Global Warming May Overshoot and Trigger the Next Ice Age, Say Scientists
Scientists have identified a critical feedback loop in Earth's carbon cycle that could theoretically trigger a future ice age. As global temperatures rise, increased nutrient runoff from land fuels massive plankton blooms in the world's oceans. These blooms absorb atmospheric CO2 and bury it in deep-sea sediments as the organisms die and decay. In low-oxygen environments, this process accelerates, drawing down carbon levels so sharply that it can cause extreme cooling. Simulations by UC Riverside researchers suggest this mechanism explains how Earth entered ancient periods of total ice coverage. While this natural "thermostat" exists, scientists warn it will not reverse human-caused climate change in the near future. Human CO2 emissions are currently heating the planet much faster than this slow natural cooling process can offset. The study emphasizes that immediate reductions in carbon emissions remain essential to prevent catastrophic environmental outcomes.