Scientists discover the world contains dramatically more trees than was thought
washingtonpost.com
washingtonpost.com
Livestock account for 18% of CO₂ emissions, agricluture 8% (75% of that from production of ag chemicals -- pesticides and fertiliser).
US EPA gives 9% of total CO₂ emissions as from agriculture:
http://www.epa.gov/climatechange/ghgemissions/sources/agricu... http://www.epa.gov/climatechange/images/ghgemissions/sources...
Nature puts the level at ⅓ worldwide:
http://www.nature.com/news/one-third-of-our-greenhouse-gas-e...
Deforestation: 6-17% of anthropogenic CO₂ emissions: http://www.nature.com/nclimate/journal/v2/n3/full/nclimate13...
None of your numbers suggest that carbon from soil is significant. The vast majority of carbon involved with agriculture comes burning fuel or from plants (such as when cows eat them and emit gas), and the carbon in plants comes from the air.
OK, here's a Wikipedia stat:
Soil carbon is the generic name for carbon held within the soil, primarily in association with its organic content. Soil carbon is the largest terrestrial pool of carbon, containing 2,200 gigatonnes (Gt) of it.[1] Humans increasingly influence the size of this pool. Soil carbon plays a key role in the carbon cycle, and thus it is important in global climate models.
Citing: Batjes, N.H. (1996). "Total carbon and nitrogen in the soils of the world". Soil Science 47 (2): 151–163. doi:10.1111/j.1365-2389.1996.tb01386.x.
Continuing:
Although the figure is frequently being revised upwards with new discoveries, over 2,700 gigatonnes (Gt) of carbon is stored in soils worldwide, which is well above the combined total of atmosphere (780 Gt) or biomass (575 Gt), most of which is wood. Carbon is taken out of the atmosphere by plant photosynthesis; about 60 Gt annually is incorporated into various types of soil organic matter (SOM), including surface litter; about 60 Gt annually is respired or oxidized from soil.[2]
And I really don'tknow how that is influenced by human activity, climate change, changes in biocover, etc.
There's also loess, a high-carbon sediment covering 10% of the Earth's surface, to depths of tens of meters, over 100 meters in parts of China.
https://en.wikipedia.org/wiki/Loess
More on CO₂ in soils: http://soilquality.org.au/factsheets/how-much-carbon-can-soi...
There's limited "missed future CO2 absorption" to deforestation, but there's a huge "immediate" released of stored carbon.
Surely that depends on where the tree goes. If it's burned, or left rotting, sure. If it's harvested for building materials, might it not even lead to increase storage of carbon overall.
http://www.nature.com/nature/journal/v455/n7210/full/nature0...
http://www.scientificamerican.com/article/old-growth-forests...
http://www.sciencedaily.com/releases/2008/09/080910133934.ht...
It's not inconceivable that trees could store roughly similar orders of magnitude of carbon per area.
x: 0,3 * 5e18 * 400/1e6 / (7000000*7000000*4*3,14)I am curious about the last assumption: Wood products can hang around for quite a while, so while long-term decomposition may release their carbon into the atmosphere, in the short term we have some very old wood around. Hell, maybe we could grow trees and sink them into oxygen-deprived water where they never decay.
Ultimately investment in this area has been reduced as the truth could be very inconvenient for the economies that rely on tree farming or land created by deforestation. See the disgraceful yellow blob: https://en.wikipedia.org/wiki/Kyoto_Protocol
I have a hard time thinking of significant amounts of wood that doesn't decompose, unless treated by humans. There are exceptions, including petrified wood or maybe wood in oxygen-deprived water (I don't know much about that) but I doubt it adds up to much. I know I've read studies about the carbon released by decaying organic matter in rivers and river deltas; it's a well-studied process as far as I know.
Agreed. That's what I was thinking of to when I wrote, "unless treated by humans".
[0] http://www.homedepot.com/c/discover_benefit_pressure_treated...
> The study also finds that there are 46 percent fewer trees on Earth than there were before humans started the lengthy, but recently accelerating, process of deforestation. “We can now say that there’s less trees than at any point in human civilization,”
> loss of 15.3 billion trees each year... 5 billion of those may grow back each year, so the net loss is more like 10 billion annually.
