emissions

Wildfires And Carbon

September 17, 2019 By EarthWise Leave a Comment

This summer has been an unprecedented year for fires in the Arctic. Major fires have burned throughout the Arctic in Russia, Canada, and Greenland. In total these fires released 50 million tons of carbon dioxide in June alone, which is as much as Sweden emits in an entire year.

In an average year, wildfires around the world burn an area equivalent to the size of India and emit more carbon dioxide to the atmosphere than global road, rail, shipping and air transport combined.

Ordinarily, this is part of a natural cycle. As vegetation in burned areas regrows, it draws CO2 back out of the atmosphere through photosynthesis. This is part of the fire-recovery cycle, which can take less than a year in grasslands, but decades in forests. But in Arctic or tropical peatlands, full recovery may not occur for centuries.

A recent study looked at and quantified the important role that charcoal plays in helping to compensate for carbon emissions from fires. In wildfires, some of the vegetation is not consumed by burning, but instead is transformed to charcoal – referred to as pyrogenic carbon. This carbon-rich material can be stored in soils and oceans over very long time periods.

Researchers have combined field studies, satellite data, and modelling to quantify the amount of carbon that is placed in storage in the form of charcoal. Their results are that the production of pyrogenic carbon amounts to about 12% of the CO2 emissions from fires and can be considered a significant buffer for landscape fire emissions.

Charcoal does not represent a solution to the problem of increasingly intense wildfires, but it is important to take it into account in understanding what is happening.

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How wildfires trap carbon for centuries to millennia

Photo, posted August 17, 2018, courtesy of the Bureau of Land Management Oregon and Washington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Falling U.S. Carbon Emissions

September 16, 2019 By EarthWise Leave a Comment

Reducing carbon emissions is a goal embraced by nearly every country in the world, but actually accomplishing it isn’t easy. It is true that renewable energy sources are playing a growing role in energy systems, but counterbalancing that trend is growing energy demand, especially in developing countries.

Here in the US, energy-related CO2 emissions actually went up nearly 3% in 2018 compared with 2017. But the US Energy Information Administration is now forecasting a 2% drop in emissions this year.

The main reason energy-related emissions are headed lower at this point is coal-fired power plant retirements. More than 90% of the coal used in the US goes toward electric power and utilities are increasingly turning away from coal.

The rapid shift away from coal has mostly been due to the increasing use of natural gas. Natural gas is not actually a clean and green fuel, but it is definitely less carbon-intensive than coal. Overall, the total installed capacity of renewable sources – hydropower, wind, solar, geothermal, and biomass – has now actually surpassed the capacity of coal plants. Given that renewables have in many places become the cheapest power option, there is little chance that coal has much of a future, despite efforts by the current administration.

The electric power sector is gradually moving away from all carbon-emitting sources – a trend that is being reinforced by legislation in many states. The real CO2 emissions leader is petroleum, which accounts for nearly half of the total. We have a long way to go to reduce emissions from the use of petroleum. There are over 250 million cars and trucks on US roads and only a little over a million of them don’t burn fossil fuels.

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Photo, posted November 6, 2017, courtesy of Cindy Shebley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Contrails And Climate Change

September 6, 2019 By EarthWise Leave a Comment

The white wispy trails of condensation produced by the exhaust from aircraft engines have been the subject of a popular conspiracy theory for quite a while. The story goes that the long-lasting condensation trails are actually “chemtrails” composed of chemical or biological agents left in the sky by aircraft and are intentionally sprayed for a variety of nefarious purposes undisclosed to the general public. This story, of course, is nonsense.

But while contrails are not deliberate efforts to modify weather, control population, manipulate psychology, or any of the other bizarre things attributed to them, it turns out that they are having unfortunate effects on the climate.

It turns out that contrails are creating an often-invisible thermal blanket of cloud across the planet that has a significant effect on atmospheric temperatures. Contrails are essentially human-made clouds that form above 25,000 feet where the air is moist and colder than -40 degrees Celsius. At times, contrails stick around in the sky, either as tight, white lines like chalk marks, or by spreading to create thin layers of ice clouds. At any one time, contrail-created clouds cover more than half a percent of global skies.

Research has shown that when contrails are around, nighttime temperatures can go up appreciably. After 9/11, when all U.S. flights were grounded for three days, the difference between daytime and nighttime temperatures actually increased by about 3 degrees Fahrenheit because nights were cooler.

