Thawing Arctic permafrost is releasing ancient carbon into rivers at accelerating rates. This process could worsen climate change as more of that carbon becomes carbon dioxide. Credit: Shutterstock A new study offers one of the clearest pictures yet of what happens as Arctic permafrost thaws. Led by geoscientist Michael Rawlins at the University of Massachusetts Amherst, the research provides detailed insight into how warming temperatures are reshaping water systems and releasing long-frozen