Chemical Weathering and Erosional Response of Northern New Guinea to Orbital‐Scale Climate Variability

Plain Language Summary We carried out the first research documenting chemical weathering in northern New Guinea for 330 ka. The breakdown of pristine minerals is recognized as being important in regulating atmospheric CO 2 and thus controlling the global climate over a variety of timescales. We explore the role played by New Guinea in modulating and responding to climate changes in 330 ka and assess its potential to affect global climate. We reconstruct the changing intensity of chemical weathering and calculate the rates of CO 2 consumption and organic carbon burial using well‐established methods. CO 2 was consumed in New Guinea more quickly during glacial times because erosion during these periods is more focused on rocks that are more mafic and thus more CO 2 consuming. This results in a positive feedback, removing more atmospheric CO 2 and allowing the Earth to cool further. The reverse occurs during interglacial times. Organic carbon burial does not vary with climatic cycles and accounts for only ∼15%–20% of the total CO 2 drawdown. Modern river sediment loads indicate that New Guinea is much more effective than the major river systems of Asia in removing CO 2 from the atmosphere.