tag:theconversation.com,2011:/institutions/helmholtz-centre-for-environmental-research-ufz-2929/articlesHelmholtz Centre for Environmental Research-UFZ2024-01-30T10:13:47Ztag:theconversation.com,2011:article/2217902024-01-30T10:13:47Z2024-01-30T10:13:47ZDes produits chimiques dangereux trouvés dans des plastiques recyclés rendent leur utilisation dangereuse : des experts expliquent les risques<p>La pollution plastique est un fléau mondial. On trouve aujourd'hui des plastiques dans tous les <a href="https://pubs.acs.org/doi/10.1021/acs.est.1c04158">environnements</a> de la planète, des mers les plus profondes à l'atmosphère en passant par le corps humain. </p>
<p>Les preuves scientifiques <a href="https://doi.org/10.5334/aogh.4056">décrivant les dommages</a> causés à l'environnement et aux êtres humains sont de plus en plus nombreuses. C'est pourquoi les Nations unies <a href="https://wedocs.unep.org/bitstream/handle/20.500.11822/39812/OEWG_PP_1_INF_1_UNEA%20resolution.pdf">se sont engagées</a> à <a href="https://enb.iisd.org/negotiations/international-legally-binding-instrument-plastics-pollution-including-marine#:%7E:text=The%20United%20Nations%20Environment%20Assembly,pollution%2C%20including%20in%20the%20marine">négocier</a> un instrument juridiquement contraignant pour mettre fin à la pollution plastique. </p>
<p>Les stratégies pour atteindre cet objectif comprennent des dispositions tout au long du cycle de vie des plastiques : production, utilisation, gestion des déchets et recyclage. </p>
<p>Lors de l'élaboration des règles de gestion du plastique, il est important de comprendre la complexité des matériaux plastiques et les flux de déchets sont complexes. Tous les plastiques ne sont pas identiques. Et les plastiques recyclés ne sont pas nécessairement de “qualité supérieure”, c'est-à-dire moins nocifs, que les plastiques vierges. S'ils contenaient des produits chimiques nocifs au départ, le recyclage ne les rend pas moins nocifs. De plus, ils sont parfois contaminés par d'autres substances.</p>
<p>Nous avons mené une <a href="https://www.sciencedirect.com/science/article/pii/S2352340923008090?via%3Dihub">étude</a> pour identifier et mesurer la concentration de contaminants dans les granulés recyclés provenant de 28 installations de recyclage à petite échelle dans le Sud. Les déchets plastiques sont souvent exportés des pays à revenu élevé vers les pays moins développés, avec peu ou pas d'exigences en matière de déclaration de leur composition.</p>
<p>Notre enquête a porté sur des installations situées au Cameroun, à Maurice, au Nigeria, en Tanzanie et au Togo en Afrique, ainsi que sur d'autres en Asie, en Europe et en Amérique du Sud. </p>
<p>Nous avons trouvé 191 pesticides, 107 produits pharmaceutiques et 81 composés industriels, parmi beaucoup d'autres, dans les granulés de plastique recyclés. Nombre de ces produits chimiques pourraient être dangereux et rendre les plastiques inappropriés pour une réutilisation.</p>
<p>Cette découverte peut servir de base à la réglementation sur les plastiques recyclés. La composition chimique du plastique devrait être vérifiée avant qu'il ne soit recyclé. </p>
<h2>Produits chimiques utilisés dans la production de plastiques</h2>
<p>Plus de <a href="https://www.unep.org/resources/report/chemicals-plastics-technical-report">13 000 produits chimiques</a> sont actuellement utilisés dans la production de matériaux et de produits en plastique. Il peut s'agir de milliers d'additifs plastiques, mais aussi de substances ajoutées involontairement. Certains produits chimiques indésirables se forment pendant la production ou la durée de vie des plastiques. Des milliers de ces produits chimiques ont des propriétés dangereuses. Les risques pour la santé de certains autres sont inconnus. </p>
<p>Tout au long de la chaîne de valeur des plastiques, pendant la production, l'utilisation, les déchets et le recyclage, d'autres substances chimiques peuvent également contaminer le matériau. Il peut en résulter des matériaux recyclés dont la composition chimique est inconnue. </p>
<p>Des études antérieures ont signalé la présence d’<a href="https://doi.org/10.1016/j.jhazmat.2017.10.014">additifs plastiques</a> dans les matériaux recyclés. Parmi eux se trouvaient des produits chimiques <a href="https://www.unep.org/explore-topics/chemicals-waste/what-we-do/emerging-issues/endocrine-disrupting-chemicals">reconnus</a> <a href="https://www.epa.gov/endocrine-disruption/overview-endocrine-disruption">pour leurs effets négatifs sur la santé</a>. Il s'agit par exemple des <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0055387">phtalates</a> (plastifiants), des bisphénols comme le <a href="https://www.france-assos-sante.org/2014/04/25/le-bisphenol-a-et-ses-effets-sur-la-sante/">BPA</a> et des <a href="https://polyestershoppen.fr/epoxy/uv-stabilisator-voor-epoxy-350.html">stabilisateurs UV</a> utilisés pour protéger les plastiques contre les dommages causés par le soleil et le jaunissement.</p>
<p>Dans le cadre de nos travaux, nous avons établi la présence dans le plastique recyclé de produits chimiques susceptibles de nuire à l'homme ou à d'autres organismes. Il s'agit notamment de pesticides, de produits pharmaceutiques et de parfums. D'autres sont des produits chimiques résultant de la combustion de matériaux naturels, des produits chimiques organiques fabriqués par l'homme et utilisés dans des applications industrielles telles que la peinture, et des filtres ultraviolets.</p>
<p>Nous avons quantifié un total de 491 substances chimiques différentes. Certaines avaient des utilisations spécifiques et d'autres se formaient à partir de la décomposition de produits.</p>
