ClimateCraft

Placing blocks, smelting and other activities add CO2 to a running total for the world. Plants and green blocks can absorb a limited amount, so a player who builds heavily or runs many furnaces pushes the total up. When the total crosses set thresholds, the effects begin: sea level rises by one block, which is irreversible, and plants in flooded areas die and disappear. Higher levels raise temperature, so crops grow toward a chance of dying, and dry conditions raise the chance of wildfires. A fire starts as a single block on a tree, and an alert appears so players can put it out before it spreads. Failing to do so can lead to a cascading environmental disaster.

Most specific values, such as thresholds and chances, are set in the climate config.json file. Leaf blocks, grass, dirt and plants also change over time: leaves can disappear, grass turns to dirt, packed dirt or dirt path with set probabilities, and dying plants turn into dead bushes. The mod runs on the server alone, so players join without installing anything. It is released under the MIT License and is open source. Files cover Minecraft 1.21 – 1.21.11 on Fabric only, with the latest file, 1.2.8, built for 1.21.11 and on the beta channel.