KERMIT OLSON MEMORIAL LECTURE: Food Supply and
World Population
March, 6, 1995, by Dr. David Pimentel
Dr Gary Gardner: I'd like to introduce Dr Mary Meyer,
who is the newest faculty member in the department of
Horticultural Science. She is an Environmental Horticulturalist,
with extension research appointment based at the Arboretum. Mary.
Dr. Mary Meyer: Thank you Gary. It is my plessure to introduce
our guest lecturer today, for the Kermit Olson memorial lecture.
Dr. David Pimentel received his Bachelor of Science degree from
the University of Masssechusets, snd his Ph D. from Comell
University. He has since studied at the University of Chicago,
Oxford University, and the Massachusets Institute of Technology.
He is currently a professor at Cornell University in 3
departments. Entomology, Ecology, and Natural Resources. Dr.
Pimentel has been the recipient of many honors and awards and he
has received national recognition for his work with food
production, population and natural resources. He is currently a
member of the National Board of Directors Carrying Capacity
Network, The committee for research and exploration of the
National Geographic Society, and the international advisory
committee 2020 vision for food, agriculture and the environment.
Now, you may wonder what the connection is between the department
of entomology, and world population and food supply. There's
really probably no more connection with that department than
there is with the department of Horticulture or the Department of
Plant Pathology, or the Department of Animal Science, or the
Department of Agronomy. And yet few of us in the scientific
community have chosen to face these major issues such as food
supply and world population. Few of us have come to grips with
them, and very few of us bring them to the attention of the
general public. So I am sure that you join me with great
admiration for the work that Dr. Pimentel has done. He's gone far
beyond the scope of his current department, to address issues
that are not only important to our scientific community, but to
our world as a whole. Please join me in welcoming Dr. David
Pimentel
Dr. Pimentel: Thank You very much, Dr. Meyer for your
kind introduction. I am honored to be delivering the Kermit Olson
Memorial Lecture. And Before I start, I would like to
congratulate all the scholarship awardees that we've seen here.
I am just going to keep this, based on the instruction I have
received to 45 minutes and leave 15 minutes or so for questions
at the end. And I am going to speak from slides, and so if they
can turn that projector on, and dim the lights.
There are seats down in front here for anybody, if you'd like
one.
I've put the first slide and the second slide only to visually
indicate to you we've got too many people. And, I think all of
you realize that. We already have 6 billion humans on earth
today. And we add a quarter of a million net gain every 24 hours.
A quarter of a million additional people to feed. Already in the
world there is 1.5 billion that are malnourished. 40,000 children
die each day because of malnourishment and disease. And about 2
billion people live in poverty. All three of these numbers are
the largest we've ever had in the history of the earth.
Now, few of you, I think. appreciate that we have a problem in
the U.S.. Or at least from my perspective that we do. In 1850,
the United States had 23 million people. Or less than the
population of New York and California, and perhaps Minnesota, but
I arn not positive on the population of Minnesota . In 1994 we
had 260,000,000. Tt's actually, you can never keep your slides up
to date, It is now 261,000,000. And the rate of growth of the
U.S. Population is 1.1% per year. Or a doubling time of just over
60 years. So in approximately 60 years, we will have a half a
billion or over 500,000,000 people in the United States. Now this
does include the regular births, and uh the number of immigrants
that we are, legal immigrants. I'm not talking about illegal
immigrants, that we have in the United States.
And I did receive 2 letters last week of people saying that's
not so. Well I must admit, it's not my data. It's U.S. bureau of
Census data. And so if you doubt a U.S. bureau of Census, then
these people said the population of the U. S. is not growing.
They gave me no data, but that was their view.
Now in the U.S. we're extremely fortunate in having an
abundance of food, high quality food and a good diverse food
supply. And I think provostly, few of you appreciate the fact
that the average American consumes 2200 lb. of food per year.
Over a ton. Actually, we're eating a little bit too much. And
this is where some of the excess is ending up. Now also the U.S.,
We've had an enormous change in technology in what we've been
doing. In 1850, when I just told you that the U.S. population was
23,000,000, we were 90%, 91%, to be exact 91% dependent on wood.
