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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."

20 of 209 comments (clear)

  1. Hmmm... by NettiWelho · · Score: 4, Insightful

    I dont think there will be any actual planetary limits on crop production, just the matter of understading all of variables and how they interact.

    1. Re:Hmmm... by fuzzyfuzzyfungus · · Score: 4, Funny

      All limits are political.

      And they say that postmodernism is dead...

    2. Re:Hmmm... by budgenator · · Score: 5, Interesting

      Well, "primary production increase" => google.com = about 134,000,000 results (0.27 seconds)

      The results surprised Steven Running of the University of Montana and Ramakrishna Nemani of NASA, scientists involved in analyzing the NASA satellite data. They found that over a period of almost two decades, the Earth as a whole became more bountiful by a whopping 6.2%. About 25% of the Earth’s vegetated landmass — almost 110 million square kilometres — enjoyed significant increases and only 7% showed significant declines. When the satellite data zooms in, it finds that each square metre of land, on average, now produces almost 500 grams of greenery per year. Surprise: Earths’ Biosphere is Booming, Satellite Data Suggests CO2 the Cause

      or if you want original sources

      Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years (1982 to 1999) of both climatic data and satellite observations of vegetation activity. Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation. Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999

      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.

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    3. Re:Hmmm... by dryeo · · Score: 4, Informative

      Actually hemp is maybe the most nutritious plant for human consumption. The seed has all the essential oils and more importantly it is one of the two (common?) plants that have all the essential amino acids, slightly less then soy 23% vs 25% protein) The leaves, I'd guess are like most greens, vitamin c, some a and lots of minerals and of course, roughage. With sunshine and a source of B12 you could live a long time on a hemp diet, longer then any other common crop and perhaps any plant.

      http://en.wikipedia.org/wiki/Hemp#Nutrition
      http://www.thenourishinggourmet.com/2009/03/hemp-seed-nutritional-value-and-thoughts.html

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  2. But are we really trying? by __aaltlg1547 · · Score: 5, Insightful

    What we're trying to do is grow SPECIFIC plants that are useful to people. We have never cared much if at all that what we are really doing is converting areas that grow one kind of plant to grow another kind of plant. If we were trying to increase primary production, no doubt we could do that, but we would be up against the same things that limit agriculture now: mainly water availability. But if you built a lot of greenhouses and water recycling systems we could probably increase primary production substantially.

    1. Re:But are we really trying? by fustakrakich · · Score: 4, Insightful

      ...mainly water availability.

      The stuff falls out of the sky every day. We just have distribution issues, only a tiny percentage of which is technical. But be ready for real fast and massive climate change if we were to suddenly 'green the deserts'.

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    2. Re:But are we really trying? by icebike · · Score: 5, Insightful

      What we're trying to do is grow SPECIFIC plants that are useful to people. We have never cared much if at all that what we are really doing is converting areas that grow one kind of plant to grow another kind of plant. If we were trying to increase primary production, no doubt we could do that, but we would be up against the same things that limit agriculture now: mainly water availability. But if you built a lot of greenhouses and water recycling systems we could probably increase primary production substantially.

      Well, that's a nice theory, but its simply not true.

      The amount of land dedicated to farming has not substantially increased, (in fact it has decreased) as farming becomes more efficient. Vast tracts of the
      midwest have returned to forest because there is simply no economic need to keep these lands under the plow.

      This whole theory is nothing but a huge rehash of the Limits To Growth, cited in TFA. Yet 40 years hence, LTG has been proven wrong in just about every single prediction they made. Their methodology and assumptions were simply wrong.

      Measurement of plant tonnage via satellite imagery has revealed that plants still grow just about everywhere they ever did. Wow. Major revelation.

      Yet the satellites seem to miss the fact that global food production has more than tripled since 1961, and worldwide, we are only using 7% more land in the process. In North America Europe, and Russia, we are actually cultivating less land, and producing vastly more food. Marginal lands have fallen fallow, and returned to prairie or forest of a 2 hundred years ago.

      Measuring the area covered by plants says nothing about the tonnage harvested every year off of that land. Nor does it say anything about the reduced pollution produced in the process, and the return of natural flora coverage. The total forest area in the U.S. has been relatively stable for the last 100 years (currently about 747 million acres). The species may change (they always have over time). But its not because we have converted the land to farming. For the last 100 years, the biggest threat to forests has been housing development, not farming.

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    3. Re:But are we really trying? by icebike · · Score: 4, Insightful

      We are greening the desert. More rain has fallen in the Sahara in the last decade than in the previous two millenia. I doubt htis is good.

      Why would it be bad? The Sahara has been growing for several hundred years, and halting or reversing that growth could well be positive.

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    4. Re:But are we really trying? by symbolset · · Score: 5, Informative

      Of course the question about terrestrial crops completely ignores the fact that the world is about 70% ocean. In terms of the ability of plants to convert solar energy to carbon trapping, the ocean has always had far more impact than the land does. In the ocean the entire height of the water column that solar energy can reach is teeming with algae doing photosynthesis - and below that other forms of life feed on the detritus. The evolution and distribution of various forms of algae and plankton are far more important.

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    5. Re:But are we really trying? by symbolset · · Score: 5, Interesting

      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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    6. Re:But are we really trying? by symbolset · · Score: 4, Insightful

      We haven't even begun to exploit clathrates. There's far more of that than there ever was of oil. The arctic and antarctic reserves of oil and gas are far more than those yet discovered. Carbon fuels have a few hundred years to go yet.

