Imagine if waste stopped being a problem for companies and became a source of income. This is not a futuristic idea but an increasingly tangible trend.
In a world where natural resources are finite and waste is growing exponentially, the transition towards a circular bioeconomy stands out as an essential pillar for a sustainable future—especially considering that every year, millions of tonnes of agri-industrial by-products, food waste, and organic streams remain underused, despite their high content of carbon, nutrients, and valuable compounds.
10% of food available for consumption in the EU is wasted in the supply and consumption sectors
So much so that it is estimated that around 10% of food available for consumption in the EU is wasted in the supply and consumption sectors (households, food service, and retail), according to Eurostat, the Statistical Office of the European Union. But what if this waste, far from being a problem, could be turned into an opportunity—and become the raw material of the future?
Each year, around 59 million tonnes of food waste are generated in the EU, equivalent to 132 kg per person, with an estimated economic value of €132 billion (Eurostat, 2022). Behind these figures lies an opportunity for innovation: transforming this waste into bioplastics, organic acids, proteins, or biofuels capable of replacing fossil-based derivatives and reducing the industry’s carbon footprint—potentially meeting up to 20% of its demand for basic chemicals with renewable carbon.
20% of the industry’s demand for basic chemicals could be met with renewable carbon
The concept of a circular bioprocess goes beyond recycling. It involves redesigning production flows so that each carbon molecule has more than one life. As highlighted in the European Bioeconomy Strategy (2024–2025), the challenge lies in turning agricultural and urban waste into feedstocks for new bioproducts, thereby reducing impacts on soil, water, and biodiversity.
This momentum is being reinforced by new regulations: the Packaging and Packaging Waste Regulation (PPWR), which will take general effect in August 2026 and requires all packaging to be recyclable or reusable (Design4Recycling). This regulation is creating a ripple effect throughout the value chain, where the demand for bio-based and recyclable materials is growing at an unprecedented pace.
From waste to resource, or how to turn waste into valuable molecules: the technology that makes it possible
Industrial biotechnology is today an essential tool for transforming organic waste, lignocellulosic biomass, or even CO₂ emissions into high value-added molecules. This conversion is achieved through platforms that combine microbiology, catalysis, and green chemistry. In CARTIF’s Biotechnology and Sustainable Chemistry (BQS) area, the process is structured around four main stages:
Smart Pretreatment: The first step is to break down the complex structure of the waste (lignocellulosic biomass, molasses, used oils) through physical, chemical, or enzymatic methods to release sugars and fermentable compounds.
Advanced Fermentation: At this stage, engineered microorganisms convert substrates (sugars, CO₂, syngas) into organic acids, biopolymers, alcohols, or single-cell proteins (SCP). This is a critical step, as productivity, selectivity, and stability determine the feasibility of the process.
Selective Biocatalysis: To convert an intermediate metabolite into a final molecule of interest, specific enzymes or biocatalytic pathways are used. These operate under mild conditions and increase the purity of the final product.
Separation and Purification Stage (Downstream): Membranes, chromatography, ultrafiltration, or spray drying techniques are used to isolate, concentrate, and prepare the product to meet industrial and quality regulatory requirements.
When all these processes are integrated into a biorefinery —which simultaneously produces several bioproducts from a single waste stream— carbon use is maximized, while costs, emissions, and risks associated with fossil raw materials are reduced.
In the Biotechnology area, we work with methodologies based on the development of technologies at the laboratory scale for subsequent scaling up to pilot plant and pre-industrial phases (TRL 2–5). These are accompanied by techno-economic analysis and carbon footprint assessment tools to ensure that innovation is both scalable and transferable to industry and the productive sector.
Technologies that generate value and market
It is not enough for a process to work — it must produce competitive products in terms of volume, cost, and quality. Circular bioprocesses make it possible to access growing industrial markets. Among the bioproducts with the greatest commercial potential are:
Organic acids (lactic, acetic, succinic): building blocks for the chemical, cosmetic, and bioplastics industries.
PHA/PHB biopolymers: biodegradable alternatives with high potential in sustainable packaging.
Microbial proteins: a source of alternative protein for animal feed or aquaculture.
Natural antioxidants and bioactive peptides: high-value ingredients for nutraceuticals and cosmetics.
Bio-oils and biochars: precursors for adhesives, coatings, or porous materials.