The effects of aviation on climate, both from the CO2 emissions from aircraft engines and from these contrail effects are becoming an increasingly important issue. To complicate matters further, as aircraft engines become more efficient, they will create more, whiter, and longer-lasting contrails.

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How Airplane Contrails Are Helping Make the Planet Warmer

Photo, posted May 15, 2012, courtesy of Mike Lewinski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reducing Methane From Animals

September 3, 2019 By EarthWise Leave a Comment

Methane emissions from ruminant livestock are currently estimated to be more than 100 million tons each year and, after rice agriculture, represent the biggest human-initiated methane source. Given that fact, there is widespread encouragement for people to reduce their consumption of meat in order to reduce the amount of the potent greenhouse gas going into the atmosphere.

But an additional strategy to lower global methane emissions is to actually reduce the amount of methane produced by each animal. To that end, researchers at the University of Otago in New Zealand have now identified new processes that control methane production in the stomachs of sheep and similar animals like cattle and deer.

They determined the specific microbes and enzymes that control the supply of hydrogen, which is the main energy source for methane producing microbes, known as methanogens. Their work is focused on the development of small molecule inhibitors and vaccines to specifically target the production of methane by methanogens. By reducing the supply of hydrogen to methanogens, it is possible to reduce animal methane emissions.

The research involved studying two types of sheep – those producing large amounts of methane and those producing less. They found that the most active hydrogen-consuming microbes differed between the sheep. Specifically, in the low methane emitting sheep, hydrogen consuming bacteria dominated over methanogens.

Ultimately, a strategy might emerge to introduce feed supplements that encourage non-methane producers to out-compete methanogens. Controlling the supply of hydrogen to the methanogens will lead to reduced methane emissions.

Having low-emission cattle would definitely help reduce the impact of agriculture on the climate.

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Scientists discover processes to lower methane emissions from animals

Photo, posted April 7, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Meeting Climate Goals With Current Energy Infrastructure

September 2, 2019 By EarthWise Leave a Comment

The Paris Climate Agreement set forth a goal to keep global warming below 2 degrees Celsius as well as a more optimistic (and preferable) goal of keeping the temperature rise to less than 1.5 degrees. Reaching either of these goals requires getting to net-zero emissions by the middle of the century.

A new paper, published in Nature, looks at the issue of whether existing power plants and other fossil-fuel-burning equipment (including vehicles) can continue to operate until they age out of functionality, or whether they need to be retired early.

The results of the study are that future emissions from existing facilities would take up the entire carbon budget needed to limit warming to 1.5 degrees Celsius and almost 2/3 of the budget needed to keep warming below 2 degrees over the next 30 years.

So, the good news is that we can still avoid a 2-degree rise without having to shut down all the existing power plants early. But we would definitely have to stop building new things with smokestacks and tailpipes that dump CO₂ into the atmosphere.

That good news is tempered by the fact that the number of fossil fuel-burning power plants and vehicles in the world has increased dramatically over the past decade, spurred by rapid economic and industrial development in China and India. In fact, China is predicted to produce more than 40% of all the carbon emissions over the next 30 years.

The 2-degree climate goal is not at all the most desirable result. The 1.5-degree target would be far better for the climate. But if the world is to achieve it, there will be dramatic changes needed in the existing infrastructure – either shutting it down or retrofitting it to drastically reduce emissions.

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Two-Degree Climate Goal Attainable Without Early Infrastructure Retirement

Photo, posted March 5, 2010, courtesy of Tennessee Valley Authority via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Climate Change With Trees

August 20, 2019 By EarthWise Leave a Comment

We cut down forests all around the world for a myriad of reasons, including livestock grazing, agricultural production, timber, and urban development. But what if we stopped cutting down forests for these things and additionally grew new forests on vacant lots and any other available parcels of land on earth? What impact could this have on our survival?

For the first time, scientists have quantified what impact this plan could have. According to a new study by researchers at ETH Zurich – a university that specializes in science, technology, and engineering – the planet could support nearly 2.5 billion additional acres of forest without shrinking current cities and farms. When all those acres of forest mature, the trees could store an extra 200 gigatons of carbon. This reforestation could stave off the most devastating impacts of global climate change.

Russia could restore the most acres of forest – 373 million acres to be precise – followed by the United States with 255 million acres and Canada with 193 million acres. Australia, Brazil, and China also have large areas well-suited for forest restoration.