<p>Certaines politiques nationales et régionales <a href="https://www.basel.int/Implementation/Plasticwaste/Globalgovernance/tabid/8335/Default.aspx">réglementent</a> la concentration autorisée de produits chimiques dangereux dans des produits plastiques spécifiques. Mais seulement 1 % des substances chimiques contenues dans les plastiques font l'objet d'une réglementation internationale dans le cadre des accords multilatéraux sur l'environnement existants. Les politiques n'abordent pas de manière adéquate la question de la transparence des rapports sur les produits chimiques contenus dans les plastiques tout au long de leur chaîne de valeur. Il n'existe pas non plus de lois régissant la surveillance des produits chimiques dans les matériaux recyclés. Il s'agit d'une <a href="https://www.science.org/doi/10.1126/science.adk9846">grave lacune</a> en matière de surveillance. Des mesures plus fortes et mieux coordonnées au niveau mondial sont nécessaires. </p>
<p>Nos résultats soulignent l'importance de réglementer le recyclage mécanique, car de nombreuses substances mesurées étaient des contaminants et non des additifs plastiques. Bon nombre des substances chimiques que nous avons identifiées peuvent avoir contaminé les matériaux au cours de leur utilisation. Par exemple, une cruche utilisée pour stocker des pesticides absorbera une partie des pesticides et contaminera le flux de déchets de recyclage. Il est également reconnu que les plastiques ont la capacité d'absorber les <a href="https://www.sciencedirect.com/science/article/pii/S0025326X11005960">polluants organiques</a>. </p>
<p>Pour évaluer la qualité des plastiques recyclés, il est essentiel de connaître les substances chimiques présentes et leurs concentrations. Ces informations peuvent orienter les réglementations relatives à l'utilisation des plastiques recyclés. Elles seront également précieuses pour les producteurs de plastiques, les personnes chargées de la gestion des déchets (y compris les recycleurs), les consommateurs et la communauté scientifique.</p>
<h2>Une voie vers une réutilisation plus sûre des plastiques</h2>
<p>Pour recycler davantage de matériaux en toute sécurité, plusieurs changements sont nécessaires. Il s'agit notamment de :</p>
<ul>
<li><p>une plus grande transparence concernant l'utilisation des produits chimiques et leurs risques </p></li>
<li><p>une simplification chimique du marché des plastiques, de sorte que les produits chimiques autorisés à être utilisés soient moins nombreux et moins toxiques</p></li>
<li><p>l'amélioration de l'infrastructure de gestion des déchets avec des flux de déchets séparés </p></li>
<li><p>l'amélioration des méthodes de recyclage, y compris le contrôle des produits chimiques dangereux.</p></li>
</ul>
<p>La simplification chimique des additifs plastiques favorisera la durabilité, la sécurité et le respect de la réglementation. Elle aidera les fabricants à minimiser l'impact sur l'environnement et les effets néfastes sur la santé des formulations chimiques complexes. Des structures chimiques plus simples améliorent également le potentiel de recyclage des plastiques et rendent le recyclage plus efficace et plus rentable.</p>
<p>La <a href="https://pubs.acs.org/doi/full/10.1021/acs.est.1c04903">simplification chimique</a> peut également réduire les risques potentiels pour la santé liés à l'élimination des matières plastiques. </p>
<p>D'un point de vue réglementaire, la simplification chimique favorise l'élaboration de lignes directrices plus claires et plus faciles à appliquer en matière de sécurité.</p>
<p>Il s'agit d'une étape cruciale vers la production et l'utilisation durables des plastiques, à l'heure où les pays s'efforcent de mettre en place un instrument juridique pour mettre fin à la pollution.</p><img src="https://counter.theconversation.com/content/221790/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bethanie Carney Almroth est financée par le Conseil suédois de la recherche pour le développement durable FORMAS (numéro de subvention 2021-00913) et la Fondation Carl Tryggers (numéro de subvention 21:1234).</span></em></p><p class="fine-print"><em><span>Eric Carmona Martinez a reçu un financement de la Fondation Carl Trygger.</span></em></p>Les plastiques recyclés ne sont pas sûrs si les produits chimiques utilisés pour les créer sont nocifs.Bethanie Carney Almroth, Associate Professor, Department of Biological and Environmental Sciences, University of GothenburgEric Carmona Martinez, Scientist, Helmholtz Centre for Environmental Research-UFZLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2204982024-01-16T14:14:16Z2024-01-16T14:14:16ZDangerous chemicals found in recycled plastics, making them unsafe for use – experts explain the hazards<p>Plastic pollution is a menace worldwide. Plastics are now <a href="https://www.science.org/doi/10.1126/science.abg5433">found</a> in every <a href="https://pubs.acs.org/doi/10.1021/acs.est.1c04158">environment</a> on the planet, from the deepest seas to the atmosphere and human bodies. </p>
<p>Scientific evidence <a href="https://doi.org/10.5334/aogh.4056">describing harm</a> to the environment and humans is growing. Hence, the United Nations has <a href="https://wedocs.unep.org/bitstream/handle/20.500.11822/39812/OEWG_PP_1_INF_1_UNEA%20resolution.pdf">resolved</a> to <a href="https://enb.iisd.org/negotiations/international-legally-binding-instrument-plastics-pollution-including-marine#:%7E:text=The%20United%20Nations%20Environment%20Assembly,pollution%2C%20including%20in%20the%20marine">negotiate</a> a legally binding instrument to end plastic pollution. </p>
<p>Strategies to achieve this goal include provisions throughout the plastics lifespan: production, use, waste management and remediation. </p>
<p>In designing rules for managing plastic, it’s important to understand that plastic materials and waste streams are complex. Not all plastics are the same. And recycled plastics are not necessarily “better” – less harmful – than virgin plastics. If they contained harmful chemicals to begin with, recycling doesn’t make them less harmful. And sometimes they are contaminated by other substances.</p>
<p>We conducted a <a href="https://www.sciencedirect.com/science/article/pii/S2352340923008090?via%3Dihub">study</a> identifying and measuring the concentration of contaminants in recycled pellets from 28 small-scale recycling facilities in the global south. Plastic waste is often exported from high income countries to less developed countries, with few to no requirements for reporting their makeup.</p>