The European market has already begun to turn interest into figures: with a high growth rate, competition among biotechnological producers is increasingly focused on niches where local supply chains, sustainability, and traceability are differentiating factors compared to fossil-based plastics.
In 2024, the packaging sector accounted for 45% of the demand for bioplastics in Europe (European Bioplastics). Forecasts point to an annual growth rate of 18% between 2025 and 2030, increasing from 0.67 to 1.54 million tonnes. Other segments, such as bioactive ingredients and technical biopolymers, are also joining this momentum, where traceability and renewable origin have become key competitive advantages.
What CARTIF contributes: infrastructure and risk mitigation
Turning a good idea into a viable industrial project requires an advanced technological platform, flexibility, and expertise in scale-up processes. This is where CARTIF contributes the experience of its highly qualified technical staff and its comprehensive laboratory and pilot plant infrastructure.
The Biotechnology and Sustainable Chemistry (BQS) area has a complete infrastructure that enables the scaling of processes from laboratory to pilot plant, featuring automated fermenters (1–200 liters), pressurized reactors capable of using gases such as CO₂ / H₂ / CO, SCADA systems, and a state-of-the-art analytical laboratory (HPLC, GC-MS, UPLC-MS, FTIR, SEM, TGA, etc.).
With these capabilities, we can simulate industrial conditions, optimize key parameters (yields, productivity, enzymatic/energy costs), and validate feasibility before scaling up.
From idea to project: recommended roadmap
For those working in companies, clusters, or technology centers, this quick guide can help design a strategy to valorize and benefit from by-product and waste streams:
1. Identify your residual streams: analyze their composition, volume, and variability.
2. Define your product portfolio: select one or two “anchor products” plus potential co-products.
3. Choose a technology and develop it with innovation and competitiveness criteria — from laboratory to pilot scale — with clear KPIs such as productivity, titers, and gross/net yield.
4. Conduct economic (TEA) and environmental (LCA) assessments under relevant regulatory scenarios.
5. Secure supply and off-take agreements with suppliers and distributors.
Thanks to its multidisciplinary expertise and collaborative network with companies, CARTIF supports industry throughout the entire development cycle — from waste characterization to pilot validation and techno-economic evaluation — applying an integrated approach that reduces technological risk and accelerates the transfer of results to the market.
📩 Contact us to develop biotechnology solutions tailored to your industry
In summary, biotechnological waste valorization is no longer a futuristic promise: it has become a necessary strategy for companies seeking to stay ahead of regulations, reduce costs or environmental reputation risks, and capture new market niches. With strict regulations such as the PPWR coming into force and ambitious targets set for 2030, those who integrate circular bioprocesses will gain a solid competitive advantage.
Circular bioprocesses offer a real pathway to transform environmental challenges into opportunities for innovation. At CARTIF — and specifically within the BQS area — we work to ensure that every molecule counts, driving a more sustainable, competitive, and knowledge-based industry.
In today’s context, agriculture is increasingly affected by the consequences of climate change. Sudden weather variations—such as torrential rains or unusually high temperatures at atypical times of the year—are contributing to the development of resistance among pests and diseases to conventional chemical treatments. For this reason, the search for natural and sustainable solutions has become a priority. In this scenario, beneficial microorganisms and spontaneous vegetation are emerging as key allies in defending both strategic crops and our urban spaces.
Agricultural soils host millions of microorganisms, such as bacteria and fungi (Trichoderma spp., Bacillus, and Pseudomonas), which, either acting on their own or in symbiosis with plants, play a fundamental role in protection against pests and diseases. These microorganisms act in various ways: they compete with pathogens for nutrients and space, produce antimicrobial compounds that inhibit pathogen action, induce plant defense systems, and improve soil nutrition and structure—thus enhancing the resilience of the plants growing there, including ornamental trees in cities.
Likewise, spontaneous vegetation, traditionally considered ‘weeds’, can be a great ally against pathogens if properly managed. These naturally growing plants, fully adapted to their environment, offer a wide range of benefits that should be exploited. They host natural enemies of pests—such as predatory insects and parasitoids—promote the presence of beneficial microorganisms in the rhizosphere (as they already possess their own microbial ecosystem), act as physical or biological barriers against pathogens, and significantly contribute to the functional biodiversity of ecosystems.
Therefore, incorporating these plants becomes essential to understanding the surrounding ecosystem and using it to generate a natural and effective system of defense against the pests and diseases affecting crops.