      As current species move toward the poles, more heat tolerant species are generated at the equator. And life backfills the change with more life. Such is at it has always been. Our dynamic world has never been stable, and should never be.

      The supposition of AGC has ever been that a static climate is a desirable thing, despite the fact that such a thing has never existed in the history of the Earth, and never will.

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    7. Re:But are we really trying? by LourensV · · Score: 4, Insightful

      As current species move toward the poles, more heat tolerant species are generated at the equator. And life backfills the change with more life. Such is at it has always been. Our dynamic world has never been stable, and should never be.

      Heat tolerant species are generated? By whom? And more importantly, how quickly? Plants generally live quite long (annuals excepted obviously) and take quite a while to reproduce, especially in extreme circumstances. That means that evolution goes slowly. Climate change is currently happening extremely quickly. Hand waving doesn't make that problem go away.

      The supposition of AGC has ever been that a static climate is a desirable thing, despite the fact that such a thing has never existed in the history of the Earth, and never will.

      Humans haven't existed for most of the history of the Earth. Like all species we have a climatic niche that we fit into (hint: deserts, rain forests and polar regions are very sparsely populated). Now we're changing the planet to reduce the amount of space that falls within that climatic niche. Has the planet seen similar circumstances before? Sure, and it was fine. But what's important to us is that our species survives and thrives. Arguing that the planet will be fine is like saying that it doesn't matter when your only car breaks down halfway during your trip because the road will still be there. That's as correct as it is useless.

  3. Or, another way to look at it... by EmagGeek · · Score: 5, Insightful

    ... no matter how much plant matter humans harvest for various reasons, the Earth is able to replenish it to its maximum level.

    1. Re:Or, another way to look at it... by Guppy · · Score: 5, Interesting

      ... 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.

  4. Developing Marginal Lands by BoRegardless · · Score: 5, Informative

    The MidEast represents instructive activities of man over 10-20 thousand years.

    Farming started between Turkey and Iraq of today, the fertile crescent, but land salting and rainfall reductions reduced that output. About 10,000 years ago the inland valleys of Egypt were incredibly productive, but later rainfall reductions then reduced that to desert.

    Hence, natural rainfall changes altered growth a lot.

    Man induced changes in that same region has caused vegetation to increase in one spot where there is economic incentive to figure out how to grow plants in marginal lands. Israel. They have developed techniques to make it work. Other peoples in the area haven't been as diligent.

    Overall, maybe it is merely the cost-benefit ratio that determines whether mankind develops marginal lands.

    1. Re:Developing Marginal Lands by ppanon · · Score: 4, Informative

      Israel. They have developed techniques to make it work.

      Yes, and those techniques involve irrigation using so much water taken from the Jordan River that the Sea of Galilee and the Dead Sea have shrunk dramatically. At this point unless something drastic is done, in another 40 years Palestinians on the "West Bank" will be able to drive to Jordan.

      But yeah, those "techniques" are totally sustainable with no side effects, aren't they?

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  5. Still regions can be more productive by TheSync · · Score: 4, Interesting

    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.

  6. Quantity != Quality by onyxruby · · Score: 4, Insightful

    Quantity of plant life does equal quality of plant life, much less diversity of plant life. Simply saying we have "X" isn't that terribly helpful without context.

    So I'll provide some context and let's put a twist on this story which is being spun for political gain. In the year 1980 we had 4,453,831,714 people (the study starts in 1982 but close enough) In just 30 years the world's population grew 6,848,932,929.

    Over the course of three decades, the observed plant growth on dry land has been about 53.6 petagrams of carbon each year

    In other words, we have grown the population of the world by 50% in thirty years and we still kept just as much plant life. Job well done with planting things to compensate for a growing population! We don't need to change a thing, we doing everything right. Neither answer is right of course, they are both ways of spinning a set of meaningless facts.

    Point of the matter is that any given set of statistics can be twisted for a given political agenda with ease. The only thing this study does is show how easily meaningless data can be slanted for gain political purposes when the data is without merit. All it does is measure quantity without context. Might as well say a ranchers supports incredible wildlife, there's 200 cows and a dozen field mice.

  7. Kudzu? by rueger · · Score: 4, Funny

    Anyone who has battled kudzu will find this report rather hard to believe.

  8. You repeat the same lies! LTG is NOT wrong! by EnergyScholar · · Score: 5, Informative

    Limits To Growth has never been proven wrong. This lie, originally created by Economists, has been told, and retold, and retold again, and I see it again in that Reason article, which I just read. Same lies! Try this: Go out and buy the original 1973 Limits to Growth book. Read it and look at the numbers. Now get CURRENT data on the same items. Compare. You will find that they match strikingly well.

    The anti-Limits to Growth hatchet jobs tend to use the same lies. The standard approach, which is REPEATED in that lame Reason article, is to deliberately misinterpret LTG as predicting stuff it never said, then 'proving' that misinterpretation wrong. It's the standard 'Straw Man' argument, and that wretched Reason article does it AGAIN.

    To repeat myself: go out and buy the original 1973 Limits to Growth book, or any of the more recent ones. Read it and look at the numbers. Now get HISTORICAL data on the same items. Compare. You will find that they match strikingly well. Nothing in Limits to Growth has been proven wrong, that is a FALSE MEME that represents a triumph of Disinformation.