A study from the University of California, Davis, simulated 100,000 possible future policy and emissions trajectories in order to identify significant elements in the climate-social system that could influence climate change in this century.

We can begin to grasp potential key differentiators that our collective fates spin around by running scenarios over and over again while modifying different factors, much like a climate groundhog day.

At global scales, understanding those pivot points becomes considerably more difficult. Predictive modeling, however, is the only way to get close to pinning down those critical components before they pass us by.

According to the study, public perceptions of climate change, the future cost and effectiveness of climate mitigation and technologies, and how political institutions respond to public pressure are all major drivers of how much the climate will change in the 21st century.

"Small changes in some variables, like the responsiveness of the political system or the level of public support for climate policy, can sometimes trigger a cascade of feedbacks that result in a tipping point and drastically change the emissions trajectory over the century," lead author Frances C. Moore, an assistant professor with the UC Davis Department of Environmental Science and Policy, said.

"We're trying to understand what it is about these fundamental socio-political-technical systems that determine emissions."

Moore and his colleagues looked across a variety of fields to find social, economic, and political elements that will influence our emission rates, which they then used to feed into computer predictions of warming levels by 2100.

They used historical data to add limits to their variables, and they discovered that certain social factors, such as public perceptions of climate change, are crucial in predicting which group of scenarios is most likely to play out.

The researchers stressed that a proclivity for social conformity can lead to tipping-point dynamics, in which a system abruptly transforms from a previously stable state due to a critical mass of proponents of an alternate norm.

This is why elements such as our society's perceptions continue to be so crucial. Moore and colleagues also addressed how cognitive biases such as the shifting-baseline effect might influence social dynamics.

The simulations indicate that we are now highly unlikely to stay below 1.5°C, even under an "aggressive action scenario," as other researchers have already warned.

This is not surprising, according to Moore and colleagues, because 1.5°C currently necessitates widespread use of negative emissions technologies that were not incorporated in the model because such technologies do not yet exist at the scale and efficiency required. That doesn't rule out the possibility that they will be more useful in the future.

The future possibilities, on the other hand, show that we still have a good chance of keeping emissions below 2°C.

This research was published in Nature.