The Earth today has about 4,100 million hectares of arable land (land with adequately fertile soil and sufficient rainfall capable of supporting traditional agriculture)–that’s 41 million square kilometers or about 16 million square miles. A little less than 5% of this land is part of protected parks and wildlife preserves. Of the rest, only 15 million square kilometers are presently used for agriculture according to the FAO (Food and Agriculture Organization of the United Nations). Arable land in these statistics includes forest land and pasture lands that could possibly be used for traditional agriculture, but might be realistically needed for other purposes. A small amount of actively farmed land in the world (mostly in the Middle East) is actually not arable–think desert land made viable by irrigation and fertilization–so, this is not an absolute limit on agriculture.

We would likely not be content turning all arable land, much of which exists as forest and other semi-wild ecosystems, into high productivity grain farming. The effects on wildlife and aesthetics would be dramatic. So, let’s assume that the world as a whole decides to protect twice the current arable area protected by parks and other reserves, and let’s assume that another 10% of the area would be made up of semi-wild managed forest, managed game lands, and similar uses. That leaves a total of 33 million square kilometers of arable land available for agriculture of which we are currently using 16 million, or about half. One might then assume that we could easily support twice the current population, but this neglects that about a billion people are malnourished today, and many more are poorly clothed and housed (agriculture also produces the fibers for clothing).

To begin, we should assure that we can generate at least 2500 calories per person per year (the average need for an adult man), which is somewhat more than necessary because it does not account for the lower needs of women and children. 2500 calories per person per year for 9.2 billion people is a global need of 23 trillion calories per day in 2050. If every acre of arable land were planted with potatoes (the highest caloric yield per acre of any crop), we could produce 8 times more than we need to support all 9.2 billion individuals’ energy needs, although potatoes alone would not meet people’s nutritional requirements for protein and other nutrients. {interestingly, apples might provide even more calories per acre than potatoes}

Instead, relying on a one-third each mixture of corn, beans, and squash combined with a rotation in similar crops would provide for almost all nutritional needs including protein, vitamins, and minerals (data on yields and caloric content can be found here, here, here, and here, organic farming yields were used where available). This combination produces a average total of 2.7 million calories per acre or enough with all arable land in production to feed 2.5 times the population in 2050. If we were to allow for more variety in our diets and incorporate additional servings of a wider array fruits and vegetables our average yield might fall to 2.4 million calories per acre and reduce the surplus to 2.3 times the population in 2050 (using tomatoes at 80 calories per pound and 20,000 lbs per acre as a proxy for a mix of other vegetables).

So, the food (14 M sq.km), timber (10 M sq.km), and fiber (1.6 M sq.km) needs of the projected population in 2050 can be met with only 78% of our available arable land (26 of 33 M sq.km). In fact, every man, woman, and child on the planet would be able to consume as much of these things as Americans typically do (or more in the case of vegetables), and that level of production would satisfy up to 11.6 billion people. While annual crop rotations are assumed in these calculations, multiple crops in a given year are not even though they are common in many places. What these figures do not include explicitly are animal products, although fish and game harvested in sustainable quantities would be an addition with no impact on the other values as would animals raised on agricultural waste products including wheat and rice straw, winter cover crops such as alfalfa, and discarded produce as well as those raised on pasture lands that do not qualify as arable (hill sides, rocky grasslands, arid grasslands, etc.). Adding animals raised on grain or other primary agricultural produce would reduce the caloric and protein productivity of the land overall, but would still be possible given the 7 million square kilometers of unused arable land revealed in this scenario. Future changes in the amount of arable land due to climate change or sea level rise are not considered here.

So, why don’t we feed everyone sufficiently today given that we have more than enough worldwide agricultural land in production? There are several reasons. One is waste. In the US 20-40% of agricultural produce is wasted for one reason or another. Another is high value but low productivity agricultural activities including grain fed cattle and alcohol production. Another is the combination of adverse incentives created by rich and poor world governments actively involving themselves in the agricultural markets to different ends. None of these practices needs to be eliminated in order to supply adequate food and other products to the worldwide population, but official encouragement and innovation and open trade between regions will be required to meet these needs. We can say then that we are not necessarily heading for an impending disaster, but whether we succeed in sufficiently providing for everyone will remain an open question.

But, waste should be seen as a failure of our system of doing things. Many of our activities are possible with little or no waste, we are just complacent towards it. As part 1 of this series, we will look at heat, how and why it is wasted and what we should do about it.

