[viivaux]

> Topsoil should properly be measured in volume, not distance

Should it though?

And regardless of how clear or unclear that is, I gotta say I dislike seeing when the sum of a multitude of reports is expressed in a headline, only for people to nitpick through it without even attempting to check the actual methodology for themselves.

1 cm/year is 33 times faster than 3 cm/100 years, not a few hundred times faster.

AFAIK terra preta is far from fully understood, and farther still from being widely used. Very cool stuff though.

[splendidtube]

Only responding to the one part of your comment, it was 3cm/1000 years, so a few hundred (333) years was accurate.

[sigmaprimus]

You are both right, farmers measure rainfall in inches, (which translates to inch acres) so it is both a mesurement of distance (inches) and acres (how many they own) think of centimeters per year the same way. Yes topsoil can be made much faster than these numbers given but there are consiquesnces, methane is released from the process of composting which is 19 times the greenhouse gas than the CO2 released from burning. Also the volume is affected by soil compaction and the production potential is affected by increased salinity from unused fertilizer, the outlook is scary but humans always adapt.

[darkpuma]

> "ROME (Thomson Reuters Foundation) - Generating three centimeters of top soil takes 1,000 years, and if current rates of degradation continue all of the world's top soil could be gone within 60 years, a senior UN official said on Friday."

The article is crap, it doesn't answer any of my questions. You think I didn't check it before I commented? It quotes Maria-Helena Semedo throwing out that figure without any clarifying context or explanation. Without saying where it came from or what it's actually a measurement of.

Also, three centimeters per one thousand years is much slower than three centimeters per century.