Today, we are 96% dependent on fossil energy. And also, to
illustrate how & out of focus we are relative to our use of
resources. The bar on your left indicates the quantity of fossil
energy that is used annually in the United States. And the bar to
the right of that one is the total solar energy that is captured
by all the plant biomass in the United States annually. That
includes forests, agriculture, lawns and what have you.
We are in fact burning 40% more fossil energy than the total
solar energy captured by all the plant biomass in the United
States. Europe is worse, but that is because they are denser.
Although, we are dependent on fossil energy in the United States,
in Europe, Japan, and Australia, and a few other developed
nations, the majority of the world's population that's about 75%
are still dependent on wood and other types of biomass resources.
That was a woman in Nepal, this is a shot in Africa, and so
forth. And crop residues are being burned and dung and so forth.
And obviously, one of the reasons our forests in the United
States are being protected is we are burning fossil energy, and
did not have to turn to cutting our forests quite extensively as
some in the world.
This is what remains of a tropical rain forest in Haiti. But
it is being duplicated in other parts of the world. World wide,
agriculture accounts for 80% of the deforestation that is taking
place, in large part due to the fact we are degrading our soils
through erosion, salinization and to replace these soils and to
illustrate that, during the last 40 years world wide, we have
been forced to abandon nearly 1/3 of our arable land. Where does
that land come from? The torests to replace that lost land. Now
to get back to the United States again, We import 60% of our oil.
At a cost of $70 billion dollars ($70,000,000,000) annually. And
the U.S. Department of Energy has indicated Alaska is our
greatest source of oil. And we peaked out in the use of oil or
the pumping of oil in 1988, and it is projected by 2015 we will
be down to the bottom of the barrel. And in fact generally in the
United States we will be out in the year 2015 or 2020 related to
oil, and natural gas comes soon after that. And we have good coal
reserves that will last us approximately 100 years. But in 2015
or 2020, we will be importing 100% of our oil at a cost of $ 150
billion or possibly $200 billion dollars annually. Now, we are
paying part of our oil imports today with about $40 billion
dollars in food that we are exporting. To pay for that $70
billion in oil. Oil imports is the primary cause of our balance
of payments debt in the U.S. And looking also to the future,
we're going to need oil obviously to produce food and all of the
other services that we depend on.
Now, also in agriculture for example, we do use large
quantities of various inputs, but to show you that you can
produce com by hand. I'm not going to go through all these
numbers, I just want to pick out a couple.
First of all the only thing you need to raise corn by hand is
an ax, a hoe and some seeds and a good strong back. It takes
approximately 500 hours, 1200 hours per hectare or 500 hours per
acre to raise corn by hand. Today, in the United States, we raise
an acre of corn with an input of only 4 hours, in contrast of
doing it by hand of 500. Now our yields since 1945 have increased
dramatically. Nearly a 3 fold increase in corn yields since 1945.
There have been some blips there, but in a large part this has
been achieved through fertilizers, hybrid corns, pesticides and
what have you. You'll note that our move to fertilizers is a
relatively recent event. In 1945 we were applying an average of 7
K. per hectar or 7 lb. per acre of fertilizer. There's been a 20
fold increase in the use of Nitrogen fertilizer in corn
production in the U.S. In fact, today the energy just to produce
the nitrogen fertilizer is more than all of the inputs that we
used in 1945, to show you how rapidly this technology is
changing. Now phosphorus and potassium have also increased, but
not as dramatically as nitrogen.
Now, another big input in agricultural production is
mechanization. That is the reason we have been able to reduce the
inputs of 500 hours per acre to 4 hours is mechanization. Now it
takes about 3000 gallons of oil equivalents to produce a piece of
machinery such as you see here. And they burn about 12 gallons of
diesel fuel an hour while in operation. To raise an acre of corn
in the U.S. requires about 140 gallons of oil equivalents to
produce anywhere from 110 to 115 bu. of corn per acre. A little
over a gallon of oil per bushel of corn that is produced. Now,
that 140 gallons per acre represents only 10% of the energy that
goes into raising corn. And that is the portion we're concerned
about, because we're rapidly running out of that resource. Most
of the energy, in fact about 90% of the energy to raise corn is
solar energy. That's the reason we can get 2 calories out for
every calorie we invest.
Now China is actually uses more fertilizer, more pesticides,
more irrigation water than we do per hectare, or per acre. But
they still have an input of 1200 hours per hectare in production.
The one surplus China does have is people.
