How will you care for your 422 trees?

Posted: September 3, 2015 by tallbloke in data

I won’t be letting these goats anywhere near mine…

From Science daily:

A new Yale-led study estimates that there are more than 3 trillion trees on Earth, about seven and a half times more than some previous estimates. But the total number of trees has plummeted by roughly 46 percent since the start of human civilization, the study estimates.

Using a combination of satellite imagery, forest inventories, and supercomputer technologies, the international team of researchers was able to map tree populations worldwide at the square-kilometer level.

Their results, published in the journal Nature, provide the most comprehensive assessment of tree populations ever produced and offer new insights into a class of organism that helps shape most terrestrial biomes.

The new insights can improve the modeling of many large-scale systems, from carbon cycling and climate change models to the distribution of animal and plant species, say the researchers.

“Trees are among the most prominent and critical organisms on Earth, yet we are only recently beginning to comprehend their global extent and distribution,” said Thomas Crowther, a postdoctoral fellow at the Yale School of Forestry & Environmental Studies (F&ES) and lead author of the study.

“They store huge amounts of carbon, are essential for the cycling of nutrients, for water and air quality, and for countless human services,” he added. “Yet you ask people to estimate, within an order of magnitude, how many trees there are and they don’t know where to begin. I don’t know what I would have guessed, but I was certainly surprised to find that we were talking about trillions.”

The study was inspired by a request by Plant for the Planet, a global youth initiative that leads the United Nations Environment Programme’s “Billion Tree Campaign.” Two years ago the group approached Crowther asking for baseline estimates of tree numbers at regional and global scales so they could better evaluate the contribution of their efforts and set targets for future tree-planting initiatives.

At the time, the only global estimate was just over 400 billion trees worldwide, or about 61 trees for every person on Earth. That prediction was generated using satellite imagery and estimates of forest area, but did not incorporate any information from the ground.

The new study used a combination of approaches to reveal that there are 3.04 trillion trees — roughly 422 trees per person.

Full story

  1. “total number of trees has plummeted by roughly 46 percent since the start of human civilization, the study estimates.” Is there a correlation between this figure and the rise in CO2?

  2. kenwd0elq says:

    Heck, there are 8 trees just in my 1/6th acre lot. And that’s not counting all of the rose bushes or the volunteer privets that I keep chopping down….

  3. Would it help not to cut them down to run e.g. Drax and to put up wind farms?

  4. E.M.Smith says:

    But what size are they?

    Cut down one 2000 year old redwood and plant 100 poplar saplings, you have a large net loss…

    BTW trees, bamboo, and even corn can scrub the CO2 from the total air column above them in a surprisingly fast time…

  5. For some areas there has been an increase in trees. I read somewhere that satellite images show that trees & vegetation in Australia has doubled in the last 20 years. That certainly is the case where i live. My humble block you can see the trees grow daily.. Several trees have grown over 20m in height in ten years (but we have had good rainfall and the soil is decomposed basaltic).
    Recently, I visited China. I noted that while the building boom has come to a temporary halt everywhere there was tree planting, new parks being built and existing parks being improved and extended.

  6. tom0mason says:

    Another paper of modeled guestimations with few error-bars.

    Yes the new science is about hitting the headline, not thoroughly researching the topic.

    “total number of trees has plummeted by roughly 46 percent since the start of human civilization, the study estimates.”

    From what date (+/- ??), 46% eh? Not 45% not 47%, how?
    Recent melting glaciers have revealed high elevation forestation during periods when CO2 levels were high than now but iceages still arrived.

    But they used a super-computer so it all must be true, eh?
    Sorry paint me skeptical about this empty ‘study’.

  7. dscott says:

    IF the number of estimated trees was off by a factor greater than 7 then clearly the calculated CO2 uptake by the biosphere is also off by a similar factor. In other words, any CO2 generated by mankind is completely absorbed by nature or at least has very little residence time in the atmosphere until it is eventually absorbed. Meaning that any increase or decrease in total CO2 in the atmosphere is strictly regulated by the oceans being the largest CO2 sink in the biosphere. Thus falsifies AGW theory.

    You can’t claim AGW IF you can’t even calculate the biosphere’s CO2 budget accurately.

  8. hunter says:

    Once again a significant variable in the carbon budget is shown to be wildly unknown.