carbon emissions

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.

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.

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.

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.

Building For Climate Change

May 13, 2019 By EarthWise Leave a Comment

The manifestations of climate change are creating increasingly familiar images: floodwaters rising up house windows, charred buildings in the wake of wildfires, and homes and businesses demolished by storm winds. As these sorts of calamities become ever more common, changes to how houses are built are going to be necessary.

How can homes become more resilient against severe and unpredictable weather?

Research at Carlton University’s Sprott School of Business looks at this issue.

As an example, houses can be framed and finished in certain ways that help protect them from wind and flooding. But such methods are currently only happening in the custom-build fringes of the housing sector. Widespread adoption will require, at the minimum, significant changes to building codes.

Revising building codes is not an easy matter. The codes themselves are highly technical and complex, and beyond that, the process Is often politicized.

Even simple things like hurricane ties, which are small pieces of hardware that prevent a roof from lifting during a severe wind are not now included in building codes. Insurance companies support their use as inexpensive protection for houses. But even though the overall cost is relatively minor, the building industry pushes back at the additional expense.

The need to reduce carbon emissions has created a push for sustainable housing. But the increasingly erratic weather means that houses also need resilience and adaptation. These features will inevitably add costs and incorporating them into building codes requires producing convincing business cases.

The U.S. experienced 394 natural catastrophe events last year costing $225 billion in damage. Finding ways to make homes and businesses more resilient is not just a good idea; it is essential.

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How to Start Weather-Proofing Homes for Unpredictable Weather

Photo, posted June 12, 2008, courtesy of U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Way to Make Hydrogen

January 31, 2019 By EarthWise Leave a Comment

Many people consider hydrogen to be the fuel of the future, both for powering vehicles and for storing energy generated by renewable sources. Hydrogen itself is a clean and green fuel. Generating energy from it using fuel cells results in only water as a byproduct.

The biggest problem with hydrogen is that the most economical way to produce it and therefore the way most hydrogen is produced today, is by reforming natural gas, which is a process that generates carbon emissions.

The desirable way to make hydrogen is to produce it by breaking apart water into its hydrogen and oxygen components, a process known as electrolysis. There are many ways to do it, but none of them to date measures up in terms of efficiency, cost, and longevity.

Researchers at the University of Toronto have recently developed a new catalyst that uses abundant, low-cost elements to split water molecules into hydrogen and oxygen. The catalyst is made from copper, nickel, and chromium, all of which are more abundant and less costly than platinum, which is the usual electrolysis catalyst.

The new catalyst performs well under pH-neutral conditions, which means it could even work on seawater without incurring the expense of desalination. The Toronto researchers also believe their catalyst could be used as part of a process to make hydrocarbon fuels from hydrogen and CO2₂. Their group is among the five finalists in the Carbon XPrize competition, which has a grand prize of $7.5 million for finding a way to convert waste CO2 into fuel.

Finding a low-cost, energy-efficient, and reliable way to make hydrogen out of water will be a big deal if it can be done on an industrial scale.

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U of T researchers discover low-cost way to produce hydrogen from water

Photo, posted July 23, 2015, courtesy of Magnus Johansson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Falling Behind On Climate Goals

December 24, 2018 By EarthWise Leave a Comment

A series of reports from both the US Government and from the United Nations has underlined the dangers presented by the increasing effects of climate change. To date, national commitments to reduce emissions have come up short.

The Cockroaches Of The Ocean

December 14, 2018 By EarthWise Leave a Comment

The coast of Northern California is home to underwater forests – huge, sprawling tangles of brown seaweed. Kelp forests play a similar role in the oceans as the one that ordinary tree forests play on land. Like trees, kelp absorbs carbon emissions and provides critical habitat and food for a wide range of species.

How To Measure Carbon Emissions

November 5, 2018 By EarthWise Leave a Comment

The Paris climate accord by nearly 200 countries seeks to reduce global carbon emissions. But how can the actions of these countries be monitored, reported, and verified? It is not an easy task.

