Republican presidential candidates Senator Marco Rubio, Ben Carson, and Senator Ted Cruz are introduced at the Presidential Family Forum on November 20, 2015, in Des Moines, Iowa. (Photo: Scott Olson/Getty Images)

Why, in the face of heavy evidence, do so many American conservatives refuse to acknowledge that humans are recklessly altering the natural environment? Common answers to that question range from economic concerns to a belief that man deserves to dominate nature.

Newly published research suggests that, on a deeper level, this denial is driven by deep-seated fear.

Among American conservatives, "Environmentalists have been characterized as watermelons: Green on the outside, but red on the inside," write Brock University psychologists Mark Hoffarth and Gordon Hodson. "At its core, this 'watermelon' characterization posits that environmentalists threaten the Western way of life."

This will seem like a bad joke to climate scientists, who argue that failing to stop the rise in temperature presents the real danger to society. The human and economic costs of coping with rising sea levels, disruptions to the food supply, and increasingly severe weather events promise to be enormous.

Clearly, unless fears about disruption are addressed, Republicans will be working hard to hinder any agreement that comes out of the current climate conference in Paris.

But to build a consensus around tackling these actual dangers, the aforementioned psychological threats need to be understood and addressed.

The study featured 384 American adults recruited online via Amazon's Mechanical Turk. Participants provided information regarding their age, race, political and ideological leanings, and beliefs regarding climate change.

To tease out the reasons behind those beliefs, additional sets of questions measured their love of nature, insistence that humans should have dominance over nature, and—most importantly for this study—whether they feel environmentalists pose a threat.

Participants rated their level of agreement or disagreement with such statements as "The rise in environmentalism poses a threat to our country's cultural customs," "The American economy cannot remain dominant if we listen to environmentalists," and "Hard-working Americans are negatively impacted by environmentalists."

The results: Viewing environmentalists as a threat "consistently, strongly, and uniquely accounted for the link between right-wing ideology and opposition to environmentalist policies and climate-change denial," the researchers report. They add that this effect manifests as "over and above views that the environment exists for economic exploitation, and other relevant beliefs."

In other words, "the political polarization of climate change is not merely due to attitudes and beliefs about the environment and concerns for the economy, but in large part due to attitudes and beliefs about environmentalists as threatening to the status quo."

Clearly, unless fears about disruption (which underlie many conservative positions on issues) are addressed, Republicans will be working hard to hinder any agreement that comes out of the current climate conference in Paris. But how can this be done?

The researchers suggest framing the issue in a manner "that is not ideologically threatening," and presenting climate change as a common enemy we all have a duty to combat.

To that point, they note that the Pentagon, "a traditionally conservative organization," has extensively researched how climate change endangers national security. A campaign addressing the issue from that perspective may be taken more seriously by those on the right.

In addition, an emphasis on how jobs in the growing clean-energy field could boost the economy may appeal to conservative voters.

To sum up, Hoffarth and Hodson "urge scientists and policymakers to consider communication strategies for reducing carbon emissions that are not reliant on overtly environmentalist concerns and solutions, and emphasize the benefits of cooperating across the political spectrum."

If that seems unrealistic, keep in mind the study's most encouraging finding: "Relative to those on the left," the researchers note, "those on the right do not necessarily feel less connected to nature."

Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.