Rapid decarbonization by 2030. Renewable energy dominates. Extreme weather events increase but remain manageable. Coral reefs survive in reduced form. Food systems adapt through innovation. Cities invest in green infrastructure. Most species survive with habitat protections. This requires unprecedented global cooperation starting today.

Most coral reefs die. Arctic becomes ice-free in summer. Sea levels rise 40-60cm by 2100. Extreme heatwaves hit every 5 years instead of 50. Water stress affects 2 billion additional people. Crop yields decline 10-25% in tropical regions. Climate migration increases significantly.

Catastrophic and irreversible changes. Amazon rainforest collapses. Greenland and West Antarctic ice sheets destabilize. Sea levels rise 1-2 meters by 2100. Mass extinction event. Billions face water scarcity. Multiple breadbasket failures simultaneously. Large regions become uninhabitable. Civilization-level threat.