Now just to show you just where some of the energy goes in
producing our food, I've taken a can of sweet corn. 455 grams, or
a one pound can. And if you ate all the corn that is in the can
it is 375 Kcal. of food energy. Now to produce the corn that is
in that one pound can requires 450 Kcal.. and then to process it
and to put it into a steel can requires about 1300 Kcal.. . or
almost 3 times as much energy tor the processing and the
packaging as it took to produce the corn that is in the can. I'm
not going to go through all these numbers, but just to pick out
one more. Shopping. To get that one pound can of corn home from a
grocery store. This is based on the average distance we travel,
the amount of groceries we bring home and the size automobile and
all that information. It takes 311 Kcal.. to get the one pound
can of com home from the grocery store. Or almost as much energy
to get the can of corn home as there is food energy in the corn
itself that there is in the can. Anyway, so you can eat 370
Kcal., that requires over 3000 Kcal. or approximately 8 Kcal. of
fossil energy per Kcal. of corn you consume. The average for our
total food system is about 10 Kcal. of fossil energy per Kcal.
that you consume.
Now, another big energy input in our food system is animal
protein. And it is because we eat so much meat, milk and eggs.
The energy is relatively high. Incidentally, the livestock
population in the united states outweighs the human population by
more than 4 times. This is where half of our grain goes to
feeding these livestock plus a lot of forage. Now you don't see
too much here on this Texas range, but in other places there is
forage. Now one trend that is a concern, world wide, food
production has been declining on a per capita basis since 1980,
despite the green revolution and biotechnology and all the rest
of it as measured by grains. Grains make up 80% of the worlds
foods. Now land is an essential resource in agricultural
production world wide, as well as the United States. And few
people appreciate the fact that more than 99% of the food in the
world including the U.S. comes from the land. Less than 1% is
from the oceans and aquatic systems. And that portion has been
declining due to over fishing, pollution and so forth. And so it
is the land on which we are going to depend in the future.
Now most of the arable land is already in production. This is
a shot I took in Guatemala a few years back showing you the
steepness of the slope in which they are raising corn and some
vegetables in the lower part that actually is terraced. And you
get a better appreciation of the steepness of the slope on which
that farmer is tilling the soil with his mule. And you can also
appreciate the erosion problem that would exist when growing corn
on a slope like this. Now one aspect we're blessed in the United
States, still with a relatively abundant land area. But we're
treating this not very effectively. I'm sure you've got some of
these around. This happens to be Los Angeles, but I'm sure around
here in St. Paul, you've got similar uses of land. And in a 30
year period from 1945 to 1975 in the U.S. we've blacktopped over
and I'm talking agricultural land now, we've blacktopped over an
area larger than the state of Ohio in 30 years. If you take all
the land that was blacktopped over during that 30 year period it
would be Ohio plus Pennsylvania. And we're still doing it. Not as
rapidly as in that period, but we're still removing. And for
every person we add in the United States requires one acre of
land in urbanization in highways and parking lots or whatever. So
that relates to our doubling of the U. S. population.
Now it's nice to see wheat growing against the blue sky. But
if you look onto the land, things aren't quite so pretty. This
happens to be in Kansas where they do have serious soil erosion
and Professor Meyer was teiling me, you have some here too. And
they sometimes... after you, at least in Kansas, use snow plows
to get the soil off of the highway. But more important than wind
erosion in soil erosion is water erosion. Here is a severe case
of erosion. Nearly 6' of soil has been eroded from this location.
Here is another shot of severe erosion. You all've seen this. Now
the seriousness of this problem is that we're losing this soil
year by year. Iowa, for example in l981 reported they'd lost one
half of their topsoil. Iowa has some of the best soils in the
world, next to Minnesota. In any case their losing soil 30 times
faster than the sustainable soil formation rate. The average in
the U.S. is 17 times faster than the sustainable soil formation.
The concern is, it takes five hundred (500) years to form an inch
of soil under agricultural conditions and you need a minimum of
6" for production. So it's an environmental problem that
once you have lost that resource, you can't sit around and wait
for it. Now you do have techniques and technologies today to
prevent soil erosion and control it. Crop rotations, contour
planting, terracing, grass strips, no till and what have you. But
we're still losing this soil. And then relative to the U.S.
population growth we graph here, currently we have 1.8 acres per
capita today, and when our population doubles to 500 million or
half a billion in the next 60 years, we'll then have .6 hectares,
I'm sorry, acres per person. And our agronomists tell us we need
a minimum of 1.2 acres per person so that you can have a diverse,
abundant food resource.
