The Climate game

Author: István Scheuring

Recommended age: 10-99

Number of players: 5-30

Space needed for the game: classroom

Difficulty level: 2

Playing time: 10-15 minutes

Preparation time: 5 minutes

Accessories: Blackboard and chalk (or similar equipment). Players should have paper, pencil and dice.

Short description: To avoid the climate catastrophe, we need continuous investment from all participants. But will there be enough investors, if success and failure threatens everyone equally?

Preparations: Have all accessories ready. (Instead of dice you can use numbers on small papers, drawn from an envelope.)

Course of the game: Each player receives, say, 40 gold ducats (instead of 40 points). In each round, players can make contributions of 0, 2 or 4 gold ducats, to the common fund. Participants' contributions will be pooled in the common fund, from which we will support investments that reduce the impact of climate change. The aim of the game is to collect at least a given amount of money in the common fund.

Let’s have 6 players in the game (but other numbers are also possible). They will play 10 rounds, where in each round the referee will ask who would invest in the common fund. With their eyes closed, players show 0, 2 or 4 fingers. The referee sums up the total investment received and writes the amount on the board. At the same time, players also make a note about their recent investment. If at least 120 gold ducats are invested by the end of the 10th round, the climate catastrophe has been avoided and players can keep their remaining money. (The threshold should be calculated by multiplying the number of players, the medium possible investment and the number of rounds. In this case, 120 = 6 x 2 x 10.) The winner is, who has the most money left. However, if the common fund did not reach 120 gold ducats, we roll the dice to decide whether the climate catastrophe has been realised or not. If we roll an even number, everyone loses their remaining money (a climate catastrophe has occurred), if we roll an odd number, they can still keep their remaining money. Can we make the right amount of investment? And who can keeps the most money? In case of much more players, players can be divided into groups depending on the number of people, and the groups can play the game separately. We recommend to create two or three groups, if you have more than 15 people. You can play the game in one group with less than 15 people.

Variant 1: Change the probability of the climate catastrophe (if the investment goal is not reached). For example, we only lose money if we roll a 6, or we only keep money if we roll a 6. (You can set much lower or higher odds by drawing numbers from an envelope.)

Variant 2: You can play the game without knowing exactly how many rounds you have. The referee draws a number between 8 and 12 from an envelope. The number drawn will be the number of rounds, the round which the dice roll follows. Only the referee knows this number, the players do not. If, for example, the selected number is the 9 and we have 6 players, then there must be at least 9 * 6 * 2 = 108 gold ducats in the common fund by the end of the 9th round. How does this rule change the behavior of players? How do they feel during the game?

Variant 3: Same as the base game, but after rounds 3 and 7, everyone announces in one word how much they will invest in the future (0, 2, 4). Let’s see if the promise will help you reach your goal!

Variant 4: Same as the base game, but in the first three rounds we collect 3 * 4 = 12 money (tax) from one half of the group at random, while we do not collect anything from the other half. Thus, at the beginning of the 4th round, there will be those with 40 ducats (rich) and those with 28 ducats (poor). How does the investment mood change if the start is uneven? The goal remains to keep as many golden ducats as possible.

Variant 5: In another possible variant, several groups of six play against each other. The goal is to have more money left in the group than in the others. The money for each group is managed by a chosen or random person. Before rounds 1, 4 and 8, there is one minute for the teams to discuss their strategy.

Biological background: The adverse effects of climate change are likely to be sudden. If CO2 emissions are not reduced effectively enough, that is, the countries of the Earth do not invest enough money to solve this, they will suffer much greater losses. We do not know exactly what the chances of this disaster are, nor exactly when it will occur. Both in the game and in real life participants face a common good dilemma: it is best to leave the investment to the others. However, if the majority thinks so, there is a certain chance that everyone will lose everything.

References:
Milinski M, Sommerfeld RD, Krambeck H-J, Reed FA, Marotzke J (2008) The collective-risk social dilemma and the prevention of simulated dangerous climate change. PNAS 105:2291–2294.
Tavoni, A., Dannenberg, A. Kallis, G., Löschel A. Inequality, communication, and the avoidance of disastrous climate change in a public goods game PNAS 2011, 108 (29) 11825-11829