Enhanced weathering is a carbon capture technology in which ocean alkalinity is increased through depositing rock particles into the ocean. It may sound simple, but there is still much to be examined as the risks are weighed against the benefits.

—

Currently, a diverse range of carbon capture methods are being used in an attempt to reach negative carbon emissions. Most of these are land-based methods and some are more controversial than others; Bioenergy with Carbon Capture and Storage (BECCS) technologies for example, require crops to be grown that will then get burned to release energy and store carbon underground. 

Enhanced weathering is a method that involves storing carbon in the ocean through a chemical reaction that removes CO2 from the atmosphere. In an effort to accelerate oceanic uptake of carbon in the least intrusive, yet most cost-effective way, scientists have concerns about the impact it will have on marine ecosystems. 

What is Enhanced Mineral Weathering?

Weathering is a natural process whereby rocks are broken down by rainwater, extreme temperatures or human activity. It is a process that takes place over millions of years, constituting an important carbon sink. 

The process begins when CO2 dissolves in droplets of water to form carbonic acid, a weak acid: rainwater has a pH of around 5 to 5.5, but because there is a lot of it available in the environment, it does a lot of weathering over time. Rocks that contain carbonates, like limestone, react quickly because the minerals they are largely made from, such as calcium carbonate, are more reactive than silicates. The dissolved calcium and bicarbonate ions formed from the carbonic acid travel in groundwater to rivers and the sea. Through the calcium carbonate-generating part of the chemical process, there is a net loss of readily-made carbon- half the amount of carbon at the end as there is at the beginning. As sediments continue to accumulate, the carbonate-rich layer will be buried under new layers of sediment that will in time turn to solid rock, like limestone. 

The carbonates that form increase the alkalinity of oceans, leading to a further uptake of atmospheric CO2. The rate of weathering is dependent on temperature, runoff (the availability of water to remove reaction products), grain size of rock or mineral and biological activity, like volcanoes. The annual potential of CO2 consumption is defined by the grain size and the weathering rate of the rocks used.

Enhanced mineral weathering is the speeding up of this natural process, whereby rocks are ground into fine particles and spread across large spans of land or the ocean. Overall, the process requires extraction, processing and the dissolution (reaction) of minerals. Through this, more atmospheric carbon dioxide can be sequestered than what would occur naturally. 

The use of enhanced rock weathering to increase ocean carbon uptake was first proposed in 1995, but was put aside due to the high energy costs of creating lime. 

Expected outcomes of enhanced weathering processes are uncertain. Current research is directed towards the function of alkalinity in the existing natural oceanic carbon cycle, what the effects on ocean chemistry imposed by artificial alkalinity could be and whether it could be maintained in a stable manner and technologies that can be used to increase alkalinity.

Enhanced Weathering Pros and Cons

Enhanced weathering may ameliorate ocean acidification. The added alkalinity also increases the saturation state of carbonate minerals which, if too low, negatively impacts carbonate-producing organisms in the ocean, such as shellfish and coral.

Enhanced weathering would not require its own land, nutrients or freshwater, with the latter only needing to be used when dust avoidance measures from rock deposition become necessary. Rock particles could be applied on open ocean regions or combined with agriculture with the additional benefit of enhancing crop yields and preventing soil erosion.

Additionally, while the range of technologies that have been proposed for increasing ocean alkalinity may pose significant engineering challenges, cost analyses suggest that they are still within the range of other negative emission technologies. 

However, speeding up or changing the course of nature can have disastrous effects. Scientists suggest that rapid uncontrolled changes in pH, carbonate saturation state, and dissolved aqueous CO2 can affect ocean ecosystems. While this process mimics a natural one, it is not natural; the substance would be delivered to ecosystems at rates far higher than normal which could create ‘dead zones’, areas where oxygen levels are too low to support life. Additionally, the amount of olivine necessary for these applications is extremely large and is comparable to present-day global coal mining, a counterintuitive proposition as the planet looks to turn away from mining. In the case of basalt, to sequester one billion tonnes of CO2, more than 3 billion tonnes of basalt would have to be spread, an amount equal to almost half of the current global coal production.

