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Has Plant Life Reached Its Limits?
hessian writes with this news from the New York Times: "Since 2000, Dr. [Steven] Running and his colleagues have monitored how much plant growth covers terra firma, using two NASA satellites in the agency's Earth Observing System. After they crunched the numbers, combining the current monitoring system's data with satellite observations dating back to 1982, they noticed that terrestrial plant growth, also known as net primary production, remained relatively constant. Over the course of three decades, the observed plant growth on dry land has been about 53.6 petagrams of carbon each year, Dr. Running writes in the article. This suggests that plants' overall productivity — including the corn that humans grow and the trees people log for paper products — is changing little now, no matter how mankind tries to boost it, he said."
All limits are political. And the whole thing sounds like bullshit. Somebody's trying to work the commodities market.
“He’s not deformed, he’s just drunk!”
Plant life has existed on land for 450 million years, which is plenty of time to reach an equilibrium where the total mass is no longer growing. It's actually a relief that human impact on the environment doesn't appreciably alter this equilibrium on the time frame of a few decades. Why is anyone surprised that there is a finite limit and that it is not subject to increase?
There are huge areas where very poor people are living on subsistence agriculture in small plots that are not very productive, especially in Africa and the backwaters of India and China.
Eventually these small plots will be joined into huge efficient and more productive farms with GPS-optimized fertilization and irrigation.
All it would really take is true land ownership rights by the current farmers (many countries do not allow their poor farmers to own the land, its ownership is governmental or transfers are highly restricted), as well as some investment in infrastructure. The first would allow farmers to sell their small plots into larger farms, and the second would make it worth the investment in the large farms to be able to bring the produce out effectively.
More development of service or manufacturing jobs would also be needed to absorb many of the current farm workers, as the larger efficient farms would be more automated and need fewer workers.
Everyone here seems to be adding their own opinions none of which are suggested or demonstrated in the article. The basis for the conversation is that the green revolution should have made it possible for us to increase the green biomass. What we're seeing is that the green we grow is offset by wild green that grows less and the total green biomass remains constant. This isn't to say it will remain constant for any arbitrary length of time.
So this tells us we can grow one 2500 sequoia, or a similar mass of corn or wheat or soybeans in any given year. We also know that the tropical forests are under assault and because the wealth if tropical forests tend to be in their canopy and not their soul, a cleared area results in erosion and growing desertification. It will be interesting to see in 10 years when we can begin to see what the legacy of slash and burn forest clearing is doing to the Tropical places on earth. Add to that heat stress and drought and we will be seeing new and interesting changes.
... no matter how much plant matter humans harvest for various reasons, the Earth is able to replenish it to its maximum level.
Globally perhaps. But maybe not with the original species useful to humans, or in the same place.
For instance, deforestation often leads to erosion and topsoil loss (see Haiti), such that even if human harvesting pressure were reduced, the forests could not grow back, instead being replaced by deserts, or grasses and scrub vegetation. The nutrients in the lost soil may end up being dispersed by wind and water, aiding plant growth elsewhere, such that global vegetative production does not suffer. But that doesn't help the local inhabitants much.
Look up "Hadley cells" and the effect AGW has on them, there is very little doubt the Sahara and the rest of the sub-tropical deserts will continue to expand. This is despite the fact that on a global scale rainfall will increase, in fact it probably already has since global average humidity has already risen 4% in the last 4 decades. We are going to have a rough time watching the deserts bite into the grain belts as they expand poleward. Possibly we can redistribute the water but there will also be floods since there is now more rain to fall but (globally) a smaller overall area where conditions are right for it to fall. According to NOAA something like 30,000 norther hemisphere species have been observed adapting to AGW by shifting their normal range pole ward in the last few decades.
From personal experience I have seen the bird species here in Oz move southward since I was a kid in the 60's. I'm sure the biosphere will adapt, and in the long run out live us. It's interesting to look at it like feedback, in that even though it is we humans that are driving the rate of those adaptations I'm not sure that humans can keep pace with the biosphere's adaptations. We are the (macro) species most capable of doing so and "all we have to do" is stop, or at least significantly slow, our efforts to set fire to every last ounce of the already sequestrated carbon. In other words, over the next century the adaptation humans will be forced to make as a species will be to aquire the gene that stops them from in their own nest.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
All limits are political.
