Materials Science Update – Research into Invisibility Cloak Yielding Heat Shield Technology Results

As much as the military and Harry Potter have sought a cloak of invisibility, the science that studies light wave deflection is looking at thermal wave invisibility for creating heat shields. French researchers are intending to build materials that shield electronics to keep them cool or do the reverse, provide concentrated heat to generate power from a light source — the Sun.

Sebastien Guenneau heads up a research team at the University of Aix-Marseille and France’s Centre National de la Reserche Scientifique (CNRS). The team intends to develop prototype thermal cloaks for microelectronics that diffuse heat around a protected area. They have published their findings in Optics Express, in an article entitled, Transformation Thermodynamics: Cloaking and Concentrating Heat Flux. This type of heat shield would have many applications within microelectronics and space science. The reverse, focusing heat on a small volume would be used for enhancing the power and heat production for the solar energy industry.

If a thermal invisibility cloak can be developed then this illustration shows how it would work. The object in the centre is a schematic for a micro-electronic device. The source of heat coming from the left side is diffused around the object rendering it "invisible" to the heat. Source: Institut Fresnel, CNRS/AMU

Current thermal protection technologies include the reinforced carbon panels, ceramic tiles and resins used by the Space Shuttle,  the plastic foams we see in the insulation used in commercial products like coolers, the aerogels that NASA has used in Martian rovers. How does “thermal invisibility” compare?

Whereas the materials described above absorb and diffuse the heat from its source, this new technology deflects it around the object rendering it invisible to the heat source. The French research team is working with PVC-type polymers, silver and gold with a prototype near completion.

Climate Change Update – Probability Not Certainty is the Cautionary Conclusion of European Climatologists Studying Recent Weather History

Does the recent warm spell over the eastern half of North America reflect climate change induced by increased greenhouse gases? When Europe experienced an extreme heat wave in 2003, two scientists at the Potsdam Institute for Climate Impact Research began a study to see if that event could be related to global warming. Dim Coumou and Stefan Rahmstorf have published an article entitled, A Decade of Weather Extremes, published in Nature Climate Change, cataloguing extreme weather events since the year 2000 including the European heat wave, the drought and heat wave that hit the American Mid-West and Southern Plain States in 2011, the rain and flooding events that struck Pakistan and Thailand in 2010, the tropical cyclone of 2007 in Oman and others.

In their conclusions the scientists stated that no single weather event proves that we are experiencing human-induced global climate change. But the frequency of unusual weather events may be an indicator of a shift away from normal climate patterns. In their cataloguing of extreme weather events one thing became exceedingly clear. The Earth is experiencing more extreme weather events than at any time in recorded history and that the events are more extreme – heavier rain and flooding, more violent storms, larger and more frequent tornadoes, and more prolonged droughts and heatwaves.

The graph above shows the increasing frequency and cost of extreme weather events in the United States from 1980 to 2011. Source: National Oceanic and Atmospheric Administration

Coumou and Rahmstorf’s data shows that globally we are experiencing three times higher monthly heat records in the 21st century than at anytime in our past. Like other climate scientists they recognize that local weather variation is not proof of global warming, but the pattern that is emerging suggests something is happening with the most likely variable in the climate model being us. We are the influence that is causing global temperatures to rise. And when the atmosphere gets warmer, weather gets more active and weather events become more extreme. So although we cannot unequivocally state that extreme weather reflects climate disruption, we can see cause…not certainty….but high probability.

 

Urban Landscapes and Agriculture Update – New Technology to Assess Water Stress

In a new study conducted by the Oak Ridge National Laboratory to be published in the journal Computers & Geosciences, in May 2012, , researchers announced a new method for assessing global water stress. The tool they developed integrates climate, population and freshwater statistics to provide future projections. The authors, Esther Parish, Evan Koda, Karsten Steinhaeuser and Auroop Ganguly are the first to integrate disparate observations to create a global picture of areas potentially vulnerable to water shortages.

Water stress is defined as availability of freshwater per capita of less than 1.7 million liters (450,000 gallons) per person per year. That seems like a lot of freshwater, 4,657 liters (1,232 gallons) per person per day. But the number represents much more than water for domestic usage such as drinking, washing and sanitation. It includes water used for industrial and agricultural purposes.

