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A fern-based insecticide

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A spore-producing bacterium is the source of various crystal toxins (known as Cry proteins) that are widely used in modern agriculture to combat insect pests – generally caterpillars and other larvae – that attack important crops.  Pest control in corn, soybean, and cotton use these insecticidal proteins for protection against major insect pests.  The pesticides are obtained from Bacillus thringiensis (Bt) bacteria to produce the proteins.

Bt Cry proteins are secreted by the bacteria but are harmless to the bacteria.  They are harmless until ingested by insects and are then activated by the alkaline environment in the gut of insects which is entirely different from the acidic environment of our own digestive systems.  In the insect’s gut, the proteins become a powerful feeding inhibitor by breaking down the insect’s gut lining.  Bt Cry proteins are considered safe for humans.

Researchers continue to seek alternative solutions because there are concerns that insect pests could develop resistance to these toxic proteins.

Researchers from two Australian universities have analyzed the structure of a novel insecticidal protein that could be effective in protecting essential crops.  The protein is naturally produced by ferns including common houseplants like brake ferns.

The newly discovered proteins offer a different mode of action from the Cry proteins and therefore are a potential solution to the problem of pest resistance to existing insecticides.  The new family of insecticidal proteins is designated as iPD113 and has been shown to be very effective against caterpillar pests of corn and soybeans.

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Discovery: ferns produce crop-saving insecticide

Photo, posted October 5, 2015, courtesy of Marianne Serra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rising Seas And Wastewater Leakage | Earth Wise

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Global mean sea level has risen nearly 9 inches since 1880, with over two inches of that over just the last 25 years.  The rising water level is primarily due to two factors:  additional water in the oceans coming from melting glaciers and ice sheets; and the thermal expansion of seawater as it warms.  Climate models estimate that over the course of the century, global sea levels will rise at least a foot even if efforts to reduce greenhouse gas emissions are quite successful and, in the worst case, levels could rise as much as 8 feet.

Faced with this situation, the greatest concerns are, initially, increasing amounts of coastal flooding and erosion and, as things get worse, inundation of coastal regions making many places uninhabitable and creating millions of climate refugees.

Recently, computer modeling studies have focused on an additional imminent problem:  the flooding of coastal wastewater infrastructure, which includes sewer lines and cesspools.

A new study by the University of Hawaii at Manoa is the first to provide direct evidence that tidally driven groundwater inundation of wastewater infrastructure is already occurring in urban Honolulu.  The study shows that higher ocean water levels are leading to wastewater entering storm drains and the coastal ocean.  The result is degradation of coastal water quality and ecological health.

The researchers used chemical tracers to detect groundwater discharge and wastewater present at multiple low-lying areas during spring tides.  During high tides, storm drains become channels for untreated wastewater to flood streets and sidewalks. 

People tend to think of sea-level rise as a future problem, but there are already serious effects going on today that are only going to get worse.

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Sea-level rise drives wastewater leakage to coastal waters

Photo, posted August 23, 2011, courtesy of Eric Tessmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Concerns About Dam Safety

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The United States has a total of 91,000 dams of various sizes and types.  Many of them are aging and sorely in need of repairs.  All that maintenance would add up to tens of billions of dollars.  Experts are increasingly worried that as extreme precipitation events become increasingly common, dams are increasingly at risk of failure, threatening lives and posing environmental risks.

In 2017, Oroville Dam in California – the tallest dam in the country – nearly collapsed.  That incident forced the evacuation of 190,000 people and cost the state of California $1.1 billion in repairs.  California is considered one of the nation’s leading states in dam safety management and yet the partial disintegration of Oroville’s two spillways during a heavy rainstorm was not anticipated.

So far, federal and state dam safety officials have not been able to get disinterested state legislatures and the U.S. Congress to fork up the money needed for repairs to the nation’s aging dam infrastructure.

Th American Society of Civil Engineers gave the nation’s dams a D grade on the latest infrastructure report card.  They estimate that the cost of rehabilitating dams whose failure would threaten human life at nearly $45 billion, and the cost of fixing all dams in need of repair at more than $64 billion.

Scientists say the likelihood of dam failures – which not only threaten lives but also release toxic sediments trapped in reservoirs behind many dams – will increase as extreme precipitation events become more frequent in a warming world.  Apart from about 1,500 dams owned by federal agencies, regulating dam safety is primarily the responsibility of the states.  So far, states have not applied remotely sufficient resources to a growing problem.

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In an Era of Extreme Weather, Concerns Grow Over Dam Safety

Photo, posted August 20, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Drilling In California

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More than one million acres of public and private land in California may soon be opened up to oil drilling and hydraulic fracturing, according to a plan recently released by the Trump Administration.  The proposal raises environmental concerns, and comes at a time when opposition to oil and gas drilling in the state is growing.  

The plan, put forth by the Bureau of Land Management, would end a five-year moratorium in the state on leasing federal public land to oil and gas developers.  In 2013, a federal judge put the moratorium in place until the environmental risks of hydraulic fracturing, or fracking, could be better evaluated.

