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A better way to produce green hydrogen

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Hydrogen has great potential as a fuel and an energy carrier for many applications.  Burning it or consuming it in fuel cells does not produce carbon emissions.  As a result, there has long been the vision for a future hydrogen economy.  Whether the hydrogen economy would ever come about given how various other technologies have evolved over time is questionable.  But regardless, hydrogen is valuable for many industrial and commercial applications including the manufacture of ammonia and the refining of metals.

Hydrogen is produced in industrial quantities from natural gas by a carbon-dioxide-producing process known as methane-steam reforming.  To take its place as a green energy source, hydrogen needs to be produced by splitting water into its constituent oxygen and hydrogen components by the process of electrolysis. 

The problem is economic.  Methane-steam reforming produces hydrogen at a cost of about $1.50 per kilogram.  Green hydrogen costs about $5 a kilogram.

Researchers at Oregon State University have developed a new photocatalyst that enables the high-speed, high-efficiency production of hydrogen.  The material, called RTTA, is a metal organic framework containing ruthenium oxide and titanium oxide.  Ruthenium oxide is expensive, but very little is needed.  For industrial applications, if the catalyst shows good stability and reproducibility, the cost of the small amount of this exotic material becomes less important.

The photocatalyst, when exposed to sunlight, quickly and efficiently splits water yielding hydrogen.  The Oregon State discovery has real potential.

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Oregon State University research uncovers better way to produce green hydrogen

Photo, posted July 7, 2023, courtesy of Bill Abbott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar forests

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Forests are one of the most iconic symbols of the power and diversity of nature but beyond that, their thick vegetation is crucial to the stability and balance of the Earth’s climate.  This is because the photosynthesis that powers the growth of plants removes carbon dioxide from the air.  Cutting down forests – especially the evergreen forests of the tropics – has played a significant role in the increasing climate crisis.  For this reason, many environmental initiatives focus on restoring destroyed forests and planting new trees.

But the truth is, even if we were to cover the entire surface of the planet with trees, there would still not be enough photosynthesis going on to absorb the huge surplus of carbon dioxide that people have been pumping into the atmosphere for the past 150 years.

A study by the Weizmann Institute of Science in Israel looked at the impact of erecting fields of dark covered solar panels – so-called solar forests – that would generate electricity, thereby replacing power stations that use fossil fuels.  But dark fields absorb heat which eventually returns to the atmosphere.

The question is:  what is the best use of a plot of land in terms of the effect on the climate?  Planting a forest or erecting fields of solar panels?

The answer depends on where the land is.  In arid environments, building solar farms is far more effective and practical than planting forests.  But in humid places, forests currently absorb close to a third of humanity’s annual carbon emissions. 

The study concludes that combining planting and rehabilitating forests in humid regions and erecting fields of solar panels in arid regions is the most effective strategy.

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The Solar Forest

Photo, posted December 27, 2015, courtesy of Gerry Machen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The importance of Alaska’s National Forests

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The world’s forests play a crucial role in taking carbon out of the atmosphere and mitigating the effects of climate change.  An analysis of U.S. national forests shows that two southern Alaskan forests are key to meeting climate and biodiversity goals.

The Tongass Forest in Alaska is America’s largest national forest, encompassing 16.7 million acres.  Alaska’s Chugach Forest is the country’s second largest at just under 7 million acres.  These two forests are not only the largest national forests, they are also the most intact. 

A study by researchers at the Oregon State University College of Forestry looked at 152 national forests and compared them in terms of carbon density and accumulation, total biomass carbon stocks, habitat for eagles, bears, and wolves, and landscape integrity – which is the extent of modification by human activity.  According to the study, almost 31% of all high-landscape-integrity area found in national forests is in the Tongass and Chugach forests.  The Tongass alone represents over 25%.

These forests are cool and wet.  Their carbon stocks are only minimally affected by wildfire, unlike many other forests in the lower 48 states.  Given the size and stability of the two forests, protecting them is a high priority for making it possible to meet global goals relating to climate and diversity of species.

Ecosystems remove about 30% of all the carbon dioxide humans put into the atmosphere and intact forests with high carbon density do most of that work.  Protecting Alaska’s forests is crucial.

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Southern Alaska’s national forests key to meeting climate, conservation goals, OSU study shows

Photo, posted August 4, 2014, courtesy of Jeff Canon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why Are Insect Populations Declining? | Earth Wise

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The world is experiencing a decline in overall insect populations as well as a collapse in insect diversity.  A recent special issue of the journal Biology Letters discusses the major causes of this alarming trend.

According to the study, the primary causes of the worldwide decline in insect biomass are land-use intensification in the form of greater utilization for agriculture and building development, climate change, and the spread of invasive animal species as a result of human trade.

