20% sounds like a lot!

Not sure if it actually is worrisome, but 20% is usually a non-trivial number. But then again, we must remember that climate change is good, and natural and nothing to worry about
Scientists are monitoring a massive pool of fresh water in the Arctic Ocean that could spill into the Atlantic and potentially alter the key ocean currents that give Western Europe its moderate climate.

The oceanographers said yesterday that the unusual accumulation has been caused by Siberian and Canadian rivers dumping more water into the Arctic and from melting sea ice. Both are consequences of global warming. [...]

German researcher Benjamin Rabe, of the Alfred Wegener Institute, said the Arctic’s fresh water content had increased 20 percent since the 1990s — about 8,400 cubic kilometers. That is the equivalent of Lake Michigan and Lake Huron together.