Fracking is the process of injecting liquid at high pressure underground in order to crack open rocks and extract oil or gas.  Well-documented risks associated with fracking include air and water pollution, as well as increased risks of oil spills and earthquakes.

Nevertheless, the Bureau of Land Management, which is part of the U.S. Department of the Interior, released its 174-page environmental impact statement with the proposal to open up 1,011,470 acres of land to fossil fuel extraction, impacting the California counties of Fresno, Kern, Kings, San Luis Obispo, Santa Barbara, Tulare, and Ventura. 

Unsurprisingly, the draft plan has been praised by industry groups who say concerns are misguided, and slammed by environmentalists who say the move poses a serious public health risk and could lead to a “fracking frenzy.”

The proposal is now subject to a 45-day period for public comment, after which the Interior Department will determine how to proceed.  A link to weigh in on the proposal can be found here.

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Trump fracking plan targets over 1 million acres in California

Bakersfield Field Office Hydraulic Fracturing Draft Supplemental Environmental Impact Statement

Photo, posted March 14, 2010, courtesy of Mike Baird via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lots Of Renewable Energy In Germany

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As the contributions to the electrical grid from renewable sources continue to rise, people have expressed concerns about what might happen as sources like wind and solar energy become dominant.  Not many years ago, there was a common concern that if wind and solar contributed more than about a quarter of the energy mix, the grid might become unstable or unreliable.  Theoretical models looked at this situation but there hadn’t been much real-world data to look at.

One place where there is now real-world data on a large scale is Germany.  Germany has been aggressively deploying both wind and solar energy for years as part of a national initiative called the Energiewende or energy transition.  Germany recently increased its renewable energy goal from 55% to 65% by the year 2030.   The increased share of renewables takes into account the decommissioning of aging nuclear and coal power plants.

A demonstration of the feasibility of such a goal occurred in the first week of March when renewable sources actually supplied nearly 65% of Germany’s electricity.  Wind power alone provided nearly half of the country’s power.  As a result, fossil fuel plants ran at a minimum output and nuclear facilities were shut down at night.

Germany has a very large domestic coal industry and indeed lignite coal generated an average of 24% of the country’s power last year.   However, recently that share was down to just 12%.  During that first week of March, solar power contributed more than 5% of Germany’s electricity, biomass 7.6%, and hydropower 3.5%.

While the week with 65% renewable set a record, the ongoing trend is very positive as well.  In 2018, renewable energy generated an average of more than 40% of Germany’s electricity.

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Renewables Generated a Record 65 Percent of Germany’s Electricity Last Week

Photo, posted April 28, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Antarctic Warming

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East Antarctica is the coldest place on Earth.  It makes up two-thirds of the continent, is home to the South Pole, and has vast ice sheets that have been around for tens of millions of years and are nearly three miles thick in places.  Temperatures there hover around 67 degrees below zero.  In 2010, a few spots on East Antarctica’s polar plateau reached a record-breaking 144 degrees below zero.

But almost unbelievably, parts of the East Antarctic seem to be melting.

Scientists are seeing worrying signs of ice loss in the East Antarctic.  Glaciers are starting to move more quickly and are dumping their ice into the Southern Ocean.  Satellite images show the fast-moving ice.  The biggest glacier – the Totten Glacier – alone contains enough ice to raise global sea levels by over 12 feet.

The Antarctic as a whole contains about 90% of the planet’s ice.  In theory, if it all melted, it would raise global sea levels by an average of 200 feet.

The growing concerns about eastern Antarctica are not that its interior plateau will soon start to melt.  It is still extremely cold there and should stay that way for a long time.  But its edges, which are in contact with warming ocean waters, are the real worry.  As the region’s ice shelves, which float atop the Southern Ocean, erode, the vast glaciers behind them could rapidly accelerate their slide into the sea.

Today, satellites show huge glaciers moving rapidly toward the coast, with wide rivers of ice sometimes moving several miles a year.  In the face of rapid change and limited data, it is difficult to predict what the Antarctic will do in the future.  But it doesn’t look good.

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Polar Warning: Even Antarctica’s Coldest Region Is Starting to Melt

Photo, posted January 3, 2013, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

New Zealand Bans Plastic Bags

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In an effort to tackle plastic pollution, New Zealand is joining a growing list of countries banning single-use plastic bags for good.  Prime Minister Jacinda Ardern says in a press statement that the ban was necessary to safeguard New Zealand’s clean and green reputation.

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Americans And Beef

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There’s ample evidence over the past decade or so that Americans are gradually changing their diets, driven by health concerns among other factors.  But there’s one change that really stands out.  According to a study by the Natural Resources Defense Council, Americans have sliced their beef consumption by 19% between 2005 and 2014. 

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Making It Rain

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It seldom rains in the United Arab Emirates.  Some areas of the UAE receive less than five inches of rain annually, and often little to none at all during the summer months when temperatures can climb above 110 degrees Fahrenheit.  These conditions have led to water security concerns particularly in Dubai, a blossoming international destination, as well as in rural, farming communities.

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