The average global temperature has risen by 1.8 degrees Fahrenheit since the start of the industrial age with its surge in greenhouse gas emissions. Temperatures are projected to rise even more in the coming years as the planet continues to warm.

Trees absorb CO2 from the atmosphere and store it in their roots and branches. The absorbed carbon becomes part of the soil when trees die and decompose, and it can linger there for millennia depending on things like temperature and soil management. Trees are critical in the fight against climate change.

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How trees could save the climate

Photo, posted June 18, 2011, courtesy of K.W. Barrett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Trees And Methane

August 14, 2019 By EarthWise Leave a Comment

The Amazon is a source of many mysteries. One that was as troubling as it was mysterious was the large amounts of methane emissions coming from the rainforest that were observed by satellites but that nobody could find on the ground. In total, there were 20 million tons of methane whose origin was unknown.

An expedition by a British postdoctoral researcher who spent two months strapping gas-measuring equipment to thousands of trees has solved the mystery. It turns out that trees, especially in the extensive flooded forests, were stimulating methane production in the waterlogged soils and pumping it into the atmosphere.

This research has uncovered a previously-ignored major source of the second most important greenhouse gas in the world. Apparently, most of the world’s estimated 3 trillion trees emit methane at least some of the time.

This in no way implies that trees are bad for the climate and therefore should be cut down. The reality is that the carbon storage capability of trees far outweighs their methane emissions. But since corporations these days are planting trees to offset their carbon emissions, it is essential to know if their numbers add up. Carbon accounting has to include the complex chemistry of trees and methane.

Wetland tree trunks can act as passive conduits for methane generated by micro-organisms in waterlogged soils. The solid-looking trunks contain spaces and channels through which gases travel up and down. But in wetland systems, trees also create the conditions, and provide the raw materials, for methane generation by micro-organisms. Trees are essentially bioreactors. Some trees even actively generate methane from photochemical reactions in their foliage.

Understanding the interactions of ecosystems and the atmosphere is a complicated business.

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Scientists Zero in on Trees as a Surprisingly Large Source of Methane

Photo, posted December 13, 2008, courtesy of Ivan Mlinaric via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Energy Demand

August 7, 2019 By EarthWise Leave a Comment

Human beings are utterly dependent upon energy both for our well-being and for societal development. Our energy use is highly dependent upon climate since so much energy is expended either keeping us warm in winter or cool in summer. As the climate changes, it is important to understand how energy demand is likely to be affected.

A new study published in Nature Communications by researchers in Austria, Italy and the United States explored this topic. The study is a global analysis using temperature projections from 21 climate models, and population and economy projections for five socioeconomic scenarios. The purpose was to determine how energy demand would shift relative to today’s climate under modest and high-warming scenarios by the year 2050.

The findings indicate that, compared to scenarios in which energy demand is driven only by population and income growth, climate change will increase the global demand for energy by 11-27% by the year 2050 under a modest warming scenario. With vigorous climate warming, energy demand would increase by 25-58%. (Large areas of the tropics, as well as southern Europe, China, and the US are likely to experience the highest increases).

These findings are important because if energy use rises and leads to additional emissions of heat-trapping greenhouse gases, it will be increasingly difficult to mitigate future climate warming. Quantifying this risk provides even more incentive for reducing greenhouse gas emissions before these effects upon demand are realized and it becomes even more difficult to prevent further impacts.

Policymakers need to be aware that even moderate levels of climate change will lead to increases in energy demand that will make it increasingly difficult to minimize the harmful effects on their societies.

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More energy needed to cope with climate change

Photo, posted December 15, 2008, courtesy of Matt Hintsa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record European Heatwave

August 1, 2019 By EarthWise Leave a Comment

Sahara Desert winds blasted Europe in June, especially during a five-day heatwave that set many records. Between that and weather elsewhere, June was not only one of the hottest ever for that continent, but also for the world as a whole.

In Europe, the average temperature was about 5 degrees Fahrenheit above the June average of a century ago. The global temperature was nearly 2 degrees Fahrenheit higher.

The European heatwave broke temperature records in France, Switzerland, Austria, Germany, and Spain. A temperature above 114 degrees was recorded near the French city of Nîmes.

The intense heat lead to wildfires in Spain and Germany, and widespread disruption across Europe. Undoubtedly, the heatwave has caused many premature deaths, but it will take some time to compile those statistics. The European heatwave of 2003 caused more than 70,000 premature deaths.

