Uncertainty surrounds the public understanding of climate change and provides fertile ground for conspiracy theories. Typically, such conspiracy theories assert that climate scientists and politicians are distorting or hijacking the science to suit their own purposes. Climate change conspiracy theories resemble other conspiracy theories in some respects, but in others they appear to be quite different. For example, climate change conspiracy theories appear to be motivated by the desire to deny or minimize an unwelcome and threatening conclusion. They also appear to be more contentious than other types of conspiracy theories. Perhaps to an unparalleled extent, people on both sides of the issue champion climate change conspiracy theories. Finally, more than other conspiracy theories, those concerning climate change appear to be more politically loaded, dividing opinion across the left-right continuum. Some empirical evidence suggests that climate change conspiracy theories may be harmful, steering people away from environmentally friendly initiatives. They therefore present a significant challenge for governments and environmental organizations that are attempting to convince people to take action against global warming.