How "Blah Blah Blah" Can Help Save the Climate
What the game theory of trust can tell us about climate pledges.
Posted November 6, 2021 Reviewed by Vanessa Lancaster
Key points
- World leaders are meeting in Glasgow and making promises about climate change.
- While promises are just words, game theory and experiments show promises can lead to change.

The United Nations Conference of Participants (COP) is gathering in Glasgow this month to negotiate the future of our planet. At these annual conferences, world leaders meet to discuss and make commitments for their governments’ actions on climate change.
These events can be raucous affairs. When I attended the COP several years ago in Copenhagen as part of a delegation from Cornell to present some of our research on Carbon offset contracts, I attended exuberant rallies led by Nobel Prize winners like Desmond Tutu, found myself in conference rooms with governors like Arnold Schwarzenegger, and sat at the same table as activists dressed up as aliens.
At this year’s COP, Swedish activist Greta Thunberg led a rally to denounce the negotiations as just more “blah blah blah.” Skeptical of politicians who make empty promises, Thunberg demanded action instead.
And yet, as I detail in my new book Why Trust Matters: an Economist’s Guide to the Ties that Bind Us when it comes to international cooperation on issues like climate change, “blah blah blah” may be the best way forward.
Fortunately, game theory (validated by some experimental evidence) provides some assurance that the promises made by leaders, the “blah blah blah” as Thunberg calls it, are promises that we can at least somewhat trust.
All Agreements Are Just Words
If you think about it, all agreements are just words. When you agree with someone, say to make a purchase, you are trusting the other parties involved to abide by the terms of that agreement. Sometimes, legal regimes create systems that help enforce contracts, but in many of the interactions we encounter in day-to-day life, we rely solely on trust. This reliance on trust is even more all-encompassing in international relations, where international institutions have little power to enforce agreements.
Yet, international agreements are reached, and treaties are negotiated, and while compliance with international treaty regimes is mixed, they do work, at least sometimes. They work because promises have power. In my research on how words rebuild trust, I find that promises, even “cheap” ones, can provide credible signals of trustworthiness because we punish those that fail to live up to them. In game theory terms, we say that while talk is cheap, a promise can credibly create trust because it creates an implicit social contract. A promise can be believed to the extent that we can commit to punishing broken promises in the future.
We see this behavior in a wide range of lab experiments and the real world. It is hard to run real-world experiments where politicians promise treatment and control groups, but we can run experiments with large corporations. In an experiment with 1.5 million actual Uber customers, we tested different messages to customers who experienced a late ride.
We find that when Uber promises getting you to your destination on time, customers reward that promise by using Uber more often. However, suppose Uber doesn’t live up to that promise, repeatedly failing to get you to your destination on time. In that case, customers punish Uber by quitting Uber at a higher rate than those in a control group who experienced similar delays but never promised to do better.
Will Game Theory and Promises Be Enough?
Of course, we see corporations and politicians failing to live up to promises all the time. Furthermore, not all broken promises are punished, but enough are that we continue to see promises made and abided by all around us. At the individual level, we use apps like Lyft or Airbnb to make and abide by agreements to share our cars or homes in new ways.
At the international level, while there are notable examples of countries walking away from treaties that they have signed, such as the Trump administration and the Paris climate accords, or Britain and Brexit, these are exceptions that prove the rule. Even when walking away from these agreements, the US and the UK took care to walk away from these agreements in an orderly and negotiated manner. All of that “blah blah blah” meant something.
In Glasgow, countries have made substantial pledges to address global warming: India has pledged to go carbon neutral by 2070, South Africa has pledged to shutter all of its coal power plants, the US has led a multilateral agreement to curtail emissions of methane.
While these promises are not enough, and countries will not live up to all of them, we have made dramatic progress toward addressing climate change, and the promises made at this COP and the 25 earlier COP meetings have been an important part of that progress. Countries have been increasing their pledges each year, and we, the people, do hold our leaders accountable for the promises that have been made.