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Denser housing can be greener too – here’s how NZ can build better for biodiversity

The majority of 25 surveyed developments around New Zealand lacked healthy, ecologically meaningful vegetation. Applying biodiversity targets for medium-density housing could turn this around.

Getty ImagesCities across Aotearoa New Zealand are trying to solve a housing crisis, with increasing residential density a key solution. But not everyone is happy about the resulting loss of natural habitats and biodiversity. Some homeowners in Dunedin, for example, are vehemently opposed to potential higher-density development in their area. They fear the loss of nature and increased use of concrete and other non-permeable surfaces it might entail. One developer acknowledged the “juggling act” councils can face when trying to balance the need for more homes with preserving natural environments. The issue isn’t going away, given the national shortage of affordable housing and the growing emphasis on increased density under the National Policy Statement on Housing and Urban Development. However, we argue that incorporating nature within built environments is not just possible, it’s essential. Density with biodiversity Urban nature helps buffer the devastating impacts of increasingly frequent and serious climate-related events in cities, such as flooding and heat waves. By embracing nature-based solutions, we can lessen the impact of these events while enjoying biodiverse surroundings (which are also beneficial to human wellbeing). Initiatives in other countries can be a guide. Melbourne, for example, has a goal of planting 3,000 trees a year to achieve a 40% tree canopy cover by 2040. This is to combat increasing temperatures and improve biodiversity. Toronto has policies to address air quality, the urban “heat island” effect, and stormwater management. The most significant is a green-roof bylaw requiring all high-density developments to have 20-60% of their roof area vegetated. Unfortunately, New Zealand has not been good at creating biodiverse residential developments. Higher density often results in less green space and more hard surfaces. Hard facts: medium-density often means a loss of permeable areas, including green spaces. Getty Images Urban nature has value Our research group, Aotearoa BiodiverCity (part of the publicly-funded People, Cities, Nature research programme) explores how to achieve more biodiverse cities through better and more strategically designed medium-density development. As part of this ongoing and yet-to-be published work, we have examined 25 developments of different sizes across four New Zealand cities. This revealed considerable variation in how well developers had integrated biodiversity. The majority were glaringly deficient in healthy, ecologically meaningful vegetation. Our analysis revealed that shifts to medium-density often mean a loss of nearly two-thirds of the original permeable area, including green spaces vital for stormwater management and biodiversity. We’ve discovered numerous barriers and challenges to achieving nature-rich cities. Fundamental is a lack of national policy and regional strategies that specifically consider biodiversity in residential development. Instead, the focus is on protecting significant indigenous habitats, reflecting an apparent assumption that biodiversity in residential areas has no value. In fact, it has enormous potential to contribute to city-wide biodiversity, and is vital to human wellbeing and climate change adaptation. Set targets and measure outcomes The lack of guidelines also creates large differences between council standards for developments. How much space is left for planting, for example, is dictated by the maximum building coverage on a site. This can range from 35% in Upper Hutt to as high as 50-60% in Lower Hutt, Wellington and Dunedin. When district plans and residential design guidelines do call for maintaining or increasing vegetation, there are no specific biodiversity goals or targets. Nor are there plans to measure and monitor biodiversity during or after construction. Professionals working on urban built environments reveal a tangle of barriers to implementing greening strategies. Cost is a big one, with developers perceiving a safer return on investment from prioritising dwellings or car parking, despite many people being willing to pay more for homes in greener neighbourhoods. Design guidelines, including landscaping specifications, are often subject to developer discretion. This can mean they adhere to few environmental mitigation measures, and potentially neglect the natural environment. More broadly, New Zealand has few precedents for incorporating green elements in denser developments. Solutions such as vegetated roofs and water-sensitive urban design are seen as experimental and risky rather than mainstream. Strengthening council district plans to include requirements for preserving and enhancing urban green spaces should be a priority. This would include clear and attainable biodiversity targets, with quantifiable outcomes. Rooftop vegetation is one solution to balancing nature with residential development. Getty Images A new tool to score developments Our team is developing the New Zealand Biodiversity Factor (NZBF), an assessment tool tailored for residential neighbourhoods. Once available, it will offer clear guidance on integrating nature into new developments, and provide performance scores and practical improvement suggestions. Using urban design principles sensitive to biodiversity, the NZBF will score developments on a variety of features: extent of permeable area, vegetation quality in public and private spaces, and street layout. Driveways and roads are the “monsters” eating up valuable permeable space. Prioritising good public and other transport options over car parking outside every home helps create a more biodiverse living environment. Loss of permeable space can be mitigated at the planning stage by exploring housing layouts, building higher, and fostering greener urban landscapes. Councils have many things to consider beyond biodiversity, of course, as well as limited financial resources for maintaining natural areas. This could be offset by enabling residents to manage their own neighbourhood green spaces, as has been successfully implemented overseas. But attaching biodiversity targets to residential development will be a necessary first step. As urban populations grow, we’ll have to adapt to higher-density living. That does not mean we have to miss out on nearby nature. Yolanda van Heezik receives funding from the Ministry of Business, Innovation & Employment's Endeavour Fund.Christopher K. Woolley receives funding from the Ministry of Business, Innovation & Employment's Endeavour Fund.Jacqueline Theis receives funding from the Ministry of Business, Innovation & Employment's Endeavour Fund.Maibritt Pedersen Zari receives funding from the Ministry of Business, Innovation & Employment's Endeavour Fund.