Can't be more true than that.
Hemp is band in many many countries just because some species of hemp happen to be marijuana.
But the use of the hemp plant is much more than marijuana.
http://en.wikipedia.org/wiki/Hemp
http://www.informationdistillery.com/hemp.htm
http://www.treehugger.com/environmental-policy/perfect-plant-7-great-uses-for-industrial-hemp.html
And most importantly, hemp grows very fast, and it can be grown in many soil types and also under various climate (from damp to arid) condition.
If that researcher took into account on the cultivation of hemp his conclusion would have been different.
Muchas Gracias, Señor Edward Snowden !
Well, "primary production increase" => google.com = about 134,000,000 results (0.27 seconds)
or if you want original sources
Oh who wrote that paper? " Ramakrishna R. Nemani1,*,, Charles D. Keeling2, Hirofumi Hashimoto1,3, William M. Jolly1, Stephen C. Piper2 Compton J. Tucker4, Ranga B. Myneni5, Steven W. Running1
Yes, I suspect your BS meter is running true. There seems to be a discontinuity between what Dr. Running said in 2003 about primary production and what he's saying in 2012.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Yeah, it's impressive. Almost nothing grows so fast as seaweed. Given the recent lesson of Japan tsunami debris we could probably just let an Algae farm go from Japan and harvest it on the West Coast of the US as it grew drifting across the open ocean. No need for fertilization, or weed management or any other service. Maybe other types of open sea aquaculture too like fish pens or mussel farms. In fact, by mixing the types the algae promote other sea life like plankton that the fish eat, and the fish feces feed the mussels and provide nitrogen for the algae, leveraging the lifecycle even more. And the mussels make mussel shells, which are primarily CaCO3 - so they reliably capture CO2 in a form that isn't readily released again. We can eat the seaweed, feed it to cattle, or process it for fuel - and it's useful for industrial chemical uses as well. The fish are protein. Probably get a good bit of bycatch as well like crabs, and no doubt shrimp and other types of sea life will swarm about the periphery of the farms. These farms could cover whole square miles each and work the ocean 150 feet deep. And we could work hundreds of thousands, or millions of them at a time - and feed the world's growing population for another hundred years.
Add some solar powered geotracking satellite comm tech and shipping warning systems and we could put near-unlimited tracts of Pacific Ocean under agriculture. Wherever the farms wander, when it's time we can go harvest them. And then we can give those ships from China something to take back with them besides coal: the rigging framework the open sea farms are made of.
We do need some new international agreements though to make it work because right now anybody who wanders out and catches such a thing on the open ocean is free to harvest it.
I would like to see an experiment taken with just one buoy with a 100m cable drop supporting a ladder of buoyancy neutral arms 100 meters long every 20 meters or so of depth seeded with seaweed and mussels and dropped off of Japan in a current likely to take it to the US west coast. Let it go and see what you get. I'm thinking it would turn into a seaweedburg of epic proportions: a 100m radius, 100m deep cylinder of biomass rich in all forms of sea life, completely surrounded by a diverse variety of ocean creature feeding off it and its detritus.
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There are at least two billion starving people on our planet who are being defended against free food by a few million men with guns. The sad fact is that the starving billions support the few millions enthusiastically, or at least tolerate them. Otherwise this could not go on for long.
Help stamp out iliturcy.
The point is that hemp could replace a lot of agricultural products that currently require significantly more arable land and resources. That leaves more land and resources available for food crops.
"Somebody has to do something. It's just incredibly pathetic it has to be us."
--- Jerry Garcia
Man is a million years old. The current interglacial is only 9000 years old. Written history is approximately 10,000 years old. The alignment of interglacial and written history is almost probably a coincidence. The fact that mile-high glaciers regularly sweep all evidence of our civilizations into the sea and clean the slate is completely irrelevant, yes?
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