State of the Planet

News from the Columbia Climate School


Dead Plants Strengthen Beliefs in Global Warming

Cues in our physical environment unconsciously influence how we process information. People rate others as having warmer personalities if they simultaneously hold a hot drink in their hand; interviewers perceive interviewees as “weightier” candidates if the resumes are presented on heavy clipboards; and individuals walk slower when primed with a word associated with the elderly—these studies, drawn from the fields of social and embodied cognition, demonstrate that sensory and motor processes (activated by stimuli in our immediate environment) inform how other people perceive us as well as how we think about ourselves. They also influence how we evaluate and act on beliefs.

If environmental cues can affect diverse behaviors and judgments, do cues related to nature affect beliefs about global warming?

A new study by French psychologist Nicolas Guéguen from the Université de Bretagne-Sud asked undergraduates to report on their beliefs regarding global warming while in the presence of a small tree or several trees. In one experimental condition, the trees had foliage; in the other condition, the trees were bare. The researchers concluded participants were more likely to believe in global warming while in the presence of a tree without foliage; the belief was amplified when in the presence of three trees without foliage (as compared to only one).

These results compliment numerous studies suggesting physical cues in the surrounding environment affect risk-perception of global warming. For example, researchers found that people who are primed with words related to heat are more likely to express beliefs about global warming compared to participants primed with neutral words. In a separate study, researchers determined people who thought that the day was warmer than usual expressed a stronger belief in global warming compared to people who thought the day was colder than usual.

The notion that surrounding objects unconsciously influence our thoughts and behavior is of interest to individuals who are interested in developing marketing strategies and design tactics to promote sustainable behavior and heighten awareness about environmental issues. For example, according to Dr. Guéguen, an experimenter could test whether people using the bathroom in the presence of dead plants are more likely to use less water while washing their hands (as compared to those in the presence of thriving plants, or no plants at all). Lessons drawn from the findings of similar experiments could inform how to design spaces that encourage people to recycle, bike to work, use less electricity, buy eco-friendly products, and make other sustainable choices. The Center for Research on Environmental Decisions at Columbia University, an interdisciplinary center that studies individual and group decision making under climate uncertainty and decision making in the face of environmental risk, has many featured projects that address these issues broadly.

Subtle stimuli in the environment exert a strong influence on the way we function. Similarly, small organisms in our physical environment exert a strong influence on the way ecosystems function. The little things in our environment, some too small to see with the naked eye, all affect the surrounding temperature, air that we breathe, and food that we eat. “The Little Things and Their Influence on the Planet,” a course that is part of the Certificate in Conservation and Environmental Sustainability, investigates the role of microorganisms in maintaining our biosphere. It meets on Thursdays, May 31, June 7, 14, and 21 (4 sessions; 6:10-8:40PM), and is available both in class and via distance learning. For more information, please contact Desmond Beirne at or 212-854-0149.

Banner featuring a collage of extreme heat images.

Recent record-breaking heat waves have affected communities across the world. The Extreme Heat Workshop will bring together researchers and practitioners to advance the state of knowledge, identify community needs, and develop a framework for evaluating risks with a focus on climate justice. Register by June 15

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12 years ago

More solid evidence that climate change is occurring, hopefully more people will become aware of this

12 years ago

[…] Haidt elaborates on his own research in moral and cultural psychology, part of the growing body of automaticity research in cognitive neuroscience and social psychology, to frame discussions on moral instincts—the […]