Spontaneous vegetation
Interaction between microbiota and spontaneous vegetation
The synergy between both elements is fundamental. Spontaneous vegetation influences the composition of soil microbiota through root exudates and can act as a reservoir for protective microorganisms. Recent studies show that plots with diverse vegetative cover present greater resistance to diseases.
These synergies are being successfully applied in strategic crops such as grapevine, almond, olive, and pistachio, providing resilience and sustainability in the face of adverse climate conditions.
The strategy to ensure this interaction is fully functional and effective involves the identification and inoculation of native microbial consortia—microorganisms fully adapted to the environment and unlikely to be rejected—alongside appropriate management of spontaneous vegetation by creating seed mixes tailored to each crop or context. Moreover, minimizing tillage and maintenance tasks helps reduce energy consumption and our carbon footprint.
Practical applications of spontaneous vegetation in Castilla y León
In Castilla y León, numerous species of spontaneous vegetation have been identified that can be strategically integrated into cultivation systems. Species such as Papaver rhoeas (common poppy), Sinapis arvensis (wild mustard), Plantago lanceolata (ribwort plantain), and Stellaria media (chickweed) are common in dryland areas and field margins. These plants not only compete with invasive species but also provide habitats for beneficial insects and enhance soil biodiversity.
One of the simplest and most practical applications of these natural resources is their implementation in urban areas (Fig. 1), transforming degraded and low-value spaces into high-biodiversity zones that significantly contribute to the human-plant-soil interaction axis.
Fig 1. Degradeed tree pit (left) and blooming tree pit with spontaneous vegetation (right). 2022. Source: Aragon newspaper
The selective management of these species, using techniques such as differential mowing or designing vegetative cover strips, is proving agronomically and ecologically beneficial in recent field trials in cereal, grapevine, and olive crops.
Conclusion: nature as an ally for agricultural sustainability
The integration of beneficial microorganisms and spontaneous vegetation represents an effective strategy for a more natural and sustainable agriculture. Promoting these practices not only helps protect strategic crops and urban gardens but also improves soil health, reduces dependency on chemical inputs, and helps control energy consumption. It is time to view the soil and surrounding environment as our true allies in agricultural protection.
– FAO (2022). *Harnessing the potential of soil biodiversity in agroecosystems*. Food and Agriculture Organization of the United Nations. – Poveda, J., & González-Andrés, F. (2021). *Biological control of plant diseases through the rhizosphere microorganisms: Emerging strategies and challenges*. Frontiers in Microbiology, 12, 671495. – European Commission (2020). *Biodiversity Strategy for 2030: Bringing nature back into our lives*. – Martínez-Hernández, C. et al. (2023). *Vegetation management and soil microbiota interactions in Mediterranean agroecosystems*. Agronomy for Sustainable Development, 43(2).
If my grandma had heard about green marketing, she would have raised an eyebrow saying: “That sounds like they’re selling you the same thing… just with a pine-scented label.”
And if I told her about the recent situation with Ursula von der Leyen, having to confirm her support for the Green Claims Directive after days of confusion in her team, she would say: “Typical, Laura… they say one thing in the morning, the opposite in the afternoon, and in the end, you don’t know if they’re talking about sustainability or horoscopes.”
And honestly, she wouldn’t be wrong.
In recent years, environmental sustainability has become a powerful marketing tool but not always supported by real actions. To stop misleading practices known as “greenwashing”, the European Union has worked on two key directives: the Consumer Empowerment Directive (2024/825), already approved and waiting to be adapted into Spanish law, and the Green Claims Directive, which sets clear rules for making environmental claims that are based on real data. It was planned to start applying from 27 September 2026. But we say was because, just before its final approval, the text was suspended after disagreements in the European Parliament, which has left the proposal at a critical point, now depending on clarification and a common position among EU Member State.
This directive aimed to bring order to the confusing jungle of green labels. The goal: make sure any environmental claim (like “100% recycled” or “carbon neutral”) is checked and supported by solid data, such as a Life Cycle Assessment (LCA). In its most ambitious version, it even required using official methods like Product Environmental Footprint (PEF) or Organisation Environmental Footprint (OEF). But political discussions have diluted the content, and now it risks being forgotten. A shame, because people need protection from greenwashing and honest companies should be acknowledged. This law wasn’t meant to annoy them. Quite the opposite.
