Climate change has become a global environmental threat that will impact virtually every ecosystem on the planet for generations to come. The widespread nature of the threat is evident in not only industrialized countries, but in remote locations, such as polar regions and oceanic islands, that are far from the intense human activity that is widely demonstrated to be the cause. The difficulty of coordinating a response to climate change was reflected in the near collapse of intergovernmental negotiations at the recent United Nations Climate Change Conference in Copenhagen (December 2009), where sharp disagreements on a wide range of issues delayed a treaty intended to coordinate an international response to climate change. Governments must continue to forge ahead with difficult political negotiations to find the common ground required to address the complexities of the challenge.

The effects of climate change will be exacerbated by ever-increasing human populations and the associated demands for food, industrialization, and global transport. The scientific community must continue its work to better understand and mitigate the causes of climate change and identify viable methods for adapting to the changing conditions. Of particular relevance for SETAC members are the interactions between climate-related ecological changes and environmental contaminants (e.g., the ecological risks and chemical fate and transport processes). The temporal and spatial scales of climate change, combined with the uncertainty associated with long-range predictions of future conditions, present critical challenges for environmental management. We will need to employ broader frameworks to prevent myopic views of environmental issues, including those that account for interactions among environmental stressors.

Understanding the effects of climate change on environmental contaminants is crucial for achieving scientific, regulatory, and long-term conservation goals. For example, the agriculture and resource management communities are greatly concerned by the combined threats of invasive species moving in response to climate change and the increased use of chemicals to control the expansion of such pests. At a minimum, these range expansions present new uncertainties regarding the sensitivity of target and nontarget species to pesticides, and additional toxicity testing and field observations would be required to recommend effective control procedures.

Though often reduced to general effects on global temperature, sea levels, and precipitation, climate change will influence other abiotic factors, including soil conditions, ocean pH and salinity, glacial ice coverage, and fire and storm frequency and intensity. These changes may alter chemical distribution in the environment (e.g., via transoceanic dust clouds, increased organochlorine volatilization and movement towards polar regions, and Arctic exploration for mining and oil drilling) as well as chemical bioavailability. Less is known about how climate change affects chemical disposition and mechanism of action in individuals, though we can learn much from studying the myriad ways that animals adapt to their environments through bioenergetic, endocrine, and other physiological mechanisms. Additionally, there is a dearth of research exploring the interactions, synergisms, and potentiations among environmental contaminants in stressed ecosystems and the resulting risks to living organisms.

The interconnectedness of stresses posed by climate change and by environmental contaminants on human and ecological health exemplify the need for increased interdisciplinary discussion and research to examine the potential impacts. These areas include organism energetics and system energy flows; increased availability and toxicity of contaminants in both wetter and drier systems; increased development pressure on polar and alpine systems (including increased vessel traffic and exploratory drilling for oil); increased extreme weather event impacts; increased eutrophication; endocrine disruption; photochemical impacts; pressures on specific species of concern and general biodiversity; increased chemical use for pest control as pest species ranges expand associated with climate change (especially in the context of biofuel production); possible feedback loops associated with fossil fuel consumption and other greenhouse gas sources; and altered contaminant transport distances due to warming compartments.

Environmental chemists, toxicologists, and risk assessors who are members of SETAC are challenged to work together to understand how global climate change will influence the mechanisms and ramifications of contaminants on humans and the environment. By providing the guidance needed to adapt assessment techniques to these changes, we strive to improve society's ability to respond to effects that are difficult to predict, evaluate, and mitigate. New quantification techniques, such as those associated with monitoring and evaluating ecosystem services for terrestrial and aquatic regions (see, e.g., the 2003 Millenium Ecosystem Assessment Report), are sorely needed to evaluate and guide responses to the combined effects of climate change and conventional stressors on the well-being of humans, wildlife, and the environment. Additionally, assessment approaches for characterizing environmental risk and natural resource injuries must be adapted to address these combined effects and integrate plausible strategies to protect, preserve, and restore human and ecosystem health.

SETAC has accepted this challenge. Two workshop initiatives are underway to engage the diverse expertise found within the Society. A Pellston Workshop will focus international expertise to anticipate global climate change effects on the foundations of environmental chemistry and toxicology, provide recommendations to the business and regulatory communities on meaningful short- and long-term measures for adapting assessments to changing climate conditions, and identify future research needs. A technical working group addressing invasive species and related stressors induced by climate change will host a workshop at the SETAC-Europe annual meeting in Seville, Spain (May 2010) and again later in the year at the SETAC-North America annual meeting in Portland, Oregon (November 2010).

SETAC workshops are intended to engage members and invite contributions of knowledge and expertise to address environmental challenges that affect us all. We encourage SETAC members to support these and other related climate change science initiatives. The time for careful scientific study is clearly at hand.

Disclaimer—The views and opinions expressed in this article are those of the authors and, except for SEF and MJH, do not necessarily represent the views of their affiliated organizations.