Additionally, at such a large scale, enhanced weathering could change the ecology of the water, leading to an increase in the microbial organisms that produce greenhouse gases such as methane and nitrous oxide. 

Although the addition of alkalinity is common practice in certain constrained marine environments such as in aquaria and shellfish production, scientists believe that more research is needed to understand the wider ecosystem response. 

Current Attitudes Towards Enhanced Weathering

In a 2017 UK survey, over 70% of participants expressed that they’d never heard of enhanced weathering. Further, support for research of the technique was found to be much stronger than support for the technique itself. Lack of public knowledge about this technology could be a factor hindering its large-scale deployment. 

The best suited locations are warm and humid regions, particularly in India, Brazil, South East Asia, and China, where almost three quarters of the global potential could be realised.

Increasing alkalinity in the ocean needs to be assessed more stringently. Some pressing issues regarding ocean alkalinity will have to address whether marine life will thrive or die in a new environment. While much of this work is still in the testing phase, enhanced weathering technologies could become economically and environmentally viable options to realise carbon capture and subsequent negative emissions this century. 

Featured image by: Richard Droker

The post Enhanced Weathering for Carbon Capture appeared first on Earth.Org.

Plastic is an inevitable part of consumer behaviour, and in recent years the plastic waste problem has become a mainstream part of the public consciousness. However, some practical challenges need to be addressed in order to reduce our reliance on the substance.

—

Plastic Packaging Waste Statistics

The packaging sector is responsible for almost half of the plastic in the world. A KPMG report says that if the growth of plastic production continues at the current rate, the plastic industry could account for 20% of the world’s total oil consumption by 2050. Almost a third of all plastic packaging leaks out of collecting and sorting systems and ends up in soil and the ocean. Additionally, plastic degrades into fine nano-sized particles that are harmful to animals and stay in food chains. 

However, cutting out plastic completely is not as easy as people would like to think. 

Why is plastic packaging used?

1. Food Preservation
   One of the biggest uses of plastic packaging is food, however there is ongoing debate as to how best to balance food and plastic waste, and food safety. The argument is that plastic is necessary to prevent food waste; roughly one third, or 1.3 billion tonnes, of the food produced for human consumption gets lost or wasted every year.

   Plastic packaging supports the safe distribution of food over long distances and minimises food waste by keeping food fresher for longer, and it provides a barrier against bacteria. For example, 1.5g of plastic film wrapping a cucumber can extend its shelf life from three to 14 days, and selling grapes in plastic bags or trays has reduced in-store wastage of grapes by 20%. However, 40%, or 9 million tonnes, of all food packaging ends up in landfills.

   Manoj Dora and Eleni Iacovidou from Brunel University London believe that a way to reduce plastic packaging is to create shorter food supply chains and ensure that food is consumed sooner before it goes to waste. Having shorter food supply chains means reducing the number of intermediaries between where the food is farmed and where it is bought and consumed. They suggest that this change will encourage a shift towards more seasonal diets, and that it will place an emphasis on the rise of community-based growers where consumers can see where their food comes from.

   You might also like: Tackling the Food Waste Crisis in China

2. Plastic Recycling Isn’t Always King
   Only 14% of all plastic packaging is collected for recycling. A large problem lies in the failure to collect plastic in the first place, and that people don’t know what type of plastic can be recycled.

   There are seven types of plastic, making recycling trickier. Designing packaging that is easier to separate is vital, like having removable outer packaging and using water-soluble glues. Alternatively, plastic can be limited to a single standard to make recycling easier; coloured plastics such as black trays are harder to identify by sorting technologies, slowing down the recycling process.

   Further, plastic packaging cannot be recycled infinitely because it degrades in quality. Contamination and mixing of polymer types can also lower the economic and technical value of the secondary plastic being made and plentiful fuel is required to melt the plastic down and re-pelletise it. Additionally, some of the most ubiquitous plastic films are difficult to recycle, such as crisp packaging and disposable cups with plastic lining.

