Here’s my story behind a Silicon Valley startup up with enormous ambitions when it comes to climate mitigation with a global client to match its lofty goals.

In mid-January, Microsoft made an astonishing pledge: a company that now emits 16 metric tons of greenhouse gases annually would become carbon negative by 2030, and by 2050, zero out all of the emissions it ever put up into the atmosphere since the company was founded by Bill Gates and Paul Allen in 1975.

Much of this effort would require “negative emissions,” or pulling carbon dioxide from the atmosphere, not merely reducing its emissions from energy, transportation and infrastructure over its 12-country footprint. To do that, Microsoft will have to be heavily involved in protecting forests from deforestation to continue to act as a carbon sink, and contribute significantly to the reforestation of vast tracts of degraded land in order to pull more pollution from the sky.

My story focuses on the company, Pachama (Andean for Earth mother) that will do the high-tech aerial monitoring to verify that Microsoft’s carbon offset investments are intact and growing. It’s a critically important job if we are to get an accurate read on whether Microsoft, and others, are truly reducing their carbon footprint. I rarely get to write optimistic stories on climate mitigation, but this one certainly qualifies. It was a pleasure to interview the company’s smart and idealistic founder, Diego Saez-Gil.