The earth has a meter, but it is n't always gentle. Soil, timbers, and abysses generally cushion change, distributing stress in ways that maintain balance. But when thresholds are crossed, systems respond with force. occasion 21 begins with extreme events — cataracts, backfires, hurricanes, famines, and heatwaves revealing the consequences of pushing ecosystems beyond their limits. These are n't arbitrary acts; they're responses bedded in Earth’s sense. Consider cataracts. downfall alone does n't produce disaster. cataracts do when soil can not absorb water, gutters are overfilled, and washes are missing or degraded. Urbanization composites the issue. Impermeable shells