The Guardian today, picking up on a paper in Nature, reports that scientists have calculated that there are more than “3tn” trees on Earth. The “3tn” means three trillion. What does “trillion” mean in British English? Did they give up on that “billion”-means-“trillion”/“trillion”-means-“quintillion” nonsense yet? Whew, yes. There are more than 3,000,000,000,000 trees.
How many more, though? Trees, though immobile, are hard to count. The previous global estimate was a mere 400,250,000,000 trees. “This has, however, been thrown into doubt by a recent broad-scale inventory that used 1,170 ground-truthed measurements of tree density to estimate that there are 390 billion trees in the Amazon basin alone,” the researchers write in Nature.
The new number is 3.04 trillion, they write: “With a human population of 7.2 billion, our estimate of global tree density revises the ratio of trees per person from 61:1 to 422:1.”
Not every denizen of Earth gets to enjoy his or her personal allotment of 422 trees, though. The Guardian offers a chart of the most and least tree-populated countries, from Russia (642 billion trees) down to Bahrain (3,000 trees). Down at the bottom of the chart, a note informs readers, “Clippeton Island, Spratly Islands and Vatican City have no trees.”
Can this be? How many trees has the pope? Zero? Is that why Pope Francis plans to detour into Central Park on his New York trip, so he can marvel at the leaf-topped things sticking up out of the ground? (“[W]e define a tree as a plant with woody stems larger than 10 cm diameter at breast height,” the Nature authors write.)
Here is a photographic map of the Vatican City from above, via Google:
Let’s look closer.
Those certainly appear to be trees, where the Guardian would have us believe there are none.
What is the relationship between the trees missing from the data and the trees that are visible in the imagery? Consider: The share of the world’s tree population that has been lost since the dawn of human civilization, according to the Nature authors, is approximately 45.8 percent. For every tree there is, there is nearly one other tree that is not.
Meanwhile, the Vatican Climate Forest, a widely publicized carbon-offset project in Hungary designed to make the operations of the Vatican City carbon-neutral, was reportedly a boondoggle that never led to any actual trees being planted. This occurred under the previous pope, Benedict XVI, before his unexpected resignation.
What is the truth about the trees of the pope?
Additional reporting by Jim Cooke.