” People need protection from greenwashing and honest companies should be acknowledged”
Meanwhile, pressure from consumers and civil organisations is already working. Just look at the recent cases of Coca-Cola and Adidas, who had to step back from their “green” messages after investigations into misleading advertising.
Source: Adidas
In Coca-Cola’s case, a complaint from European consumer and environmental groups led the Commission to act. The company agreed to change phrases like “made with 100% recycled plastic”, because it only referred to the bottle’s body, not the cap or label. Adidas, on the other hand, had to stop advertising a shoe line as “more sustainable” without explaining how or why. These cases show one thing clearly: it’s not enough to use a green leaf or the recycling symbol. It’s not about looking green, you have to prove it.
So, while some still confuse sustainability with decoration, we at CARTIF provide solid technical tools to help companies move towards models that are truly sustainable and transparent. Our Sustainability and Climate Neutrality team has worked for years with companies that want to improve and base their decisions on real, measurable data.
And how do we do that without magic balls or green leaves? With tools like these:
Life Cycle Assessment (LCA): because understanding a product’s environmental impact requires robust calculations based on ISO standards, not just guessing.
Environmental footprinting: starting with carbon (the celebrity of the group), but also including others like acidification or land use… to support decisions that are grounded in real impact, not in excuses.
Eco-labelling and green communication support: because telling the truth also needs practice.
Eco-design strategies: because if something is poorly designed from the beginning, no label can save it. This is where sustainability starts, in the plans, the materials, the packaging… and yes, even in the stylish decisions (with less waste and more purpose).
By combining all these tools, our mission is to help companies move towards models that are not only more environmentally sustainable, but also more honest and consistent. We guide them to measure, improve and communicate (in that order). We want them to share their sustainability story with confidence, and make sure their storytelling matches their storydoing.
And to Úrsula, we ask just one simple (but urgent) thing: don’t leave out the companies doing things right. The ones that choose to measure, improve and communicate with transparency while competing with those selling green smoke.
Because yes, it is possible to talk about sustainability without green make-up. All it takes is rigour, commitment… and a bit of common sense. Just like my grandma had.
Clothing and textile consumption has increase with the expansion of so-called “fast fashion”, giving rise to enromous amounts of waste. In Europe, the European Environment Agency (EEA)1 reports that each EU citizen purchased an average of 19kg of clothing, footwear and household textiles in 2022, up from 17kg in 2019. Furthermore, around 6.94 million tons of textile waste was generated in the EU. However, collection infraestructure has not kept pace with this growth, and most of this waste is not recovered. Only around 15% of textile waste in Europe is collected separately or recycled, meaning the remaining 85% ends up in the trash, incinerated or in landfills without any second life.
In Spain the situation is also worrying. Our country exceeds the European average in fashion consumption, with an estimated generation of nearly 900,000 tons os textile waste per year. According to the Spanish Federation for Recovery and Recycling (FER), only 11% of used clothing in Spain is collected in specific containers. This enormous waste of materials reflects the fact that the vast majority of our used clothes never find a second life.
F
The obstacle of fiber mixtures in traditional recycling
Why is so little clothing recycled? One of the main obstacles is the propper composition of the clothes. It is common that they are confeccionated with fibre mixture, for example, a t-shirt with 50% cotton and 50% polyester, or fabrics that combine synthetic and natural fibres. These mixtures, joint with colour and additives applied to fabrics, difficults the traditional mechanical recycling that consists on TRITURAR the used clothes to obtain reusable fibres.
Why is clothing recycled so little? One of the main obstacles is the composition of the garments themselves. They are often made from blends of fibers, for example, a T-shirt with 50% cotton and 50% polyester, or fabrics that combine polyester with viscose. In fact, most post-consumer textile waste contains combinations of synthetic and natural fibers. These blends, along with the dyes and additives applied to the fabrics, make traditional mechanical recycling, which involves shredding used garments to obtain reusable fibers, extremely difficult.
This process requires fairly pure and uniform waste streams to be successful. If we introduce a blend of cotton and polyester into the shredder, we will obtain a mass of mixed fibers of different natures that cannot be easily spun into new, high-quality yarn. Furthermore, with each recycling cycle, the fibers become shorter and weaker. Therefore, mechanical recycling typically repurposes recovered fibers into lower-value products—a process known as “downcycling”—such as insulation, cushion stuffing, or construction materials, rather than being converted back into clothing.