First, the heat we are talking about is not the heat for our homes in the winter, although that would also be included (in as much as it escapes to the environment without helping us). The term heat in the Physics or Engineering sense refers to all energy that has not been applied to a useful task, which results in this energy being released as heat. How does that work? Well, imagine a electric motor using 1.5 kilowatts that raises a 100 kilogram load of equipment 100 meters to the place of a work site on a tall building in 100 seconds, it has utilized 980 watts in productively moving the equipment, while the other 520 watts has apparently disappeared.

Well, in fact that 520 watts did disappear through being converted into heat, which was eventually lost into the air one way or another. All of the 1500 watts of power was supplied to the motor, but some was lost to heat because of the electrical resistance of the wires and other components in the motor. Some power was lost as heat because of friction in the motor bearings and in the other pulleys used to lift the equipment. Some power was converted to noise, which warms the air a small amount.

The other main way heat is lost is through it being discarded as unusable. Put your hand next to the exhaust of a car or truck; you will feel a very warm stream of gases, and those gases have already been cooled considerably by their path through the exhaust system. The engine of the vehicle burns fuel, and that chemical reaction creates heat and volume expansion that provides power to run the vehicle. If it is during the winter season, some of the heat is then used to warm the passenger cabin. The remainder of the heat is discarded to the environment as unusable by the vehicle, even though it still retains as much as two-thirds of the total energy created by the combustion.

Electrical power plants running a combined cycle (gas turbine, then steam turbine, then water heat exchanger) do a much better job with using the available heat from fuel combustion, but even they will discard at least one-third of the heat to the environment as unusable, and usually much more.

The last category of wasted heat is that of misdirected functions. A fan blowing in a room to cool a person or people who are not present results in 100% of the energy provided to the fan being lost as waste heat eventually. Another example is electric lights utilized in some area where no one is around to see it. While the reason for this lost heat is different, the result is the same, all of the power supplied to that device ends up as heat added to the local environment, with no other end effects.

In all of these things: electrical resistance, friction, noise, thermodynamic discarding, and wasted functionality, we (whether the user, buyer, seller, designer, or regulator) are expending valuable effort (collecting, transforming, and transporting energy) for absolutely no gain to ourselves or the larger society. There is a small amount of this waste that is inevitable given our current technology, but most of it is not. After covering the other problems of waste, we will consider some of the solutions.

Analyzing and controlling risk is one of the most important aspects of the engineering design process. These risks include health and safety, design robustness and reliability, maintainability, marketability, cost, schedule, and performance.

Yet, many of these risks are managed only by the intuition of the project manager or management team. While many are skilled enough to investigate and control most of these risks, the number of projects that fail to meet functional requirements, cost limits, scheduled deadlines, reliability expectations, or other thing, serves as testament to the fact that the complexity of risk management on modern projects is beyond the capabilities of our current system of doing things.

In large organizations, multi-disciplined teams of experts may investigate and score project risks by a standardized methodology, communicate regularly with the entire project team, and evaluate proposed solutions to issues by established criteria, only to see those projects also suffer many of the same problems.

But, what if things did not have to be that way? What if the assessment of risks could happen automatically as the thousands of tiny decisions made by many different project team members began to coalesce towards one of the many possible given outcomes? And then, what if the manager or managers of the project could immediately see the course in which their project was headed, to evaluate the need to make corrections, and could see the kind of correction needed?

This situation is not so far fetched as it once would have been. The growth of collaborative project management, design, and manufacturing tools have put almost all of the data required for this risk assessment and control system in an accessible place. New research on the psychology of decision making has illuminated how people over- and under-estimate risks, enabling an accurate communication of risk information much more possible, no longer relying on one person’s interpretation of a vague risk assessment output. With a directed effort, a comprehensive, integrated risk management and control application could be available to transform the project management practices at small and large enterprises greatly improving the success of all types of engineering projects during all phases of the life cycle.

Problem – Evolving Needs during Life Cycle

Many of the processes and tools for evaluating and controlling risk in existence today only operate well at one particular phase of the product life cycle. Many have been developed, for example, to survey products in the field to identify the likelihood and severity of problems through statistical trending analyses. Others are used in the late phases of product design to anticipate problems based on system properties like reliability as determined by engineering analyses or testing programs.
The risk assessment tools must not only work throughout the design process from beginning to end taking into account the appropriate amount of uncertainty, they must also prompt decision makers to select the correct option. If a risk is somehow underestimated or overestimated by the person interpreting the analysis, the risk assessment and control process has not performed properly.

