A climate change skeptic is someone who is unconvinced the climate is changing mostly as a result of human activity. That’s it.
Climate change skeptics may or may not:
Deny that human-caused climate change is happening*.
Believe the climate is changing.
Be concerned about climate change.
Consider human activity at least partly responsible for climate change.
Understand the effect of greenhouse gases on global temperatures.
Want to reduce society’s dependence on fossil fuels.
Care deeply about environmental issues.
According to a recent Pew Research survey, just 36% of participating Republican or Republican-Leaning Millennials endorsed “Earth is warming mostly due to human activity”. Yet 60% of this group felt climate change was having an effect on the US and almost half felt the government was doing too little to reduce the effects of climate change. And their doubts about human-caused global warming didn’t prevent them from supporting expansion of renewables (83-87%) or wanting the government to do more to protect animals and habitat (60%).
There’s plenty of evidence that climate change beliefs do not increase pro-environment behavior such as recycling, using public transportation, or buying environmentally friendly consumer products. According to the authors of one study (Hall, Lewis et al, 2018), the “highly concerned” [about climate change] were the least likely to engage in pro-environmental behaviors while the “skeptics” were the most likely to engage in pro-environmental behaviors. That finding was not a fluke. A 2016 meta-analysis of similar studies (Hornsey et al, 2016) found essentially the same thing. To quote: “…climate change beliefs have only a modest impact on the extent to which people are willing to act in climate friendly ways” (p. 2).
While not a skeptic myself, I do think it’s a waste of time to focus on whether or not people believe in anthropogenic climate-change. Find common ground and go with it.
* Skepticism spans a continuum from “not 100% convinced” to “strongly deny”.
“For Earth Day, how Americans see climate change in 5 charts” by Cary Funk and Brian Kennedy/Pew Research Center April 19, 2019 https://www.pewresearch.org/fact-tank/2019/04/19/how-americans-see-climate-change-in-5-charts
Hall, M. P., N. A. Lewis, et al. (2018). "Believing in climate change, but not behaving sustainably: Evidence from a one-year longitudinal study." Journal of Environmental Psychology 56: 55-62. https://www.sciencedirect.com/science/article/pii/S0272494418301488
Hornsey, M. J., Harris, E. A., Bain, P. G., & Fielding, K. S. (2016). Meta-analyses of the determinants and outcomes of belief in climate change. Nature Climate Change, 6, 622e626. https://www.nature.com/articles/nclimate2943