Arctic sea ice melts over the summer, reaching its lowest point sometime during September. Then, during the winter, ice builds up again and reaches its highest level in March.

Researchers reported Arctic Ocean ice levels reached a summertime low of 3.7 million square kilometers on September 15. That is the second lowest level recorded since 1979, when satellite observations of the sea ice began.

The lowest level recorded was in 2012, when the ice shrank to 3.4 million square kilometers. In the 1980s, the ice cover was about 2.7 million square kilometers bigger than current summer levels.

Melting sea ice does not directly add to rising sea levels. But scientists say it can have a direct effect on rising temperatures.

In another recent study, U.S. researchers suggested the Arctic has experienced such intense warming in recent decades that it is now changing to a completely “new climate state.”

The scientists based their research on hundreds of detailed computer models and observations of Arctic climate conditions. They used this data to define climate conditions of what they considered the “old Arctic.” The team then attempted to identify future climate changes linked to human-caused warming.

The study was based on high-end predictions for future levels of greenhouse gases, pollutants that trap heat in Earth’s atmosphere. The researchers noted that lower greenhouse gas levels would lessen future climate changes in the Arctic.