James W.C. White started the INSTAAR Stable Isotope Lab in 1989. In recent years, his research has helped to show that large climate changes tend to occur in the natural system as abrupt and rapid shifts in mode probably driven by internal adjustments in the Earth climate system, rather than slow and gradual adjustments to changing external conditions, such as the amount of energy received from the sun. His research has also helped to show that land plants are capable of removing large amounts of carbon dioxide from the atmosphere, amounts that equal our input of CO2 from fossil fuel burning on short time scales. Such large changes in the uptake of CO2 by plants is a key piece in the puzzle we must solve to address future CO2 levels and climate change.