CO2Sim
Each participant runs a country or a company and decides, round after round, how much to produce. Growth pays, but every shift adds CO₂ to a shared atmosphere everyone depends on. Profit today, or a habitable planet tomorrow.
The hardest problem in the room: cooperating
CO2Sim confronts participants with the dilemma that defines climate change — short-term individual growth against long-term planetary stability — and turns the tragedy of the commons into something you feel, not just something you discuss.
An authentic climate dilemma
A realistic balance between economic profit and CO₂ emissions: the same trade-off every government and every board faces today.
Collective consequences
Individual production decisions add up to one shared outcome: the global temperature everyone lives with.
Critical tipping points
Penalties escalate at +1.5°C and +2.0°C, and at +3.0°C the world collapses — game over for everyone.
Competitive multiplayer
Five countries or companies decide at the same time, each tempted to free-ride on everyone else’s restraint.
A world at the tipping point
The planet has already warmed +1.0°C. International agreements exist, but the pressure to grow is immense: citizens want jobs, shareholders want returns. You hold the throttle.
The setup
You represent one of five countries or companies. Round after round, you decide how many production shifts to run. More shifts mean more revenue, and more CO₂ pushing the global temperature upward.
Cross +1.5°C and economic penalties begin; +2.0°C and they bite hard; reach +3.0°C and the world collapses, so everyone loses everything. The goal: maximise your cumulative profit without tipping the planet over the edge.
Key parameters
| Current temperature | +1.0°C |
| Danger threshold | +1.5°C |
| Critical point | +2.0°C |
| Catastrophic collapse | +3.0°C |
| Revenue per shift | €1,000,000 |
| Fixed / variable cost | €3,000 · €50/shift |
The question the whole simulation turns on: do you grow today, or survive tomorrow?
Everyone’s rational choice burns the planet
Three forces pull at every round. Producing more is the smart move for you and, multiplied by five, it is exactly what tips the world past +3.0°C. Pick a production level and watch the thermometer.
Your self-interest
Each production shift earns about €1,000,000. The rational move, the one shareholders applaud, is to run at full throttle.
Produce moreThe shared atmosphere
Every shift, by anyone, adds CO₂ to one common sky. Emissions accumulate and the global temperature only climbs.
One atmosphereThe collective outcome
If all five run at maximum, the world passes +3.0°C and collapses, and everyone’s accumulated profit is wiped out.
CollapseClimate simulator
If all five economies choose this production level every round, in a 10-round game:
Illustrative projection based on the documented design of the simulation (shift → CO₂: 0 → −5, 1 → 0, 2 → +5, 3 → +10; revenue of €1M per shift; penalties of €200 at +1.5°C and €400 at +2.0°C per player and round; collapse at +3.0°C). The free-rider trap: maximum production pays best for you alone, but if all five do it, everyone loses everything.
A simple decision, round after round
The mechanic is deliberately minimal — pick a number from 0 to 3 — so that all the complexity lives in the strategy and the group dynamics, not in the interface.
Choose your shifts
Pick 0 to 3 production shifts for the round.
Everyone commits
All five players lock in their choice at once.
Emissions add up
Total CO₂ rises and the global temperature updates.
Profit and penalties
Revenue is booked and temperature penalties are charged.
Next round
Repeat, until survival or collapse.
| Shifts | Operation | CO2 | Gross revenue |
|---|---|---|---|
| 0 | Active reduction | −5 | €0 |
| 1 | Carbon-neutral | 0 | €1,000,000 |
| 2 | Moderate | +5 | €2,000,000 |
| 3 | Maximum | +10 | €3,000,000 |
Each extra shift pays you almost a full €1,000,000: the variable cost is trivial. The real cost of producing is paid by the shared atmosphere, not by your account.
A simple choice
One number, 0 to 3, each round: easy to learn, hard to master.
Real-time feedback
Temperature and finances update live as the round resolves.
Optional bots
Bots fill empty seats, copying the most conservative human choice.
Profit maximisation
Win on cumulative profit, without tipping the world into collapse.
What participants take away
An experiential bridge from abstract theory to lived experience: the tragedy of the commons, collective-action problems, and why coordinating climate action is so hard even when everyone understands what is at stake.
Tragedy of the commons
The conflict between individual incentives and collective welfare, and how hard cooperation is without enforcement.
Collective action and free-riding
Why voluntary coordination breaks down, and how opportunistic free-riding undermines the group.
Systems thinking
The cumulative effect of small decisions, and the non-linearity of tipping points in complex systems.
Intertemporal trade-offs
Short-term gains against long-term stability, and the pull of present bias and temporal discounting.