When a garment contains multiple types of fibers glued together or includes complex chemical treatments, it often cannot be recycled mechanically at all, and that mixed garment ends up directly in the landfill. In short, our current garments are full of mixtures and finishes that traditional recycling can’t separate, and they end up wasted.
Chemical recycling: decompose clothes to recover materials
Faced with this problem, chemical recycling is positioned as a promising solution. Through processes such as selective dissolution or depolymerization, it allows fabrics to be broken down at the molecular level and their basic components recovered: cellulose, plastic monomers, or new regenerated fibers. Instead of shredding or melting, the raw material is “rewound” to “start over.”
Some recent examples show that this technology is already taking steps towards industrial reality. The German startup Eeden, for example, is building a pilot plant to recycle cotton and polyester blends. Its process allows for the recovery of high-purity cellulose from cotton and polyester monomers (such as terephthalic acid), which can be reused in the manufacture of new fibers.
For their part, BASF and Inditex have developed Loopamid®, the first nylon 6 recycled entirely from textile waste. Thanks to a chemical depolymerization and repolymerization process, it is possible to obtain a new polymer with comparable quality to the original, which has already been used to manufacture garment prototypes.
Although still an emerging technology, chemical recycling is demonstrating its ability to close the textile loop even in the most complex cases, and will be key to moving toward truly circular fashion.
Through circular economy in fashion
In short, chemical recycling of textile waste is emerging as a necessary and complementary solution to mechanical recycling to address the fashion waste crisis. Faced with an ever-increasing volume of discarded clothing—and, especially, the challenge posed by mixed-fiber garments, omnipresent in our wardrobes—chemical technologies offer the possibility of recovering materials with original quality, overcoming the limitations of traditional methods. Although they still need to be scaled industrially and reduced in cost, it has already been demonstrated that it is technically feasible to convert a used garment into a new one, separating polymers and removing impurities in the process.
In the future, combining better designs (longer-lasting and more recyclable garments), responsible consumption, efficient collection and sorting systems, and all available forms of recycling will be key to achieving a truly circular economy in the textile sector. In this scenario, chemical recycling will become an essential ally so that that used T-shirt we today consider waste can be “reborn” into high-quality raw materials, reducing the environmental burden of fashion and closing the textile cycle.
In a situation where soil salinity poses a significant threat to global agricultural productivity, scientific research is increasingly focusing on the vital role of soil microorganisms.
According to the Food and Agriculture Organization (FAO), soil salinity is a major challenge for agriculture worldwide, impacting over 20% of arable land. This issue arises from the accumulation of soluble salts, such as sodium, magnesium, and calcium, in the soil, which hinders plants’ ability to absorb water and essential nutrients necessary for their growth. Additionally, suboptimal soil management practices— including excessive irrigation without adequate control, deforestation, and urbanization— exacerbate this challenge. Research indicates that improper irrigation practices can result in salt accumulation due to water evaporation, consequently diminishing crop productivity.
As climate change affects rainfall patterns and increases global temperatures, the increase in salinity is threatening food security and affecting key crops in multiple regions. This situation of overexploitation and mismanagement of water resources not only exacerbates salt stress but also leads to soil degradation, a well-documented issue that diminishes the soil’s capacity for regeneration and directly affects biodiversity and ecosystems.
Impact of salinity on plant development. Source: Global map of salt-affected soils. GSASmap v1.0. 2021, Rome. Food and Agriculture Organization of the United Nations (FAO).
The rise in salinity is one of the most pressing challenge in modern agriculture. The scientific community is proactively tackling this issue by developing innovative solutions. In this regard, Next-Generation Sequencing (NGS) has emerged as a valuable technology. Recent advancements in NGS have allowed researchers to analyze plant genomes with great precision, which has been facilitaterd the identification of key genes linked to salt stress resistance. The integration of NGS with genetic studies has advanced crop improvement through genetic engineering, aiming to transfer salt tolerance traits from halophytes -plants that thrive in high salinity environments- to more susceptible crops. This strategy provides a promising avenue for cultivating more resilient crops, ultimately enhancing agricultural productivity in salt-affected soils and contributing to future food security.
Similarly, Next-Generation Sequencing (NGS) has facilitated substantial advancements in our understanding of soil microbiota, the diverse community of microorganisms (including bacteria, fungi, actinobacteria, and others) that inhabit the soil and are essential for its health and plant development. Metagenomic and bioinformatic studies are offering clearer insights into the microbial diversity found in soils, particularly those impacted by salinity, and how this microbiota can affect plant tolerance to challenging conditions. A well-balanced soil enriched with microbial biodiversity enhances plant resilience under various stressors, thereby improving agricultural productivity. Consequently, understanding and effectively managing soil microbiota -especially in saline environments- emerges as a crucial strategy for fostering more sustainable and efficient agricultural practices.
