Southern Ocean carbon sink failing

[Barrett808]

In the Southern Indian Ocean, climate change is leading to stronger winds, which mix waters, bringing carbon dioxide up from the ocean depths to the surface. As a result, the Southern Ocean can no longer absorb as much atmospheric CO2 as before. Its role as a 'carbon sink' has been weakened, and it may now be ten times less efficient than previously estimated. The same trend can be observed at high latitudes in the North Atlantic.

(more)

http://desdemonadespair.blogspot.com/2009/02/southern-ocean-carbon-sink-failing.html

[GoesTo11]

1. What does ten times less efficient mean?

Do they mean 1/10th as efficient? The use of "x times less" always confuses me.