We’re seeing the impacts of local weather change in actual time. There’s an pressing want to cut back greenhouse gases (GHGs) within the environment to keep away from extra catastrophic local weather change impacts. It will require each reductions in GHG emissions and the elimination of GHGs from the environment. Lately, this want has pushed curiosity in seaweed as a pure local weather resolution, as seaweed can take up carbon and develop shortly.
However it’s not that easy. Seaweed largely absorbs carbon dissolved in seawater – not atmospheric carbon. Which means situations need to be proper to lead to local weather change advantages. Carbon sequestration by seaweed is variable and troublesome to measure due to the complexity of ocean ecosystems and seaweed carbon processing. There’s nonetheless so much we don’t know.
Final 12 months, EDF convened consultants to establish data gaps that have to be crammed in order that seaweed carbon sequestration could be precisely measured. These findings are summarized in our latest paper. Now we’re filling these data gaps by finishing up analysis on our demonstration seaweed farm within the Philippines.
A serious uncertainty revolves across the results of merchandise made out of seaweed on GHG ranges within the environment. Most seaweed is used to make meals and colloids (the gelatinous stuff in seaweed that’s utilized in numerous merchandise to make them easy and creamy). These don’t sequester a lot carbon as a result of they’ve quick life spans, returning carbon to the environment after they’re used. However meals and colloids should not the one merchandise that may be made out of seaweed.
Our new report, ‘Seaweed Product Evaluation: Course of Maps for Seaweed Merchandise with the Potential to Mitigate Local weather Change’ comprehensively examines the merchandise made out of seaweed and assesses their potential to retailer carbon and keep away from GHG emissions. This report describes how these merchandise are made and the way they might contribute to local weather change mitigation. It’ll function the idea for all times cycle assessments geared toward quantifying the web impacts of those merchandise after accounting for GHG emissions related to producing the seaweed, manufacturing the merchandise, utilizing the merchandise, and disposing of the merchandise. That is a part of our technique geared toward rising the local weather change mitigation advantages of seaweed.
Biostimulants are soil components blended with different merchandise and used to stimulate plant development. Biostimulants made out of seaweed have been noticed to extend crop yield, which might permit farmers to make use of much less fertilizer. If farmers substitute biostimulants for some fertilizer, this could eradicate the emissions of GHGs that may have been launched by making and delivery the fertilizer. However, these local weather mitigation advantages are nonetheless unsure as they’re dependent upon many variable elements, like local weather situations and farmer conduct.
Seaweed could be was development supplies that retailer carbon. Whereas this can be a promising avenue for GHG discount, there are uncertainties in regards to the impacts of constructing, distributing, utilizing and disposing of those merchandise. Storing carbon in such merchandise for many years has an unsure influence on the local weather system. Ideally, carbon could be saved for hundreds of years or millennia.
Sure species of seaweed can cut back methane emissions by cattle when small quantities are included of their feed. As methane is a way more highly effective GHG than carbon dioxide, this could have main optimistic local weather change impacts. Nevertheless, extra analysis is required to research whether or not feeding cattle seaweed has any well being impacts and if it’s a possible long-term technique for methane suppression.
Most moldable is made utilizing petroleum feedstocks, so changing this plastic with seaweed bioplastic might lead to GHG reductions. The marketplace for plastics could be very giant and laws geared toward decreasing plastic waste are creating demand for low-carbon options that don’t degrade into microplastics. The commonest makes use of of seaweed bioplastic are for meals or clothes packaging, which is a gigantic market. These market traits could enhance demand for bioplastics made out of seaweed.
Much like cattle feed, sure seaweed species look like able to suppressing methane emissions from manure. This may very well be important, as manure is a serious supply of methane. However there may be numerous uncertainty for this pathway as only a few research exist.
Many seaweeds could be made into pure fuel and biodiesel. These merchandise may end up in prevented emissions to the extent they exchange fossil fuels and different GHG-intensive sources of biofuels (e.g., corn grown with fertilizers). The marketplace for seaweed-based gasoline is in its infancy, and there are issues over scaling this local weather resolution given prices relative to fossil fuels.
As a result of seaweed can take up heavy metals and accumulate them, it’s attainable to extract heavy metals, important minerals, and uncommon earth components from them. A few of these metals are key parts of batteries and different features of the inexperienced financial system. The choice for accumulating these metals comes from terrestrial or deep-sea mines, that are depending on fossil fuels – to not point out different damaging impacts like habitat destruction, labor abuses, and air pollution. Seaweed heavy steel absorption is carbon impartial or optimistic, so prevented emissions may very well be excessive. The associated fee-effectiveness of extracting important metals from seaweeds stays to be seen.
They already are, a minimum of to some extent. Pure seaweed beds and seaweed farms could also be sequestering a number of hundred million tons of carbon dioxide every year by way of their pure processes. This pure sequestration course of is tough to measure, making carbon financing for these options difficult. Capturing the carbon absorbed by seaweed by making the seaweed into merchandise that may retailer that carbon, exchange GHG-intensive merchandise, or suppress GHG emissions can dramatically enhance the local weather mitigation advantages of pure seaweed beds and farms, and should lead to extra correct quantification of those advantages.
A number of issues and uncertainties should be resolved for this potential to be realized. This contains the consequences of heavy metals absorbed by seaweed on the security and efficacy of seaweed merchandise, the impacts of seaweed-based cattle feeds on cattle well being (and on the security of milk and meat), and excessive prices of manufacturing and different elements that restrict the scaling of those seaweed merchandise.
Simply as we’re seeing the consequences of local weather change in actual time, we’re additionally seeing the speedy growth of potential options. The seaweed resolution will not be so simple as it’d seem, however we expect it’s effectively value exploring.
