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Curbing food waste

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According to the U.S. Department of Agriculture, as much as 40% of the food supply in the United States is wasted.  In fact, Americans generate more food waste than all but two countries.

To address this problem, the federal government announced a goal nearly a decade ago to cut food waste in half by 2030 compared to 2016 levels.  Doing so would bring food waste down to approximately 164 pounds per person annually.

However, according to a new study led by researchers from the University of California – Davis, since 2016, per capita food waste has actually increased instead of decreasing. 

The study, which was recently published in the journal Nature Food, looked at how state policies align with federal targets.  The research team found that state policies focus more on recycling methods, such as composting and anaerobic digestion, rather than on prevention and rescue strategies, like food donations or repurposing food for animal feed.

In 2021, the EPA revised its definition of food waste to no longer include recycling methods.  But when food is wasted, the resources used to grow the food, including energy, water, and fertilizer, are also wasted. 

In the study, the researchers analyzed state-level food waste reduction efforts across four areas: prevention, rescue, repurposing, and recycling.  They found that recycling policies offered the most potential for diversion. Despite this, most states still fell short of the federal goal of 164 pounds per person annually. 

According to the research team, more comprehensive policies to address food waste must be implemented as soon as possible.

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States Struggle to Curb Food Waste Despite Policies

Photo, posted June 28, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megafires and orchard health

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The frequent and massive megafires in places like Canada and the American west have led to a lot of research on the impact of smoke on humans but there has been less study of the effects of smoke on plant health.  Researchers at the University of California, Davis have found that trees are just as vulnerable as humans are to the harmful effects of long-term exposure to smoke.

The Davis researchers studied almond, pistachio, and walnut trees at 467 orchard sites in California’s Central Valley from 2018 to 2022.  In 2022, so-called megafires burned more than 4.2 million acres in California, pouring ash and smoke into the sky.  The researchers had been studying how trees store carbohydrates to cope with heat and drought. 

With the onset of the fires, they saw an opportunity to study how smoke affects carbohydrate levels.  Trees use stored carbohydrates to sustain them through winter dormancy and spring growth.  Trees produce carbohydrates via photosynthesis and thick smoke blocks the amount of light reaching the trees.  Beyond that, there are other aspects of wildfire smoke, such as particulate matter and ozone that appear to affect photosynthesis.

The team found that the smoke not only reduced the amount of carbohydrates in trees but also caused losses that continued even after the fires were extinguished.  This led to nut yield decreases of 15% up to 50% in some orchards.  The researchers expected to see some impact on the trees during periods when smoke was really dense but were not expecting the smoke to have such a lingering effect and result in a significant drop in yield.

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Smoke From Megafires Puts Orchard Trees at Risk

Photo, posted October 1, 2008, courtesy of Suzi Rosenberg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trends in rooftop solar

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Rooftop solar power in the United States has increased by a factor of ten over the past decade and the majority of that growth has been in the past six or seven years.  At this point, about 7% of American homes have solar panels on their roofs – about 5 million in total. 

Rooftop solar really began experiencing widespread use about 20 years ago.  Over that time period, the amount of electricity that panels are able to produce has grown substantially and the cost of solar power systems has dropped dramatically.

Twenty years ago, the median sized residential solar system generated 2.4 kilowatts of power.  In 2023, the median size was 7.4 kilowatts.  Roofs haven’t gotten bigger; solar panels have gotten better.

More importantly, 20 years ago, the average cost of installing solar power was $12 a watt. In 2023, the cost was $4.20 a watt.

Americans in fact pay considerably more for solar power than citizens in many other countries.  The reason is not the price of the equipment; it is so-called soft costs.  These include labor, financing, and permitting. Driving down soft costs is complicated and difficult. For one thing, it is important for solar industry jobs to have high pay and good benefits.

The cost of solar also varies significantly by state.  California is the leading state for solar power and its median solar cost is the $4.20 a watt, the same as the national average.  Nevada has the lowest cost at $3.40 a watt and Utah has the highest at $5.20 a watt.

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Bigger and Less Expensive: A Snapshot of U.S. Rooftop Solar Power and How It’s Changed

Photo, posted September 18, 2011, courtesy of Team Massachusetts 4D Home via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric cars: Boom or bust?

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Media coverage of electric cars in this country is pretty confusing.  Are electric cars taking over or has the EV bubble burst?