Emissions From Electric Buses

September 12, 2018 By EarthWise Leave a Comment

Municipalities and transit agencies are gradually replacing conventional diesel buses with cleaner alternatives such as natural-gas-powered, diesel-electric hybrid, or fully electric buses. The goal is to reduce the substantial carbon emissions associated with buses as well as reducing unhealthy air pollution. Diesel buses on average get less than 5 miles per gallon as they transport passengers around, so there is plenty of motivation to find more efficient ways to power them.

Greener Concrete

August 23, 2018 By EarthWise 1 Comment

The battle to reduce carbon emissions is heavily focused on electricity generation, transportation, buildings, and agriculture, which collectively account for more than 75% of the total. However, there are other sources of carbon emissions that cannot be ignored. Among industrial activities, the production of cement is responsible for 7% of industrial energy use and is the second largest industrial emitter of carbon dioxide. Making cement accounts for about 7% of global emissions.

[Read more…] about Greener Concrete

A New Catalyst For Splitting Water

August 13, 2018 By EarthWise Leave a Comment

Hydrogen is widely considered to be a desirable source of clean energy. It can be used in fuel cells to power electric motors in cars or can be burned directly in internal combustion engines. If it is compressed or converted to liquid, it can be efficiently stored and transported. Most of all, when it is used as an energy source, the only emission it produces is water.

Bursting The Carbon Bubble

July 25, 2018 By EarthWise Leave a Comment

One way or another, the fossil fuel industry seems to be destined to shrink away. A combination of technological advances and climate policies are going to drastically reduce the global demand for fossil fuels over the course of time. New research shows that the demise of the fossil fuel industry will have profound consequences.

Trouble With China And Climate Progress

July 12, 2018 By EarthWise Leave a Comment

With the United States backing away from the Paris climate agreement and with Europe taking a less active role in climate negotiations, China has become the bellwether on global climate change. Recent climate negotiations in Bonn, Germany were rather acrimonious as countries accused other countries of not doing their part or keeping their promises.

Climate Change And Biodiversity

April 19, 2018 By EarthWise Leave a Comment

According to a new study recently published in the journal Climatic Change, up to half of the plant and animal species in the world’s most naturally-rich areas could face local extinction by the turn of the century due to climate change. This projection, jeopardizing the biodiversity in places like the Amazon and the Galapagos, assumes carbon emissions continue to rise unchecked.

Natural Climate Solutions

February 13, 2018 By EarthWise Leave a Comment

The Paris Climate Agreement embodies a commitment to hold the increase in the global average temperature to less than 2 Celsius degrees above preindustrial levels. Most strategies to achieve this goal involve reductions in greenhouse gas emissions from human activities such as burning fossil fuels as well as various land use activities. But there are also so-called Natural Climate Solutions, which relate to the storage of carbon and reduction in carbon emissions across global forests, wetlands, grasslands, and agricultural lands.

A Carbon Loophole

February 12, 2018 By EarthWise Leave a Comment

Many power plants in Europe and elsewhere are replacing coal with wood. For example, the Drax Power Station in Britain was its largest coal-burning plant and is now using wood pellets shipped from the southern U.S. in its boilers. According to the carbon accounting rules at the EU and elsewhere, the process is considered to be “carbon neutral.” But is it?

The idea is that new trees are being planted in the forests where the trees are cut to be burned in power plants. So, there is carbon neutrality. In principle.

European countries have embarked on a massive effort to switch to generating power from renewable energy. While there has indeed been major growth in wind and solar power in the 28 countries of the European Union, much of the new “green” power has come from burning wood in converted coal power stations.

A group of 200 scientists wrote to the EU last September insisting that bioenergy from forest biomass is not carbon neutral and that there must be tighter rules to protect forests and their carbon. Wood burning has become a loophole in controlling carbon emissions.

There are problems with the claims of carbon neutrality. There is no way to know whether enough new trees are actually being planted to replace those being burned. And then there is the time lag for tree replacement. Trees don’t grow overnight. There are also the carbon emissions associated with harvesting, processing and transporting wood.

There are most certainly ways in which burning biomass can be carbon neutral and can represent real progress over the use of fossil fuels. But caution must be taken to avoid exploiting loopholes in current climate rules that might actually result in increased carbon emissions.

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