What was done
The authors review the status of the mapping and measurement of glaciers, outlining plans for new satellite imaging platforms, automatic techniques for image analysis, and ground studies needed for validation of these techniques.

What was learned
It was determined that the practitioners of this branch of science have a mountain of work ahead of them.  There are an estimated 160,000 glaciers in the world, only about 67,000 of which have been inventoried over 50 years or more.  In this regard, they note that "it has been common practice for a single pair of glacier scenes to consume an entire year's effort by a small team of glaciologists."  Hence the need for automated image analysis and the long time that will be required to validate the analysis techniques.

What it means
Although the authors say that "the data available have proven that small ice bodies are disappearing at an accelerating rate," they also state that "before glacier data can be used to address critical problems pertinent to the world's economic and environmental health, the data need to become more comprehensive, more homogenous in detail and quality, and managed within Geographic Information Systems."  Hence, it will be some time before we will know the bottom line of the story that the world's glaciers have to tell us about past and future climate change.