Next-Generation Sequencing (NGS) process based on soil samples.Source: DeFord, L., Yoon, J.Y. Soil microbiome characterization and its future directions with biosensing. J Biol Eng 18, 50 (2024). doi: 10.1186/s13036-024-00444-1.
The halophilic microbiota found in saline soils plays a vital role in assisting plants in managing salt stress. Utilizing Next-Generation Sequencing (NGS), we can identify and comprehensively characterize the microorganisms present in these environments, particularly those adapted to high salinity. NGS facilitates the mapping of microbial diversity, enabling the identification of specific bacteria and fungi that promote plant growth, as well as assessing their metabolic capabilities. Certain microorganisms, including particular fungi and bacteria, can produce bioactive compounds that serve as protective barriers for plant roots, helping to mitigate the adverse impacts of salinity. This molecular approach presents new opportunities for developing microbial inoculants derived from these beneficial microorganisms, which can be directly applied to saline soils to enhance agricultural productivity in a more sustainable and resilient manner. By adopting these technologies, we can also reduce dependence on chemical products, which, while sometimes effective, may pose risks to ecosystems and human health.
“NGS facilitates the mapping of microbial diversity, enabling the identification of specific bacteria and fungi that promote plant growth, as well as assessing their metabolic capabilities.”
This approach -integrating the study of soil microbiota with Next-Generation Sequencing (NGS) technology– offers a more efficient strategy for addressing salinity while promoting sustainable agricultural practices. It supports long-term soil health and minimizes environmental impact. In this context, soil microbiota emerges as a pivotal ally in confronting one of the most significant agricultural challenges of the 21st century.
From our laboratory at CARTIF, we have the technological capabilities and the necessary expertise to study and characterize both soil microbiota and its interaction with plants under saline stress conditions. Through the use of next-generation sequencing (NGS) tools, bioinformatics analyses, and molecular assays, we can identify beneficial microorganisms that promote soil health and crop resilience, thereby contributing to the development of more sustainable agricultural practices adapted to today’s environmental challenges.
1Global status of salt-affected soils, Foro Internacional del Suelo y el Agua. 2024 Bangkok. Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO).
2 Singh AK, Pal P, Sahoo UK, Sharma L, Pandey B, Prakash A, Sarangi PK, Prus P, Pașcalău R, Imbrea F. Enhancing Crop Resilience: The Role of Plant Genetics, Transcription Factors, and Next-Generation Sequencing in Addressing Salt Stress. Int J Mol Sci. 2024 Nov 22;25(23):12537. doi: 10.3390/ijms252312537.
3 Frąc M, Hannula SE, Bełka M, Jędryczka M. Fungal Biodiversity and Their Role in Soil Health. Front Microbiol. 2018 Apr 13;9:707. doi: 10.3389/fmicb.2018.00707.
4 Mishra A, Singh L, Singh D. Unboxing the black box-one step forward to understand the soil microbiome: A systematic review. Microb Ecol. 2023 Feb;85(2):669-683. doi: 10.1007/s00248-022-01962-5.
5 Pérez-Inocencio J, Iturriaga G, Aguirre-Mancilla CL, Vásquez-Murrieta MS, Lastiri-Hernández MA, Álvarez-Bernal D. Reduction in Salt Stress Due to the Action of Halophilic Bacteria That Promote Plant Growth in Solanum lycopersicum. Microorganisms. 2023; 11(11):2625. doi:10.3390/microorganisms11112625.
6 Adomako MO, Roiloa S, Yu FH. Potential Roles of Soil Microorganisms in Regulating the Effect of Soil Nutrient Heterogeneity on Plant Performance. Microorganisms. 2022 Dec 3;10(12):2399. doi: 10.3390/microorganisms10122399.
When summer arrives and temperatures starts to increase, is frequent making the same question: why in the city center temperatures are higher than in an edification area in a rural environment?
The answer is simple: is due to the urban heat island effect.
But, what urban heat island effect is?
