Now, at 70, she’s telling her story — at least the parts she’s allowed to talk about — and admirers are praising her highly classified struggle to put the nation’s spy satellites onto a radical new job: environmental sleuthing.

“It was fun,ȁ she said of her C.I.A. career. “It was really a lot of fun.ȁ

r. Zall’s program, established in 1992, was a kind of wayback machine that looked to as long ago as 1960. In so doing, it provided a new baseline for assessing the pace and scope of planetary change. Ultimately, it led to hundreds of papers, studies and reports — some classified top secret, some public, some by the National Academy of Sciences, the premier scientific advisory group to the federal government. The accumulated riches included up to six decades of prime data on planetary shifts in snowfall and blizzards, sea ice and glaciers.

While much of the defense and intelligence business is incredibly wasteful, they have some unique capacities, especially in the domain of remote sensing that are essential to better understanding what is happening on our planet.