The IPCC's worst-case projection is a temperature rise of 2.6 degrees C to 4.8 degrees C by 2100, and the few studies that go beyond that year suggest that warming would slow because of the physics of greenhouse gases at high concentrations. Tokarska and her team say that these past projections failed to include the complex give-and-take of carbon on Earth. Most importantly, oceans—like a saturated sponge—lose their ability to absorb more heat and carbon, leaving it nowhere to go but the atmosphere.