CNET también está disponible en español.

Ir a español

Don't show this again

Sci-Tech

Wildfires likely torched more than 7 percent of Earth's trees in the past decade

New research estimates that there are currently more than 3 trillion trees on Earth, but CNET's Eric Mack ran the numbers and found a shocking number are going up in smoke.

Wildfire smoke seen swirling above Russia in 2012. NASA

My last memory of the Alaskan Bush, where I lived from 2002 until 2004, is of walking toward the village airstrip along the banks of the Yukon River one overcast day and feeling as though I was choking. My eyes watered and my throat burned from all the wildfire smoke in the air. As my plane to Fairbanks ascended, rising above the smoky haze hanging over the forest, I realized that it was actually a sunny, cloudless afternoon.

That was September 2004 -- the worst wildfire season on record in Alaska. Until perhaps this year, that is, which is quickly approaching the more than 6.6 million acres burned 11 years ago.

The 2004 Alaskan wildfire season is not even included in the calculations I made after reading new research in the journal Nature released Wednesday, finding the total number of trees on Earth is an estimated 3.04 trillion, a full order of magnitude higher than previous guesses.

I've lived within a mile of National Forest land for most of my adult life, both in Alaska and here in New Mexico, where the threat of wildfire looms perennial. I couldn't help but morbidly wonder how many of those three trillion beauties will go up in smoke in the next decade.

So I decided to try to figure out how many of them have burned since that day in 2004 where the most pristine wilderness I'd ever known choked me as the particulate remains caught in my lungs.

My educated-but-not-fully-scientific guess is pretty shocking. When I ran the numbers, I found that over 248 billion trees have burned in the past decade -- if we play it conservative and assume the 3.04 trillion tally doesn't include these burned trees, that means at least 7.5 percent of the world's trees have been burned in wildfires in the last decade.

I say "at least" because I'm only working with wildfire data from three countries -- the United States, Canada and conservative estimates of acres burned in Russia based on NASA satellite observations.

I want to emphasize that I've just done some simple number crunching here based on the data in the Nature paper and the above data sources, nothing scientific or peer reviewed. Some wildfires burn grasslands or less dense forests, after all, but in the three countries I have data for, they're mostly burning northern, boreal forests like the one where I lived in Alaska. These tend to be the most dense forests around and they're also areas currently facing the brunt of climate change.

The crazy thing is that these numbers don't even take into account other places like China and Indonesia that have regular wildfire seasons, or the estimated 47.4 million acres of global forest cover that are lost every year, mostly for other reasons like development or agriculture.

Wildfires aren't all bad, of course. Some of them are natural and good for healthy forests. When some trees burn others grow back in their place -- that's actually how you get a lot of the nice fall foliage from aspen trees here in the Rockies. But you may have noticed that trees don't grow back especially fast -- that's why forestry is not yet considered a spectator sport. They certainly aren't maturing at a rate to replace the 25 billion per year being burned in those three countries.

So yes, we have more trees than we thought and that's cool, but you may still want to consider becoming a tree hugger. Trust me, hugging that rough old bark feels a lot better than inhaling it.