<p>Our investigation covered facilities in Cameroon, Mauritius, Nigeria, Tanzania and Togo in Africa as well others in Asia, Europe and South America. </p>
<p>We found 191 pesticides, 107 pharmaceuticals and 81 industrial compounds among many others in the recycled plastic pellets. Many of these chemicals could be hazardous and make the plastics unsuitable for reuse.</p>
<p>This finding can inform regulations for recycled plastics. The chemical composition of the plastic should be checked before it is recycled. </p>
<h2>Chemicals used in production of plastics</h2>
<p>More than <a href="https://www.unep.org/resources/report/chemicals-plastics-technical-report">13,000 chemicals</a> are currently used in the production of plastic materials and products. They can include thousands of plastics additives – but also substances that are added unintentionally. Some unwanted chemicals form during the production or life of plastics. Thousands of these chemicals have dangerous properties. The health risks of some others are unknown. </p>
<p>Throughout the plastics value chain, during production, use, waste and recycling, other chemicals can contaminate the material too. The result may be recycled materials whose chemical composition is unknown. </p>
<p>Previous studies have reported the presence of <a href="https://doi.org/10.1016/j.jhazmat.2017.10.014">plastics additives</a> in recycled materials. Among them were chemicals that are <a href="https://www.unep.org/explore-topics/chemicals-waste/what-we-do/emerging-issues/endocrine-disrupting-chemicals">known</a> to have <a href="https://www.epa.gov/endocrine-disruption/overview-endocrine-disruption">negative effects on health</a>. Examples include <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0055387">phthalates</a> (plastic softeners), bisphenols like <a href="https://www.sciencedirect.com/science/article/pii/S0303720706002292">BPA</a>, and <a href="https://www.sciencedirect.com/science/article/pii/S0048969721044478?via%3Dihub">UV-stabilisers</a> used to protect plastics from sun damage and yellowing.</p>
<p>In our work, we established the presence of chemicals in recycled plastic that can cause harm to humans or other organisms. They include pesticides, pharmaceuticals and fragrances. Others are chemicals that result from burning natural materials, man-made organic chemicals used for industrial applications like paint, and ultraviolet filters.</p>
<p>We quantified a total of 491 different chemical substances. Some had specific uses and others formed from the breakdown of products.</p>
<p>Some national and regional policies <a href="https://www.basel.int/Implementation/Plasticwaste/Globalgovernance/tabid/8335/Default.aspx">regulate</a> the allowable concentration of hazardous chemicals in specific plastic products. But only 1% of plastics chemicals are subject to international regulation in existing multilateral environmental agreements. Policies don’t adequately address the issue of transparent reporting of chemicals in plastics across their value chain. Also, there are no laws to govern monitoring of chemicals in recycled materials. This is a <a href="https://www.science.org/doi/10.1126/science.adk9846">serious gap</a> in oversight. Stronger and more globally coordinated measures are necessary. </p>
<p>Our findings emphasise the importance of regulating mechanical recycling, as many of the substances measured were contaminants and not plastic additives. Many of the chemicals we identified may have contaminated the materials during use. For example, a jug used for storing pesticides will absorb some of the pesticides and will contaminate the recycling waste stream. Plastics in the environment are also known to absorb <a href="https://www.sciencedirect.com/science/article/pii/S0025326X11005960">organic pollutants</a>. </p>
<p>To assess the quality of recycled plastics, it’s crucial to know which chemicals are present and in what concentrations. This information can guide regulations about how recycled plastics may be used. It will also be valuable for plastics producers, waste management workers (including recyclers), consumers, and the scientific community.</p>
<h2>A path towards safer reuse of plastics</h2>
<p>To recycle more materials safely, several changes are necessary. These include:</p>
<ul>
<li><p>increased transparency regarding the use of chemicals and their risks </p></li>
<li><p>chemical simplification of the plastics market, so that fewer and less toxic chemicals are permitted for use</p></li>
<li><p>improved waste management infrastructure with separated waste streams </p></li>
<li><p>improved recycling methods, including monitoring of hazardous chemicals.</p></li>
</ul>
<p>Chemical simplification of plastic additives will promote sustainability, safety and regulatory compliance. It will help manufacturers to minimise the environmental impact and adverse health effects of complex chemical formulations. Simpler chemical structures also improve the recycling potential of plastics and make recycling more efficient and cost-effective.</p>
<p><a href="https://pubs.acs.org/doi/full/10.1021/acs.est.1c04903">Chemical simplification</a> can also reduce potential health risks in the disposal of plastic materials. </p>
<p>From a regulatory perspective, chemical simplification supports clearer and more enforceable safety guidelines.</p>
<p>It’s is a crucial step towards the sustainable production and use of plastics, as countries work towards a legal instrument to end pollution.</p><img src="https://counter.theconversation.com/content/220498/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bethanie Carney Almroth receives funding from the Swedish Research Council for Sustainable Development
FORMAS (grant number 2021-00913) and The Carl Tryggers Foundation (grant number 21:1234).