According to calculations by climate scientists, the record-breaking heatwave in June was made at least 5 and as much as 100 times more likely by climate change. Global heating caused by the carbon emissions from burning fossil fuels and other human activities means that heatwaves are becoming more probable and severe. So-called attribution studies estimate how much more likely and severe such events are.

The researchers used temperature records stretching back to 1901 to assess the probability of a heatwave last month and in the past. They also examined climate change models to assess the impact of global heating. More than 230 attribution studies to date around the world have found that 95% of heatwaves were made more likely or worse by climate change.

It was the hottest June on record in Europe by a country mile and there are likely to be more months like it in the future.

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Climate Change Made Last Month’s European Heatwave At Least Five Times More Likely

Photo, posted February 13, 2018, courtesy of Guilhem Vellut via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The New York Climate Plan

July 24, 2019 By EarthWise Leave a Comment

New York lawmakers have passed a sweeping climate plan that requires the state to eliminate almost all of its greenhouse gas emissions by 2050. The plan calls for the phase-out of gasoline cars and oil- and gas-burning furnaces and requires all of the state’s electricity to come from carbon-free sources.

The Climate Leadership and Community Protection Act requires the state to slash its carbon emissions to 85% below 1990 levels by 2050 and to offset the remaining 15% by other means such as removing carbon dioxide from the atmosphere. The bill requires New York to get 70% of its electricity from renewable sources by 2030.

The challenges of reaching the program’s goals are daunting. New York has so far only reduced its emissions by 8% since 1990. The state currently does get 60% of its electricity from carbon-free sources – mostly hydroelectric dams and nuclear power plants – but it will require offshore windfarms, ramped-up solar installations, and battery storage systems to push the numbers dramatically higher.

Transportation, which is responsible for a third of New York’s emissions, will be particularly tough to tackle. The Trump administration is rolling back federal vehicle efficiency rules and is trying to prevent states from setting stricter standards. Currently, electric car ownership is primarily attractive for single-family homeowners who can plug in their cars at home. Far more pervasive charging stations – for example, all over the streets of New York City – would be needed to make electric cars practical for everyone.

The plan aims for industries to bear most of the financial burden, but supporters say that the costs of not acting on climate will be vastly greater for businesses. The plan’s deadlines for major emissions reductions are a decade away but there will be much to do quite soon.

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New York to Approve One of the World’s Most Ambitious Climate Plans

Photo, posted September 17, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Choose Chicken Over Beef?

July 22, 2019 By EarthWise Leave a Comment

Food production is a major driver of climate change. It’s responsible for more than a quarter of all greenhouse gas emissions. But the environmental impact of different foods varies greatly, and making seemingly insignificant changes can actually have significant impacts.

According to a first-ever national study of U.S. eating habits and their carbon footprints, choosing chicken over beef will cut your dietary carbon footprint in half.

The National Health and Nutrition Examination Survey asked more than 16,000 participating Americans to name all the foods they consumed in the past 24 hours. The research team then calculated the carbon footprint of what people said they ate. If a respondent consumed broiled beef steak, for example, researchers calculated what the carbon footprint would have been had broiled chicken been consumed instead.

The study’s findings illustrate how making one simple substitution can significantly reduce a person’s dietary carbon footprint. A diet’s carbon footprint is the amount of greenhouse gas emissions that result from the energy, fertilizer, land use, and other inputs necessary to produce food.

In general, animal-based foods have a bigger carbon footprint than plant-based foods. For example, producing beef uses 20 times the land and emits 20 times the emissions as growing beans (per gram of protein), and requires 10 times more resources than producing chicken.

According to the World Resources Institute, keeping the increase in global warming below 2°C will be impossible without limiting the global rise in meat consumption.

Last year, the EAT-Lancet Commission report found that a radical transformation of the global food system was needed because it’s threatening the stability of the climate.

Make a change – big or small – today.

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Choosing chicken over beef cuts our carbon footprints a surprising amount

Photo, posted August 30, 2011, courtesy of Ken Hawkins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Degraded Permafrost In The Arctic

July 11, 2019 By EarthWise Leave a Comment

Permafrost is defined as rock or soil that has been at or below the freezing point of water for two or more years. Most of it is located in high latitudes in and around the Arctic and Antarctic regions. Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost can contain many different materials including bedrock, sediment, organic matter, water and ice. Because of the presence of organic matter, permafrost is potentially the source of significant methane emissions if it thaws and the trapped biomass begins to rot.

