How Trees Will Save The Planet

And How Jewish Law Nailed The Solution Centuries Ago

Zoe Samuel
3 min readJun 2, 2019


EARTH TO HUMANITY: More of this, plz. Kthx.

A study has come out by soil expert Dr. Thomas Crowther, who you may remember as the man who proved that prior estimates of Earth’s tree population were far too law. Four years ago, he proved the planet has, get this, three trillion trees on it. However, that’s down from 5.6 trillion trees before humans invented agriculture.

Trees are key to local and global climates. Locally, they improve air quality by scrubbing pollution from the air, reducing asthma, cancer, and other adverse health impacts. They reduce temperatures, not just by providing shade. They anchor soil, which captures more carbon than the tree alone, and improves soil quality. They also help keep water in the soil, which reduces forest fires.

On a larger scale, trees capture and store carbon in a semipermanent form. Indeed, one theory of the second part of the Little Ice Age — a colder period several centuries ago — suggests it was triggered by genocide of Native Americans. How? Trees took over large parts of the continental USA that the murdered residents had farmed. Thanks to all the new trees, atmospheric carbon dropped 7 parts per million (ppm), literally cooling the planet — until European colonists cut them all down again, of course (along with other Industrial-era climate impacts). The resulting cool period decimated crop yields in some of the colonists’ homelands, in a sort of climactic retribution.

So: trees matter — and today, Dr. Crowther is back to prove it yet again with a new study showing that simply by restoring some forests and placing trees on degraded and abandoned land, we have space to grow 1.2 trillion trees. These new trees would suck up so much CO2, they would erase the last decade of greenhouse gases entirely — that is, they could take us from our current 415ppm back down below 400ppm, temporarily at least. This would buy humanity a whole additional decade to complete our switch over to a green economy. This is why the UN has renamed their Billion Tree Campaign the Trillion Tree Campaign.

The upshot is that planting trees is either the most effective climate solution available to us, or certainly in the top few — and with genetic engineers working on improving some plant species’ ability to capture carbon, it’s even possible that is potential has been underestimated. On top of its climate benefits, it could also provide income for the owners of unproductive land in the form of carbon rebates for their trees, making them one more group of winners in the potentially very profitable green movement. (If you’re a farmer or just someone with a vacant lot, you should be advocating hard for a carbon dividend.)

This solution doesn’t just delight me as someone who cares whether our grandchildren live in a world in which Bangladesh has fallen into the sea. It’s also confirmation of possibly the single loveliest rule in Jewish tradition, which goes thusly: if the Messiah ever comes back, a Jew is supposed to drop whatever they’re doing and run to greet him — unless what they’re doing is planting a tree. In that case, the law is, finish planting the tree, then go and greet the Messiah. Indeed, Jews have a festival every year on the cusp of spring, called Tu BiShvat. It’s also known as Rosh HaShanah La’Ilanot, which literally translates to, “The New Year of the Trees”. Trees are that important.

Dr. Crowther’s new study confirms what our tradition tells us: planting trees is the highest expression of our duty of care toward God’s creation. To paraphrase someone decidedly not Jewish, Martin Luther, “Even if I knew that tomorrow the world would end, I would still plant my apple tree.” Perhaps he also knew, planting that apple tree is the best tool we have to prevent the end of the world.