CITIES-  How and why concrete is so ever-present in our lives. Concrete is quite literally the foundation of our modern civilization. It is relatively cheap, strong, made from resources that we (seemingly) have an abundance of, can take many shapes, and has a very long lifespan.Think of concrete as the skeleton of a building. It is typically used for the foundation and construction, meaning the average building is roughly 80% concrete. First used by the Romans to create buildings such as the Pantheon and the Colosseum, concrete became the go-to building material in Europe after the Second World War because of the huge demand for cheap housing. But as we produce more and more concrete, compounding environmental issues are cause for concern. We will explore how using more sustainable materials and design strategies could alleviate the impacts of the construction sector. The UN has predicted that more than 66% of us will live in a concrete jungle by 2050. We are seeing a radical shift to megacities, which have a population of more than 10 million people, with 33 megacities identified in 2020 and a predicted six more by the end of the decade. At this rate, we will have to build 2 billion new homes before the end of the 21st century. That is like adding eight New York City’s every yearIt is very likely that we will build these homes with concrete, the most used building material in the construction sector. We use more than twice as much concrete as all other building materials combined. This makes it the second most used material in the world (after water) and the most consumed man-made material with a staggering 10 billion tons of it produced each year. This would be enough to cover all of the UK in a 2 cm layer of concrete or to build 1,700 Hoover Dams each year. It is very likely that we will build these homes with concrete, the most used building material in the construction sector. We use more than twice as much concrete as all other building materials combined. Unfortunately, there are some negative consequences to using concrete, notably, the emission of CO2 during the production process. Taking in all stages of production, concrete is responsible for 4 to 8% of the world’s CO2. Half of concrete’s CO2 emissions are created during the manufacture of clinker, the basis of cement and what binds together all the components in concrete. To make this, limestone and several chemical additives are heated to 1450 C, so it is by far the most energy-intensive part of the cement-making process. But beyond CO2, there are even more issues to be addressed. With the increased consumption of concrete over the last century, sand is becoming a sought-after resource, which has started to affect the world around us. Regulations in the West protect the (natural) environment but other parts of the world have seen a “sand mafia” emerge. The uncontrolled taking of sand can devastate local habitats and species. In Africa, China, and Southeast Asia, where we see huge population growth, extracting sand from rivers and lakes creates standing pools of water that become breeding sites for mosquitoes carrying malaria and other emerging diseases.Concrete also uses a lot of water during its production process, almost 2.5 liters of water for every kilogram of concrete produced. Right now about 10% of the world’s industrial water use goes toward concrete production; this does not take into account the water used later on the building site. In the next 35 years, an expected 590–710 cubic kilometers of water will be needed to make concrete, if these production methods remain the same. This is roughly equivalent to all the water that flows through the Nile in eight years....and there's more including solutions.........https://www.metabolic.nl/news/rethinking-concrete/

When it comes to sustainable cities, Scandinavia is knocking it out of the park, according to the world’s first-ever crowdsourced urban sustainability index, with Stockholm scoring highest and Oslo, Copenhagen, and Lahti, Finland close behind on a list of 50 high- and middle-income cities. Developed by Toronto-based Corporate Knights, the 2022 Sustainable Cities Index responds to the urgent need to boost cities’ sustainability amid rising urban populations. The index is seeded with publicly-sourced data on 12 key indicators like per capita greenhouse gas (GHG) emissions and consumption emissions, air quality, climate change resilience, water access, and vehicle dependency, among others. Vancouver and Toronto rank eighth and ninth, and Canadian cities are generally the highest-scoring North American cities on the index, Corporate Knights finds. But seven of the top ten cities are in the United Kingdom and Europe, a result “attributable to sustainability leadership,” the report states. Tokyo ranks seventh, first among cities in Asia and Oceania, and well ahead of San Francisco and New York City, which place sixteenth and nineteenth on the index as the most sustainable cities in the United States. While cities with smaller populations tend to score higher, the fact that London ranks fifth with a population of eight million, and Tokyo comes in seventh with its population of 13 million, shows that megacities can be highly sustainable.                https://www.theenergymix.com/2022/06/19/europe-outshines-north-america-in-new-sustainable-cities-ranking/?utm_source=The+Energy+Mix&utm_campaign=ab15ab13ff-TEM_RSS_EMAIL_CAMPAIGN&utm_medium=email&utm_term=0_dc146fb5ca-ab15ab13ff-509990701

