People Can Make Rain

Reversing Destructive Land-Use Patterns Can Improve Local Water Cycles

Through an examination of tree rings dating back 2,500 years, scientists have determined that from the 1500s until the 1970s, California was uncharacteristically wet. The latter 130 years of this period cover the modern development of the state. Understandably, planning parameters have been based on overly optimistic figures for rainfall. Not only are our expectations outside the long-term range of weather patterns, but we are making the climate hotter and drier through human-induced climate change.

There are two moisture cycles in nature. The most widely understood one is rain flowing down rivers to the sea, where it evaporates from the ocean surface, condensing into clouds that drift over land to rain again. This, however, only accounts for about half of rainfall. The second cycle is a smaller, more local one. Moisture evaporates from plants, trees, and the soil, making clouds overhead and subsequently falling as rain in the region.

To make clouds, microscopic particles are needed. These were thought to be inert minerals like dust. Only within the past 50 years have scientists begun understanding that bacteria can also be nuclei around which water vapor can coalesce. Studies have shown that cloud-making bacteria exist in every part of the world. One study of cloud-water revealed 28,000 different species of bacteria. Plants and algae create conditions for microbe propagation, of which some become lifted by winds and attract water vapor. Bacteria multiply rapidly and are among the most resilient organisms on the planet.

The knowledge that microbes from plants and soil play a central role in rain cycles over land has profound implications. For example, the removal of vegetation by overgrazing or exposing bare soil in monocrop farming can create conditions for drought. Conversely, the restoration of a plant-rich ecosystem could increase precipitation. Cloud-seeding bacteria can be deliberately cultivated to boost water cycles. 

Reversing destructive farming, ranching, and forestry practices creates opportunities to restore carbon stocks in soil, plants, and trees. Healthy, carbon-rich soils store a great deal of water and foster abundant microbial communities, leading to increased evaporation, water vapor, and clouds. Evaporation is usually seen as a loss, something to be minimized. We need to change this perspective and start seeing it as a source of precipitation.

A Dutch company, Water Makers, has a project to transform the upper half of the Sinai desert from brown to green, filled with farms, plants, animals, and forests. Centuries ago, the Sinai was green with life, before degrading activities by people dried it out.

With droughts and wildfires in California ever more frequent, it is time to start transforming our industrial agriculture and landscape into carbon-sequestering soils and plants, thereby improving the local rain cycles.

3D-Printed Houses

Speedily Built, Disaster Resilient, Energy and Resource Efficient, and Attractive

Big challenges face our society and our planet, none bigger or more pressing than climate change. A ray of hope is how innovative new technologies are tackling a number of these challenges simultaneously. In the housing sector, the 3D-printing process, without much publicity, is launching a revolution in construction materials and methods that are addressing affordability, energy-efficiency, durability, and beauty while erecting structures in record time and at scale.

The software, robotics, and new mixes of materials are technically complex but once the large printers, equipped with robotic arms that travel on rails, are set up, the process is simple. Nozzles at the ends of the robotic arms extrude environmentally friendly concrete mixes, plastics, hemp, mud, wood fibers, and other materials in a layering sequence to create solid, three-dimensional walls. Large sections of the building are printed and then assembled. Tech firms and architects are teaming up to produce designs that incorporate undulating curves that would be extremely time-consuming and prohibitively expensive to create using traditional building practices.

Jason Ballard, CEO of one of these pioneering tech firms, says, “With 3D printing, you not only have a continuous thermal envelope, high thermal mass, and near zero waste, but you also have speed, a much broader design palette, next-level resiliency, and the possibility of a quantum leap in affordability. This isn’t 10 percent better; it’s 10 times better.”

This type of construction is being employed in the Netherlands, Mexico, Canada, the U.S., and in areas impacted by natural or man-made disasters where quick rebuilding is urgent. These houses are built to withstand hurricanes and earthquakes. Entire communities are being designed and constructed; sometimes the printing is on-site and sometimes close by. Lennar Construction, one of the country’s largest builders, is building a 100-unit 3D-printed home development in Texas. Austin, Texas, has become a hub of robotic construction in this country. For example, it is turning out 400-square-foot homes to house 480 homeless people, or 40 percent of its street dwellers. The cost is $4,000 per unit. Printing time for an entire home varies between 24 hours and a week and a half, the longer period being for larger custom homes.  

Biophilic design, the recent term for increasing occupants’ connectivity to the natural world, is being embraced in most of these ventures. The mechanical nature of the production process may give the impression of uniformity and starkness, but the irregularities and imperfections of the striations have led some to compare the homes to adobe architecture. Similarly, the softer curves often harmonize with nature. Carefully thought-out, intricately designed print paths accommodate and hide high-performance mechanicals. 