This map depicts the current state of freshwater on the planet. Areas in blue do not suffer from water scarcity. Areas in red are currently in crisis. Areas in the shades of orange are approaching or experiencing physical water scarcity.

The team used high-resolution Global LandScan population distribution datasets, combined these with population projections from the Intergovernmental Panel on Climate Change (IPCC) the Community Climate System Model 3, and current freshwater supply to come up with projections estimating demand for freshwater by 2025, 2050 and 2100. Interestingly, the variable that most impacts the data modeling is not rising temperatures from global warming, but rising human global population.

Results from the study show that in North America, Florida and the American Southwest are most vulnerable to water stress in the near and longer term. The Great Lakes region on the other hand should be sustainable.

On a global scale the data concludes that by 2100, 56 to 75% of the world’s population will experience freshwater stress. Central and South America may experience massive population shifts based on projected water scarcity data.

Urban Landscapes Update – Seattle Building Designed to be Autonomous and Green for 250 Years

Creating “living buildings” requires a new approach to design and construction that recognizes the need to reduce our energy footprint. With this in mind the designers of  the Bullitt Center, a 6-storey headquarters for the Bullitt Foundation, intend to create a sustainable office building that minimizes its environmental footprint.

The new building being constructed in downtown Seattle, and opening in late 2012, uses 1/3 of the energy normally consumed by a standard office building of equal size. The building generates its own electricity using solar arrays, collects rainwater for internal consumption, and treats sewage and wastewater on site. Although still connected to the electrical grid the building systems send power back to the grid when producing beyond the needs of its tenants resulting in net zero electricity usage from utilities.

The builders estimate costs at 33% higher than traditional construction but expect their creation to endure for 250 years. Compare that to the average office building lasting 40 years, more than justifying the extra investment in initial construction.

Located in Seattle, Washington, the Bullitt Center is a commercial building with a net-zero environmental footprint. Source: Metal Construction News

The Bullitt Center will be the largest net-zero office building in the United States. To meet the net-zero challenge the Center includes:

• Roof solar panels extending over the sides of the building and efficient enough to generate power even in a cloudy environment like Seattle
• 26 geothermal water wells, each 400 feet deep in earth to main a constant temperature of  12 degrees Celsius (55 Fahrenheit) for heating and cooling.
• A 56,000 gallon cistern for collecting rainwater from the roof through a special membrane  and ultra filtration and ultraviolet light treatment for purification.
• 10 basement composters for treating sewage which will then be turned into fertilizer offsite.
• Use of timber frames certified as sustainable wood.

The Bullitt Center is one of a few select buildings that are changing the face of the urban landscape to meet sustainability challenges.

Bioengineering Update – If the Climate Changes Wouldn’t it be Easier to Change Us?

Re-engineering the planet may be tougher than re-engineering humanity argues S. Matthew Liao, of New York University, in an article, Human Engineering and Climate Change published in Ethics, Policy & Environment. With the impact of greenhouse gases and rising atmospheric temperatures, and with the growth in human population expected to exceed 9 billion by mid-century, Liao and his co-authors, Anders Sandberg and Rebecca Roache, of Oxford University, create an argument for altering our species to better adapt to a changing world.

The arguments for this approach include:

1. Human engineering may be potentially less risky than geo-engineering the planet to mitigate climate change.
2. Human engineering could decrease human-induced climate change.
3. Human engineering could solve many of our social and health problems and contribute to a more sustainable planetary footprint.
4. Biomedical modification is already within sight with the mapping of the human genome and our ability to insert genetic information into the DNA of individuals suffering from genetically induced diseases.

Why would re-engineering us be better than re-engineering the planet?

1. Geo-engineering is a very imperfect science and climate scientists are still trying to perfect models to explain the interaction between atmosphere, solar radiation, our oceans and land masses.
2. Geo-engineering requires all nations to commit to a common strategy for reducing our carbon footprint. Humans have shown a disinclination to achieve any kind of consensus on a common approach to date.
3. Ge0-engineering could have unforseen consequences that further damage the environment globally. We could create a runaway cold event or induce more rapid heating if we choose the wrong technological solution.