Urban heat island effect is a local climatic phenomenon that causes the built environment to exhibit significantly higher temperatures than the surrounding areas. This effect is especially intensified at night and during the hottest times of the year, such as summer. The occurence of this phenomenon generates negative effects on both the health and quality of life of city dwellers, but also has a considerable impact on vegetation and the urban environment in general, contributing significantly to increasing the effects of climate change.
“Urban heat island effect is a local climatic phenomenon that causes the built environment to exhibit significantly higher temperatures than the surrounding areas.”
The origin of the urban heat island lies in the characteristics of the built environment itself. Materials such as asphalt, concrete and brick absorb radiation and retain heat during the day and release it slowly at night, preventing temperature regulation. This problem is often exarcebated when urban vegetation is reduced or scarce, when the design and orientation of streets limits air circulation and therefore the evacuation of heat accumulated during the day and the existence of anthropogenic emission sources, i.e., heat from vehicles, industries and air conditioning systems. All this contributes to the fact that, on average, the temperature in the city centre can be several degrees higher than in its peryphery or in rural environments.
What effects or negative consecuencies generate about the people life and environment?
Firstly, it has a significant impact on health, since high temperatures can cause general malaise, respiratory problems, sunstroke, dehydration, fatigue and even increased mortality due to heat stroke1. Secondly, there is the need for higher energy consumption due to cooling requirements, which is often associated with higher electricity prices. Thirdly, the urban heat island contributes to a worsening of air quality, aggravating the greenhouse effect problem. Finally, the economic impact it causes should be highlighted, as it can double the losses predicted by climate change.
And to reduce these effects, what measures are efficient in face of the impact of the urban heat island?
Fundamentally, strategies such as the increase in plant surfaces and bodies of water (green and blue infrastructure), where the planting of trees and the creation of urban parks to help regulate the temperature of the environment, or green roofs and vertical gardens that cover buildings with vegetation to improve thermal insulation and reduce surface temperature, are of particular importance. Other strategies include the use of reflective materials (high albedo) that reflect sunlight instead of absorbing it, thus contributing significantly to reducing heat accumulation. However, one of the most efficient measures is proper urban planning through strategies that integrate climatic conditions into the design of the built environment, such as the promotion of a balanced density to ensure energy efficiency, access to services and open spaces without generating thermal overcrowding, the promotion of streets and public spaces aligned with the prevailing winds, allowing natural ventilation while reducing the thermal canyon effect associated with narrow streets. Finally, it is also worth mentioning sustainable mobility strategies, whether through the design of walkable cities, with access to public transportation and non-motorized means, or the promotion of electric vehicles that help reduce the heat emitted by engines.
Although major urban transformations that can generate highly visible impacts of the urban heat island require decisions by governments in collaboration with urban planning experts, every citizen can contribute with his or her small grain of sand to reduce the impact of the urban heat island. Small actions such as planting trees in yards and gardens, opting for light-colored paint for roofs and facades of houses, reducing energy consumption by regulating the thermal comfort of the home, using more public transport, walking or cycling can all make a significant contribution to reducing the impact of the urban heat island. All these measures can make a significant contribution to reducing the heat accumulated in the urban environment. Joint action that integrates small individual actions and large collective initiatives can be presented as the most efficient way to mitigate the urban heat island, which is considered one of the most important challenges of modern urbanization.
From CARTIF, we work to help the different public administrations in the development of solutions, plans and strategies for adaptation to climate change and its effects. It is worth mentioning the project in which we work together with GEOCYL Consultoría S.L. and the Natural Heritage Foundation of Castilla y León (CENCYL_ISLACALOR) in which we have worked on the quantification of the urban heat island effect in three Spanish cities (Valladolid, Salamanca and Ciudad Rodrigo) and five Portuguese cities (Almeida, Aveiro, Coimbra, Guarda and Viseu) of the CENCYL network, in which we also evaluated the impact caused by the increase in temperatures and defined relevant indicators for monitoring. For this purpose, Sentinel 2 and Sentinel 3 images have been used to define high resolution maps (10 meters) for daytime and nighttime surface temperature, which have been integrated into a multi-criteria decision analysis to define in detail the areas with the highest thermal load at city level. In addition, in the CLIMRES andINHERIT projects, we are working on the development of climate services to help reduce the effects of rising temperatures on the building sector and heritage, respectively.
1In 2022 natural disasters in Spain caused 45 deaths, 45% of which were caused by high temperatures. (Source: Aon Spain Foundation based on data from the Ministry of the Interior (2023))