The potential of 3D-printed housing embraces beauty, livability, economy, and resource efficiency while cutting construction time to a fraction of that required by traditional building methods. How quickly will it move to mainstream?

Insect Saliva Might Be Our Best Plastic Recycler

Once Again the Natural World Is Providing the Ideal Solution

The rapid decline of bee populations, native and European, is well-known. For beekeepers, one of the threats to our hives is waxworms or wax moths. A hive weakened by pesticides can easily become infested by wax larvae.

A few years ago, Dr. Federica Bertocchini, a microbiologist and amateur beekeeper in Spain, made an accidental discovery when cleaning out her waxworm-overrun hive. The larvae were not only chewing through the plastic bag she had put them in but were also dissolving the bag chemically. She and fellow scientists investigated exactly how the insects accomplished this feat. They found that the enzymes or proteins in the waxworm saliva led to the rapid breakdown of polyethylene plastic. These are the first animal enzymes that we know about to degrade plastic, and they do it in a matter of hours and at room temperature.

Because plastic is made to be durable, it is a ubiquitous waste product in our environment, polluting seafood, water, and even human bloodstreams. Over time, it eventually breaks down into small particles, ultimately becoming micro and nano plastic pieces. These particles are found everywhere, from Antarctica to raindrops to tap water, and are posing a growing problem to human health.

Polyethylene bags and other products make up 30 percent of all plastics. In the environment, they break down over hundreds of years through a process known as oxidation. The only large-scale recycling of plastics happening today involves mechanical processes of glycolysis, pyrolysis, and/or methanolysis, all requiring a great amount of energy. Even with these approaches, only about 10 percent of all plastics on the planet are recycled. 

The waxworm’s saliva enzymes oxidize plastic fast and without fossil energy. The only downside could be the release of carbon dioxide if billions of plastic-metabolizing insects are exuding saliva on plastic. More research is needed, but current research suggests scenarios where plastic waste can be “bio-recycled” and eliminate the release of microplastics into the environment. There are indications that these enzymes might yield useful chemicals as part of the degrading process, or even with additional processing steps become new plastic molecules, negating the need for virgin plastic produced from petroleum. 

As saliva enzymes start breaking down plastics at scale, the processes will need to be contained to ensure that our valuable bee colonies are not further threatened.

The Battery Storage Challenge Is Being Solved

Researchers Are Using Less Costly, More Abundant, and Environmentally Benign Materials in Battery Innovation

Using electricity rather than fossil fuels to power our world offers many pluses, especially since electricity is increasingly being produced from the sun, wind, ocean currents and tides. Microgrids and sophisticated software monitoring power needs and providing instantaneous switching are making communities even less dependent on fossil fuels for peak demand periods. Battery storage is the key component that will enable us to get to 100 percent clean electricity. One of the biggest obstacles in this trajectory is the limited, costly, and environmentally damaging mining of lithium, nickel, and cobalt — all of which are used in the manufacture of batteries.

A lot of research is going into making batteries using other, more abundant materials with fewer of the drawbacks of current batteries, namely, flammability and spiky dendrites. The spikes are caused when batteries are charged too quickly and result in shortening the battery’s life.

One international team is getting results using aluminum as one of the electrodes and sulfur as the other with a common salt as the electrolyte. The 230-degree Fahrenheit temperature required to melt the salt and run the battery can be generated internally by normal charging and discharging cycles — charging from the sun during daylight and discharging after dark when electricity is needed. The scientists estimate that the cost will be 12-16 percent of today’s lithium-ion batteries.

In Finland, a functioning sand battery seems to solve the problem of year-round green energy for heat. It works by heating sand (100 tonnes) in an insulated silo using electric-resistant heat produced from surplus wind and solar energy. The sand heats up to almost 1,000 degrees Fahrenheit and maintains this temperature for months until demand and energy prices are high. When needed, air flows through a heat exchanger in the sand to extract the heat for use in a district (neighborhood) heating system or for industries that use a lot of heat like food and beverage processing. The town of Kankaanpää is using the first commercial installation of a sand battery.

Researchers at the University of Cambridge have developed a battery system with a non-toxic form of blue-green algae (Synechocystis) that takes in solar energy by photosynthesis. They have used it to power a microprocessor of a computer for more than six months. It is biologically based, produces renewable energy, and multiplies naturally, making it easily scalable. The device does not require any inputs other than sunlight.

Another solution gaining traction is to produce hydrogen from excess renewable electricity and store it until electricity demand is high and renewable generation low.

These are a few of the storage innovations that are likely to be part of the ensemble of processes that get us to our mid-century, carbon-neutrality goal.