Now, some people say, don't worry about the loss of our land
to erosion or population growth and so forth. We can convert the
deserts into productive areas. That's true with 2 big if s. First
of all, that you have water, secondly that you have a lot of
energy.
First of all crops require an enormous amount of water. Just
for transpiration alone, a corn crop, during the growing season
will transpire 4.2 million liters per hectare or 500,000 gallons
of water just during the growing season, that's per acre. This is
the reason, that, to produce 1 kg. of food requires 1400 Kg of
water, or 1400 liters of water. If you want to translate that
into lb., it's 1500 lb. of water to produce 1 lb. of corn and so
forth and other foods for that matter.
Now the energy use in irrigation is enormous. This is data
from Nebraska. To produce rain fed corn for example requires
about 6 million Kcal.. To produce irrigated corn, the same yield,
but under irrigation requires more than 3 times as much energy.
So it's not only water demanding, but it's energy demanding. In
the U.S. and I'm talking now irrigation, Agriculture consumes 85%
ofthe water. The average for the world is 87%. So, we're very
close to that average. The thing is agriculture takes the water
out, but through transpiration and so forth it doesn't go back.
The public and industry takes the water out, they use it,
sometimes they pollute it, but at least we're very close to that
average. The thing is agriculture takes the water out, but
through transpiration and so forth it doesn't go back. The public
and industry takes the water out, they use it, sometimes they
pollute it, but at least they put it back. But in agriculture, we
don't and that's why we get this, these data on consumption.
Now this is a shot in Africa. And, I don't care how much
genetic engineering you have you are not going to produce a crop
of corn or any other food in a situation like that.
Now another group of organisms that share our food with us are
insects, diseases, weeds, rodents, and so forth. And we do use an
enormous amount of pesticides world wide and in the U.S. too to
protect our crops. The U. S. for example uses I billion pounds of
pesticides annually. Whereas the world appiication of pesticides
is about 5 billion pounds. In other words, the U. S. uses about
20% of the total world 's pesticides in control. Now despite the
use of all these pesticides world wide, and other controls, we
loose 35% of all potential production to again insects, diseases
and weeds. After we harvest that 65% we lose another 20% to
another group of pests, insects, microbes, rodents and so forth.
So that the total loss of food world wide due to pests, and
despite our efforts to prevent these losses is nearly one half.
Clearly this needs some improvement here.
Now, I talk about improvements in science and technology, and
I am a great believer in science and technology. However, I am
also a realist on what science and technology can do for us.
There are too many people who believe, "don't worry about
energy, don't worry about land, don't worry about water, or food.
Science and technology will solve all these problems for
you." To a degree it can help, but there are limits. Fish
production in the world, we've built more ships faster ships
larger nets. Fish populations are declining. And on a per capita
basis the amount of food we're getting from the oceans and the
aquatic systems are declining, despite all of our knowledge and
all of our technology. And certainly building larger and faster
ships is not solving that problem. As far as forest production is
concerned, larger and more chain saws is not helping the
production of forests. And as far as water resources, to
illustrate that one, the Colorado river that is shared by
California, Nevada, and Arizona and Colorado and so forth, by the
time it reaches Mexico it is neariy dry. I'd appreciate knowing
from anyone here what science and technology you know that will
double the flow of the Colorado river.
Another one, on arable land, I told you we lose 12 million
acres due to erosion and salinization annually. We have a
shortage of arable land generally in the world, what technology
do you know that will double the arable land of the world? And
biodiversity and pollination and to give you one illustration
here, in New York State for example, I'm going to give you that,
my estimate. I made a calculation on what honey bees and wild
bees and the number of blossoms they pollinate on a bright sunny
day in New York State. The number is I trillion blossoms. And
what technology do you know of that would allow us to pollinate
one trillion blossoms in New York State or Minnesota for that
matter. Well I could go on about this, but. I believe in science
and Technology, but I also recognize there are limits.