3. Bioplastic Alternatives
   Alternative plastics must be created which are just as lightweight, durable and convenient as conventional plastics. Plant-based plastics, or bioplastics, made from corn starch or sugarcane, are one such solution.

   Bioplastics produce significantly fewer greenhouse gas emissions than traditional plastics over their lifetime. There is no net increase in carbon dioxide when they break down because the plants that bioplastics are made from absorbed that same amount of carbon dioxide as they grew.

   However, while their biodegradability is an advantage, most bioplastics need high temperature industrial composting facilities to break down, and very few cities have the necessary infrastructure; bioplastics therefore often end up in landfills where, deprived of oxygen, they may release methane. Further, when these plastics aren’t discarded properly, they can contaminate batches of recycled plastic and harm recycling infrastructure- if bioplastic contaminates recycled PET (Polyethylene Terephthalate, the most common plastic), the entire lot could be rejected and end up in a landfill. Separate recycling streams are necessary to be able to properly discard bioplastics.

   The land required for bioplastics also competes with food production as the crops that produce bioplastics can also be used to feed people. In 2019, The Plastic Pollution Coalition projected that 3.4 million acres of land were needed to grow the crops. Additionally, the fuel used to run the farm machinery produces greenhouse gas emissions.

   Lastly, bioplastics can be costly. PLA (Polyactic Acid- made from the sugars in corn starch and sugarcane) can be 20-50% more expensive than comparable materials because of the complex processes involved in converting corn or sugarcane into PLA. However, as more efficient and eco-friendly strategies for producing bioplastics are devised, prices are expected to come down.

4. Sacrificing Convenience
   “The reality is, you’d have to use some reusable bags 3 000 times to basically neutralise the carbon footprint of the disposable bag that’s produced today,” says Karl Deily of sustainable packaging company Sealed Air.

   The way to rely less on plastic is to use none at all. But in the age of convenience, it is not that simple. A number of start-ups such as Loop, a supermarket delivery service using only reusable containers, is starting to gain momentum and it is these innovations that are vital to reducing plastic usage.

   With massive polluters like China announcing the ban of single-use plastic bags, there is hope yet for a world that relies less on plastic. Additionally, the amount of material used in packaging declined by 28% between 2004 and 2014 as a consequence of advanced technologies, indicating a global push towards a less plastic-centric world. 

The post Why We Can’t Quit Plastic appeared first on Earth.Org.

The complexities of global trade raise questions about how best to address the way countries fairly compensate for their environmental impact on others. Pricing carbon, specifically through a carbon tax, is one such way to address these equity issues and reduce global carbon emissions. We explore the benefits of a carbon tax and what this looks like around the world.

—

What is Carbon Pricing?

Carbon pricing is an approach to reducing carbon emissions that uses market mechanisms to pass the cost of emitting to emitters. Its goal is to discourage the use of fossil fuels, address the causes of the climate crisis and meet national and international agreements. 

Well-designed carbon pricing can change the behaviour of consumers, businesses and investors while encouraging technological innovation and generating revenue that can be used productively.

There are a few carbon pricing instruments, such as a carbon emissions tax and cap-and-trade programmes. 

Current Situation on Carbon Pricing and Carbon Tax

The International Monetary Fund, the Organisation for Economic Co-operation and Development (OECD) and others have recommended more stringent fiscal measures to reduce emissions, such as increasing the carbon price or taxation to further incentivise corporations to reduce their emissions and align themselves with the Paris Agreement goals. However, with these plans arise not only political complications such as aligning inconsistent national policies with international trade, but also the issue of equity. With 50% of carbon emissions attributed to the richest 10% in the world, and 10% of emissions attributed to the poorer 50% of the world, it raises the question of who contributes to the climate crisis and who really suffers the consequences of it. 