EVs currently represent about 8% of the US new car market.  But they continue to face some relatively unique headwinds in this country.  A very powerful and influential oil industry makes sure that anti-EV stories occupy center stage in the media.  Traditional car dealers don’t want to sell EVs because they don’t make much money from parts and service.  And EVs often find themselves tangled up in American politics.

Meanwhile, the rest of the world tells a very different story.  Globally, EVs constitute 20% of new car sales, but in some places, they are doing much better than that.

So far this year, almost 87% of new car sales in Norway are electric and in August, the figure was 94%.  Norway has some incentives in place for EV owners, but the fact that nearly all new cars on the road are electric is far more than the result of incentives.

One might argue that Norway, a country with only 5 million people, faces a much easier task of transitioning to EVs.   But how about China with its 1.4 billion people?  In July, plug-in vehicles in China were 51% of new auto sales.  And the numbers continue to rise.

There are plenty of articles out there explaining why electric cars just can’t meet people’s needs, have insurmountable problems, and how having too many of them would collapse electric grids and otherwise wreak havoc with society.  Apparently, the Norwegians and Chinese, among a growing number of other countries, haven’t gotten the memo.

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Elbil Thinks Electric Car Sales In Norway Could Hit 100% By Next Year

Photo, posted July 27, 2024, courtesy of Amaury Laporte via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cities and rainwater

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Cities across the country are grappling with the problem that bigger, more frequent rainstorms occurring as a result of climate change are overtaxing the systems put in place to handle stormwater.  Cities use a combination of so-called green infrastructure – such as rain gardens and porous pavements – and traditional gray infrastructure, such as pipes, tunnels, and pump stations.

In 2011, Philadelphia drew national attention for its Green City, Clean Waters program that was designed to manage the increasing amount of storm water using mostly green infrastructure.  Thirteen years later, the city is experiencing billions of gallons of polluted stormwater overflowing its sewage outfall pipes each year.  Green infrastructure is cheaper and faster to build, but it is not coping with increasing rainfall.

About 700 U.S. municipalities, mostly in the Northeast and around the Great Lakes, rely on these combined sewer systems.  Based on updated climate projections, many are having to greatly increase gray infrastructure projects that include concrete holding tanks, tunnels, and pipes that can divert and hold onto flows until the rain stops, and water treatment plants can recover.  These projects can take decades to implement and cost billions of dollars.

All across the country, cities are going to need to bite the bullet and make large-scale investments in conventional sewage infrastructure and repairs to stop billions of gallons of raw sewage from running into rivers.  The increased storms present a daunting challenge for America’s cities.

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Faced With Heavier Rains, Cities Scramble to Control Polluted Runoff

Photo, posted August 29, 2011, courtesy of Reggie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A lake in Death Valley

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Death Valley in California is the driest place in North America, averaging only 2 inches of rain each year.  Badwater Basin in Death Valley is the lowest point in North America with a depth of 282 feet below sea level.  Currently, Badwater Basin is the site of an ephemeral lake called Lake Manley.

The lake formed again last August after Hurricane Hilary drenched the California desert.  Water levels in the lake dropped throughout the fall, but it never quite dried up.  But then the relentless rains of early February filled the lake once again.

Water that gathers in Badwater Basin usually evaporates faster than it can be replenished, leaving the lakebed dry.  But between the hurricane and the February storm, nearly 4 inches of rain have fallen, and the lake has stayed alive.  There is a river that feeds the lake – the Amargosa – that is really flowing in the aftermath of the storms.

The lake is nearly 7 miles long and 4 miles wide, but the water is only about a foot deep.  This is not the first time it has formed but it is an unusual occurrence.  It formed in 2005, but only lasted about a week.  Death Valley National Park officials expected that the lake would be gone by October, but it persisted into the new year which then brought the atmospheric river-driven California rainstorms.

At this point, it is unclear how long the lake in the driest place in America will be around.  While it is there, visitors to the national park can enjoy beautiful views of the nearby mountains reflected in its waters.

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Deep in Death Valley, a Sprawling Lake Takes Form

Photo, posted February 19, 2024, courtesy of Tom Hilton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Airplanes, corn, and groundwater

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The aviation industry wants to slash its greenhouse gas emissions.  One proposed strategy is to replace ordinary jet fuel with ethanol.  Ethanol in this country mostly comes from corn.  The airlines are enthusiastic about the idea; corn farmers are enthusiastic about the idea.  Ethanol suppliers are obviously enthusiastic about it.  But is it a good idea?