What kinds of changes would we consider making to humans?

1. Make humans smaller so they need less to eat and use fewer resources.
2. Make all humans vegans by genetically modifying them to not tolerate meat and thus free up land currently used for the meat industry and repurpose it for crops.
3. Make humans less prolific in reproduction to reduce population.
4. Make humans more sympathetic and altruistic to reduce war and conflict.

I recently read Margaret Atwood’s messianic novel of the future, Oryx and Crake.  If you are not familiar with it, the subject focuses on bioengineering with outcomes darker than that suggested by the proposals made by Liao et al. The authors freely admit that human engineering solutions may be considered preposterous but if we are to survive as a species in a habitable Earth, it is an option worthy of debate.

Geoengineering Update – Proposals for Dealing with Arctic Methane Permafrost Release

For the last two weeks here in Toronto the temperature has been abnormally warm. Today, March 19, 2012, we will see late May, early June daytime high temperatures. This is the second winter in the last three to produce a winter that by Toronto standards can only be called balmy. Which brings me to the topic at hand – the warming of our northerly extremes and the potential release of methane bound up in permafrost.

In a proposal to British parliamentarians in the last week, Stephen Salter, an engineer at Edinburgh University, proposed constructing 100 towers for pumping seawater into the atmosphere to create clouds to reflect solar energy into space and cool the Arctic.

Artificially inducing cloud cover is one proposal being suggested by engineers to deal with a warming Arctic. In this picture the towers installed on ships moored in Arctic waters spray seawater into the upper atmosphere.

With Arctic Sea ice melts increasing each year saltwater temperatures in the north are rising rapidly. Dr. Slater noted that in 2007 the water off the northern Siberian coast warmed to 5 degrees Celsius (41 Fahrenheit). The warming at sea is impacting permafrost in the seabed and in the adjacent land. Permafrost contains methane and methane is more potent as a greenhouse gas than carbon dioxide.

Climatologists believe that abrupt methane releases 55 and 251 million years ago played a significant role in mass extinctions. A large methane release from the permafrost in Siberia, northern Canada and the Arctic sea bed could lead to an average temperature rise between 5 and 9 degrees Celsius (9 to 16 Fahrenheit) in Arctic regions.

Geoengineering is often not considered seriously when talking about climate change. Governments look at policies related to reducing carbon emissions as the primary way to mitigate global warming. But we may have to do a combination of both or learn to live with a radically altered North.

Geoengineering Update – Rising Sea Levels Represent a Distinct Risk in the 21st Century

With one island nation, Kiribati, already planning an exit strategy, and climatologists and oceanographers marking the steady rise in ocean surface levels, the 21st century looks like it will witness the first definitive impact of global warming. The government of Kiribati recently revealed its purchase of real estate in Fiji for the bulk of its population. Two other island nations, the Maldives in the Indian Ocean and Tuvalu in the Pacific will soon follow Kiribati’s example with their citizens becoming the first climate change refugees in the century.

Kiribati is one of several island nations with little margin for survival in the event of rising sea levels.

Rising sea levels are a fact whether we ascribe them to man-made climate change or natural variability. Since the late 19th century the average global rise in sea levels amounts to 20 centimeters (8 inches). When sea levels rise in areas where land is subsiding the potential for storm surges causing significant on land incursions is dramatically heightened. Such is the case in areas like Chesapeake Bay or the Mississippi Delta in Louisiana. The noted rise in sea levels has been steady for much of the last century but recently appears to be accelerating.

Climatologists predict a rise of 30 centimeters (12 inches) over the 21st century. What does that mean for low altitude coastal areas throughout the planet – extensive re-engineering of  areas to protect vulnerable populations, or abandonment. For example, in the United States 3.7 million people live within a few feet of sea level. Florida is most vulnerable to the encroaching Atlantic and Gulf of Mexico.

But even a worse fate is in store for Bangladesh on the Bay of Bengal. Rising sea levels recently ended a territorial squabble between that nation and India when the disputed island, known as New Moore in India and South Talpatti in Bangladesh disappeared under the waves. Bangladesh, of all the nations on the planet is most vulnerable to rising sea levels. An average of 11 Bangladeshi citizens lose their homes to rising water every hour. By 2050, 17% of the country will disappear displacing 20 million. Parts of India will submerge by 2020 representing 15% of the Sundarbans region on the Bay of Bengal.