Beauty Berry: Nature’s Insect Repellant

Walking along the edge of the woods in the southern United States you may have stopped in awe at the sight of vibrant magenta berries waving with broad leaves under the canopy of trees in the fall. In the spring a hiker may stop to view the lilac clusters of flowers that are attracting the bumble bees. This magnificent shrub is the American Beautyberry, a natural plant to the southern U.S. states that feeds birds, wildlife and historically, indigenous people. If you are lucky you will find them growing without care on your property for vase cuttings that last many weeks on the table.

Walking along the edge of the woods in the southern United States you may have stopped in awe at the sight of vibrant magenta berries waving with broad leaves under the canopy of trees in the fall. In the spring a hiker may stop to view the lilac clusters of flowers that are attracting the bumble bees. This magnificent shrub is the American Beautyberry, a natural plant to the southern U.S. states that feeds birds, wildlife and historically, indigenous people. If you are lucky you will find them growing without care on your property for vase cuttings that last many weeks on the table. ‍An ethnobotanic story of the beautyberry is that the chemical properties stored in the roots, leaves, and berries were historically used by the southern Choctaw, Creek and Seminole Native American tribes for medicinal purposes. They used the roots to treat dizziness, stomachaches and dysentery. Roots and berries were boiled and consumed to treat colic. Sweat baths were conducted using the roots to treat malarial fevers and rheumatism. The beautyberry was recently brought back into a study led by scientists at Emory University and the University of Notre Dame for treatment of COVID-19. Beautyberry studies are proving the plant extract as an innovative solution to treat the issue of antibiotic resistance to infectious diseases.‍To prevent insect bites one can simply crumple the fresh leaves in hand and rub them directly on the skin. A preferred alternative to questionable DEET products is to boil leaves in water on the stove to release the compound, allow to cool and transfer the liquid to a spray bottle for use to repel mosquitoes, red ants and ticks. However, amateur home herbalists can easily make this organic recipe shared by Out More USA as a moisturizing cream that can be applied safely to people and pet paws to deter biting insects:‍Beauty Berry Insect Cream‍Vitamin E is great for your skin and citronella has insect repellent properties of its own so this cream is likely more effective than using Beautyberry alone.‍Ingredients:3 cups boiling water1 cup Beautyberry leaves, chopped2 tablespoons beeswax 1/3 cup Grapeseed Oil1 teaspoon Vitamin E Oil10 drops Lemongrass essential oil (optional)10 drops Citronella essential oil (optional)Directions:Gently simmer chopped leaves for 20 minutes, covered. Pour the water into a jar while straining out the leaves. Melt the bees wax and the grapeseed oil by putting them in a glass canning jar and place the jar in a pot of water on medium heat. As soon as the wax is melted, remove the jar and add Vitamin E oil. Add 1/2 a cup strained water (make sure it is still warm) to the wax/oil and mix well until it becomes creamy. Add the citronella and lemongrass essential oils, cover and shake well. If you see any separation between the water and oil as it cools, shake more until it is well emulsified.One can purchase an American Beautyberry, Callicarpa americana shrub or dried seeds to add to gardens in zone 6b-11a. We’ve attached a wonderful growing guide provided by the Florida Native Plant Society for successful planting.

Gainesville Representative introduces bill to protect waterways

“Nearly a million acres of estuaries and 9,000 miles of rivers and streams in the state of Florida are verified impaired for fecal indicator bacteria,” Berman said. “Thirty-five percent of the verified impaired bodies have been on the impaired list for at least eight years.”

