What was done
Sea surface temperature and salinity data, together with measurements of seawater and atmospheric partial pressure of CO2, were collected before and after the passage of hurricane Felix in 1995 in a region of the western North Atlantic Ocean known as the Sargasso Sea.  Using these data, the authors estimated the contribution of hurricane Felix to the ocean-atmosphere exchange of CO2.  With additional hurricane and tropical storm data for the period 1983-1992, they also estimated the influence of all such storms on the global carbon cycle.

What was learned
The strong winds of hurricane Felix increased summertime loss of CO2 from the portion of the ocean it traversed by nearly 30%.  When data from nearby hurricanes Luis and Marilyn were included, this figure jumped to 45% of the total summer net CO2 efflux from this region of the ocean.  And in calculating the influence of all hurricanes and tropical storms located between 40°N and 40°S latitude, the authors found that they could account for a significant portion of the yearly global air-sea exchange of CO2.

What it means
This study demonstrates that hurricanes and tropical storms may play an important role in determining the yearly global flux of CO2 from the atmosphere to the ocean.  This finding is significant because it reveals the existence of a major feedback mechanism that was previously unknown and therefore not included in global carbon cycling and climate models, illustrating once again the danger of putting too much faith in the predictions of the current generation of GCMs.