</span></em></p><p class="fine-print"><em><span>Eric Carmona Martinez received funding from Carl Trygger Foundation. </span></em></p>Recycled plastics are not safe if the chemicals used in creating them in the first place are harmful.Bethanie Carney Almroth, Associate Professor, Department of Biological and Environmental Sciences, University of GothenburgEric Carmona Martinez, Scientist, Helmholtz Centre for Environmental Research-UFZLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1517992021-07-01T16:56:18Z2021-07-01T16:56:18ZTen talismans for a new understanding of cities in post-pandemic times<figure><img src="https://images.theconversation.com/files/409177/original/file-20210630-21240-9ibvts.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C1386%2C1033&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Urban green spaces are essential for the well-being of both human and and non-human residents of a city. </span> <span class="attribution"><span class="license">Fourni par l'auteur</span></span></figcaption></figure><p>For more than a year and a half, the SARS-CoV-2 pandemic has kept the world locked down. Schools, universities, cafés and restaurants, cultural institutions and stores have been closed for long stretches of 2020 and 2021. In many parts of the world, travel has slowed to a crawl and sometimes stopped completely. While the number of flights is climbing as some restrictions are lifted, they remain <a href="https://www.icao.int/sustainability/Pages/Economic-Impacts-of-COVID-19.aspx">significantly lower</a>. Even 18 months later, it feels as if life itself has come to a relative standstill. </p>
<p>Mandatory <a href="https://theconversation.com/cities-are-at-centre-of-coronavirus-pandemic-understanding-this-can-help-build-a-sustainable-equal-future-136440">social distancing and movement restrictions</a> have profoundly changed what we could do, particularly for those living in cities across the globe. At the same time, <a href="https://www.thenatureofcities.com/2020/05/04/enabling-access-to-greenspace-during-the-covid-19-pandemic-perspectives-from-five-cities/">green spaces within urban areas</a> allowed city dwellers to get some air and compensate for the absence of holiday and travel options. As car travel fell, flora and fauna were even able to (temporarily) make a <a href="https://www.bbc.com/news/world-52459487">surprise return to urban centres</a>.</p>
<h2>Reflections from urban scholars</h2>
<p>During the last year, urban scholars – be they planners, ecologists, social geographers, or risk researchers – have had the opportunity reflect upon the following issues: </p>
<ul>
<li><p>The process, form, density and extent of <a href="https://www.nature.com/articles/s41893-019-0436-6">urbanisation</a> and the related loss or regeneration of ecosystems inside and around cities.</p></li>
<li><p>The extent and accessibility of green spaces in cities for recreation, public health and refuge.</p></li>
<li><p>How nature and humans are <a href="https://www.nature.com/articles/s42949-020-00008-4">co-habiting</a> and what we can do to prevent <a href="https://link.springer.com/article/10.1007/s13280-016-0809-2">future zoonoses</a>.</p></li>
<li><p>The role that science-based facts, expert knowledge and social media have in shaping the public discourse about cities, and their material and immaterial matter.</p></li>
</ul>
<p>Here are 10 premises – I call them “talismans” to emphasise that they’re opportunities – that can act as a guide to reflecting about the above issues.</p>
<h2>1. Co-habitational distancing, not social distancing</h2>
<p>Humans and nature should go for a new kind of <a href="https://link.springer.com/article/10.1007/s13280-020-01449-y">co-habitational distancing</a> based on mutual respect. During the pandemic, we have learned what social distancing is – to keep distance to safeguard the others. This was a good and a successful strategy, but we applied this strategy exclusively to the human society. Following the idea of <a href="https://theconversation.com/the-one-health-concept-must-prevail-to-allow-us-to-prevent-pandemics-148378">One Health</a>, we should extend the idea of distancing to all living creatures on our planet. This would help preserve ecosystems and safeguard their health, and in so doing, safeguard ours. </p>
<p>Mutual respect means distancing as humans and animals spheres overlap and let them interact, but not in most cases and not everywhere. Co-habitational distancing means sharing land for common needs as well as spare land for individual interests and needs.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388592/original/file-20210309-15-7ducus.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Green spaces give human, animals and plants a place to breath.</span>
<span class="attribution"><span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<h2>2. Encourage co-habitation of nature and humans in cities</h2>
<p>Diverse cities must be exactly that. They require a respectful attitude for all human beings as well as nonhuman beings. In a <a href="https://www.cogitatiopress.com/urbanplanning/article/view/1901">superdiverse city</a>, space is required. This is what we learned for humans – Setha Low’s <a href="https://www.researchgate.net/publication/285787631_Public_space_and_diversity_Distributive_procedural_and_interactional_justice_for_parks">“Public space and diversity”</a> is a key text – and the same is true for the other creatures with whom we share this planet. </p>
<p>In cities we already have excellent forms that enable us to realise different intensities of <a href="https://link.springer.com/article/10.1007/s13280-020-01449-y">human-nature co-habitation</a> – gardens, urban parks, zoological gardens, brownfields and nature reserves are all spaces that allow for either cohabitation or distancing.</p>
<h2>3. Guaranteeing rights not only for city dwellers, but also for nature</h2>
<p>The pandemic clearly revealed the double standards we have about humans (societies) and nature (ecosystems). We must drop this double standard and work to <a href="https://en.wikipedia.org/wiki/Reconciliation_ecology#:%7E:text=Reconciliation%20ecology%20is%20the%20branch,biodiversity%20in%20human%2Ddominated%20ecosystems">ensure rights for both humans and nature</a>. We must also invest the time and effort required to explore what are rights of nature not only in the establishment of reserves and national parks but also in daily co-habitation.</p>
<h2>4. Cities can show how we can reduce land, material and food consumption</h2>
<p>Getting healthier and happier while demanding less from nature is essential for us keep more core habitats intact. For decades, urban ecologists have dealt with core habitats and buffer zones. We have the theoretical knowledge, but we betray this knowledge with misguided ideas of endless growth and higher and higher per-capita living. </p>
