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Ocean-based Climate Intervention And Deep-sea Ecosystems | Earth Wise

May 2, 2023 By EarthWise Leave a Comment

Deep-sea ecosystems cover more than 40% of the Earth. These regions are some of the least well-known and understood areas of our planet but are home to numerous ecosystems. The deep seas are already directly exposed to the effects of human-induced climate change but could potentially be greatly threatened by efforts to artificially counteract climate change.

A class of geoengineering solutions called ocean-based climate interventions are increasingly being claimed as promising ways to mitigate climate change. Such interventions would remove carbon dioxide from the atmosphere and sequester it in the deep sea. There is very little known about the impact of such efforts on ocean biogeochemistry and the biodiversity of ocean ecosystems.

One approach is direct CO₂injection into the deep ocean, which would sequester large amounts of it and reduce the concentration in the atmosphere. However, too much carbon dioxide in the water is called hypercapnia, which can have serious consequences on marine life.

Other approaches include ocean fertilization – which is enhancing phytoplankton production at the surface, leading to their eventual deposition on the deep-sea floor – and crop waste deposition – which is deep-sea disposal of terrestrial crop waste.

A multinational study led by the Scripps Institution of Oceanography warns that there needs to be much more research and governance before any such interventions ever take place. The deep sea faces unprecedented threats from industrial fisheries, pollution, warming, deoxygenation, acidification, and other climate-related problems. Ocean-based climate intervention represents yet another serious threat to the functioning of these essential ecosystems.

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HKU Marine Scientist contributes to research assessing the potential risks of ocean-based climate intervention technologies on deep-sea ecosystems

Photo, posted January 6, 2010, courtesy of Emrys Roberts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Should We Block The Sun? | Earth Wise

May 10, 2021 By EarthWise Leave a Comment

There is growing concern that greenhouse gas emissions are not falling quickly enough to avoid dangerous levels of global warming. As a result, there is the impetus to examine other options. Among these are geoengineering, which is one of the most contentious issues in climate policy. Geoengineering embodies many risks that make even seriously considering it seem risky in itself.

Despite this, the National Academies of Science, Engineering, and Medicine has issued a report saying that governments urgently need to know whether solar geoengineering could work and what its side effects might be.

Solar geoengineering is also called solar radiation modification, which entails reflecting more of the sun’s energy back into space. This would likely be accomplished by injecting aerosols into the atmosphere, much like what happens after large volcanic eruptions.

Schemes for solar geoengineering raise numerous issues. Although solar geoengineering might cool the earth’s surface to a global temperature target, the cooling may not be evenly distributed, affecting many ecosystem functions and biodiversity. It would likely upset regional weather patterns in potentially devastating ways, for example by changing the behavior of the monsoon in South Asia. It might dangerously relax public commitments to reduce greenhouse emissions.

Despite these concerns, or perhaps because of them, the committee that produced the report believes that technology to reflect sunlight deserves substantial funding and should be researched as rapidly and effectively as possible. Once any geoengineering projects get into the hands of policymakers, they may gather momentum that bypasses the advice of scientists. So, it important to make progress on the science while geoengineering is still only theoretical.

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Should We Block the Sun? Scientists Say the Time Has Come to Study It.

To intervene or not to intervene? That is the future climate question

Photo, posted August 3, 2018, courtesy of Tomasz Baranowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Geothermal Power In The Energy Transition | Earth Wise

February 22, 2021 By EarthWise Leave a Comment

The heat beneath the earth represents a vast repository of energy that in principle could provide for a significant part of our needs. In some places, geothermal energy is easy to get to and is already being exploited. California and Nevada operate dozens of geothermal electric generating plants. Boise Idaho heats 92 of its biggest buildings with the river of hot water that flows 3,000 feet below the city. In total, the U.S. produces enough geothermal electricity to power more than a million homes.

But all these examples make use of relatively rare local features that are not available to the great majority of locations. As a result, geothermal energy has generally not been viewed as being able to play a major role in the alternative energy transition.

A number of experts around the world disagree with this assessment. To a fair extent due to the deep-drilling techniques and knowledge about underground formations developed by the oil and gas industry during the fracking boom, there is growing interest in a type of geothermal energy called deep geothermal that accesses hot temperatures in the earth’s mantle as far down as two or three miles.

Deep geothermal can either access extremely hot water that exists down at those depths or water can be injected into hot rock down there, which is a technology known as enhanced geothermal systems.

There is enormous untapped potential for geothermal energy. A 2019 report by the U.S. Department of Energy says that by 2050, geothermal could provide 8.5% of the United States’ electricity as well as direct heat. Geothermal could be an important part of the so-called all-of-the-above future energy strategy.

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Can Geothermal Power Play a Key Role in the Energy Transition?

Photo, posted August 2, 2008, courtesy of ThinkGeoEnergy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Drilling In California

May 16, 2019 By EarthWise Leave a Comment

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.

Growing Rocks To Store Carbon

April 24, 2019 By EarthWise Leave a Comment

The US Geological Survey recently published a comprehensive review of geological carbon storage in sedimentary rocks through carbon mineralization. That is the process by which carbon dioxide becomes a solid mineral, such as a form of carbonate. Certain rocks undergo a chemical reaction when exposed to carbon dioxide and turn into different minerals as a result.

The idea is to use carbon mineralization as a way to permanently store carbon dioxide that has been captured from power plant emissions, other industrial activities, or even directly from the atmosphere.

Two basic approaches are injecting the CO2 deep underground or exposing it to crushed rocks at the surface. The two types of rock best suited for mineralization through injection are basalt and various ultramafic rocks. Pilot studies have shown that injection into basalt can lead to mineralization in under two years.

Exposing carbon dioxide to crushed rock at the surface generally makes use of crushed mining waste. Mineralization can be much faster in this case because there is more surface area on the crushed rock where mineralization occurs. (However, the quantities of rock available at the surface are much less than what exists deep underground).

Like all carbon capture and storage approaches, the key consideration is cost. The USGS study estimates that underground injection would cost around $30 per metric ton of CO2. The crushed rock approach might only cost $8 per metric ton, but that assumes the crushed rock is already available. If it must be newly mined, the costs would obviously go up significantly. To put this into perspective, a typical car produces around 4 metric tons of CO2₂ per year. So, it would cost somewhere between $30 and $120 a year to eliminate the emissions from one car. Perhaps that is a price we need to pay until we ditch gasoline cars.

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How Growing Rocks Can Help Reduce Carbon Emissions

Photo, posted October 17, 2011, courtesy of Glen Bledsoe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Earthquakes And Injection Wells

October 8, 2018 By EarthWise Leave a Comment

The expanded use of injection wells and fracking has brought about a significant increase in earthquakes in places that didn’t have very many before. Wastewater injection in Oklahoma increased earthquake totals from dozens per year to over 900 in 2015 before collapsing oil prices reduced the use of the technique. Increased earthquakes in Alberta, Canada were triggered by fracking in that area.

Lots Of Credit For Carbon Capture

March 23, 2018 By EarthWise Leave a Comment

These days, the federal government has mostly turned its back on efforts to mitigate climate change or, for that matter, to even recognize its existence. However,the budget bill passed in February contained a major increase in the tax credit known as 45Q, which provides incentives to businesses to develop and utilize carbon capture, utilization and storage technologies.