The other problem is that even a conscientious risk mitigation program must switch between tools for different stages of a project losing valuable information each time and a valuable opportunity for feedback for the information collected in each stage to inform the other stages. Additionally, appropriate measures of uncertainty cannot be tracked along the development path when tool changes are made.

First, a statistical method needs to be incorporated to evaluate likelihoods and uncertainties in the early initial concept stage, later evaluating additional information as design detail and intent is added, and then incorporating actual test and use data. Currently, most organizations must tolerate different data input and output content and formatting for each stage of the process, potentially confusing how risks evolve over the course of the project.

Problem – Ambiguous Results and Responses

A clean, clear choice in each case must be provided to those responsible in a manner appropriate to the risk in question, with all the necessary information visible in an easy to comprehend manner. An equitable process must compare safety and reliability risks, for example, and their interconnections. The entire process and software tool must navigate the path from vague uncertain notions of the design to detailed parts lists and drawings to testing and then field use without requiring conversions, or implementing entirely new ways of doing things.

Second, the data must be presented in a way that is understandable to the technical manager, someone not necessarily highly trained in risk assessment, and it should be presented in a way such that the right decision is most likely to be made. The difficulties of clearly presenting information on likelihood, severity, and uncertainty for different types of risks at the same time must be overcome to accurately inform the decision maker of the risks he or she currently faces.
Third, the data must be usable to make decisions regarding future outcomes at each stage, suggesting a priority, direction, and magnitude of a potential response to the problem identified. This would include the assessment of various potential solution options, including making available those that have been developed during the normal design process activities. The manager should have the means to be able to appropriately identify the choices, which would most improve the overall project risks.

Problem – Poorly Integrated Risk Analysis Process

Fourth, the software tool must be as seamlessly integrated into the design process as possible using all available data from modeling tools and currently available analyses, so that no new analysts or practitioners are required; it should also draw on previous experience as recorded with the risk assessment tool from other projects and programs. System architects and designers will provide the majority of the initial data moving risk analysis further upstream in the design process as other forms of engineering analysis have recently moved in that direction since the integration of stress analysis and fluid mechanics analysis capabilities with solid modeling applications.

Proposed Solution

A single process and assessment software tool should be developed to track, identify, analyze, and evaluate uncertainty on all kinds of risks from conception of a project to fielding and finally decommissioning. This software application and process should not require the creation of new technicians and analysts, but use the knowledge already contained within an organization, and be as seamless as possible with the design process.

Beyond the capabilities of procedures and software tools available today, the implementation and realization of this new application will involve these main capabilities:
– All risks will be included within a common assessment system
– All project members will directly have access to inform the assessment of project risks with real factual information as up to date as possible.
– Only very limited additional interaction will be required by each team member as most data will be harvested from other existing collaborative engineering design tools.
– From idea sketches of solutions to detailed proposals, the application will enable a common assessment of which solutions could have the best impact on the overall risk posture of the project.
– Risk information and solution assessments will be presented to decision makers in a manner such that the actual situation can be easily and correctly determined.

Conclusion

This solution is potentially a very broadly applicable method and application for improving any system design and implementation. More specifically, it would initially be developed for the engineering system design process, where it could replace several separate methods and tools including preliminary hazard analysis, reliability prediction analysis, design and management risk analysis, and failure surveillance analysis and problem reporting systems.

An effective, integrated, software-assisted approach could make risk assessment and management processes more routine beyond the largest corporations and organizations, who are currently the primary practitioners. This expansion and standardization could significantly increase engineering systems and business efficiency in the most important properties of overall life cycle costs, resources consumed, and benefits obtained.

Development Plan

The development plan for this integrated application is focused on 4 areas as described below:
– Quantitative Risk Assessment Mathematics – a set of statistical and other quantitative procedures to accurately evaluate severity and probability of risks from early data through surveillance of field performance. These procedures would also evaluate the effectiveness of proposed solutions.
– Effective Analysis and Display of Risk Information – a set of visual data interpretation aids that get past the innate human biases and accurately reflect risks to decision makers.
– Engineering Database Leveraging – pulling risk information from collaborative engineering design and planning tools to eliminate the separate and parallel risk assessment process.
– Process Streamlining – to integrate risk management with the project planning and design and operation process

Support this Work

If you our your organization would like to be a part of this research and development effort, please contact Jeremy Gernand through this website’s contact page.