The study concludes that it is not just these factors that are driving the global disappearance of insects, but also that these three factors are interacting with each other.  For example, ecosystems that are deteriorated by humans are more susceptible to climate change and so are their insect communities.  Similarly, invasive species can establish themselves more easily in habitats damaged by human land-use and displace native species.  Many native insect species decline or go extinct while others – often invasive species – thrive and increase, leading to decreasing insect diversity.  Warming temperatures are making many locations undesirable for various insect species and they often cannot migrate to anyplace better.

Declining insect populations and diversity results in concomitant declines in plant species that depend on pollinators.  This in turn threatens the stability of entire ecosystems.

The researchers advocate for continued monitoring of insect diversity across many habitats and countries and propose the creation of a network of interconnected nature reserves such that species can move from one to another. 

We often think of insects as pests, but they are a crucial part of the world’s ecosystems.

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The reasons why insect numbers are decreasing

Photo, posted April 17, 2011, courtesy of Dean Morley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Smart Heat-Blocking Window | Earth Wise

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An international research team led by Nanyang Technological University in Singapore has invented a ‘smart’ window material that controls the transmission of heat without blocking the view through the window.  The technology could help reduce the amount of energy needed to cool and heat buildings.

The new material can be the basis of an electrochromic window that can block or pass infrared radiation at the flick of a switch.  Current electrochromic windows can be darkened when switched on and are found in many ‘green’ buildings as well as in many car mirrors.  But these windows are only effective in blocking visible light so infrared radiation – meaning heat – still passes through them.

The new coating material blocks up to 70% of infrared radiation when switched on but still allows up to 90% of visible light to pass through.  The material is a specifically designed composite nanostructure and utilizes advanced materials including titanium dioxide, tungsten trioxide, neodymium, niobium, and tin oxide.  It is intended to be coated onto glass window panels and be activated by electricity when needed.  The material was put through rigorous on-off cycles to assess its stability and durability and it appears to offer superior performance in that regard compared with current electrochromic technology.

The researchers also created a switchable system that helps control conducted heat, which is the heat from the external environment.

The combination of the two technologies could result in smart windows that control two types of heat transmission:  infrared radiation and conduction heat.  Such technology could help conserve energy used for the heating and cooling of buildings and could contribute to the future design of sustainable green buildings.

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Scientists invent ‘smart’ window material that blocks rays without blocking views

Photo, posted March 11, 2016, courtesy of Open Grid Scheduler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Improving Solar Cells With Human Hair | Earth Wise

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Researchers at the Queensland University of Technology in Australia have been able to improve the performance of perovskite solar cells using material made from human hair.

Perovskite solar cells are an up-and-coming technology that offers the possibility of making solar cells less expensive, more efficient, and flexible so that there could be solar-powered clothing, backpacks, or even tents for camping.  While the technology has been shown to be as effective in converting sunlight to electricity as currently available silicon technology, it faces problems with stability and durability.

The Australian research centered on the use of carbon nanodots to improve perovskite solar cell performance.  The nanodots were created in a rather unique way.  The carbon came from hair scraps from a Brisbane barbershop that were first broken down and then burned at nearly 500 degrees Fahrenheit. 

By adding a solution of the carbon nanodots into the process of making the perovskites, the dots formed a wave-like layer in which the perovskite crystals in the cells are surrounded by the carbon dots.  It serves as a protective layer, essentially a kind of armor, for the active portions of the material.

The result was solar cells with a higher power conversion efficiency and greater stability.  The researchers did not explain why they chose human hair as the source of carbon, but it does make for an interesting sidelight to the promising research.

Perovskite solar cells could be very important for spacecraft applications where reducing weight is paramount.  But in order to be able to use them for this purpose, perovskite solar cells will need to be able to cope with the extreme radiation and temperature variations in space.

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Carbon dots from human hair boost solar cells

Photo, posted October 3, 2009, courtesy of Arktoi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Breaking Down Polystyrene | Earth Wise

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The proliferation of global plastic waste continues to be a growing problem for the world.  Hundreds of millions of tons of plastics are produced each year and most of it is used once and then discarded.  The properties that make plastics so attractive – durability and chemical stability – make it difficult to do anything with discarded plastics other than deposit them in landfills – where they don’t easily degrade over time – or burn them, which dumps carbon dioxide and various hazardous gases into the atmosphere.

Polystyrene is one of the most widely used plastics.  It is found in foam packaging materials, disposable food containers, plastic cutlery, storage containers, and many other places. 

Recycling plastics like polystyrene is generally not economically feasible.  Sorting plastics by type is time and labor intensive and the chemical processes required to break down plastics into usable precursor materials require significant energy input and the use of toxic solvents.

