Naked Science Forum
General Science => General Science => Topic started by: Karsten on 18/02/2009 12:31:44
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If we stop eating meat as much and distribute food more evenly, can we still produce as much food as we do now if/when fossil fuels are not available?
Your thoughts?
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This is a good reason for getting back to locally produced food. When we run out of fossil fuels we may be forced to return to steam ships. There will be no more fresh fruit and vegetable transported by airfreight.
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Couldn't other fuel sources be used/developed for that sort of thing?
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The manufacture of a fuel to replace high octane aviation fuel would be prohibitively expensive.
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Could it ever be possible to run planes on battery? Generate the electricity with solar or whatever else and then store it? Can batteries be made to last the length of long flights?
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What other fuel sources do you have in mind? Reverting back to wind-power for ships is always a possibility, if not a probability; various schemes ranging from conventional sails, through wing-sails, to kites have been constantly explored to improve the efficiency of surface vessels, but there's just not really any viable alternatives for heavier-than-air powered flight. Steam power could be used in lighter-than-air vessels but the weight of the fuel would take a huge bite out of the lifting capacity as well as introducing the problem of maintaining constant lift as the weight of remaining fuel decreases; you don't want to just vent off the lifting gas to compensate, but that then means using extra energy to re-compress it.
One of Spike Milligan's Goon Show quips: "Bring back the horse-drawn Zeppelin" might actually have some mileage in it.
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Could it ever be possible to run planes on battery? Generate the electricity with solar or whatever else and then store it? Can batteries be made to last the length of long flights?
In a word; No. Solar powered aircraft have been made but they have to be very light and can carry hardly any cargo/payload. Batteries are out too, until a radically new design comes along. Batteries also come with their own potential problems; a battery storing that much power, regardless of it's weight, would be very dangerous if there was any risk of shorting, either internally or externally, as all it's stored energy would be released at once.
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I assume that some of the transportation issues could be solved with bio fuels. At least agricultural machines (and maybe construction machines) could operate with vegetable oils if they cannot operate on electricity in remote locations. I believe it is even possible to fly jets with bio fuels, however most likely not in numbers that are even close to current numbers. We will not be able to afford to fly, ship, or truck vegetables around the world as much.
But can we still MAKE as much food as today? I still wonder if there are alternative materials that can be used to create today's high performance fertilizers or pesticides that are based on petrochemicals. Without those fertilizers/pesticides I fear we will have a huge drop in food production. Eating local foods that are in season will help a few. Eating no/less meat will help a few. But can we still create the chemicals we currently use to run a low-labor, high-yield agriculture without fossil fuels? Are there viable alternatives? Are we prepared to feed billions who do not know how to (or cannot) grow their own food when fossil fuels are expensive again and stay that way?
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We will have to learn and adapt. I think it will balance out the gap between the wealthiest countries and the poorest. At present we are USERS of the majority worlds wealth and produce. Our trade laws dictate who wins and who loses. I think it would cause a massive turn about in today's situation.
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Bio-diesel is already in use. But to run all our cars, trucks, ships, plant machinery, power stations and so on, on this fuel would be out of the question.
If we do not commence on a project of returning to local produce in the very near future, we are going to come down to earth with an almighty bump one day in the not too distant future.
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Hydrogen?.
Wonder how they get those big space shuttles into orbit.
Cheers
justaskin
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Rocket fuel - far too volatile
Hydrogen - Where will you get all this hydrogen from?
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Who says that we're going to run out of fossil fuels? There are still many decades-worth of coal and oil to be extracted. It's more a question of cost/benefit, and there are likely to be new and innovative ways to extract the more inaccessible fossil fuels in the future, which is coupled with industrial and political will.
I'm not saying that it's right though.
Fossil fuels are used predominantly to create electricity. This can be replaced by nuclear power generation.
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Hydrogen - Where will you get all this hydrogen from?
I think its the most common substance in the universe isn't it?.
From electrolysis of water.