Game theory
The iterated prisoner’s dilemma: dominant strategies, Nash equilibrium and Pareto-optimal cooperation.
Environmental economics
Negative externalities, abatement cost against damage cost, and the role of climate policy and regulation.
Pedagogical anchors: Hardin on the commons, Ostrom on governing shared resources, Axelrod on the evolution of cooperation, with a direct line to the COP negotiations and the Paris Agreement.
Private wins, shared losses
Each player tracks their own income statement while one number belongs to everyone: the global temperature. The chart shows the cliff — profit climbs with production, then collapses to zero the moment the world tips.
Income statement
Revenue, fixed and variable costs, temperature penalties and net profit, round by round.
Cumulative profit
The individual scoreboard: who is winning the private race.
Global temperature
The shared verdict: the background itself shifts colour as the planet heats.
Comparable across cohorts
Instructors get a unified results view and can run parallel worlds — pure competition against negotiation allowed — to compare cooperation rates, free-riding and the round of collapse side by side.
One engine, many sessions
A real-time panel runs the room, and a set of modes turns the same simulation into a pure-competition energiser, a model-UN negotiation, or a policy lab.
Pure competition
No communication between players: maximum tension, the commons at its starkest.
With negotiation
Pause between rounds for non-binding verbal agreements: the closest thing to real climate talks.
Asymmetric roles
Give some players developed-economy capital and others growth needs: it adds climate justice.
Policy injections
Introduce a carbon tax or an abatement subsidy mid-game and watch behaviour shift.
Tune the economy
Set fixed and variable costs, the number of rounds and the refresh rate from the panel.
Bots fill the seats
Run with fewer than five humans; bots copy the most conservative human move.
Built-inSpot the free-riders
Monitor cooperation patterns live and identify leaders and opportunists round by round.
Pause, advance, revert
Full round control: advance manually, revert mistakes, or reset the game.
From the game to the real COP
Whether the world survived or burned, the debrief is where it connects to prisoner’s dilemmas, Paris-Agreement realpolitik and the everyday commons inside any organisation.
Briefing
Set the climate context and the rules. Emphasise the one that changes everything: at +3.0°C, everyone loses.
Active simulation
Run 8 to 12 rounds of 4 to 6 minutes each. Watch cooperation form, or free-riding take hold near the thresholds.
Observe the dynamics
Note who leads, who defects, and the rounds where behaviour flips at the critical temperatures.
Debrief and connect
Did they survive? Who won? Tie the strategies to the theory and to real climate negotiations.
Discussion questions that drive it home
Did the world survive, or collapse? At which round did the temperature trend become irreversible?
Was running at full production the rational move for you individually, even though it doomed the group?
Did anyone lead by example or broker an agreement? Who defected first, and what happened to trust?
Where is the gap between the Nash equilibrium and the Pareto optimum here, and what would close it?
How does this mirror the COP process and the Paris Agreement: non-binding pledges, free-riding nations?
Which mechanism would have helped most: a carbon tax, binding quotas, communication, or enforcement?
The insight to land
The small per-round penalties never deter anyone: only the +3.0°C catastrophe does, and by then it is too late to reverse. Rational, self-interested players burn a planet nobody wanted to lose. Naming that, and then exploring enforcement, pricing and communication, is where climate strategy stops being a slogan.
CO2Sim at a glance
Everything you need to position, schedule and run the simulation.
Answers to the most frequently asked questions
Between 60 and 90 minutes of play plus 30 to 45 minutes of debrief. A typical session runs 8 to 12 rounds of 4 to 6 minutes each, and the number of rounds is configurable from the instructor panel.
Five countries or companies decide at the same time. If fewer than five people are in the room, optional bots fill the empty seats and copy the most conservative human move, so the dilemma still works.
One number per round: how many production shifts to run, from 0 to 3. Zero means active reduction, one is carbon-neutral, and each extra shift adds both revenue and CO₂. Everything else — the tension, the negotiation, the strategy — grows out of that single choice.
A real-time panel: fixed and variable costs, the number of rounds, round advance, revert and reset, and a live view of who is cooperating and who is free-riding. The same simulation can be run as pure competition, with negotiation between rounds, with asymmetric roles, or with a carbon tax injected mid-game.
MBA and executive education programmes in sustainability and ESG, environmental economics, public policy and climate diplomacy, and any game theory or negotiation course that teaches the tragedy of the commons. It is available in Spanish and English.
Let us talk about your implementation
Write to us about how CO2Sim can help you achieve your learning objectives.
General inquiries
info@eurekasimulations.comPhone
(+34) 877 245 676Technical support
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Bring climate action into your classroom
Request a demo and we will show you how CO2Sim fits into your sustainability, economics or negotiation syllabus.