A recent study looked at the results of 30 years of aerial surveys and extensive ground mapping of an area of Canada’s high Arctic polar desert known as the Eureka Sound Lowlands. This area has an extremely cold climate and the permafrost there is over 1/3 of a mile thick. It has long been assumed that this landscape was stable.

Research led by McGill University in Montreal has found that this is not the case. The increases in summer air temperatures seen in recent years are initiating widespread changes in the landscape.

A particular landform known as a retrogressive thaw slump that forms when ice within permafrost melts and the land slips down is widely occurring in the area. The absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures.

The research indicates that despite the cold polar desert conditions that characterize much of the high Arctic, the interaction between ice-rich permafrost systems and climate factors is complex and the links between global warming and permafrost degradation are not well understood.

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Widespread permafrost degradation seen in high Arctic terrain

Photo, posted August 11, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The U.S. Military And Climate Change

July 9, 2019 By EarthWise Leave a Comment

According to new research by scientists from Durham University and Lancaster University, the United States military is one of the largest climate polluters. The U.S. military consumes more liquid fuels and emits more greenhouse gases than most countries.

The study, published in Transactions of the Institute of British Geographers, finds that if the U.S. military were a country, it would be the 47^th largest emitter of greenhouse gases in the world, falling between Peru and Portugal. And this only takes into account the emissions from its liquid fuel consumption. For this study, the U.S. military’s 2015 consumption was compared with the 2014 World Bank country liquid fuel consumption.

In 2017, the U.S. military purchased more than 269,000 barrels of oil a day, emitting more than 25,000 kt- CO2e by burning those fuels. The Air Force accounted for $4.9 billion worth of this fuel, followed by the Navy at $2.8 billion, the Army at $947 million, and the Marines at $36 million.

The Air Force and the Navy are not only the U.S. military’s largest purchasers of fuel, they also use the most polluting types of fuel. The Air Force is the largest emitter of greenhouse gases at more than 13,000 kt CO2e, nearly double that of the Navy’s 7,800 kt CO2e.

Despite this study’s findings and a general uptick in awareness, it’s unlikely that the U.S. military’s dependence on fossil fuels will change. That’s because the military continues to pursue open-ended operations around the globe, and the lifecycle of its existing military equipment insures dependence on hydrocarbons for many years to come.

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U.S. military consumes more hydrocarbons than most countries — massive hidden impact on climate

Photo, posted July 8, 2016, courtesy of Alan Wilson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Return Of An Old Threat

July 3, 2019 By EarthWise Leave a Comment

The 1987 signing of the Montreal Protocol was one of the biggest victories for global environmental stewardship. The 197 signatory nations banded together to address a planetary emergency: the depletion of the ozone layer in the upper atmosphere resulting from the use of chlorofluorocarbons or CFCs.

Over the years, there were celebratory headlines like “The Earth’s Ozone Hole is Shrinking” and “Without the Ozone Treaty, You’d Get Sunburned in 5 Minutes”. And indeed, the hole in the ozone layer has shrunk over time.

However, the presence of CFCs in the atmosphere is continually monitored and studies in recent years reported new emissions of about 13,000 tons of CFC-11 a year from somewhere in eastern Asia starting in 2012. That was two years after the 2010 date for ending all CFC production under the terms of the Montreal Protocol.

A new study published in Nature has pinned down the source of more than half of the new CFC emissions to the provinces of Shandong and Hebei on the northeastern coast of China. The bulk of these emissions are believed to come from small factories using the chemical to manufacture foam insulation used in refrigerators and buildings.

The Chinese government has already shut down two manufacturing locations, but undercover agents have found that 18 out of 21 manufacturers in the region are using the banned substance. They appear to be quite adept at circumventing enforcement.

The new emissions aren’t large enough so far to be catastrophic, but the Chinese government needs to crack down on this illegal activity. It is difficult to stop because these are small companies operating in meth lab-like facilities. Saving the earth’s atmosphere from ourselves is a tricky business.

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How an Illicit Chemical Is Jeopardizing Recovery of the Ozone Layer

Photo, posted July 28, 2012, courtesy of Beth Scupham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Schools And Solar Power

June 19, 2019 By EarthWise Leave a Comment

A new study from Stanford University looked at the benefits of installing solar panels on the rooftops of schools. According to the study, taking advantage of all the viable space for solar panels could allow schools to meet up to 75% of their electricity needs and reduce the education sector’s carbon footprint by as much as 28%.