<p>But there is hope: In cities such as New York, <a href="https://theconversation.com/cities-are-at-centre-of-coronavirus-pandemic-understanding-this-can-help-build-a-sustainable-equal-future-136440">land prices have soared</a> and per-capita living space has dramatically declined. In such dense urban areas, can we find approaches that will enable us to preserve space for nature? All organisms need space, after all – humans for housing and animals for hunting and nesting. Significant undisturbed ecosystems would be the best strategy for preserving the quality of life as well as reducing the chance of future pandemics.</p>
<h2>5. Learning from what the arrival of Covid-19 is telling us</h2>
<p>Rethinking the ability to access basic resources, wealth and education is essential. Urban societies can enable all their residents have better health and escape poverty. This in turn will reduce susceptibility to the pandemics and root out the inequalities in our societies that lead to overproduction, food waste, malnutrition and obesity and extreme urbanisation, all at once. Here too, Setha Low’s <a href="https://www.researchgate.net/publication/285787631_Public_space_and_diversity_Distributive_procedural_and_interactional_justice_for_parks">three-dimensional concept</a> is essential.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/409180/original/file-20210630-21240-48gj05.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Manchester street scene.</span>
</figcaption>
</figure>
<h2>6. Reasoning from what happened and concluding from factual evidence</h2>
<p>In pandemic and post-pandemic times, it is worth asking questions as a way to provokes deeper learning. In similar times, what did our ancestors do? What can we see in the shape and morphology of cities that were witnesses to past pandemics? What can urban history and city regulations and planning literature tell us about earlier solutions to pandemic situations? What worked and what did not? Are there tipping points? Are there points of return?</p>
<h2>7. Make evidence the base of policy advice and decisions</h2>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S1618866718303352?via%3Dihub">Green cities</a> could be a sustainable, space-saving way for humans to settle at this planet, including green roofs, rooftop gardens and “living walls”. But unless developed in a smart and comprehensive way, they won’t be enough to compensate for global ecosystems loss – the decline of Brazilian tropical rain forests’ for soybean fields or the clear-cutting in South East Asia for palm-oil plantations, for example. The levels of both impacts – global and local – do not fit, and nor do the benefits and burdens hit the global urban and rural populations in a similar/equal way (<em>Haase</em>, 2020).</p>
<h2>8. Social media data can build awareness our urban social-ecological systems</h2>
<p>Data gathered by citizen scientists and shared through social media can provide a wealth of information (<a href="https://static1.squarespace.com/static/552ec5f5e4b07754ed72c4d2/t/5be1dae270a6adf7bb5a6609/1541528292607/ilieva+and+mcphearson_+nature+sustainabilty+2018.pdf"><em>Ilieva and McPhearson</em>, 2014</a>. What new plants and insects have arrived? Where do animals show irregular behaviour? What species have disappeared? The direct, almost real-time input that local administrations can obtain has the potential to establish more meaningful connections between citizens and institutions, as well as between citizens and the nature around them. This will bringing new synergies to the management of urban ecosystems and the vital services it provides to humans and other living organisms in the city. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=314&fit=crop&dpr=1 600w, https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=314&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=314&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=394&fit=crop&dpr=1 754w, https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=394&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/409181/original/file-20210630-21256-hrj1mq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=394&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chequamegon, Nicolet National Forest.</span>
<span class="attribution"><a class="source" href="https://www.wpr.org/tribal-forests-more-diverse-sustainable-surrounding-forests">Joshua Mayer/WPR</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>9. Use traits to expand our understanding of environmental changes</h2>
<p>Through their direct relation to ecosystem services such as cooling and fresh air, easy-to-understand <a href="https://www.nature.com/articles/s42949-020-00008-4">traits</a> can be an entry point for awareness of nature. To do so, it is vital for us to understand the diverse characteristics of urban society, including cultural background, physical mobility, gender, age, education levels, access to information, purchasing power and political influence. All these factors affect the needs, preferences, and values of individuals and groups, and the way each interpret human-nature relationships. </p>
<p>Large-scale monitoring needs to be coupled with <a href="https://www.sciencedirect.com/science/article/pii/S0169204620308860">in-depth understanding of response mechanisms and their impact on ecosystem functions</a>. Only by taking all these factors into account can we create more inclusive urban systems that foster multiple benefits for both people and biodiversity.</p>
<h2>10. Understand cities as complex systems at all scales</h2>
<p>Cities are complex systems from their smallest unit up to the largest. This includes:</p>
<ul>
<li><p>Individuals: personal perceptions, behaviour and activism.</p></li>
<li><p>Local areas: neighbourhood greening initiatives, urban gardening, <a href="https://link.springer.com/article/10.1007%2Fs13280-014-0506-y">nature stewardship</a></p></li>
<li><p>Districts : environmental justice, access to public green spaces</p></li>
<li><p>Cities: periurbanization and cities’ involvement in <a href="https://www.ufz.de/index.php?en=20939&pub_id=22205">urban telecouplings</a> and <a href="https://www.pnas.org/content/109/20/7687">teleconnections</a>, politicians and parties that promote nature-destroying policies, investors funding the heedless exploitation of nature. </p></li>
</ul>
<p>Taken together, these 10 “talismans” can guide us when reflecting about the challenging times in which we’re all living. In particular, they can help us understand how the form, density and extent of urbanisation interact with ecosystems at every level, driving positive or negative change. We think too rarely about feedback loops, too often we ignore the cognitive gap, too often we follow linear thinking schemes despite the fact that we know better – and must do better. </p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Created in 2007, the Axa Research Fund supports more than 500 projets around the world conducted by researchers from 51 countries. Find out more about Dagmar Haase’s work on the <a href="https://www.axa-research.org/en/projects/haase-dagmar">dedicated site</a></em>.</p><img src="https://counter.theconversation.com/content/151799/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dagmar Haase has received funds for her research from the Axa Research Fund.</span></em></p>As we look beyond a world besieged by Covid-19, the relationship between humans and nature in our cities must be shaped and reclaimed.Dagmar Haase, Professor of Landscape Ecology, Humboldt Universität zu Berlin, Helmholtz Centre for Environmental Research-UFZLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/917902018-02-19T22:09:25Z2018-02-19T22:09:25ZInondations et canicules : quelles solutions pour y faire face en ville ?<p>Janvier 2018 : Paris boit à nouveau la tasse. La Seine et la Marne sont <a href="http://www.bbc.com/news/world-europe-42856634">sorties de leur lit</a>, obligeant certains habitants de la banlieue à regagner leur domicile en barque, tandis que le célèbre zouave du pont de l’Alma se pare d’un <a href="https://www.reuters.com/news/picture/paris-under-water-idUSRTX4NY5Y">gilet de sauvetage</a>. La montée des eaux a également suscité de vives inquiétudes <a href="http://www.euronews.com/2018/01/26/lyon-s-twin-rivers-threaten-floods-as-rhone-saone-rise">autour de Lyon</a> et dans les environs de Strasbourg, où le Rhin a atteint des niveaux préoccupants.</p>
