Last April, we presented the film "The Return of Old Growth Forests" at the Simsbury (Connecticut) Public Library; it was the first film in the New England Forests America 250 series.
In that film, the Biotic Pump theory was described by its co-author, atmospheric physicist Anastassia Makarieva, who described how large, contiguous, old natural forests bring fresh water inland from oceans during photosynthesis by transpiring water vapor into the air. That water vapor leads to precipitation, creating a feedback loop that keeps water vapor coming inland and the land hydrated... forests bring water to themselves, and us. That's part of the Earth's hydrologic cycle. Furthermore, with contiguous forest cover, water is effectively "pumped" across continents. As a result, not only do we get a terrestrial fresh water supply, but our climate is regulated, stabilized, and moderated as well. But that biotic pump mechanism can be shut down by degraded, interrupted, or eliminated forests.
On Monday, February 23, 2026, we are pleased to be showing the second film in the New England Forests America 250 series, which is a follow-up to that film entitled "Old Growth Forests - Nature's Biotic Water Pump".
For decades now, we've been hearing considerable discussion of how greenhouse gases, particularly CO2, cause climate change. But what has been almost totally ignored is the effect that alteration of land cover has on our climate. It's not just about carbon, and never was.
Keeping the land hydrated is crucial to terrestrial life, but many cultures have destroyed the very thing that makes the land habitable... forests! Places such as Egypt, Africa, Australia, and others, have become deserts because their forests were cut to the point where the hydrologic cycle was disrupted, then the soil dried out and could not recover on its own (ie, it became a "landscape trap"). That destructive behavior is still happening today in places like Canada, America, Chile, and the Amazon, putting those places also on the trajectory to desertification.
Change to land cover, especially the cutting and removal of forests, is referred to as "the second leg of climate change". The greenhouse gas effect is just one half of the climate story; land cover change is the other half, and just as important.
This story is told in much more detail in "Old Growth Forests - Nature's Biotic Water Pump". Anastassia Makarieva has become world renowned for her continuing research on the critical role of forests; in this film, she adds more information about the biotic pump mechanism.
This event, co-sponsored by Simsbury Land Trust, Simsbury Grange, the Simsbury Public Library, and Real Art Ways, is free and open to all, and will begin at 6:30pm. A Q&A session will follow the film.