.In Big Cities, Green Spaces Are Magic.......Good access to nature has consistently been proven to increase physical and mental health, especially for city dwellers. Several Canadian provinces even allow health-care professionals to offer “nature prescriptions” for their patients, consisting of free passes to national parks, to improve well-being. In Vancouver, many people turn to regional parks on the North Shore, [the  UEL lands to the west, Central Park in Burnaby, and more] abundant with mountainous hiking trails among old-growth forests, for a chance to reconnect with nature. Of course, it’s important to remember that relationships to nature and land are also complicated. Many hikers visit these natural spaces without making a proper effort to engage with their ongoing significance as Indigenous lands, even though many Indigenous-led natural tours offer a more respectful way to experience them. Not everyone has the time or the means to visit bigger destination forest parks, either. Many national and regional parks may require a long journey on public transportation, or are only accessible by car. So, where else to go for a comforting, considerate, yet convenient dose of nature? Urban forests provide one alternative.                                                                                                                                                              Technically, the city’s official urban forest strategy considers all trees on public and private lands to be part of the urban forest. As a result, the definition of “urban forest” can be broad. It can refer to fully forested areas in large public parks and the street trees planted in city boulevards, as well as the individual trees grown in private backyards. Andy Yan, director of Simon Fraser University’s City Program, reiterates that all of these trees are a key part of our urban infrastructure. Every tree is a welcome contribution to the city’s overall urban forest. Yet an individual street tree arguably still differs from a tree that grows collectively with others in a forested environment. Larger forested parks can accommodate a more natural forest ecosystem, enhancing the habitat for native species of plants and wildlife. Additionally, ravines can frequently play a central role in connecting the network of animals, vegetation and water needed to sustain these habitats, especially in urban settings. Bigger forested parks remain concentrated near wealthier neighbourhoods on the west side of the city. Stanley Park is adjacent to Vancouver’s West End and Coal Harbour. Pacific Spirit Regional Park is in West Point Grey near Vancouver’s Dunbar neighbourhood. The locations of both parks reflect the general pattern of shade inequality that has left lower-income neighbourhoods with reduced canopy cover from less trees, and even fewer that are fully grown enough to provide adequate shade...... read more.....     https://thetyee.ca/News/2022/05/26/Big-Cities-Green-Spaces-Magic/?utm_source=daily&utm_medium=email

High-density, low-rise urban housing is the key to accommodating another three billion people over the next 80 years without costing the Earth, writes architect and urbanist Vishaan Chakrabarti.By the year 2100 there will be 11 billion people on the planet, according to the United Nations – three billion more than there are today. Meanwhile, the world is already experiencing the extreme impacts of anthropogenic climate change, as well as an omnipresent energy crisis fuelled by the war in Ukraine. A surging population risks putting an even greater strain on the environment and comes with even more demand for energy.  How can our housing needs be part of the solution rather than part of the problem? How can we use today's technologies to design new housing that is not only sustainable, not only low in embodied energy, but also truly carbon negative? To house our existing and future population affordably and with dignity we need to build over 2.4 trillion square feet globally, which is the equivalent of adding one New York City to the planet every month for the next 40 years. We simply don't have the technology today to build carbon negative towers. We can conserve where we can, such as by adaptively reusing some of our existing building stock, particularly older office buildings made obsolete by the pandemic. But this alone won't make a dent in our impending housing needs – we must build, and we must build better. I for one am tired of hearing about solutions that don't have a chance of widespread, affordable, global adoption for decades, even the great technology of mass-timber skyscrapers made from carbon-sinking, environmentally friendly and fire-retardant wood, but we simply don't have the technology today to build carbon negative towers. We're also decades away from realising clean grids in our existing cities, where most global population growth will occur, because of challenges ranging from inefficient transmission lines to the fossil fuel lobby's chokehold on our governments.                                                                                                                                                       The answer is hiding in plain sight: a "Goldilocks" type of high-density, low-rise urban housing that sits between the scale of sprawling single-family houses and large-scale towers, advocated by many architects and urbanists for decades. From the hutongs of Beijing to the rowhouses of Boston, this scale of housing has created some of our most beloved urban neighbourhoods. If adopted en masse, it would enable us to house everyone while drastically reducing the emissions impact of our homes. Importantly, at two to three stories – but no higher – under the international building code this low-rise housing is required to have only one communal stair if wheelchair accessible units are provided at grade. [However in situations where there is a scarcity of available land, the webmasters feel that the height limit should be four to five storeys.] That allows for less concrete, lower building costs, and more community connection by dispensing with elevators and the banal experience of double-loaded corridors, while small shops and workspaces can also occupy the ground floor. In most sunny climates, which is where we anticipate the most population growth, this Goldilocks prototype hits the sweet spot between the number of residents it can house and the amount of roof area needed for enough solar panels to supply more energy than these residents need. Solar panels, which are decreasing in cost while gaining in efficiency, could also be supplemented with existing state-of-the-art battery systems that level out solar supply and user demand to provide a constant energy source, and because of its structural simplicity, Goldilocks housing can be built by local workers in accordance with local climates.                   https://www.dezeen.com/2022/05/16/goldilocks-housing-vishaan-chakrabarti-opinion/?utm_medium=email&utm_campaign=Daily%20Dezeen&utm_content=Daily%20Dezeen+CID_42507d7dc1dc1b4423f0f71c47d782a2&utm_source=Dezeen%20Mail&utm_term=Read%20more