Click here to download a copy of this proposal

A number of options exist or are being developed on the alternative energy front. Purely from an energy standpoint, renewable sources are more than capable of providing our energy needs; the issue at this point is refining our alternative energy technologies to the point where we can harness a significant fraction of that energy. Solar irradiance (the amount of solar energy that reaches the surface) is about 145 watts per square meter; when you take into account atmospheric variables, the usable amount of solar energy received for locations in the USA ranges from 4 to 7 kilowatt-hours per square meter per day for a flat-plate solar array. At the present, the maximum efficiency for solar power systems of any type is about 40%, though there are some technologies that promise even higher efficiencies. At 40%, that translates to 1.6 to 2.8 kilowatt-hours per square meter per day.

Looking at the EIA’s figures for household energy usage in 2001, it would appear that this energy demand could be met by thirty eight square meters per household (based on a 25% efficiency rating rather than the 40% maximum) or just under three million acres; to put this in perspective, thatt is less than the size of the area of the National Petroleum Reserve in Alaska that the U.S. government opened up to drilling in July. This would be why DARPA is taking another look at space-based solar power. Given current and emerging trends in energy availability combined with the average efficiencies now available (and the undiluted, unscreened sunlight that’s available in space), it doesn’t look quite so ridiculous any longer.

Wind power is starting to come into its own, as well. Today’s windmills owe little to their forebears except for concept. Wind power’s lack of required infrastructure at ground level has made it a popular choice among farmers (and even some towns) in areas of relatively low relief and high wind speed. Small-scale wind generators are available for homes, and a hybrid solar/wind strategy combined with battery storage would provide reliable, consistent round-the-clock power. Offshore sites have especially high potential for wind power, as this map demonstrates.

Other articles have already addressed both space-based solar and offshore wind power, I refer you to those for in-depth information.

Water issues could be addressed in a number of ways. Permeable pavement technology is already being used “in the field” and research is ongoing, though weight and speed-related restrictions keep it from being used for roads and highways. Runoff collection systems such as rain barrels and the like are another effective solution. Perhaps the best solution of all is to utilize native plants to control water conditions at a site. Stormwater management can also be handled by creating rain garden-like buffer zones and landscaping with native plants- the deeper the root structure, the better! Vegetation also helps to create clouds through transpiration. Polyculture and permaculture farming methods reduce the need for chemical inputs, which decreases the amount of pollution downstream.

Improved runoff control would also address the issue of soil erosion, and no-till farming methods (exactly what the name implies) keep soil structure and organisms intact; in the long run, maintaining the soil ecology helps to continuously renew the soil’s store of nutrients.

One straightforward, though undoubtedly less popular, means of increasing the amount of food that can be produced on the available arable land is to lower meat consumption- the rule of thumb is that, for each level you move up the food “chain”, about 80-90% of the usable energy is lost. (Coincidentally, environmental contaminants become more concentrated as you ascend the chain, which is the reason for heavy metal contamination of fish such as tuna.) Because of that efficiency drop, it takes far more land to produce a given amount of calories via meat. Commercial meat production also generates vast amounts of waste, yet another (controllable) source of environmental pollution.

As I’ve given evidence to here, there are many ways in which we can curb our effects on our world and achieve long-term sustainability and viability; it remains to be seen whether we will choose to do so or not.

The first picture shows world population on a logarithmic scale- the current population is estimated at about 6.6 billion.

As for population growth, demographers often speak in terms of the doubling time of a population. This value can be determined by dividing 70 by the growth rate in percent. According to the CIA World Factbook, the present world population growth rate is 1.188%, which gives us a doubling time of about 58.9 years. The rate does appear to be decreasing, so we can at least rest easy on that account. Still, on the basis of this chart, it would seem obvious that we’re likely to exceed ten billion by the end of the century, all else being equal.

However, the rate at which developing countries are increasing their resource use is a definite concern. Let’s work with three examples- soil, water, and energy.

In the case of energy, the estimated per capita energy consumption in 2003 was equivalent to 1.6 metric tons of oil per person, or ten billion tons in total- converted into barrels, this works out to around 200 million barrels per day. (Thankfully, all of this is not in the form of oil!) If we projected our future rate of consumption based on the 2003 estimate, a population of ten billion would mean an increase to 328 million barrels/day, however, with the growing standard of living (and commensurate increase in energy usage) in developing nations, that number is surely going to rise. The global demand for energy is already at a high, and, while record energy prices have made the extraction of hard-to-reach fossil fuels profitable, nonrenewable fuels cannot sustain such an energy appetite indefinitely.