Given the long list of spending priorities for schools, solar power seems like a luxury item. But the Department of Energy estimates that K-12 schools spend more than $6 billion a year on energy and, in many districts, energy costs are second only to salaries. In the higher education sector, yearly energy costs add up to more than $14 billion. In total, educational institutions account for approximately 11% of energy consumption by U.S. buildings and 4% of the nation’s carbon emissions.

The Stanford study suggests that investments in the right solar projects combined with the right incentives from states could free up much-needed money in school budgets.

To no surprise, the study finds that three large, sunny states – Texas, California, and Florida – have the greatest potential for generating electricity from solar panels on school rooftops.

Apart from measurable effects on air pollution and electricity bills, solar installations at schools can also provide new learning opportunities for students. In fact, some schools are already using data from their on-site solar energy systems to teach students basic ideas about fractions, as an example, as well as more sophisticated concepts such how shifting solar panel angles can affect power production.

According to the study, nearly all states could reap value from school solar projects.

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What happens when schools go solar?

Photo, posted February 28, 2011, courtesy of Black Rock Solar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Our Growing Appetite For Energy

June 13, 2019 By EarthWise Leave a Comment

Energy consumption in the United States set a record high in 2018. Overall, energy consumption reached 101.2 quadrillion BTUs or quads last year, breaking the previous record of 101.0 set in 2007. Most of us are not too familiar with quadrillions of anything, nor with BTUs for that matter. If it is any more illuminating, 101 quads are the equivalent of about 300 billion kilowatt hours. Our energy use increased by 3.6% from 2017, which was the largest annual increase since 2010.

Wind, solar, and natural gas provided the largest increases in energy supply. In 2018, solar and wind energy were both up by 0.18 quads, representing a 22% gain for solar and a 7.5% increase for wind. Over the past ten years, overall renewable energy has doubled in the U.S., with wind increasing by a factor of 5 since 2008 and solar by an amazing factor of 48.

Natural gas generation increased by 10.7%, or a total of 3 quads over the previous year. The growth in natural gas use isn’t good news, but since much of it represents replacing coal, it at least corresponds to reduced greenhouse gas emissions.

The unfortunate part of our energy consumption is that the majority of it is still in the form of “rejected energy”. It most often takes the form of waste heat, such as the warm exhaust from automobiles and furnaces. The efficiency of our cars, lightbulbs and factories determines how much waste heat is produced and in turn how much fuel and electricity can be put to productive use.

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US energy consumption hits record high in 2018, solar/wind/natural gas grow

Photo, posted April 27, 2015, courtesy of Mathias Appel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mass Timber

June 10, 2019 By EarthWise Leave a Comment

Mass timber is a type of construction typically characterized by the use of large solid wood panels for wall, floor, and roof construction. Large structural panels, posts, and beams glued under pressure or nailed together in layers, with the wood’s grain stacked perpendicular for extra strength – are prized as innovative building materials, superior to concrete and steel in many ways. Mass timber has pushed the perceived boundaries of wood construction, leading to building heights and spans that traditionally have required concrete, steel or masonry for structural support. The move to mass timber has become something of a construction revolution and many see it as a significant part of a climate change solution.

The question is just how green is mass timber construction? How sustainable is it in terms of the forest management, logging, manufacture and transportation of wood products involved?

A number of environmental groups are very skeptical. There is not yet comprehensive data on the subject. Only recently have interdisciplinary scientists begun to study the potential climate impacts of the wide use of mass timber.

Despite these questions, the mass timber industry is taking off. Demand for mass timber posts and beams has led to new sawmills opening in the U.S. Northwest and many new jobs for loggers.

The aesthetics and economics of mass timber are both very attractive compared with conventional large-scale construction materials. The real unknowns relate to the environmental impact of its widespread use. If that can take place in a sustainable and environmentally conscientious way, it would be very important in the fight against climate change. Carbon dioxide emissions from the building industry account for more than a third of global emissions, primarily from the concrete and steel industries.

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As Mass Timber Takes Off, How Green Is This New Building Material?

Photo, posted March 19, 2018, courtesy of Freres Lumber Co via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hybrid-Electric Aircraft

May 20, 2019 By EarthWise Leave a Comment

The commercial aviation industry is a major source of carbon dioxide emissions and, as other industries try to move towards decarbonization, its share is getting larger. But reducing emissions from aircraft is challenging because powering planes without burning fossil fuel is hard to do.