<p>Et si cette situation devenait la norme ? <a href="https://phys.org/news/2018-01-global-poses-substantial-central-western.html">D’après certaines études</a>, le coût des dégâts liés aux inondations en Europe devrait plus que doubler en raison du réchauffement climatique pour s’établir à quelque 15 milliards d’euros.</p>
<p>Dans nos régions, ces inondations dévastatrices et coûteuses <a href="http://science.sciencemag.org/content/357/6351/588">seront désormais monnaie courante</a>, et ce même si nous réussissons à maintenir limiter ce réchauffement à moins de 1,5 °C, comme le recommande l’<a href="https://theconversation.com/fr/topics/paris-agreement-23382">Accord de Paris</a>.</p>
<p>Les villes européennes risquent dans les années à venir d’être écrasées par des vagues de chaleur qui céderont la place à des épisodes pluvieux extrêmes, donnant du fil à retordre aux urbanistes et aux services de santé. Pour éviter ces périls, les <a href="http://www.euronews.com/2018/02/02/rising-sea-levels-threat-a-shrinking-european-coastline-in-2100">villes devront entièrement revoir leur politique</a>. Si la réduction des émissions de gaz à effet de serre est essentielle pour ne pas aggraver les dérèglements climatiques, d’autres options s’offrent également aux municipalités pour faire face à ces aléas.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"960097098166341632"}"></div></p>
<h2>Informer la population</h2>
<p>Il est primordial d’informer la population des vagues de chaleur à venir, par toutes les sources de communication et d’information possibles. Les applis et les réseaux sociaux tels que WhatsApp ou Facebook peuvent en effet s’avérer très pratiques, à condition d’être utilisés de façon cohérente, comme l’expliquent des spécialistes des sciences sociales chargés d’observer la <a href="https://www.scientificamerican.com/article/how-social-media-is-changing-disaster-response/">réaction des réseaux sociaux aux catastrophes</a> en <a href="http://heroicproject.org/">Californie</a>.</p>
<p>Les infrastructures du quotidien, comme les supermarchés, les pharmacies et les cafés, peuvent aussi se révéler très utiles. À Vienne, les <a href="http://wiev1.orf.at/stories/377527">églises ont ainsi accueilli touristes et habitants</a> pendant les vagues de chaleur de 2015 et 2017.</p>
<p>Des <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168875/">services d’information mobiles</a> doivent être mis en œuvre pendant les épisodes caniculaires afin d’aider les services de santé et les travailleurs sociaux à localiser les personnes âgées, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3536512/">souvent isolées</a> et <a href="http://inpes.santepubliquefrance.fr/CFESBases/catalogue/pdf/1033.pdf">particulièrement vulnérables</a> aux fortes températures. Rappelons qu’en France, la <a href="https://www.senat.fr/rap/r03-195/r03-19515.html">canicule de 2003</a> avait fait des milliers de victimes parmi ces classes d’âge.</p>
<p>Dans cet esprit, la Poste a lancé à l’été 2017 un <a href="http://www.lemonde.fr/societe/article/2017/05/24/veiller-sur-mes-parents-le-service-que-generalise-la-poste-inquietent-les-facteurs_5133079_3224.html">projet pilote</a> proposant à ses clients un service payant d’aide pour leurs proches isolés.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mur végétal à Milan, 2015.</span>
<span class="attribution"><a class="source" href="https://pixabay.com/en/exhibition-milan-2015-1157790/">faverzani/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Végétaliser les espaces urbains</h2>
<p><a href="https://www.springer.com/fr/book/9789400770874">Les trames bleues et vertes</a>, futures normes en matière de planification et de construction, permettent de réintroduire des éléments naturels au sein des bâtiments. Elles consistent à multiplier les étendues d’eau et à créer des zones spécifiquement inondables (dans les zones humides de la Seine, par exemple) ou des endroits où l’eau peut stagner. <a href="http://www.sciencedirect.com/science/article/pii/S2212613915000112">Ce type de solution technologique</a> peut convenir dans les cas où les zones humides ou riveraines sont indisponibles ou totalement remblayées.</p>
<p>La présence de la végétation permet en effet d’affronter la chaleur et les fortes précipitations par filtration, absorption, percolation et écoulement. Les sols non artificialisés des parcs, cimetières et jardins publics remplissent parfaitement ce rôle, de même que les toits et murs végétalisés. Véritables « tampons thermiques », ils permettent de rafraîchir les zones fortement urbanisées.</p>
<p>C’est également le cas des immeubles écologiques et autres <a href="http://bit.ly/2sFBkod">jardins de pluie</a> courants à Milan ; ceux-ci se sont avérés par exemple très utiles à New York, en absorbant <a href="http://www.corriere.it/ambiente/15_marzo_31/rain-garden-bombe-acqua-giardini-pioggia-ec2ddfae-d7bc-11e4-82ff-02a5d56630ca.shtml">près de 50 % des précipitations ambiantes</a>.</p>
<p>Autre option de végétalisation : les anciens terrains industriels à convertir en vastes parcs publics et espaces verts, comme ces fermes urbaines installées <a href="https://www.deutschland.de/en/topic/business/innovation-technology/urban-farming-in-the-middle-of-berlin">dans le centre de Berlin</a>, à <a href="http://www.cityfarmer.info/2009/10/04/investigating-the-potential-for-the-expansion-of-urban-agriculture-in-the-city-of-edinburgh/">Édimbourg</a>, Malmö ou encore <a href="http://annalinde-leipzig.de/blog/urban-farming-conference-2017/">Leipzig</a>. Autre solution, les <a href="https://www.grownyc.org/openspace/green-infrastructure-toolkit/bioswales">rigoles de drainage biologiques</a> ; ces canaux linéaires recouverts de végétation ont été spécialement conçus pour atténuer et traiter le ruissellement des eaux pluviales.</p>
<p>La présence d’arbres contribue tout autant à combattre la chaleur, les fortes précipitations et les émissions dues au transport automobile (particules, oxyde d’azote).</p>
<p>Toutes ces techniques concourent à bâtir des <a href="https://www.geographie.hu-berlin.de/en/professorships/landschaftsoekologie-en/standardseite?set_language=en">villes dites « résilientes »</a>.</p>
<figure>