Today, nearly 40% of America’s corn crop is turned into ethanol.  Twenty years ago, the figure was around 10%.  The massive growth was the result of mandates for ethanol augmentation of gasoline for environmental reasons.

But the environmental benefits of corn ethanol have always been controversial at best when all the energy factors are considered. But apart from that, a very serious issue is that corn is a water-intensive crop, and it can take hundreds of gallons of water to produce a single gallon of ethanol.  As the climate warms and corn crops expand, groundwater in many corn-growing areas is being increasingly depleted and groundwater provides half our drinking water and meets far more than just the needs of corn farmers.

Corn farmers and ethanol producers see the rapid growth of electric vehicles as a threat to their lucrative business of supplying the auto fuel industry.  The ambitious goals of the airline industry to reduce its emissions would likely require nearly doubling ethanol production.

The situation is a powerful example of the tradeoffs that can arise as the world tries to make the transition away from fossil fuel.  Even green solutions can have their own environmental cost and sometimes that cost may be too steep.

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Airlines Race Toward a Future of Powering Their Jets With Corn

Photo, posted September 2, 2007, courtesy of Rosana Prada 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

A Historic Western Drought | Earth Wise

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The American Southwest has suffered from drought conditions since the year 2000.  The drought has reduced water supplies, devastated farmers and ranchers, and it has helped to fuel numerous wildfires across the region.  It has generally been considered to be worst in 500 years.

According to a recent analysis, the drought has become so severe that it has actually led to the driest two decades in at least 1,200 years and the changing climate is largely responsible.  The summer of 2021 was especially dry; about 2/3 of the West was in severe drought conditions.

Scientists at UCLA used tree ring data to gauge drought.  Based on that analysis, 2000-2021 is the driest 22-year period since 800 A.D. which is as far back as the data goes.

The study confirmed the role of temperature, more than precipitation, in driving exceptional droughts.  Precipitation levels can go up and down over time and can vary in different regions.  But the ongoing emissions of greenhouse gases into the atmosphere are causing temperatures to generally rise over time.  Warmer temperatures make the air more capable of pulling water out of the soil, out of vegetation, out of crops, and out of forests.  All of that makes drought conditions more severe.

A megadrought is generally considered to be one that is both severe and long.  But even during one, there can be wet years.  2005 was a notable one.  But there must be enough consecutive wet years to actually end a drought.

Several previous megadroughts over the past 1,200 years lasted as long as 30 years.  So, the current drought is in full swing and may go on for a long time to come.

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How Bad Is the Western Drought? Worst in 12 Centuries, Study Finds.

Photo, posted September 25, 2021, courtesy of David Sierralupe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Great Christmas Tree Debate | Earth Wise

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Along with cookies and carols, the Christmas tree is a quintessential part of the holiday season for many people.  According to the American Christmas Tree Association, approximately 75% of Christmas trees in American homes this year will be artificial.  But are artificial trees really the better option for the planet?

The short answer is no.  But it’s more complicated than that.  Ultimately, the answer depends on a variety of factors.

If you decide to go with an artificial tree, you need to use it for a very long time. Studies suggest artificial trees would need to be reused anywhere from 8 to 20 years in order to be considered the more environmentally-friendly option. You should seek out trees manufactured from polyethylene plastic as it’s not as toxic as polyvinyl chloride plastic.  And since the majority of artificial trees are imported from China, look for a “Made in USA” label to reduce the carbon footprint.

If you decide to go for a live tree, shop local. This keeps the carbon footprint low and helps support the local economy in the process.  While some tree farms do spray, researchers say the use of pesticides in tree production is relatively low.  Live trees can also be composted or recycled afterwards.

It’s important to note that live Christmas trees can also be purchased with roots and planted after the holidays.  Some companies even allow you to rent live trees.  Each rented tree can be re-rented for up to seven years, after which it’ll be too large for in-home use and gets planted in its forever home. 

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Photo, posted December 17, 2017, courtesy of Alan Sandercock via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Potential For Solar Canals In California | Earth Wise

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California’s network of almost 4,000 miles of aqueducts is the world’s largest water conveyance system.  It serves the state’s Central Valley which produces a quarter of America’s food.  About 20% of the nation’s groundwater demand is pumped from Central Valley aquifers.