The biggest problem is that powering aircraft with electric motors instead of fossil fuel motors requires so much energy that the batteries needed to supply it become impractically heavy. While research goes on to develop lighter-weight batteries, an interim concept may pay dividends.

Just as hybrid cars represent a stepping stone towards full electrification, hybrid-electric aircraft may be a way to obtain substantial reductions in aircraft emissions. The idea is to use battery-powered electric motors to power planes, but to greatly reduce the capacity requirements of the batteries by having an on-board fossil-fuel generator to charge the batteries and supply additional needed power.

A study by the University of Illinois looked at the potential emissions reductions for hybrid-electric aircraft taking into account the emissions associated with generating the electricity that charges the batteries in the plane. The requirements in the study were that the plane needs to be able to carry the same number of passengers and travel the same distance as current aircraft.

The results were that a drivetrain that gets 50% of its power from battery charge reduced emissions by about 50% over the full lifecycle of the plane.

As batteries get lighter and the electric grid gets greener, the possibility of making major reductions in aircraft carbon emissions looks increasingly realistic. But there is a long way to go.

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Study Examines Commercial Hybrid-Electric Aircraft, Reduced Carbon Emissions

Photo, posted September 26, 2014, courtesy of Jeff Turner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

How Much CO2 Can The Oceans Hold?

May 2, 2019 By EarthWise Leave a Comment

The carbon dioxide that enters the atmosphere doesn’t necessarily stay there. As part of the natural carbon cycle, much of it goes into plants, soil and, very significantly, the ocean. In fact, the world’s oceans are a sink for human-generated carbon dioxide without which the extent of global climate change would be far worse.

Oceans takes up CO2 in two steps: first the CO2 dissolves in the surface water. Then, the ocean’s overturning circulation distributes it. Currents and mixing processes transport the dissolved CO2 from the surface deep into the ocean’s interior, where it accumulates over time.

A long-standing priority for climate researchers is to determine how much of the CO2 we produce is being absorbed by the oceans and, ultimately, how much can they hold?

An international team of scientists has recently provided some answers. As reported in Science, the researchers have determined that the oceans have taken up from the atmosphere as much as 37 billion tons of human-made carbon between 1994 and 2007. This figure corresponds to nearly a third of all the anthropogenic CO2 emitted during that time.

Furthermore, they found that the percentage of CO2 taken up by the oceans has remained relatively stable compared to the preceding 200 years even as the absolute quantity has increased. So, evidently, the oceans’ capacity for carbon dioxide has not yet been saturated.

That’s the good news. The bad news is that putting all that CO2 into the oceans has a steep price: the dissolved CO2 acidifies the water. The consequences for a wide range of marine life including coral reefs are serious and getting worse. We need to drastically reduce carbon emissions.

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Ocean sink for human-made carbon dioxide measured

Photo, posted November 5, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Whopping Change

April 10, 2019 By EarthWise Leave a Comment

Burger King, the global hamburger fast food giant, recently made a huge announcement: Customers will soon have the option to select either a beef patty or a plant-based patty when ordering the iconic Whopper sandwich.

Burger King’s plant-based patty will be made by Impossible Foods, a California startup founded in 2011 with the explicit goal of decreasing the world’s reliance on animal agriculture. Impossible Foods signature product, the Impossible burger, has already debuted as a slider in White Castle’s 380 or so stores. It’s also being added to the menu at all 570 Red Robin locations. Other plant-based innovators, such as Beyond Meat, have also found some mainstream success. But the Impossible Whopper and the planned national roll-out at Burger King’s 7,200 locations is the biggest deal to date.

Impossible Foods’ major innovation comes from its use of heme, which is an iron-rich protein that in essence is what makes meat taste like meat. Impossible Foods cultivates heme directly from plants – soybean plant roots to be exact – and then mass produces it using yeast. This is then mixed with other plant-based ingredients to achieve the nutty texture of ground beef.

Meat production is one of the biggest single contributors to climate change. The Impossible burger represents a better choice for the environment. It requires 87% less water, 96% less land, and produces 89% fewer greenhouse gas emissions when compared with beef burgers. At Burger King, the Impossible Whopper will have the same amount of protein as the regular Whopper, but 15% less fat and 90% less cholesterol.

Meatless continues to push into the mainstream.

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Behold the Beefless ‘Impossible Whopper’

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.