Today marks the 16th installment in a series of articles by HumanProgress.org titled, Heroes of Progress. This bi-weekly column provides a short introduction to heroes who have made an extraordinary contribution to the wellbeing of humanity. You can find the 15th part of this series here.

Our 16th installment of Heroes of Progress features Abel Wolman and Linn Enslow. These two 20^th century American scientists discovered how to safely use chlorine to purify drinking water. Enslow and Wolman’s formula was perfected in 1923 and thanks to their discovery more than 190 million lives have been saved worldwide so far.

Using chlorine to purify water did not start with Wolman and Enslow. During a cholera epidemic in 1854, chlorine had been used to purify London’s drinking water. Similarly, the first American patent for a water chlorination system was granted in 1888. While it was accepted that chlorine could kill bacteria, little was understood about the cleansing process and, since chlorine can be poisonous to humans, using the chemical for water purification purposes remained dangerous.

In the early 1900s, cities across America were expanding at a rapid pace and luxuries such as indoor running water were becoming more widespread. With no safe or effective measures to clean their drinking water, city water suppliers often became unwitting disseminators of an array of diseases, including cholera, dysentery and typhoid. This is where Wolman and Enslow enter our story.

Abel Wolman was born in June 1892, in Baltimore, Maryland. Wolman was one of six children of Polish-Jewish immigrants to America. Although Wolman had initially wanted to go into medicine, his parents encouraged him to study engineering. In 1915, Wolman became the fourth person to receive a BS degree from John Hopkins University’s newly established Engineering School.

Linn Enslow was born in February 1891 in Richmond, Virginia. Enslow studied chemistry at John Hopkins University and it was there that he first met Wolman. After graduation, both Enslow and Wolman began working at the Maryland Department of Public Health. In 1918, the pair teamed up to study chlorine’s effect on water purification.

In creating their method of water purification, Enslow and Wolman analyzed chlorine’s effect on the acidity, bacterial content and taste of drinking water. By 1923, the pair had created a standard formula detailing the amount of chlorine needed to safely purify water supplies. Enslow and Wolman’s rigorous scientific research laid the foundation for water purification across the world.

After their breakthrough, Wolman took a more active role than Enslow in encouraging states and countries to adopt the formula. Eventually Wolman was able to apply the new water purification method to Maryland’s drinking water supply. By 1930, typhoid cases in the state had declined by 92 percent. By 1941, 85 percent of all U.S. water systems used the Enslow-Wolman formula. The rest of the world followed America’s lead.

Wolman’s career flourished. He became chair of the state Planning Commission in his early 30s, acted as a consultant to the U.S. Public Health Service, was the Chief Engineer at the Maryland Department of Public Health, and established the Department of Sanitary Engineering at The Johns Hopkins University in 1937

Throughout his life, Wolman sat on numerous boards and advised governments on water purification systems throughout the world. Wolman eventually retired in 1962. He died in 1989 in his native Baltimore at the age of 96.

In the meantime, Enslow went on to become the editor of the magazine Water and Sewage Works. He worked in that role until his sudden death from a heart attack in 1957.

Thanks to the work of Enslow and Wolman, billions of people now have access to drinking water that is free from an array of potentially deadly diseases. It is estimated that the adoption of their formula in water systems worldwide has saved almost 200 million lives. It is for this reason that Linn Enslow and Abel Wolman are our 16^th Heroes of Progress.

PS: Linn Enslow is on the left of our cover picture and Abel Wolman is on the right of our cover picture.

Critics of Steven Pinker’s book Enlightenment Now argue that he is too optimistic about the role of technology in solving environmental problems. However, Israel’s success in desalination shows that market-driven innovation can solve environmental challenges and create abundance from scarcity.

Since he published his bestselling book, Enlightenment Now: The Case for Reason, Science, Humanism, and Progress, Steven Pinker has been criticized for excessive optimism. Jeremy Lent, for example, argues that Pinker is insufficiently concerned about depletion of the planet’s natural resources, including freshwater reserves. He faults the Harvard University psychologist for embracing a “neoliberal, technocratic belief that a combination of market-based solutions and technological fixes will magically resolve all ecological problems.” As Israel’s desalination efforts show, however, technological fixes and market-based solutions are an important part of humanity’s efforts to overcome environmental challenges.

Lent begins his piece by noting some worrying environmental trends, including “the rise in CO2 emissions; the decline in available freshwater; and the increase in the number of ocean dead zones from artificial fertilizer runoff.” Pinker does not deny that, in addition to many positive trends, including reduction of absolute poverty, increasing lifespans and declining violence, humanity faces important challenges. “Progress,” he writes, “is not the same as magic. There are always blips and setbacks… Clearly we have to be mindful of the worst possible setback, namely nuclear war, and of the risk of permanent reversals, such as the worst-case climate change scenarios.”

Take, for example, the freshwater supply. Between 1962 and 2014, renewable water resources per person declined from 17,220 cubic meters to 7,462 cubic meters. However, note that 71 percent of the Earth’s surface is covered by water. What’s needed in the areas most affected by drought, such as North Africa and the Middle East, is an affordable process of desalination that separates salt particles from water molecules. Israel has pioneered a desalination method that makes freshwater consumed by Israeli households 48 percent cheaper than that consumed by the people of Los Angeles. Desalination, writes Rowan Jacobsen in Scientific American,

Lent critiques Pinker for failing “to take into account the structural drivers of [environmental] overshoot: a growth-based global economy reliant on ever-increasing monetization of natural resources and human activity.” In reality, free enterprise is not the problem. It is the solution. Relative scarcity leads to higher prices, higher prices create incentives for innovations, and innovations lead to abundance. Scarcity gets converted to abundance through the price system. The price system functions as long as the economy is based on property rights, rule of law and free exchange. In relatively free economies, resources do not get “depleted’ in the way that Lent fears – as witnessed by the fact that Earth is yet to run out of a single non-renewable resource.