Gas Stove Pollution Lingers in Homes for Hours Even outside the Kitchen

Gas stoves spew nitrogen dioxide at levels that frequently exceed those that are deemed safe by health organizations

Gas Stove Pollution Lingers in Homes for Hours Even outside the KitchenGas stoves spew nitrogen dioxide at levels that frequently exceed those that are deemed safe by health organizationsBy Allison ParshallNearly 40 percent of U.S. homes have gas stoves, which spew a host of compounds that are harmful to breathe, such as carbon monoxide, particulate matter, benzenes and high quantities of nitrogen dioxide.Decades of well-established research have linked nitrogen dioxide, or NO2, to respiratory conditions such as asthma and chronic obstructive pulmonary disease, which especially affect children and older adults. This harmful link is so well established that some states have begun banning gas appliances in new construction. And now a new study has shown in stark detail just how long and far this gas spreads and lingers in a home. By sampling homes across the U.S., the researchers found that in many, levels of exposure to NO2 can soar above the World Health Organization’s one-hour exposure limit for multiple hours—even in the bedroom that is farthest from the kitchen."The concentrations [of NO2] we measured from stoves led to dangerous levels down the hall in bedrooms ... and they stayed elevated for hours at a time. That was the biggest surprise for me," says Rob Jackson, a sustainability researcher at Stanford University and senior author of the study, which was published on May 3 in Science Advances.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.The researchers collected real-world data on NO2 concentrations before, during and for several hours after the use of gas and propane stoves in houses and apartments in California, Colorado, Texas, New York State and Washington, D.C. In six homes, they tested the levels of NO2 in the bedroom farthest from the kitchen for a basic “bread baking” scenario: they set the gas or propane oven to 475 degrees Fahrenheit (245 degrees Celsius) and left it on for an hour and a half. The team continued sampling the air for up to six hours after the oven was turned off.In all six homes, the NO2 concentration in the bedroom quickly exceeded the WHO’s chronic exposure guideline of about five parts per billion by volume. And in three of the bedrooms, the levels soared even above the Environmental Protection Agency’s and the WHO’s respective one-hour exposure guidelines, which both set the limit at about 100 parts per billion by volume. (The EPA’s guidelines are intended for outdoor air exposure because the agency does not regulate indoor air pollution.)The bedroom exposure data from the new study can be seen in the graph above. “Think about that graph happening two times a day," Jackson says. “You cook at lunch, and then you cook again at dinner. Maybe you cook breakfast. It’s over and over again, hundreds of days a year.”Jackson and his colleagues next wanted to find out which factors had the greatest impact on the level of NO2 exposure from gas stoves. So they used a computer model to estimate airflow and contaminant concentration in indoor spaces. They validated the model by comparing its estimates with directly measured concentrations of NO2 from 18 homes of differing sizes and layouts before, during and after using a gas stove. The researchers tested this with the range hood on and off and with the kitchen windows open and closed, airing out the residences between each trial.After confirming that their real-world observations matched the model’s predictions, the team could then use the program to estimate how much NO2 someone might be exposed to depending on many different factors, such as their home’s size and layout, the amount of time they spend with the windows open and how often they use the stove’s range hood.The researchers found that those living in homes smaller than 800 square feet or making under $35,000 a year were being regularly exposed to levels of NO2 at or far exceeding the WHO’s threshold for chronic exposure. Finally, by combining these data with previous research on the link between long-term gas and propane stove exposure and pediatric asthma, the researchers calculated that such exposure could account for 200,000 current cases of childhood asthma, with 50,000 of those attributable to NO2 alone."I think that this modeled data is valuable because it gives you very clear numbers” to see how much NO2 we’re being exposed to at different time points during and following gas stove use, says pulmonologist Laura Paulin, who studies indoor air pollution at the Geisel School of Medicine at Dartmouth. “We are blowing past these outdoor air regulations [and] recommendations” with indoor NO2 exposure alone, she says.In a 2014 study, Paulin and her colleagues showed how people can decrease concentrations of this pollutant in their home. The best way is to swap out a gas or propane stove for an electric one. But for some people, especially renters, this may not be a feasible option.If you’re stuck with a gas stove, Paulin suggests turning on your range hood every time you cook with gas, even if the fan is loud and annoying. Still, these aren’t always very effective: Jackson and his colleagues found that the hoods in the homes they surveyed were anywhere between 10 and 70 percent effective. Those numbers applied only to hoods that vented outside. Some hoods instead spew air right back into your living space and do little more than disperse the pollutants throughout it.Another way to improve ventilation is to open your windows while you cook—if weather permits and if the outside air is not polluted as well.And if all else fails, high-efficiency particulate air (HEPA) air purifiers can help filter out some of these indoor pollutants. If the purifier has a carbon prefilter, it can remove some NO2 from the air. In Paulin’s 2014 study, she found that placing such filters in the kitchen could reduce NO2 levels by 20 percent.As we spend more of our lives indoors, it becomes increasingly important to pay attention to the quality of the indoor air we breathe. “Our outdoor air is getting cleaner. But we have ignored indoor air pollution in considering risk for people in this country,” Jackson says.