A fair system must be developed, one that acknowledges and compensates for the fact that wealthy nations emit far more carbon than poorer nations, who suffer more from the impacts of the climate crisis. Termed ‘carbon inequality’, efforts are being made to tackle environmental and social injustices through political and economic means. 

The discussion around not only pricing and taxing carbon, but developing fair climate policies is not a new one, however there is an increased focus on the degree of responsibility a country should take- how much countries should be paying, and to whom.

At UN climate negotiations in 2018, Chinese delegate Xie Zhenhua addressed the mismatch of cause and consequence between developing and developed countries. He said, “developing countries are not comfortable or happy. We need to see if developed countries have honoured their commitments. Still some countries have not started their mitigation efforts, or provided financial support to poor nations. We strongly urge them to pay up on their debts.”

Carbon pricing policies in selected countries (Source: Statista)

Carbon Taxes Around the World

A carbon tax is imposed by a government and is defined by per-tonne tax on the carbon emissions embedded in fossil fuels or other products. It puts a direct price on greenhouse gas (GHG) emissions and creates a financial incentive to lower emissions by switching to more efficient processes or cleaner fuels. 

Cap-and-trade systems such as the EU Emissions Trading System (ETS) impose a cap of GHGs that can be emitted every year, called ‘carbon credits’. Those industries with low emissions can sell their extra allowances to larger emitters. This supply and demand for emissions allowances establishes a market price for GHG. The cap helps ensure that emission reductions will take place to keep emitters within their pre-allocated carbon budget.

A national carbon tax is currently implemented in 27 countries around the world, including various countries in the EU, Canada, Singapore, Japan, Ukraine and Argentina. However, according to the 2021 OECD Tax Energy Use report, current tax structures are not adequately aligned with the pollution profile of energy sources. For example, the OECD suggests that carbon taxes are not harsh enough on coal production, although it has proved to be effective for the electricity industry.

A carbon tax has been effectively implemented in Sweden; the carbon tax is USD $127 per tonne and has reduced emissions by 25% since 1995, while its economy has expanded 75% in the same time period. 

Where Should the Money Go? 

With some carbon tax systems already in place, core criticisms around carbon pricing instruments centre around public trust in the system. Despite long-term environmental benefits, surveys shows that individuals are concerned about how their daily lives will be affected and where revenue will be directed. For example, some concerns include the belief that carbon pricing will add further financial stress on the elderly and those in poorer households by increasing the cost of energy. 

Another survey conducted by Nature with 4997 participants in Australia, India, South Africa, the US and the UK proposed different hypothetical carbon tax mechanisms to examine their public’s acceptance to them, whereby ‘funding for mitigation projects worldwide’ received the highest support.

To make carbon taxes politically feasible and economically efficient, governments must choose how to use the revenue. Options include cutting other kinds of taxes, supporting poorer households and communities, increasing investment in green energy or by giving the money back to people as a dividend.   

These concerns are already being addressed in some countries such as Switzerland, where residents receive their dividend as a rebate on a compulsory health insurance. Canada’s incoming federal scheme is aiming for 90% of the carbon tax revenue to be returned to residents. 

Lack of a Common Commitment 

On committing to the Paris Agreement, UN Climate Chief Christiana Figueres said that countries are not looking to save the planet for altruistic reasons. “They’re doing it for what I think is a much more powerful political driving force, which is for the benefit of their own economy,” she said. 

There is a disparity between the interconnected global economy and the disparate carbon policies in different countries (some with carbon tax, some implementing cap-and-trade systems, some without a system in place at all). For example, the EU uses their ETS system, yet the majority of the US has yet to implement a carbon tax. These factors make equilibrating the different carbon-pricing schemes on a global basis challenging yet crucial if equity is to be achieved. 

Economist Peter Cramton and colleagues emphasise that current ‘pledge-and-review’ processes that came from the Paris Agreement are based on self-interest and that responding only to domestic concerns will not be enough to address the problem at hand. He mentions that Paris was successful in that a collective goal was set, but that individual contributions do not add up. 