<iframe src="https://player.vimeo.com/video/67238469" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Le principe des rigoles de drainage biologiques.</span></figcaption>
</figure>
<h2>S’adapter, expérimenter</h2>
<p>Au-delà de ces considérations techniques, il faut aussi souligner la dimension politique de l’aménagement urbain au sein des villes résilientes : c’est ici l’ensemble des habitants qui doit pouvoir accéder gratuitement, dans le cadre d’un service municipal et public, aux informations nécessaires à l’atténuation du risque de catastrophe.</p>
<p>Élémentaires, ces méthodes compléteront des solutions écologiques plus techniques, à l’image des mesures de prévention des inondations instaurées à Vienne ou Cologne et <a href="https://www.ecologyandsociety.org/vol21/iss2/art39/">qui ont fait leurs preuves</a>.</p>
<p>En Allemagne, après les <a href="https://link.springer.com/chapter/10.1007/978-90-481-3167-9_18">crues désastreuses de l’Elbe au cours des deux dernières décennies</a>, les digues ont ainsi été déplacées et modifiées pour élargir la plaine inondable naturelle et laisser plus de place au fleuve. <a href="https://www.theguardian.com/world/2013/jun/09/german-floods-elbe-thousands-evacuated">Malgré tout, le barrage a cédé il y a quatre ans</a>.</p>
<p>C’est la raison pour laquelle d’autres villes appliquent la stratégie inverse : accueillir l’eau, au lieu de la retenir. C’est le cas à Hambourg, qui <a href="https://www.citylab.com/environment/2017/06/hamburg-germany-climate-change-floods-elbe-river/529629/">envisage de créer une nouvelle plaine inondable</a> pour l’Elbe afin de rétablir « un certain équilibre naturel dans sa zone portuaire », soumise à des conditions difficiles depuis un demi-siècle en raison d’un trafic maritime intense.</p>
<p>S’il est certain que des rigoles de drainage ou du gazon planté le long d’une plaine inondable paraissent bien dérisoires face à une crue centennale, ces solutions peuvent néanmoins la ralentir et en réduire les pics, laissant ainsi plus de temps à la population pour réagir.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Créé en 2007, Axa Research Fund soutient plus de 500 projets à travers le monde portés par des chercheurs de 51 nationalités.</em>
<em>Pour en savoir plus sur le travail de Dagmar Haase, rendez-vous sur le site du <a href="https://www.axa-research.org/fr/projets/haase-dagmar">Axa Research Fund</a>. Cet article a été traduit de l’anglais par Angélique Avit pour <a href="http://www.fastforword.fr/">Fast for Word</a>.</em></p><img src="https://counter.theconversation.com/content/91790/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dagmar Haase a reçu des financements du Axa Research Fund pour ses travaux.</span></em></p>Sous l’effet des changements climatiques, ces risques pèseront de plus en plus lourd sur les villes européennes.Dagmar Haase, Professor of Landscape Ecology, Humboldt Universität zu Berlin, Helmholtz Centre for Environmental Research-UFZLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/912582018-02-08T21:01:08Z2018-02-08T21:01:08ZWhen climate comes unhinged, we need to re-think how to build our cities<figure><img src="https://images.theconversation.com/files/205064/original/file-20180206-14067-3ydqd4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Paris "under water" and other European cities facing drastic climate change should trigger planners to think urban spaces differently.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/tromal/27666594030/">S.Faric/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>In late January 2018, Paris seemed to be drowning. Both the Seine and the Marne rivers <a href="http://www.bbc.com/news/world-europe-42856634">overflowed for their banks</a>, forcing some suburban city-dwellers to have to row to reach their houses, while the iconic Zouave statue on the Pont d’Alma was even <a href="https://www.reuters.com/news/picture/paris-under-water-idUSRTX4NY5Y">given a life-vest</a>. That was just before snow engulfed the French capital.</p>
<p>Rising waters in the Lyon region <a href="http://www.euronews.com/2018/01/26/lyon-s-twin-rivers-threaten-floods-as-rhone-saone-rise">have also been of great concern</a> as well as in the north-east near Strasbourg, where the Rhine river (which also flow through Germany) was extremely high. A new normal? <a href="https://phys.org/news/2018-01-global-poses-substantial-central-western.html">According to research</a>, “flood damage from rivers in Europe will more than double to about 15 billion euros ($19 billion)” as a result of global warming. Flooding will <a href="http://science.sciencemag.org/content/357/6351/588">be a recurrent feature of our regions</a> even if we manage to keep global warming below the 1.5 Celsius degree recommended by the <a href="https://theconversation.com/fr/topics/paris-agreement-23382">Paris agreements</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=381&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=381&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=381&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=479&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=479&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205070/original/file-20180206-14111-1uiamv5.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=479&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The historic Seine flood, Passy, Paris, January 1910. Will this become a routine part of our regular winters?</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:ND_141_-_PARIS_-_La_Grande_Crue_de_la_Seine_-_R%C3%A9tablissement_de_la_circulation_par_passerelles_au_Quai_de_Passy_inond%C3%A9.JPG">Claude Shoshany/Wikimedia</a></span>
</figcaption>
</figure>
<p>Cities in Europe will suffer from heat and heat waves as well as from extreme rainfall which will be a new challenge for planners and health care services. <a href="http://www.euronews.com/2018/02/02/rising-sea-levels-threat-a-shrinking-european-coastline-in-2100">Cities will need to adapt drastically</a> to avoid catastrophes. While reducing carbon emissions is key to tackle the global issue there are various ways to make cities more resilient.</p>
<h2>Informing people</h2>
<p>Informing people about approaching heat waves is one important issue. Doing so, all possible information and communication sources should be activated. Apps, social networks such as WhatsApp or Facebook groups can prove handy provided they are used with consistency as explained by social scientists observing <a href="https://www.scientificamerican.com/article/how-social-media-is-changing-disaster-response/">social media response to disasters</a> in <a href="http://heroicproject.org/">California</a>.</p>
<p>Use of everyday infrastructure such as supermarkets, pharmacies and cafés can also help. In Vienna, <a href="http://wiev1.orf.at/stories/377527">churches opened for tourists and residents</a> during the heat waves in 2015 and 2017.</p>
