (6.87 p.p.m. wet weight) and Cr (6.91 p.p.m. wet weight) in cricket frog (Acris crepitans) tadpoles were the highest ever reported in tadpoles. The Zn in the tadpoles exceeded the levels found in sediments by six to 11 times. The concentrations of As, Cr and Zn in Finfeather Lake in 1994 may have been toxic because tadpoles could not be found there. Ranid tadpoles and a newly transformed ranid frog found dead in Lateral Pond and Municipal Lake in 1994 may indicate that the elements reached toxic levels in some individual amphibians. The concentrations of As, Cr and Zn found in the tadpoles in this study might be toxic to predators. Mortality of turtles showing symptoms linked to chronic exposure to As was reported in Finfeather Lake in 1973. Turtles were not reported in Finfeather Lake again until 1996. Observations at Municipal Lake in 1994–1996 showed abundant tadpoles and turtles but no snakes, which also have not been seen at Finfeather Lake. This absence of snakes may indicate that their sensitivity or exposure to the existing contaminants is greater than that of frogs and turtles.

The National Contaminant Biomonitoring Program (NCBP) was maintained for two decades by the U.S. Fish and Wildlife Service (FWS) to document temporal and geographic trends in concentrations of environmental contaminants that may threaten the nation’s fish and wildlife resources. Initiated in 1967 as a component of the National Pesticide Monitoring Program, the NCBP comprised the periodic collections of freshwater fish, European starlings (Sturnus vulgaris) and duck wings and the analyses of these samples for persistent environmental contaminants (52). The NCBP provided information on the success of legislative and regulatory actions intended to reduce environmental concentrations of bioaccumulative toxins and on the effects of changing agricultural practices.

Four species of reptiles (diamondback water snake [Nerodia rhombifer], blotched water snake [N. erythrogaster], cottonmouth [Agkistrodon piscivorus], and red-eared slider [Trachemys scripta]) were collected at two contaminated and three reference sites in Texas, USA. Old River Slough has received intensive applications of agricultural chemicals since the 1950s. Municipal Lake received industrial arsenic wastes continuously from 1940 to 1993. Blood samples were analyzed for organochlorines, potentially toxic elements, genetic damage, and plasma cholinesterase (ChE). Dichlorodiphenyldichloroethylene (DDE) concentrations reached as high as 3.0 ppm (wet weight) in whole blood of a diamondback water snake at Old River Slough, a level probably roughly equivalent to the maximum concentration found in plasma of peregrine falcons (Falco peregrinus) in 1978 to 1979 when DDE peaked in this sensitive species. Possible impacts on diamondback water snakes are unknown, but at least one diamondback water snake was gravid when captured, indicating active reproduction. Arsenic was not found in red-eared sliders (only species sampled) from Municipal Lake. Red-eared sliders of both sexes at Old River Slough showed declining levels of ChE with increasing mass, suggesting a life-long decrease of ChE levels. Possible negative population consequences are unknown, but no evidence was found in body condition (mass relative to carapace length) that red-eared sliders at either contaminated site were harmed.