Climate change and the private solution trap

In the fight against climate change, prioritising private mitigation measures over public initiatives to reduce greenhouse gas emissions weakens the effectiveness of global efforts, increases inequality, and leaves poorer countries and more vulnerable citizens exposed to greater risks. This is the “private solution trap” into which wealthier nations are especially likely to fall: in seeking to protect their own populations, they end up worsening the negative effects of global warming.

These dynamics are explored in an international study published in PNAS, to which researchers from the University of Bologna also contributed. The research involved more than 7,500 people from 34 countries, who took part in a simulation on how economic resources are allocated to address climate change.

“One of the central issues in climate negotiations is how to distribute the economic effort required from different countries to limit global warming,” said Alessandro Tavoni, Professor at the University of Bologna’s Department of Economics and one of the study’s authors. “Our findings show, however, that those with greater resources tend to invest more in private mitigation measures and less in broad public action to reduce emissions. This behaviour only increases inequality and moves a global solution further out of reach.”

Public healthcare, public education systems and public transport networks are all examples of how societies have developed shared responses to challenges that affect everyone. At the individual level, however, private alternatives also exist—from private health insurance and private schools to the use of privately owned cars.

In the context of climate change, the global solution is well known: reducing greenhouse gas emissions. At the same time, governments can also invest in private mitigation measures aimed at limiting local impacts—for example, managing river systems to reduce flood risk. Both approaches are legitimate and necessary, but the key question is how resources should be balanced between them.

To understand what shapes these choices, the researchers ran a series of simulations involving 7,504 participants from 34 very different countries, from Colombia to Denmark and from South Africa to India. Participants were organised into groups of four: two players represented wealthier countries, with greater resources to invest, while the other two represented poorer countries. Each participant had to allocate their available resources by choosing between a private and a public solution in order to avoid catastrophe—that is, the loss of their earnings. The results showed that players with greater resources were more likely to invest in local private solutions than in a global public response.

“Participants who were assigned more resources at the beginning of the game invested in private solutions twice as often as those who started with fewer resources, and contributed proportionally less to the shared investment in the public solution,” Tavoni said. “This is a genuine private solution trap, one that slows progress towards a global response and puts countries with fewer resources and more vulnerable citizens at greater risk.”

The researchers also identified differences linked to participants’ national backgrounds. Those from countries whose cultures place greater emphasis on hierarchy and merit tended to favour private solutions, while those from countries where community and fairness are more strongly valued were more likely to support shared public responses.

“Despite these cultural differences, in the long run everyone tends to fall into the private solution trap,” Tavoni added. “There is, however, one encouraging sign: groups that invested quickly and cohesively in the public solution often succeeded in reaching the common goal, thereby discouraging private alternatives.”

According to the researchers, this approach could prove effective in the fight against climate change through mechanisms such as climate clubs—groups of countries that are willing to take the lead—or investment compensation schemes designed to encourage swift, coordinated action.

The study was published in PNAS under the title The private solution trap in collective action problems across 34 nations. For the University of Bologna, the contributors were Giorgio Dini and Alessandro Tavoni of the Department of Economics.