Sundarbans on the Bay of Bengal is being devoured by rising sea levels. This area and neighbouring Bangladesh are most vulnerable to what scientists believe is a consequence of climate change.

Identifying the Problems of the 21st Century – A Commentary on James Martin’s 16 Challenges

When I was a younger man working in the world of information technology I was an avid reader of James Martin’s books on computers and telecommunications. Recently I came across one of his books of which a part is published online. Entitled, “The Meaning of the 21st Century,”  it outlines 16 challenges that humanity faces in the coming century. I’ve added comments of my own in Italics.

1. GLOBAL WARMING Global warming will lead to severe climate change. Unless stopped, it will upset the basic control mechanisms of planet Earth.
2. EXCESSIVE POPULATION GROWTH World population may grow to 8.9 billion people, with a growing demand for consumer goods and carbon-based energy, far exceeding what the planet can handle. Forecasts of population growth indicate human population will start to peak around mid-century, level out and then slowly decline. Peak variable projections indicate a population as little as 9 billion or as high as 12 billion.
3. WATER SHORTAGES Rivers and aquifers are drying up. Many farmers will not have the water essential for food growing. There will be wars over water. Freshwater is one of the most challenging issues we face.
4. DESTRUCTION OF LIFE IN THE OCEANS Only 10% of edible fish remain in the oceans, and this percentage is rapidly declining. Aquaculture is only a partial solution to the problem of the collapse of fish stocks. Climate change influencers like CO2 are acidifying the ocean changing impacting krill, coral and shellfish, principal food sources for most marine life.
5. MASS FAMINE IN ILL-ORGANIZED COUNTRIES Farm productivity is declining. Grain will rise in cost. This will harm the poorest countries. Agricultural production in the Developing World needs to reach the same yield levels as in the factory farms of the Developed World replacing subsistence agriculture.
6. THE SPREAD OF DESERTS Soil is being eroded. Deserts are spreading in areas that used to have good soil and grassland. Grazing and improper land use including deforestation continue to impact soils in the Developing World contributing to desertification.
7. PANDEMICS AIDS is continuing to spread. Infectious pandemics could spread at unstoppable rates, as they have in the past, but now with the capability to kill enormous numbers of people. Although pandemics will always put humans at risk we have the means today to contain outbreaks and develop rapid response to them when they occur.
8. EXTREME POVERTY 2 to 3 billion people live in conditions of extreme poverty, with lack of sanitation. The difference between rich and poor is becoming ever more extreme. This is even a problem in the Developed World as indicated by the recent Wall Street protest movement and Arab Spring.
9. GROWTH OF SHANTYCITIES Shantytowns (shantycities) with extreme violence and poverty are growing in many parts of the world. Youth there have no hope. We need a global commitment to addressing informal urban environments and the poverty and despair associated with these areas.
10. UNSTOPPABLE GLOBAL MIGRATIONS Large numbers of people are leaving the poorest countries and shantycities, wanting to find a life in countries with opportunity. Migration from rural to urban is happening today at the rate of 80,000 per day. Migration from the Developing World to the Developed is increasingly more difficult although illegal immigration continues at a steady if not increasing pace.
11. NON-STATE ACTORS WITH EXTREME WEAPONS Nuclear or biological weapons are becoming easier to build by terrorist organizations, political groups or individuals, who are not acting for a given state. The evidence of this development frames the beginning of the 21st century and may be with us for a long time to come.
12. VIOLENT RELIGIOUS EXTREMISM Religious extremism and jihad may become widespread, leading to large numbers of suicide terrorists, and religious war between Muslims and Christians. This is nothing new. Religion, nationalism, and tribalism have been a part of the human condition and will continue. The real challenge will be to overcome our baser nature.
13. RUNAWAY COMPUTER INTELLIGENCE Computers will acquire the capability to increase their own intelligence until a chain reaction happens of machines becoming more intelligent at electronic speed. Artificial intelligence and humanity will experience convergence throughout the century. The question will become can we distinguish one from the other?
14. WAR THAT COULD END CIVILIZATION A global war like World War I or II, conducted with today’s vast number of nuclear weapons and new biological weapons, could end civilization. War in the 21st century will be fought in entirely new ways. Cyberattacks, militarization of space and new weapon technology (robotics, lasers) will change war just as the first atomic bomb altered the rules of warfare in the 20th century leading to the disappearance of global conflicts only to be replaced by regional wars.
15. RISKS TO HOMO SAPIEN’S EXISTENCE We are heading in the direction of scientific experiments (described by Lord Martin Rees) that have a low probability of wiping out Homo sapiens. The combination of risks gives a relatively high probability of not surviving the century. Humanity will survive the century. This is just too pessimistic.
16. A NEW DARK AGE A global cocktail of intolerable poverty and outrageous wealth, starvation, mass terrorism with nuclear/biological weapons, world war, deliberate pandemics and religious insanity, might plunge humanity into a worldwide pattern of unending hatred and violence – a new Dark Age. We are just as likely to emerge at the end of the 21st century with entirely new purpose as we look outward bound beyond our planet while using technology to restore much of what the Industrial Age has wrought.

