Spin the Greenhouse Gamble™ Wheels
The Greenhouse Gamble™ Wheels were developed by the MIT Joint Program on the Science and Policy of Global
Change to convey the likelihood of human-forced climate change. Each wheel represents a different set of greenhouse
gas policies, and the width of each slice gives the probability of the range in global temperature change by 2100.
More information on the Greenhouse Gamble™ Wheels
The Greenhouse Gamble™ Wheels were developed by the MIT Joint Program on the Science and Policy of Global Change to convey uncertainty in climate change prediction. Each wheel represents a different set of greenhouse gas policies, and each slice shows the likelihood of temperature change in that range by 2100.
The wheels are based on data from the following paper: Morris, J., A. Sokolov, A. Libardoni, C. Forest, S. Paltsev, J. Reilly, A. Schlosser, R. Prinn and H. Jacoby (2021), A Consistent Framework for Uncertainty in Coupled Human-Earth System Models.
Wheels represent the estimated probability of potential change in global average surface temperature in 2091-2100 compared to 1861-1880. Each wheel represents a different set of greenhouse gas policies following the below scenarios:
| Scenarios | Description | Median Global Temperature Outcome* |
|---|---|---|
| No Paris Accord | No Paris targets, but expansion of renewables policies. | 3.5°C |
| Paris Accord | Nationally Determined Contributions (NDC) targets are met by all countries by 2030 and retained thereafer. | 3.1°C |
| 2°C Policy | Paris NDC targets are met by all countries by 2030, afer which there is an emissions cap, implemented with a global emissions price, ensuring 2100 global surface mean temperature does not exceed 2°C above pre-industrial levels with a 66% probability. | 1.9°C |
| 1.5°C Policy | Paris NDC targets are met by all countries by 2030, afer which there is an emissions cap, implemented with a global emissions price, ensuring 2100 global surface mean temperature does not exceed 1.5°C above pre-industrial levels with a 50% probability. | 1.5°C |
*Average global surface air temperature in 2091-2100 relative to 1861-1880.
Humankind will be spinning the "No Paris Accord" roulette wheel as long as we allow global emissions to increase without global coordinated policies and accords; expansion of renewables policies will not be sufficient. However, if coordinated policies to reduce emissions are enacted, we will get to spin one of the three other wheels, depending on the policy, which gives us significantly increased chances of constraining global temperature change to below 3°C in 2100.