Recently, a team of scientists at Ames Laboratory in Iowa has developed a process based on ball-milling that deconstructs commercial polystyrene in a single step, at room temperature, in ambient atmosphere, and in the absence of harmful solvents.

Ball-milling is a technique that places materials in a milling vial with metal ball bearings which is then agitated to initiate a chemical reaction.  This approach is known as mechanochemistry.

The method represents an important breakthrough that enables dismantling of a polymer that includes its chemical breakdown without requiring solvents or the high temperatures generally needed to thermally decompose it.  This discovery opens up new avenues for low-temperature recovery of monomers from polymer-based systems that include composites and laminates.  It could be a very useful weapon in the battle against plastic waste.

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Polystyrene waste is everywhere, and it’s not biodegradable. Scientists just found a way to break it down.

Photo, posted December 11, 2010, courtesy of Warrenski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sharks On The Decline | Earth Wise

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During the past 70 years, global shark populations have been on the decline.   Many species have become threatened or endangered.  Conservation efforts have been underway in many places, but shark populations continue to be at risk because of over-fishing and habitat loss.

A comprehensive study by marine biologists at Texas A&M University deployed more than 15,000 baited remote underwater video stations on 371 coral reefs in 58 countries.   The study included 59 different shark species in the Atlantic, Pacific and Indian Oceans.  The researchers were surprised to find that no sharks at all were detected in almost 20% of the locations surveyed and were almost completely absent from coral reefs in several nations. 

Scientists believe that demand for shark products, such as fins and meat, and bycatch (that is, sharks captured in nets by fisherman trapping other kinds of fish) are strong contributors to the widespread declines in shark numbers around the world.

The study shows that if corrective steps are not taken in regions where marine management is still ineffective, continued depletion of shark populations is highly likely. 

Sharks have important roles in marine ecosystems.  When their habitats deteriorate and their populations decrease, ecosystem stability and health is degraded because sharks help regulate prey populations.

Some countries, notably the Bahamas, are combating the problem by providing sanctuaries for sharks where fishing and harvesting is prohibited.  Such places support some of the healthiest shark populations in the world.  However, the decline of coral reefs is just another challenge facing shark populations around the world.

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Study Shows Alarming Decline In Shark Numbers Around The World

Photo, posted January 9, 2017, courtesy of Kris-Mikael Krister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rapid Antarctic Melting

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The Ross Ice Shelf in Antarctica is the world’s largest ice shelf, covering an area roughly the size of France.  Scientists have spent several years building up a record of how the northwest sector of the enormous ice shelf interacts with the ocean beneath it.  Their results show that the ice is melting much more rapidly than previously thought because of in-flowing warm water.

In general, the stability of ice shelves is thought to be mostly influenced by their exposure to warm deep ocean water.  But the new research has found that surface water heated by the sun also plays a crucial role in melting ice shelves.

The interactions between ice and ocean water that occur hundreds of meters below the surface of ice shelves have a direct impact on long-term sea level.  The Ross Ice Shelf stabilizes the West Antarctic ice sheet by blocking the ice that flows into it from some of the world’s largest glaciers.

When ice shelves collapse, the glaciers that feed them can speed up by a factor of two or three.  None of the collapsing shelves in the past have come anywhere close to the size of the Ross Ice Shelf, which is more than 100 times bigger.

The new study by New Zealand’s National Institute of Water and Atmospheric Research showed that sun-heated surface water flowing into the cavity under the ice shelf near Ross Islands caused melt rates to nearly triple during the summer months.  This indicates that the loss of sea ice resulting from climate change is likely to increase melt rates in the future.  While the Ross Ice Shelf is still considered to be relatively stable, the new findings show that it may be more vulnerable than previously thought.

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Rapid melting of the world’s largest ice shelf linked to solar heat in the ocean

Photo, posted February 15, 2009, courtesy of Alan Light via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Another CO2 Milestone

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The global concentration of carbon dioxide in the atmosphere was measured at 400 parts per million for the first time in recorded history in May of 2013.  It was a brief event at the Mauna Loa Observatory in Hawaii at the time.  Within the next couple of years, however, readings of at least 400 ppm became standard.

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Fracking And Streams

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Hydraulic fracturing – better known as fracking – is a method of extracting oil and gas from shale deposits in which millions of gallons of freshwater and chemicals are injected into deep underground deposits.  There has been a great deal of concern related to the effects that this process has on water quality and also on the stability of the ground in the vicinity of where it takes place.

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Is The World’s Largest Sea Turtle No Longer Endangered?

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The rapid disappearance of many plants and animals around the world has many scientists saying we are experiencing a sixth mass extinction – the first since the dinosaurs were wiped out some 66 million years ago.  Despite all sorts of conservation efforts, living things are struggling as a result of climate change, habitat loss, and countless other natural and manmade pressures.  Conservation success stories have been few and far between. 

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