Carbon Climax

Burning fuel in a furnace, mining ore or chopping trees adds CO to the atmosphere, and the level is tracked in real time. As CO rises, the temperature responds, and players need shade, water, or high altitude to stay cool or risk overheating and taking damage. Heat also drains thirst faster and can trigger heatstroke debuffs, while animals stop breeding and may die off.

Climate feedback runs through the world. Rising seas, melting ice and snow, faster crop growth alongside water loss from irrigation, typhoons and floods hitting coastlines, and ocean acidification all follow from the climate model. Once temperatures climb too high, permafrost releases methane, which accelerates warming further. Crossing a threshold pushes back against the player, while pushing CO below 300 ppm triggers a climate reversal achievement.

The mod requires Fabric API and runs on Fabric for Minecraft 1.21.1 only. It is client and server, so the server and every player need it. The first Fabric build, 1.0.0 for 1.21.1, was published on 2026-07-12 on the beta channel. The code is under the MIT License, and the project is not open source.