Now I was in Uganda earlier this year. This still shook.. has
shaken me, there was a large article in the newspaper, that the
farmers in Uganda could not afford $5 to buy a hoe to till their
soil this year. The annual income per capita is $170.00 so the $5
is a large number. So there are people that are really, sincerely
desperate today. Now over the last 10 years, what's happened to
some of our resources as shown here, land per capita has declined
21%, irrigation has declined 12%. This is all on a per capita
basis. Fish production has declined 10%, and fossil energy 7%.
Now we made a study a year or two ago on what would be the
optimum population of the world and the U.S. Based on a standard
of living like Europe . That means cutting consumption if you
want to know the relative to the United States, cutting our
consumption of energy and foods and water by 1/2. So if you use a
standard of living like the Europeans, that would be like cutting
consumption and also making the assumption that we stop soil
erosion, we stop mining the ground water and conserving our other
resources, we estimate we could support a world population of 2
billion and the U.S. could support a population of 200,000,000.
Now I think all of us realize, now obviously you can have more
people than this, we've got more in the world today, but they're
not living a very good standard of living And we won't have as
high a standard of living if we double or quadruple our
population in the U.S. There is no question that we humans are
going to have to stop reproducing, or growing some time in the
future. Either we ourselves with our wisdom or knowledge control
our numbers or nature is going to do it for us. We've got two
choices. Because if we let nature, it is through starvation,
violence, disease, and so forth and not a very pleasant . In fact
you can see this already in many parts of the world if you travel
to some of the developing countries. Now, I've given you some I
suppose of not terribly encouraging information about population
growth, the environment, living standards for many people of the
world. But I am optimistic at least from this point of view. That
if humans will make up their mind on what we want, I think we can
achieve a better life for everyone in the U.S. and the world.
(Applause)
Dr. Meyer: We have time for questions. If we can have
the lights back on in the back, thank you.
Q (Intelligible)
Dr. Pimentel: Well they don't, The great majority, I
agree with you, do say that probably 95%. There is a small
percentage that is growing. Herman Daily, John Chapman, and there
are several others that are taking, and Carl Folk in Sweden and
so forth that are taking a different view. They call themselves
ecological economists. And in fact there is a society that Herman
Daily is contributing toward. Now, yes I received some letters
making the statement, don't worry, if you get the price up
they'll find oil anywhere, or everywhere. And I just wish they
were correct. Now I 've been talking to geologists and so forth
and their statement when you say " well look at the oil we
were discovering, isn't there a lot under the ground that you can
discover or find for us." And they say that statement would
have been true in the 1930's or possibly early 40's . But they
said our knowledge of what exists in the ground is very good, and
maybe we're a 1% or 2% off, but when it takes more than a gallon
of oil to get that gallon of oil out of the ground, it's time to
quit. Now we can use some of the new technology of steam and so
forth to recover and their estimate is that perhaps we can get
another 10%. But there's no question we're getting down to the
bottom of the barrel and world wide I say, we peaked out 2 years
ago, or maybe 3 years ago in the per capita use of fossil energy
world wide. Remember 80% of the fossil energy today is being
utilized by 25% of the worlds population. And the majority of the
poor people in developing countries are only getting 20% of that
share. I just wish the economists were correct, but I must admit
I don't agree with them. And I had one come up also who wanted to
make a bet with me, if I could name 5 resources, this was in a
letter to me, that in 5 increasing.<?> And I did write him
a letter offering to bet him the $1000. But then I never received
a reply from him after that.
Q: From a world wide viewpoint, should we not be
putting more of our resources into nuclear fusion for so energy
would be a non issue. And wouldn't that be a good Manhattan
project rather than these other things we are talking about.
Dr. Pimentel: The question is shouldn't we invest in
fusion. I ..my.. the lady here says no, but I think we should,
and I was a member of the advisory, science advisory staff of the
Department of Energy a few years back and I think a majority of
the members supported this. However, it's not a panacea. And
that's where I agree with you. There are radio activity problems,
not as much as fission, but there are problems. Number 2 and the
major factor as to where we would have problems with supplying
all of our needs with fusion, and I don't believe we ever will,
is that there is a heat pollution problem. To illustrate that
with fission, a physicist, in fact a Nobel physicist at MIT made
the calculation if we supplied all of our needs, that is
electrical needs in the U.S. today, which accounts for about 30%
of our energy consumption with fission, the water temperatures of
our lakes and streams would increase 15, I think 12 or 15
degrees. Now, we can cool these units with air, now they're not
as efficient, but even then of course you'd be adding quite a bit
of heat to the atmosphere. But again you get back to, how many
people do we want to have. It is still going to take land to
produce food. It is still going to take water to produce that
food. And we still want water for drinking and other purposes and
we cannot eliminate all of our species on earth, and we be the
only species or with our crops, that's not going to work either.