Another iteration of carbon taxes being discussed is carbon border taxes, as discussed in the EU’s ‘European Green Deal’, which imposes a fee on any product imported from a country that does not have a carbon pricing plan in place. Criticisms about the border carbon tax say that it would discourage international collaboration rather than encourage it.

You might also like: What Countries Have A Carbon Tax?

Is a Shared Responsibility Approach Necessary for Carbon Taxes?

Cramton believes that reciprocity is key in developing policies that drive global climate cooperation. He uses an analogy of a game with a common pot of money; each country has $10, some or all of which the players may simultaneously pledge, and for every $1 (for carbon) that is put into the pot, it is then doubled (by natural climate benefits) and the surplus is redistributed to the recipients.

A referee ensures that they honour their pledges. If individuals are allowed to choose their contributions into the pot, a self-interested member may contribute nothing because they will still reap the benefits, relying on others to contribute to the pot. 

However, with a common commitment version of the game, players condition their contributions on others’ pledges: the referee ensures that they all contribute the amount of the lowest pledge. It is a reciprocal, co-dependent model, but does not say what everyone must do – an ‘I will if you will’ mentality.

No one is forced to contribute more than expected, yet everyone gains. If countries are completely selfish, they cannot lose but only gain if they pledge the lowest pledge. Common commitment policies can convert selfish behaviour from ‘contribute nothing’ to ‘contribute everything’ because the concept protects against free riding. 

To supplement Cramton’s view, a study posits that to be fair for both developed and developing nations, there needs to be a shift away from a production-based approach to a shared responsibility approach in the form of carbon emission ‘burden-sharing schemes’. The production-based principle means that a country should be responsible for all the emissions generated by its production activities within its borders.

The study views this method as outdated in the context of globalisation because it does not take international trade into account. For example, developing countries such as China would take the burden of carbon emissions associated with exporting goods to developed countries. 

Uniform Carbon Pricing

The lack of a central body regulating the implementation of such carbon pricing strategies around the world also hinders this issue of equity. Carbon pricing has been demonstrated as the preferred climate policy instrument, and would also be beneficial to promote international cooperation. To implement carbon pricing globally though, research suggests a ‘global system of harmonised carbon taxes’ rather than one unified global tax so that countries can retain control over revenues. 

Cramton believes in the implementation of a uniform carbon price instead. He compares setting different carbon prices to setting speed limits, saying that “if drivers chose their own speed limits, there would be no use enforcing them because everyone would drive at their desired speed.”

To ensure that enforcement strengthens a collective rather than an individual effort, Cramton proposes a global carbon price commitment decided by a voting majority. It would allow a country to choose how it complies, via taxes, cap-and-trade, or other schemes, as long as the country’s average carbon price (cost per unit greenhouse gas emitted) is at least as high as the agreed price. 

Incentive Fund 

In conjunction with the suggestions above, Economist Raghuram Rajan suggests the creation of a global incentive fund. Rajan posits that there should be a system in place where countries that produce emissions above a defined carbon threshold should have to financially compensate those countries that produce emissions below it.

Essentially, countries that emit more greenhouse gases than others should pay into a fund that rewards low emitters (for example through the Green Climate Fund). Critics of this optimistic, yet idealistic system suggest that it is oversimplistic, failing to take into account other factors such as population growth, existing ecosystems, biodiversity and GDP.

What’s Next For Carbon Tax?

Carbon taxing is just one way of holding large emitters accountable for their role in harming the environment. It represents a departure from the West’s traditional model of letting market forces guide decision-making by allowing governments to mandate emission targets, which is one of the reasons it hasn’t been as widely implemented around the world as it should be. However, if the planet is to have any hope of meeting the Paris Agreement goals, drastic measures that consider both the economic and social wellbeing of nations’ inhabitants must be taken.

You might also like: Cap-and Trade vs Carbon Tax

The post Benefits of A Carbon Tax: A Shared Global Responsibility For Carbon Emissions appeared first on Earth.Org.