THE AMOUNT of carbon transported via Finnish rivers to the Baltic Sea has risen substantially in the past few decades. This was found in a collaborative study by the University of Helsinki, Aarhus University and the Finnish Environment Institute. The researchers don’t know the exact effects yet. The researchers investigated changes in the amount of organic carbon by exploring water-quality monitoring data for 30 rivers and a period of 25 years. The data demonstrated that Finnish rivers now transport 280,000 tonnes more carbon to the Baltic Sea each year than they did in the early 1990s.