Already hydrogen filling stations in the USA and maybe elsewhere.
Cheers
justaskin
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Couple of things – yes there are many decades worth of oil and coal underground, there is an increasing issue of the cost of extraction, both in financial terms and return on energy invested. For the interested google Energy Return on Energy Invested.
Uranium is subject to the same problem as fossil fuels – yes it is relatively abundant, but existing high %U reserves (viable at today’s prices) have a life of around 30 years (at current rates of consumption). Of course as the price goes up, lower grade orebodies become viable – but other costs start to rise – a currently marginal site in Southern Africa is producing 1 tonne of Uranium (which needs further processing to be used as a fuel) for 1,000,000 tonnes of rock quarried. To extract U the 1,000,000 tonnes of rock needs to be ground down to flour, consuming 18 tonnes of steel in the process and various cyanide compounds and a lot of water are needed to finish the process.
Hydrogen would be a great clean fuel if the electrolysis was carried out using renewable energy. History has shown that it is a difficult substance to store and transport, but I suspect that technology and materials will improve rapidly when necessary. An obvious solution would be floating platforms in the oceans using wind/ solar power for the electrolysis and some sort of tankering system as we use for oil today.
To return to the thread, alongside the availability of fossil fuel dependent inputs, there is a question over the long term sustainability of such intensive agriculture on the soil anyway the US dust bowl of the 30’s is a lesson in what can happen if you try and take too much too quickly – it may be better to grow as much food in a hydroponic system than conventionally, as it can reduce seasonality of foods we now take for granted (such as salad) and reduces pesticide inputs.
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Hydrogen - Where will you get all this hydrogen from?
I think its the most common substance in the universe isn't it?.
From electrolysis of water.
Already hydrogen filling stations in the USA and maybe elsewhere.
Cheers
justaskin
Abundant yes, readily available, no.
it may be better to grow as much food in a hydroponic system than conventionally, as it can reduce seasonality of foods we now take for granted (such as salad) and reduces pesticide inputs.
It's all very well growing the odd few tomatoes on a system like this, but the entire requirement of a nation such as the UK with 60 million mouths to feed???
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Whilst I heartily agree with the production and consumption of locally grown food (and personally do my best to consume it) there are serious limitations - particularly when looking at the current and projected UK population.
Hydroponics can make a significant contribution - not just tomatoes - to issues of land use and energy / water consumption in food production. Pretty much anything can be grown hydroponically, with generally higher yields and shorter cropping times than conventional techniques. I would go so far as to suggest that it is the only way that 60 million mouths could be filled with locally grown food.
One of the principle disadvantages with trying to persuade the UK to go back to only consuming conventionally grown seasonal, locally produced foods is resilience to the vagaries of the weather. The other is that consumers (rightly or wrongly) have an expection to be able to consume many things year round and indeed are positively encouraged by government and health care professionals to do so.
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We are all forgettinf that water is not an infinite resource too. We all have to use our share of the earths carbon, water and land wisely. It is something of a balancing act.
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We can feed the world with no problems whatsoever. We just need fewer people.
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Hydroponics can make a significant contribution - not just tomatoes - to issues of land use and energy / water consumption in food production. Pretty much anything can be grown hydroponically, with generally higher yields and shorter cropping times than conventional techniques. I would go so far as to suggest that it is the only way that 60 million mouths could be filled with locally grown food.
Can hydroponics be applied anywhere where people currently live in large numbers? Does this method use more water than conventional agriculture? Can it happen outside? Can it feed the current world population (not only the UK)? How about the large cities like Bombay, LA, Tokyo?
Who says that we're going to run out of fossil fuels?
I would say that we are going to run out. It is a conclusion based on the fact that we are not replacing it and it is not replacing itself. So, sooner or later the stuff is gone or just too expensive to get. WHEN that happens is a different question. I prefer to plan ahead and would like us to be ready to live without it when the time comes. Are we ready? Will we "adjust" when forced to do it or could we plan ahead a bit more?