In my blog I don’t just point out the problems but show how our human inventiveness is finding solutions. Nonetheless, James Martin has pointed out challenges we must face and overcome for humanity and the other travellers on our planet.

Urban Landscapes in the 21st Century – Part 5: The Evolution of Cities

In urban environments water plays many roles. It is used for drinking, cooking, washing, gardening, parks, recreation, sanitation, and manufacturing. On coastlines and where rivers cut through cities it serves as a transportation artery.

The Drinking Water Dilemma

In a 1996 published paper the author provided statistics showing that freshwater consumption was 40 times greater than consumption in 1700 and that half of that increase had taken place since 1950. With human population continuing to grow this may mean cities in the Developed and Developing World may find themselves without enough freshwater to sustain their populations.For the cities of the Developing World, growing faster and with less freshwater infrastructure the crisis will be unlike anything we have seen before.

In a 2010 published article in 24/7 Wall Street, the authors listed 10 of the largest American cities most likely to run out of freshwater. In order of most likely to least likely they are:

1. Los Angeles
2. Houston
3. Phoenix
4. San Antonio
5. San Francisco-Oakland-San Jose
6. Fort Worth
7. Las Vegas
8. Tucson
9. Atlanta
10. Orlando

Note that these cities occupy the southern areas of the U.S. and many are in the Southwest where migration over the last half century has resulted in increasing water demands for growing populations. Los Angeles long ago ran out of local freshwater and relies heavily on water from the Colorado River basin. Los Angeles receives less than 380 millimeters (15 inches) of rain annually. But its population continues to grow attracting low-income migrants from Mexico and Central America.

Houston, the second city on the list, receives a lot more rain than Los Angeles, 1,400 millimeters (53 inches) annually. This sounds like more than enough to meet population demands. But that’s not the case. Houston is growing rapidly and the withdrawal of water from the local aquifer under the city is causing the land to subside leading to rising sea levels and salinization of freshwater sources.This is a problem for coastal cities in Florida as well.

Many cities on this list are in semi-desert and desert climate zones already water deficient. As these cities continue to grow because of their favourable climate they are depleting all the freshwater sources close by as well as those far away. Like Los Angeles, the cities of Phoenix, Tucson and Las Vegas rely on water from the Colorado River. At their current rates of growth the Colorado River may run dry by the mid-century.

Some recent studies estimate that reservoirs in the Colorado River basin will run dry by 2057. Water demands on the river from urban growth in the U.S. southwest are increasingly unsustainable. Source: PlanetSave

Drought in the Southern U.S. has put other cities at risk. Atlanta, Fort Worth and Orlando have depleted freshwater reservoirs and aquifers through droughts that seem to be longer in duration. Proposed solutions include piping water from wetter areas of the United States and even Canada. This type of solution has led to pushback from local populations at the source who fear that their freshwater resources will be depleted by this growing demand.

