Climate Models Disagree on Strength of Carbon Land Sink (image) University of Massachusetts at Amherst Share Print E-Mail Caption Annual net ecosystem productivity, (NEP, in grams of carbon per square meter per year) across the study region as an average across the nine climate models. Standard error range is shown in gray. Annual NEP, which closely tracks the net CO2 sink, shows an increase through the first four decades, and remains relatively stable since 2000. Credit UMass Amherst Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.