A recent study by the University of California Santa Cruz and UC Merced has determined that covering these aqueducts with solar panels could be an economically feasible way to advance both renewable energy and water conservation.  California’s aqueducts might more properly be called canals because they are located at ground level.  

The concept of solar canals has been gaining increasing interest around the world as the changing climate leads to more droughts in many regions.  Placing solar panels above the canals can shade them to help prevent water loss through evaporation.  In addition, some types of solar panels can work better situated over canals because the cooler environment improves their operation.  In addition to the increased solar panel output and the water evaporation savings, shade from solar panels could help control the growth of aquatic weeds, which are a costly canal maintenance issue.

Spanning canals with solar panels can be accomplished either by using steel trusses or suspension cables, either of which is more expensive to build than ordinary ground-mounted solar panel supports.  But the research study showed how the benefits of solar canals combine to outweigh the added costs for cable-supported installations.

Apart from the economic benefits of a solar canal system, producing solar energy in the canal system could eliminate the use of 15-20 diesel-powered irrigation pumps, helping to reduce air pollution in a region with some of the nation’s worst air quality.

Solar canals could be a real winner.

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New analysis shows potential for ‘solar canals’ in California

Photo, posted July 23, 2015, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

SUVs And Carbon Emissions

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Global carbon dioxide emissions increased between 2010 and 2018.  The largest contributor to this increase was the power sector as electricity demand around the world continued to grow.   The second largest contributor to increased emission turns out to be SUVs, even while emissions for other cars actually decreased.

During that time period, SUVs more than doubled their global market share from 17% to 39% and their annual emissions rose to more than 700 million tons of CO2, which is more than the yearly total emission of the UK and the Netherlands combined.

This dramatic shift toward bigger, heavier SUVs has offset both efficiency improvements in small cars and savings from electric vehicles.  If SUV drivers were a nation, they would rank 7th in the world for carbon emissions.

SUVs are bigger, they are heavier, and their aerodynamics are poor.  As a result, it takes more gas to drive them.  They started to become popular in the 1980s – mostly in American suburbia – but now they have become globally popular.

The demand for SUVs is thought to be driven by perceptions of heightened safety or increased social status.  There is also the marketing and business strategy of manufacturers who obtain larger profit margins in the SUV segment.  Of course, for at least some consumers, the utility aspects of sport utility vehicles are actually important and not just the status.

For whatever reasons, SUVs are likely to be extremely popular for the foreseeable future as demand for sedans continues to decline.  Fortunately, electric SUVs are beginning to enter the market – including next year’s mass-market priced Tesla Model Y.  Such cars are the best solution to emissions from SUVs.

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Demand for SUVs a Major Contributor to the Increase in Global CO2 Emissions

Photo, posted May 9, 2017, courtesy of Yonkers Honda via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Humans And Vertebrate Mortality

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According to a new study, more than one-quarter of the planet’s land vertebrates die because of humans.  This is a “disproportionately huge effect” on the other land vertebrates that share planet’s surface with us. 

Researchers from the SUNY College of Environmental Science and Forestry and the U.S. Department of Agriculture reviewed 1,114 published studies in which nearly 43,000 animals had perished.  Their study, which was recently published in the journal Global Ecology and Biogeography, found that 28% of the animals’ deaths were directly attributable to humans.  The other 72% died from natural sources.  

Mammals, birds, reptiles, and amphibians that died between 1970 and 2018 in the Americas, Asia, Africa, Europe, and Oceania were the foundation of the study.  All of these vertebrates had been either collared or tagged as part of other research projects. 

The researchers point out that humans are only one among more than 35,000 species of terrestrial vertebrates globally.  The fact that humans are responsible for more than one-quarter of their deaths illustrates the profound magnitude of the problem.  And that statistic is just the direct causes.  According to the researchers, when urban growth and other land use changes that erode habitat are considered, the human impact is likely even greater. 

The study found that the impact of humans across all the different species was not equal. In fact, larger animals were more likely to be killed by humans than smaller animals. Adult animals were more likely to be killed by humans than juveniles. 

The researchers conclude that humans are such a major contributor to terrestrial vertebrate mortality that they could potentially impact both evolutionary processes and ecosystem functioning. 

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On the land, one-quarter of vertebrates die because of humans

Photo, posted March 6, 2019, courtesy of USFWS Midwest Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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