<p>During catastrophe such as heat waves, dedicated <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168875/">mobile information services</a> should be implemented. It could be helpful for health or social workers to localize older people <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3536512/">who are often isolated</a> and <a href="http://inpes.santepubliquefrance.fr/CFESBases/catalogue/pdf/1033.pdf">more affected</a> by high temperatures. Thousands of senior citizens died in France <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1950160/">in the 2003 massive heatwave</a>. In France, “La Poste”, the official public mail service, launched last summer <a href="http://www.lemonde.fr/societe/article/2017/05/24/veiller-sur-mes-parents-le-service-que-generalise-la-poste-inquietent-les-facteurs_5133079_3224.html">a pilot project</a>. It offers individuals to look after an isolated parent against a compensation.</p>
<h2>Blue and green cities</h2>
<p><a href="https://www.springer.com/fr/book/9789400770874">Greening and blueing cities</a> can also become a new norm when we talk of planning and building.</p>
<p>These practices bring nature back into the built space and make use of its great properties to balance heat and also heavy rainfall by filtration, absorption, percolation and seeping functionality. Open soils in parks, on lawns, in cemeteries or urban gardens are highly suitable for this but also green roofs, rooftop raingardens or green walls. All buffer heat and emit transpiration coolness.</p>
<p>We can think for instance of rain gardens and green houses <a href="http://www.milanocittastato.it/news/rain-gardens-isole-verdi-contro-gli-acquazzoni-unidea-per-arginare-le-esondazioni-di-seveso-e-lambro/">in Milan</a>, which already proved useful in New York, as they could absorb <a href="http://www.corriere.it/ambiente/15_marzo_31/rain-garden-bombe-acqua-giardini-pioggia-ec2ddfae-d7bc-11e4-82ff-02a5d56630ca.shtml">about 50% of the rainfall</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205086/original/file-20180206-88775-1se1bwe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Exhibition of a green wall proposal in Milan, 2015.</span>
<span class="attribution"><a class="source" href="https://pixabay.com/en/exhibition-milan-2015-1157790/">faverzani/Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Revitalized brownfields and their conversion into large public parks and greenspaces can become a hit such as the urban farms set up <a href="https://www.deutschland.de/en/topic/business/innovation-technology/urban-farming-in-the-middle-of-berlin">in the middle of Berlin, Germany</a>, in <a href="http://www.cityfarmer.info/2009/10/04/investigating-the-potential-for-the-expansion-of-urban-agriculture-in-the-city-of-edinburgh/">Edinburgh in the UK</a>, Malmö or Leipzig in Sweden just to <a href="http://annalinde-leipzig.de/blog/urban-farming-conference-2017/">list a few</a>. It can also take the shape of <a href="https://www.grownyc.org/openspace/green-infrastructure-toolkit/bioswales">bioswales</a> – linear vegetated channels, specifically designed to attenuate and treat storm water runoff.</p>
<figure>
<iframe src="https://player.vimeo.com/video/67238469" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">How bioswales work.</span></figcaption>
</figure>
<p>Trees and forests, in addition, also emit essentials which are good for human’s lung function and respiratory power. Thus, green spaces have great synergies to balance heat, heavy rainfall and transport emissions (particles, nitrogen oxides).</p>
<p>Blueing the city means to increase open water surfaces and create areas which can be flooded (in the Seine wetlands for example) or where water can stand. <a href="http://www.sciencedirect.com/science/article/pii/S2212613915000112">These are the more technological answer</a> in case wetlands or riparian areas are not available or totally embanked.</p>
<p>These practices help build what we call <a href="https://www.geographie.hu-berlin.de/en/professorships/landschaftsoekologie-en/standardseite?set_language=en">“resilient cities”</a>.</p>
<h2>Toward resilient cities</h2>
<p>A resilient city in terms of its eco-climatological conditions is a city which takes into consideration what I sketched above and which holds areas for greening and blueing and invests in an excellent and flexible information/communication network.</p>
<p>In addition, complementaries between green, blue and built (grey) infrastructure should be taken into consideration and not mutually ignored. For example, dams are sometimes necessary as bioswales can only take up a certain amount of water.</p>
<p>Beyond technical considerations, we also need to take into account the political aspect of a resilient city : first and foremost, it is a space where citizens should all access the necessary information to mitigate catastrophe, free of charge, as a civil and municipal service.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/205087/original/file-20180206-88791-1ctr2uy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A small urban agriculture project in Amsterdam (www.stadsboeren.org), 2011.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/f/f1/Urban_agriculture_in_Amsterdam.jpg">Kaz Alting/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>These basic adaptation practices will complement more technical and green solutions such as flood protection in Vienna or Cologne <a href="https://www.ecologyandsociety.org/vol21/iss2/art39/">that proved to be successful in the past years</a>.</p>
<p>For instance, after Germany’s <a href="https://link.springer.com/chapter/10.1007/978-90-481-3167-9_18">disastrous Elbe river floods of the last two decades</a>, dikes were relocated and modified to broaden the natural floodplain and to give the river more room. <a href="https://www.theguardian.com/world/2013/jun/09/german-floods-elbe-thousands-evacuated">Yet the dam burst four years ago</a>.</p>
<p>That is why, instead of blocking the water, other cities think to welcoming it. For instance, the city of Hamburg, in the Netherlands <a href="https://www.citylab.com/environment/2017/06/hamburg-germany-climate-change-floods-elbe-river/529629/">has the project to create a new floodplain</a> for river Elbe to restore “some natural balance to a dockland area”, which has been under stress for half a century due to heavy ship traffic.</p>
<p>Of course a large 100-years flood cannot be buffered or balanced by bioswales or lawns along a floodplain; but it can reduce peaks and make flood velocity lower and give people more time to react.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><em>Created in 2007, the Axa Research Fund supports more than 500 projets around the world conducted by researchers from 51 countries. Find out more about Dagmar Haase’s work on the <a href="https://www.axa-research.org/en/projects/haase-dagmar">dedicated site</a></em>.</p><img src="https://counter.theconversation.com/content/91258/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dagmar Haase has received funds for her research from the Axa Research Fund.</span></em></p>In the future, Europe will suffer from more heat waves as well as extreme rainfall, presenting new challenges for planners and health care services. Building resilient cities can help.Dagmar Haase, Professor of Landscape Ecology, Humboldt Universität zu Berlin, Helmholtz Centre for Environmental Research-UFZLicensed as Creative Commons – attribution, no derivatives.