For coastal cities like Los Angeles, San Francisco and Houston, desalinization of seawater represents a technological solution that comes at a pretty steep price. Like their Australian urban cousins, most which hug the coastline of that country, desalinization is in their present or near future.

The Freshwater Crisis in the Developing World

In a 1995 study, 31 countries representing almost 500 million population were classified as freshwater stressed or scarce. What is the definition of “stressed” and “scarce?” Hydrologists use the following benchmarks to measure freshwater availability.

1. Adequate = greater than 1,700 cubic meters of water per person per year
2. Stressed = 1,000 and 1,700 cubic meters
3. Scarce = less than 1,000 cubic meters

Most countries of the Northern Hemisphere are classified as Category 1. The exceptions are countries in Central Asia (former republics in the Soviet Union) and regions within very large countries like Russia and the United States (see discussion above on U.S. cities running out of water).

Countries in the Southern Hemisphere more often fit Category 2 and 3. For these countries scarce is becoming more common, and particularly reaching dangerous levels in countries defined as part of the Developing World where migration to cities is continuing to accelerate along with water consumption.

Category 3 has many implications. Freshwater scarcity puts agriculture, the environment, population health and economic growth in jeopardy.

What is even more disturbing is what is forecasted for the Developing World between now and mid-century. By 2025 based on current consumption trends, the number of Category 2 and 3 countries will grow to 50 affecting 3.3 billion people. And by 2050, Category 2 and 3 countries will number 54 and 4 billion people. Almost all affected countries will be in Africa and the Middle East.

In our next blog on the urban landscape we will look at how new urban models, water usage patterns and technology can help avert the growing scarcity of freshwater supply.

Urban Landscapes in the 21st Century – Part 4: The Evolution of Cities

In our last blog we talked about the challenge of dealing with solid urban waste in cities in both the Developed and Developing World. With urban growth in the 21st century expected in cities of the Developing World, add managing the air to the litany of challenges to be faced and overcome.

Developed World cities have the same problems with air pollution as cities in the Developing World. The difference is in length of time in which these problems have appeared. Developed World cities grew at a slower pace than the Developing World cities of today.  So although emissions from automobiles, trucks, home heating, industrial plants, and power stations contributed to ground-level ozone, CO2, and urban-created smog, these problems became apparent over a half century or more, not over a decade or even less time than that.

Air pollution in cities spreads far and wide regardless of the location of the city in the Developed or Developing World. In addition the demands cities put on their hinterlands exacerbate the problem. Cities need energy. Coal-fired power plants produce that energy and may be hundreds of kilometers away but their emissions pollute from point of origin and downwind often contributing to greater problems for the cities they heat and light.

Beijing, China, experiences many days each year when air pollution reaches such dangerous levels (see picture below) that it is unsafe to be outdoors. Cities of the Great Lakes in Canada and the United States get the drift of air pollutants from local origin as well as the emissions from coal-fired power plants up wind. Tailpipe emissions from cars, trucks and buses create ground-level ozone making walking on local sidewalks in urban settings hazardous to the health of those who have asthma or other respiratory diseases.

Coal-fired power plants, industry, and traffic contribute to the smog experienced in Beijing for much of the year, 16 times worse than New York City. Source: tdaxp.com

Air Pollution in Urban China

Before Beijing hosted the Olympics,it began a program to greatly decrease air pollution. This involved restricting traffic, reducing the operations of coal-fired power plants, and limiting the hours that heavy industry could operate. Even with regulation the quality of the air during the 2008 Olympics was only marginally better. When measured throughout the Games Beijing air contained higher than acceptable levels of ozone, sulfur dioxide (SO2), carbon monoxide (CO), carbon dioxide (CO2), reactive aromatics (toluene, xylene), nitrogen dioxide (NO2), reactive nitrogen (NOy), alkanes and benzene. For the athletes the exposure presented minimal risk but for Beijing citizens living in the city before and after the Games, air pollution is a major contributor to chronic respiratory disease.

Air pollution in China is not limited to Beijing. Shanghai, China’s largest city, experiences air pollution so thick that residents report it is often impossible to see buildings a few blocks away, or the road from as little five stories above. Beijing and Shanghai have had to close their international airports on days when the air pollution has made it impossible to safely take off and land. Space shuttle and International Space Station astronauts have reported that many of China’s cities are invisible from space because of the blanket of pollutants that shroud them from view.

