The U.S. is losing its ability to track climate changes because of a lack of technology and, most importantly, the research ships required to track global warming from the oceans, according to a study by the National Academies of Sciences released Friday.

The study, “Sustaining Ocean Observations to Understand Future Changes in Earth’s Climate,” said the U.S. needs to expand its fleet of research vessels if it is to accurately assess the effects of climate change, which the Earth’s oceans are key in monitoring.