That’s because the totality of our resources, including freshwater, are not fixed. Yes, the total number of atoms on Earth is finite, but the ways in which those atoms can be combined and recombined are infinite. What matters, then, are not the physical limits of our planet, but human freedom to experiment and reimagine the use of the resources that we have. As New York University economics professor Paul Romer writes,

In contrast to free economies, statist societies without property rights, rule of law and free exchange tend to be much worse stewards of the planet. The Soviet Union and Maoist China, for example, were reckless abusers of their resources, including the most precious resource of all – human beings. The biggest distinction between free and statist societies is the value they place on human life. Free societies treat human beings as a valued resource, because it is only humans who have ideas and creative energy to convert those ideas into innovations. In contrast, statist societies tend to consider members of the human race as liabilities. As such, the road to statist utopias is strewn with corpses.

Lent is wrong to dismiss technological fixes and market-based solutions to our environmental problems. Within the context of a market economy, human beings not only use resources, but replenish and enlarge them. As such, Israel’s desalination plants supply drinking water not only to the Israelis, but also the inhabitants of the West Bank and diplomatic efforts are afoot to supply Israeli drinking water to the surrounding Arab countries. That’s progress.

This first appeared in CapX.

Dystopian visions of the future are as old as humanity itself. As I noted in a previous column, one of our most consistent concerns is the interplay between population growth and the supposed finality of natural resources. According to conventional wisdom, a rising population – there will be 10 billion of us by 2050 – must result in poverty and famine. 

Yet, human beings, unlike other animals, can innovate their way out of scarcity by increasing the supply of natural resources or developing substitutes for overused resources. Human ingenuity, in other words, is “the ultimate resource” that makes all other resources more plentiful. Now is a good time to look at one concrete example: the water supply. 

A brief search on Amazon.com yields a veritable smorgasbord of books and videos concerning the supposed impending shortage of the vital liquid. The “problem” is not new. As an undergraduate student of international relations, I was taught that water was “liquid gold” and future wars would be fought over it. 

Twenty years later, the BBC has published an article entitled, “Is this the real liquid gold? Why tapping into Earth’s most precious resource could be the next big thing.” According to the BBC, “The problem isn’t that there’s too little water on the planet, it’s that there’s not enough clean fresh water to go around. Only 1 per cent is consumable by humans, according to the US Environmental Protection Agency. Desalinisation plants, which convert salt water … to clean water, are still expensive to build.” Well, that’s rapidly changing. 

Before proceeding: a bit of physics and chemistry. Reverse osmosis is a water purification technology that uses a semipermeable membrane to remove larger particles from drinking water. During the process:

Put differently, the supply of fresh water depends on the availability of cheap and environmentally-friendly energy. 

When reverse osmosis desalination started being commercialised in the late 1970s, scientists faced the problem of low energy recovery systems and inefficient membranes. The energy consumption to generate the pressure needed to overcome osmotic pressure was as high as 10 kilowatt hours of electricity per cubic metre of fresh water (10kWhr/m3). The average energy consumption rate of today’s desalination plants is 4.5kWh/m3. 

Trouble is that some sources of energy are more preferable than others. One of the main problems concerning desalination is the emission of CO2. That is especially true of the large desalination plants in the Middle East. In Saudi Arabia, for example, it is estimated that nearly 300 thousand barrels of oil are used daily to generate electricity needed to power desalination plants. But, what if you could replace burning of fossil fuels with solar power? 

According to a 2011 study in Renewable and Sustainable Energy Reviews, the first solar-powered reverse osmosis desalination test took place in Saudi Arabia in 1981. The results were not encouraging. The Saudis were only able to produce 3.2 cubic meters of desalinated water per day and the energy needed was enormous – between 16 and 19kWh/m3. 

But things have changed. A 2016 Renewable Energy Market Analysis: The GCC Region notes that the cost of solar energy has decreased so much that it is competitive even in the oil-rich Middle East. As an example, the Mohammed bin Rashid Al Maktoum Solar Park in Dubai produces solar energy at US 5.85 cents per kWh. 

The same report states that the combination of solar power and reverse osmosis can be competitive with fossil fuel-based desalination at oil prices as low as US$20 per barrel. Estimates also indicate that using off-grid systems, such as solar-diesel hybrids can get prices as low as US$2 per m3. In contrast, systems powered entirely by diesel cost, on average, US$2.2 per m3.

Today, solar-powered reverse osmosis plants account for only 0.8 per cent of global desalination capacity. If solar panels satisfied 44 per cent of the annual energy load of each reverse osmosis desalination plant, however, solar power could reduce the use of diesel fuel by 2 billion barrels annually. It could also reduce CO2 emissions by 832 million tons per year. 

Happily, the world’s largest solar-powered desalination plant is under construction in the city of Al Khafji, Saudi Arabia. This project, which was launched by King Abdulaziz City for Science and Technology in cooperation with IBM, is expected to be fully functional later this year. The plant will cost US$130 million and be capable of producing 60,000m3 per day. As such, it will pay for itself in less than six years. 

Solar power will not work as efficiently everywhere on Earth. Luckily, places that need fresh water most are also places with abundant sunshine. Humanity will face many challenges in the future, and solar-powered desalination is a testament to human ability to solve one of them. 

Not bad, ape descendants! Turns out that our Latin moniker Homo Sapiens (wise man) may be well earned after all.

This first appeared in CapX.