Worse is the situation concerning water- while most of the planet may be covered with water, the amount of freshwater available is a fraction of that total.

Global water footprint per capita was ~1200 cubic meters/year in the period 1997-2003 (ranging from a low of 702 for China to a high of 2,483 for the US on a list of selected countries), with the lion’s share being used for industrial and agricultural uses. The majority of accessible fresh water is groundwater, a source that is being depleted at an increasingly rapid rate and requires long periods of time to recharge. This situation is being complicated by the destruction of wetlands that serve as nature’s water filtration systems and the use of  large areas of impervious surface in urban centers (such areas increase runoff, which in turn increases the rate at which freshwater enters the ocean and becomes inaccessible). Deforestation also contributes to the problem, since plants serve to trap water and return it to the atmosphere via transpiration. Not least of the human-induced factors is industrial and agricultural pollution, both of which can render water undrinkable with minimal (on a quantitative basis) amounts of chemical inputs.

Soil may seem an odd thing to put on a list of resources being depleted, but that is precisely what is occurring in some regions of the world. Soil is a complex ecosystem in and of itself, consisting of minerals, organic matter, and macro- and microorganisms, All soil is not equal, and the mineral (and organic) content, pH, water capacity, and drainage of a soil all combine to give soils a distinct character that is best suited to supporting certain kinds of vegetation. Agricultural practices such as tilling and irrigation improve the short-term yield of a soil at the expense of its long-term viability, forcing the use of more chemical fertilizers that, in turn, harm the environment via algal blooms and the resultant dead zones. Runoff erodes topsoil at a rate that can turn farming into a form of mining the land (some estimates place the loss of agricultural land as high as 24 million acres per year).

Food pressures are adding even more pressure to the mix, as indicated by the last two years’ widespread rice shortages and increases in the price of wheat and corn. Add to this the 40 kg of meat that each of us consumes per day on average, and the result is quite a situation to deal with…

After a quick trip into a public restroom to wash your hands, you are likely to find something near the exit with which to dry your hands. What is it? Commonly paper towels or an air dryer or sometimes both (or occaisionally cloth towels) are present for your benefit. On the face of an air dryer you can often find this statement: “Uses Less Energy Than Paper Towels.” We are going to systematically address that claim.

First, paper towles require something to hold them, usually a steel or plastic box of some sort. The paper towels themselves are stored inside either folded together or on a large roll. We’ll assume either two kilograms (kg) of steel or one kilogram of plastic is required. At 38 Mega-Joules (MJ)/kg for steel and 90 MJ/kg for plastic, the embodied energy content of the paper towel holder is approximately 80 MJ.

Then the paper towels themselves at 3.8 g per towel have an energy content in the case of virgin paper of 25 MJ/kg or recycled paper of 16 MJ/kg. Assuming 50% recycled content for our paper towels, we can anticipate an energy content of 0.0779 MJ per person using the towels.

The air dryer, on the other hand has a total manufactured mass of about 8.2 kg, which is divided between steel, copper (100 MJ/jg), brass, other alloys, and some plastic probably leaving us with an average energy content of approximately 60 MJ/kg. So, our dryer’s energy content as installed is about 492 MJ.

The dryer when activated consumes power at the rate of 2300 Watts (W) for a period of 30 seconds. Therefore, for each person using the dryer, the dryer is consuming energy at the rate of 0.069 MJ per person.

So, now, for the paper towel option we have a intial usage of 80 MJ plus an ongoing energy cost of 0.078 MJ per person. Then, for the air dryer, we have an initial energy usage of 492 MJ, followed by an ongoing cost of 0.069 MJ per person. So, we have a situation where there exists a breakeven point in terms of the volume of usage, small traffic volumes will be more efficient using the paper towels, while large traffic volumes will be more efficient using the air dryer.

The breakeven point can be calculated by taking the difference of the two initial values, 412 MJ, and the difference of the two per person energy costs, 0.009 MJ/person, and dividing the former by the later. So, in the end, any location that expects to see more than 45,777 individual visits per dryer over the life of the dryer would be better off in terms of energy usage choosing the air dryer over the use of paper towels.