For China’s it is a tradeoff between air quality and production and its urban population as its economy rapidly expands. In a 2010 study of air pollution in urban China it stated that one-third of 113 Chinese cities failed to meet air quality standards. A World Bank report indicated that 16 of the 20 worst air polluted cities were in China with 20% of the urban population exposed to heavily polluted air. The primary cause is the burning of high-sulphur coal, the principal mined fossil fuel in China. Six million tons is burned daily not just for power and industrial plants, but also as a domestic heating and cooking source. The total health cost of airborne particulate matter in a 1995 study was estimated to equal $54 billion annually or 8% of Gross Domestic Product (GDP). Considering the expansion of the Chinese economy since 1995, that number is today much greater. Today China is adding a new source of air pollutants to the mix. The number of motor vehicles is rapidly on the increase. The result, airborne lead in major Chinese cities such as Shenyang and Shanghai is contributing to blood-lead levels 80% percent higher than those normally considered dangerous to mental development. With a rising middle class and a lot more automobiles and trucks on the road lead pollution will only get worse.

Air Pollution in Developing World Cities

The same factors that contribute to the problems in Chinese cities exist in cities throughout other parts of the Developing World. More than a billion urban dwellers in these cities experience dangerous levels of air pollution, contributing to 2 million premature and prenatal deaths annually. It is estimated that urban air pollution costs Developing World countries 5% of GDP annually compared to 2% for the Developed World. More than 90% of the pollution is attributable to transportation and domestic use, not power and industrial plants as in China. Older vehicles, poor vehicle maintenance and poor-quality highly leaded gas are major culprits. Burning kerosene and other fuels for domestic cooking contribute to the bad air in these urban environments. Local industries rely on diesel generators because of a lack of power from central utilities.

In Lagos, a city we have documented in previous blogs, traffic, flaring of waste gas from petroleum refineries, kerosene burning for cooking, and incineration of solid wastes, have contributed to air pollution that is 500% higher than safe levels established by the World Health Organization (WHO). In 2007 the WHO estimated that air pollution contributed to 14,700 deaths in Nigerian cities.

Pollution in Developing World cities, such as Lagos, Nigeria, pictured here, is largely caused by inefficient use of fossil fuels, the poor quality, maintenance and age of motor vehicles, traffic gridlock, low-grade leaded gasoline, industrial generators, and domestic cooking using kerosene. Source: The Foreign Policy Group, LLC.

Solutions for Cleaner Air in Developing World Cities in the 21st Century

What can be done to clean up the air over the cities of the Developing World? What is affordable? What technologies exist today or will exist in the near future to mitigate and end this growing problem that not only contributes to premature death but also to climate change?

In China, South Asia and Africa the goal to decrease air pollution involves a cooperative effort among government, industry and citizens. Technology solutions exist at the macro and microeconomic level. What are these?

Substituting cleaner fuels for generating power, heat and electricity. In China, washing coal before burning it would greatly decrease (SO2) and acid rain. Better yet getting off coal by finding alternatives will dramatically reduce many of the other pollutants that shroud Chinese cities. Diversifying means using renewable power sources such as wind, photovoltaics and other solar technology, hydroelectric power, nuclear power, natural gas and oil.

Today, China is the world’s largest manufacturer of wind turbines not just for export but also for domestic use. China is building variable-sized wind turbines with sizes deployable off the grid for rural power generation. Small wind turbines represent a supplementary power source for clusters of homes or single family dwellings.

One of the many challenges in cities in places like Africa is the lack of capital to invest in manufacturing at a level of sophistication and in quantity as in China. Instead, small-scale manufacturing projects involve the use of local materials. A good example is a project in Cameroon. The town of M’muock, population 7,000, is working with Green Step, a German company, to build and operate small wind turbines and other renewable energy power generators from locally sourced wood, and old car and radio parts.