> does not in any way change our understanding of the current rates of deforestation... “It does not say there’s more forest. It just says there’s more trees in the forest,” says Lovejoy.
> deforestation is making global warming worse... if we were living on an Earth with close to 6 trillion trees, rather than 3 trillion, climate change would be less severe.
"satellite observations and ground-based ecological work. The former gives an overall view of where forests do and don’t exist on the Earth’s surface. But the latter goes underneath the canopy to determine how many trees exist in a given area in a given type of forest."
It seems that satellites give a good measure of the acreage covered by forests but are not suitable for differentiating individual trees. To do that requires on the ground sampling and as more sampling is done it is being discovered that the actual number of trees differs substantially from previously established estimates.
(I didn't read the article)
So I guess the answer it depends what you're trying to measure.
I guess the need never arise for an automated tree counting algorithm.
I'm sure we can count trees from pictures reasonably well, but we can't count tree mass that's entirely obscured by other objects.
To count trees accurately from pictures would require a vast quantity of footage taken from under the canopy.
Recent developments with laser scanning using drones is likely to improve accuracy too.
Are you a programmer? Have you never had to deal with someone who thinks they're smarter than they are and thinks they know everything get pushy about the simplicity of doing things that are not as simple as they assume? I have, and I can't say I'm a fan of those conversations or the people who initiate them. Your comment feels a lot like that.
Perhaps you need to chill down a bit. This isn't Reddit. We're all here to learn something.
Some trees will be obscured by others so you will need a number of different cameras to create a 3D map. You would also need to measure the distance between the cameras to determine what area they cover.
A 10 minute analysis revealing a list of complexities as long as my arm is not a good start. It will probably be easier (let alone more accurate) to just count the trees.
> The scientists were able to reach these estimates by merging together two separate mechanisms for sampling trees — satellite observations and ground-based ecological work. The former gives an overall view of where forests do and don’t exist on the Earth’s surface. But the latter goes underneath the canopy to determine how many trees exist in a given area in a given type of forest. Thus, the study amplified satellite views with no less than 429,775 separate measurements of the density of trees at different locations around the globe.
A 10 cm trunk diameter pine is not a tree, is a... (let's invent a new word for this) a 'treeddler', a baby. This is a classical case of apparent amount of population after dissapearing of the older trees. You can pack instead a lot of little trees in less space, but is not even remotely the same and only one or two will survive.
The claim is that the number of trees was dramatically underestimated in previous studies. Which definition of tree was used doesn't make a difference as long as the same definition was used in the previous studies. Unfortunatly this is not made explicit in the article, anyone knows?
Only if it treeddles! If not, might sapling be a satisfactory existing word? Some dictionaries constrain sapling to 4 inches, which is ~10 cm.
Maybe to make people understanding the consequences of deforestation we need to create a new system and talk instead of ecological categories like seed, seedling, 'treedler', tree and perhaps 'treelder', but I'm just having fun with the words.
Ash, for example, is equal to "a common tree" but people forget often that the morphospecies "a 500 years ash" is extinct in most forests (as all species that depend on it). This is like if we try to define and understand human societies just looking at "people from 20 years or less".
Wouldn't you consider a 7.6x change in your salary "dramatically more"?
>It's not even an order of magnitude more!
That's irrelevant. Even in software profiling, making something run "merely" 2x as fast can result in HUGE profits and savings (e.g. the movie studio that gets its rendering done in 3 months instead of 6).
>In the past few decades, the world's forests have absorbed as much as 30% (2 petagrams of carbon per year; Pg C year−1) of annual global anthropogenic CO2 emissions1 — about the same amount as the oceans.
Furthermore, for reasons not yet understood, even static forests appear to be a continuing carbon sink over measured timescales.
> Much has been learned about the carbon cycle in forests, but there are still too many gaps in our knowledge. New observations have called long-accepted theories into question: the finding that unharvested forests, for example, are absorbing more carbon than they release2, accounting for half the sink, is contrary to the tenet of ecology, known as Odum's framework, that carbon flows in natural forests should be in equilibrium.
http://www.nature.com/news/carbon-sequestration-managing-for...
Paul.