We can feed the world with no problems whatsoever. We just need fewer people.
That is replacing one problem (=feeding the world's population) with another one (=getting rid of most of the world's population). Or we "just" wait. The environment will balance, no doubt, I wonder though if this balancing act will be catastrophic or merely extremely hard.
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We can feed the world with no problems whatsoever. We just need fewer people.
That is the answer to most of the world's current problems.
Karsten: You are right to question whether hydroponics can feed the whole world. I doubt it.
MIL: Right again, fresh water for irrigation, commercial and domestic use is finite.
Mazurka: If we are unable to transport food over long distances, we will be forced to source locally. As consumers, we will have no option but to lower our expectations. We must learn that we cannot have that which is not available.
The sooner we embark on a programme of locally supplied produce for local people, the easier it will be on us all when the time ultimately comes when we have no other choice.
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We can feed the world with no problems whatsoever. We just need fewer people.
BC - I'm not sure that that is right, it's just an obvious solution. The earth as a whole can easily sustain this many people, it's just that the processes and resources aren't evenly spread.
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One of the beauties of hydroponics is that it can be practised on almost any scale from windowsill to hectares. This makes it potentially a very effect system within cities, where disused industrial buildings/ warehouses would be an obvious place to start commercially. As the water is recycled and extra nutrients added to it it uses less water than conventional systems. It also uses fertiliser more efficiently than conventional systems as there is no run off and the nutrients go directly to the roots.
I guess its principle disadvantage is high set up costs and higher electricity costs (even if grown in polytunnels/ glass houses) electricity is required to circulate the nutrients. The other disadavantage is that it is difficult to implement in the open as rain etc could upset the system. However as transportaton and other inputs such as pesticide and fertiliser become more expensive and energy from biomass/ photovoltaics become more practical, power costs will be reduced and i would suggest that the need for cover/ controlled conditions is outweighed by the significantly greater yield and cropping rate.
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So, it sounds to me that hydroponics is a possibility if fewer people have to be fed and electricity is available easily and with fewer limits. Do we have large hydroponic facilities working already? Facilities that supply produce for thousands or (better) hundreds of thousands of people. The fertilizers required for hydroponics are not made based on petrochemicals?
One day we may not have choices and will implement whatever works. I would like to see it working already at a scale that leaves hope that it may work on a global level when we are forced to do it, no matter what the set-up costs.
If we do not use nuclear power, will we be able to create enough electricity to do all this (even if we, hahaha, all begin using CFLs)? We are doing a lot of talking and innovating regarding more efficient household appliances, transportation vehicles, electronic gadgets, etc. but I am getting quite worried about the basics. If fossil fuels are exhausted for most practical purposes, and nuclear power is not implemented, how do we make electricity enough to use hydroponics? That should probably be a new thread though.
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We can feed the world with no problems whatsoever. We just need fewer people.
BC - I'm not sure that that is right, it's just an obvious solution. The earth as a whole can easily sustain this many people, it's just that the processes and resources aren't evenly spread.
Earth can easily sustain which people? Americans? Europeans? Indians? Ethiopians? I would love to know what life style is sustainable. I doubt it is the American life-style. While I am not worried about our planet, I am worried about the people on it. How good can our lives continue to be if we spread evenly resources and processes around the globe? And how does this "even spread" look like if we take fossil fuels out of the equation?
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I believe that there will be substantial temporary problems - famine war, etc, if these can be called problems, but that the species will survive. The interregnum? Watch out. Dig your survival shelter.
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I'm very strongly inclined to agree with you JimBob. I do think that the race will survive, so the worst case scenario isn't complete extermination, just the death of several billions of people, mostly the poor.
From the Hitch Hiker's Guide to the Galaxy:
"...because no one was really poor — at least no one worth speaking of."
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So, I fear the answer may be:
Yes, after a major "correction" of numbers of human beings on this planet, we will be able to feed the world when we run out of fossil fuels.