Seawater is water from a sea or ocean. On average, seawater in the world’s oceans has a salinity of about 3.5% (35 g/L). This means that every kilogram (roughly one liter by volume) of seawater has approximately 35 grams (1.2 oz) of dissolved salts (predominantly sodium (Na+) and chloride (Cl−) ions). A clear change in salinity has been detected in the world’s oceans, signaling shifts and acceleration in the global rainfall and evaporation cycle tied directly to climate change. In a paper published Friday (April 27) in the journal Science, Australian scientists from the Commonwealth Scientific and Industrial Research Organization (CSIRO) and Lawrence Livermore National Laboratory reported changing patterns of salinity in the global ocean during the past 50 years, marking a clear symptom of climate change.