The researchers studied changes in humidity in Tibet over the past 40 years by analyzing temperature, precipitation, and evaporation data. They found that temperatures have been increasing, especially in winter. Precipitation decreased from 1961-1980 but increased significantly from 1981-2000, particularly in the flood season. Evaporation increased in the 1960s and 1970s but decreased notably from the 1980s onwards. The ground surface initially dried up but became wetter in the late 1980s and 1990s due to increased precipitation and decreased evaporation. Overall, the 1960s were cold and wet, while the 1990s were warm and wet.