Using locally available materials to create power generation is one way to begin to address the problem of substituting dirty fuels for clean solutions to combat air pollution. Source: Green Step

Refining gasoline to get the lead out. Lead as an additive in gasoline was first introduced in the 1920s despite its known toxicity and it has taken 90 years to eradicate it from the production of this fuel. The United Nations has set a goal of 2013 to end production of leaded gasoline globally. Once this is achieved new lead sources will no longer contribute to the problem. But the residual environmental threat remains.

Even though leaded gasoline was banned in 1986 in the United States, lead remains in the soil and air because it is almost indestructible. For children this represents a greater risk because they ingest lead 5 to 8 times more rapidly than adults. Children absorb up to 50% of inhaled lead. Those living near highways, playing on roads or in playgrounds near parking lots are at greatest risk as dust with lead gets ingested into lungs.

Inexpensive lead remediation programs involve combining compost with contaminated soils to inactivate the lead. Lead when exposed to phosphates forms an insoluble compound. Similarly lead is remediated when exposed to soluble iron oxides.

Replacing polluting motor vehicles with low-emission and zero-emission alternatives. Older automobiles and trucks are major contributors to air pollution in urban environments. Emissions include (NO2) nitrogen dioxide, (CO) carbon monoxide, (CO2) carbon dioxide, benzene and other partially combusted hydrocarbons. Internal combustion engines (ICE) are the principal polluters even those with catalytic converters although a converter halves the amount of NO2 that gets into the atmosphere.The combination of partially combusted hydrocarbons, NO2 and sunlight cause ground-level ozone and smog. Recycling the older vehicles that clog the roads of Developing World cities can at least begin to reduce NO2. Proper maintenance of older vehicles to improve the air-to-fuel ratio can dramatically reduce CO emissions.

Ideally the arrival of electric vehicles with infrastructure for managing both the charging of batteries and their disposal will dramatically reduce air pollution.

Implementing emission control technologies in industrial and power generating plant smokestacks. Reducing emissions whether in cars or trucks, or from industrial and domestic sources will lower air pollution levels in Developing World urban centres. Proven technologies include:

Cyclones to create cyclonic motion in the smokestack air stream to cause pollutant matter to drop out. Cyclones are inexpensive and useful for removing large airborne particles only.

Settling Chambers like cyclones alter the air stream, not by spinning the gases but by passing them through a larger space in the smokestack causing the air speed of the effluent to drop and precipitating out large particles. Settling chambers are inexpensive to implement.

Wet scrubbers filter out pollutants from the air stream by passing through water. Pollutants combine with water droplets and precipitate into settling tanks. Pollutant-laced water is discharged into settling ponds which can become quite large over time and highly toxic.

Fabric filters use porous temperature and corrosion-resistant fabrics to remove pollutants from the air stream as it passes up the smokestack. The filters need frequent replacement.

Electrostatic filters are the most effective tools for removing smokestack emissions. They can capture almost 99% of airborne pollutants. They do this by ionizing the particles in the gas and then using magnets to remove pollutants.

Catalysts create a chemical reaction that binds airborne pollutants to a catalytic medium. Catalytic converters in cars use platinum and rare earth metals. In industrial plants catalysts in their current form are very expensive to implement.But the future is promising with developments in nanotechnology catalysts because the nanoparticles expose so much more surface to the air stream capturing a much greater volume of pollutants. Nanocatalysts made from cobalt and platinum are effective in removing NO2. Gold combined with manganese oxide in a nanocatalyst can be used to breakdown volatile organic compounds at room temperature.

Nanostructured membranes are under development that separate CO2 from the air stream for carbon capture. Structures under development use crystals with nano-sized pores to trap the gas. The captured CO2 can be converted to methanol or for use in building carbon nanotubes.

Replacing kerosene and coal as domestic cooking and heating fuels with cleaner alternatives. Urban dwellings in Developing World cities may not have access to reliable utility-delivered electricity or natural gas. Being off the grid is more common than not. Using generators that run on gasoline or other highly polluting fuels just contributes to air pollution. Building homes that can generate their own electricity through wind, solar and battery storage is one way to reduce airborne pollution. Where the infrastructure can deliver reliable electricity and natural gas, reductions in pollution will result. Houses like those being built using Eco-Tec designs represent a model for construction in these urban environments.

In our next edition of urban landscapes we will address water pollution in the 21st century.