Gas stoves increase nitrogen dioxide exposure above WHO standards – study

Science Advances report also finds people of color and low-income residents in US disproportionately affectedUsing a gas stove increases nitrogen dioxide exposure to levels that exceed public health recommendations, a new study shows. The report, published Friday in Science Advances, found that people of color and low-income residents in the US were disproportionately affected.Indoor gas and propane appliances raise average concentrations of the harmful pollutant, also known as NO2, to 75% of the World Health Organization’s standard for indoor and outdoor exposure. Continue reading...

Using a gas stove increases nitrogen dioxide exposure to levels that exceed public health recommendations, a new study shows. The report, published Friday in Science Advances, found that people of color and low-income residents in the US were disproportionately affected.Indoor gas and propane appliances raise average concentrations of the harmful pollutant, also known as NO2, to 75% of the World Health Organization’s standard for indoor and outdoor exposure.That means even if a person avoids exposure to nitrogen dioxide from traffic exhaust, power plants, or other sources, by cooking with a gas stove they will have already breathed in three quarters of what is considered a safe limit.“When you’re using a gas stove, you are burning fossil fuel directly in the home,” said Yannai Kashtan, lead author of the study and a PhD candidate at Stanford University. “Ventilation does help but it’s an imperfect solution and ultimately the best way is to reduce pollution at the source.”Nitrogen dioxide irritates the airways and can exacerbate respiratory illnesses such as asthma. The Stanford study estimates that chronic stove-based nitrogen dioxide exposure is linked to at least 50,000 cases of pediatric asthma in the United States each year. The research, which measured NO2 in more than 100 homes before, during, and after gas stove use, found that pollution migrates to bedrooms within an hour of the stove turning on, and stays above dangerous levels for hours after use.“It’s moving throughout our whole home much faster than we expected,” said Rob Jackson, professor of Earth system science at Stanford and co-author of the study. “You have to think about the effects of this not just in one cooking event, but multiple times a day, for lunch and dinner, across weeks and months.”Roughly 38% of households in the US use gas stoves, according to the Energy Information Administration, but not all of them are exposed to NO2 equally. The study suggests that size of the home is an important factor, with people living in residences less than 800 sq ft showing chronic exposure four times the rate of people living in homes with 3,000 sq ft.“Older homes are more likely to be smaller, and more often have gas stoves which reflects the nature of our housing stock,” said Jon Samet, professor of environmental and occupational health at the Colorado School of Public Health, who was not involved in the study. “It’s good to see this work focusing attention on indoor air, particularly in our homes, because that’s where we spend most of our time.”The results also highlight the unequal racial and socioeconomic burden of exposure. The study found that American Indians and Alaska Natives are exposed to 60% more NO2 from gas and propane stoves than the national average. Black and Latino or Hispanic households breathe in 20% more NO2 from their stoves.People in households making less than $10,000 a year are breathing NO2 at rates more than twice that of people in households making over $150,000.“People in poorer communities are more at risk because their outdoor air is bad and and in many ways their indoor air is worse,” said Jackson. Low-income communities and communities of color are more likely to live near highways, ports, industrial sites and other polluting zones.While this study looked at stovetop pollution from cooking, which is a relatively short period of exposure, some people who struggle to afford utility bills rely on stoves and ovens for heat during colder months.“There’s an underlying assumption that people are only using their stove or oven to cook and to prepare meals,” said Diana Hernandez, sociologist at Columbia University who was not involved in the Stanford study. A recent survey conducted by Hernandez and her team found that over 20% of New Yorkers used stoves or ovens to heat their homes.“That’s a less efficient and much more toxic way of providing heat, and more costly,” Hernandez said. “You’re talking about heating an entire home, or apartment, probably for hours on end, with a device and appliance that wasn’t meant for that.”Gas stoves also emit methane, a potent greenhouse gas, and cities across the US are adopting building electrification measures that would phase out gas stoves in new homes.Dorris Bishop, a resident of River Terrace neighborhood in Washington DC, said she recently joined a waitlist to trade her gas stove in for an electric appliance after a local advocacy group tested her home for NO2 and found elevated levels.“I’m hopeful that this report will push for all of the new homes to put electric stoves in,” she said.