Agriculture depends on these other organisms. Yes. and then?
Q: You know in China, you are only allowed to have one
baby. If everyone on earth were only allowed to have one baby,
per couple, how long does it take us to get to where you want us
to be?
Dr. Pimentel: It would take us a little over 100. The
question here is if you allowed everybody, or made I mean
everybody agreed to have one child per couple, how long it would
take us to get down to 2 billion from 6 billion. A little over a
hundred years. Now for the first. What's that? No, I agree with
you.... you know, the first 50 years, there would be very little
change, because of the age structure. just to illustrate, lets
use China. If they had fully implemented this I child per couple,
their population in the next 20 years they would have added a
population equivalent to the United States. A little over 200
million, and it is because of the young age structure. The number
of teenagers and twenties that would be reproducing for example,
would just totally overwhelm the system, even with one child per
couple. To illustrate that with Mexico, if they adopted ZPG
tomorrow as 2.1 children per couple, the Mexican population would
more than double in the next 60 years. It's that young age. We've
got a tremendous momentum built into the world population. So,
even with going to one child per couple, we would slightly
increase during that period, but eventually when you get a lot of
elderiy like myself,. there would be a dip, a very rapid dip in
the world population.
Q: One of the big problems it seems to me is that that
a great number of individuals in legislatures that make policy
decisions, that allocate funds etc. . are abysmally ignorant
about environmental education about biology, about energy
transactions and the whole business. And so, one of the major
issues it seems to me is to get those characters well educated,
and I think one of the things that could have been done would
have been to have him on public radio and it's too bad it did not
happen at this point. And so, how do you go about that and get to
talking to legislators.
Dr. Pimentel: You are correct, I think most of you
heard. You are correct, politicians, incidentally, I am an
elected official in the mayor's council, are generally, well, not
well educated in the terms of environmental issues and certainly
not in the terms of population issues and they do not want to
touch it. In fact, it is a political no no. They are wimps!
Right! But, I can assure you that you can't,-- incidentally
politicians are followers, they are not leaders. They wait to
hear from you and me, that is the voting public, and make sure
that there is a great majority out there before they will make
any decision. And so, it's you and I to speak and write, I mean
it's ... up to us.
(Tape change missed end of answer and beginning of next
question)
Q:... population growth by the United Nations is not 2
billion in 100 years, it's 12. And so does that imply since
you're optimistic that you have more faith in technology than you
indicated in your remarks here today?
Dr. Pimentel: I'm optimistic only from this point of
view. The question related to population growth is we're going to
have about 12 billion in the next 40 to 50 years. And I must
admit I think that's probably an accurate number and that's
probably where we're going to end up. My, why I am optimistic,
it's not relative to science and technology, although it would be
nice if we could put something in the water throughout the world
to stop this reproduction, but uh, what I am optimistic about is
once humans make up their mind on what we should do and have the
will, we've really been able to accomplish great things and this
is what I am counting on that there will be, and I must admit it
is an awful thing to say, is there are going to be some spots in
the world we're going to have some real serious disasters. And it
appears that it takes disasters, for the, now, blame the public
now, not only politicians, it takes disasters to get public
opinion going and then eventually to get politicians moving to
try to do something about these issues. Now, I hope we don't get
in the similar disastrous situation that China is in, that Africa
is in, India is in, Bangladesh is in before we make a decision
that we ought to do something about our population. Now hardly
anybody talks about the U.S. as having a population problem. They
do recognize China's got a problem, India's got a problem, and we
invest money and we give advice to them. We in the United States
do not have a population policy. I was asked to testify before a
Senate Committee a while back on what our immigration rate should
be. They wanted to know what resources we have and how many
people this would support. And I told them, tell me what your
population policy is. How many people, and what standard of
living do you want to have in the United States, and then I'll
comment about your immigration rate. I'm not quite as optimistic
as I said.
