A new study places before us an old and humbling truth: nature, once disturbed, does not simply wait for us to act. Researchers have found that warming ecosystems — thawing Arctic permafrost, weakening ocean carbon sinks, stressed forests — may set in motion self-reinforcing cycles that amplify global heating by 20 to 30 percent beyond what human emissions alone would produce, potentially rendering current climate models dangerously optimistic. The finding does not remove human agency from the equation; it sharpens its urgency, reminding us that the window in which our choices remain decisive