Every year the yard becomes a bit brighter, the sun more inescapable. Every year the pools of light go up against the patches of shade. And the light is winning.

While this is comforting in a metaphorical, good-versus-evil way, it does not bode well for the tall oaks. There’s another one dead this summer, and another that is ailing. Is it drought or cold? Improper care? Lack of mulching?

None of the above, I imagine. It’s probably old age, the natural life span of this venerable fellow. Eight decades are enough; he’s had it.

But a report yesterday in Nature puts my yard in perspective. A team of scientists aided by satellite measurements and computer models found that there are a little over 3 trillion trees on Earth, 422 per person, a lot more than previously thought. But apparently not nearly enough, because we are losing 10 billion trees annually. Trees counteract global warming by capturing and storing carbon dioxide. We need trees now more than ever.

The Plant a Billion Trees Campaign aims to plant a billion trees by 2025. It has ten years and hundreds of millions of trees to go. Makes my tired oaks seem pretty insignificant.