Q: I was curious about the, your commentary about
topsoil. You said it takes about 500 years to develop 1" of
topsoil under agricultural conditions. I was wondering if that
could be increased by different policies of composting or
applications of more crop residues back onto fields, and also
what in your views are the best techniques for preventing more
erosion.
Dr. Pimentel: Well, on increasing topsoil, you can get
it. I remember one stage, I was trying to improve a soil that was
heavy clay, that had been eroded quite a bit. And I put on 500
tons of manure per acre and 500 tons of sludge per acre. That is
a lot. And it did improve the soil. The question is where can we
get all this organic matter to incorporate into the soil. Now
your second question is what soil conservation techniques do I
favor? I favor all of them! And we ought to! It depends on the
particular land. You know, crop rotation, strip crops, contour
planting, even though no till uses a lot more pesticides, I favor
no till, even with, or despite the pesticides. Because, that is a
problem we can deal with-- over,-- in a relatively few years. But
you can't sit around and wait 500 years for one inch of top soil.
And there are mulchers, there's ridge till, there's a whole array
of technologies that we've got available today that we could
produce crops and lose a minimum of only 1 ton per hectare per
year, which is the soil formation rate. But we ought to get at
it, and do it.
Q: Recently, last week at the University of Minnesota
here, in a test in the College of Natural Resources, there was a
question on how soon will the human population double, and the
answers were 60, 80, 90, 100. And the answer that the professor
had was 100. And when a student went up there and said adamantly
opposed that and said it was 60, he said well we'll get back to
you. And they were a little red faced about that. And when they
graded the test and handed it out the next day, or the following
week, they said, we'll throw out that question and everyone will
get credit for it. The question is how can we expect people to be
educated when our educators are ignorant?
Dr. Pimentel: You are correct. Don't believe everything
I said, or anybody else that you hear or read. Go and check it
out on your own. No, there's no question, perhaps that, I'll try
and defend that faculty member. Perhaps what he was looking at is
that the population reference bureau states that the rate of
growth of the U.S. population is either . 7 or .8% per year.
They're ignoring immigrants. But if you include the immigrants,
they account for about half that population growth. And so, again
the statistic from the U. S. Bureau of Census is 1 .1% per year.
And if you calculate that out it's a doubling time of 60, to be
exact, 63 years.
Q: Intelligible.
<Look(?)> for the Department of Energy on this question.
Because there was so damn much misinforrnation on this subject.
They didn't know what or who to believe. And we did produce a
report in 1980. And it did, I must admit we should have been
blunter than we were, but we knew that we were up against a lot
of politics. And so we did point out all the numbers. It takes
72% more energy to produce one gallon of ethanol, as the actual
energy that you get out. It costs 3 or 4 times, what it does,
depending on what state you're in and the subsidies, it costs 3
or 4 times dollar wise to produce that. The environmental impacts
are enormous. There's erosion, use of pesticides, and even the
pollution issue is a boondoggle. The only thing that burning
ethanol in an automobile helps you, it reduces the carbon
monoxide, but it produces just as much nitrous oxides, and it
also produces aldehydes that are carcinogenic and so forth and so
on. The only reason, and let me comment on our little study, it
cost only three thousand dollars to produce. There were no
consulting fees or anything like that to me or the committee.
Just for travel, to produce this report, we've got 22 pages
length, or something like that. And, But it disturbed, it did
make Washington Post and Wall Street lournal and whatever, only
because some people started accusing us of being in the pockets
of big oil. This then prompted some congressmen from the corn
growing region to invest .. they then asked G.A.O. to investigate
me and the committee, which they did. I asked the investigators
what the study was costing. It was over $60,000. They produced a
report of about 10 times the length of ours, and totally
supported our findings. But it was a form of harassment. The only
reason we're producing ethanol in the United States is, and ADM
<Archer Daniels Midland>I think is in your back yard isn't
it? Is that, and they produce 65% of the ethanol, is that they,
he gives big bucks to the presid, to Bush, to Clinton, to
congressmen, and also the congressmen from the corn producing
states get votes by saying, look we're producing ethanol, it's a
renewable energy and all that jaz. But no, it is one of the big
losers that we have.
Do you want to quit?
Dr. Meyer: I'm sorry but our time is up. We will have a
reception and more people can ask Dr. Pimentel questions, and
lets thank him again. (Applause)
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