Why More Green Space is Essential for Cities
"Green space is essential for good health but, in many cities, we don’t have enough of it or it is in the wrong place. We all enjoy a walk in the park, a street lined with trees or a view of trees from our window, but for those of us who are urban dwellers, we may not experience as much of this as we should." Barcelona Institute for Global Health
The Institute recently analysed more than 1,000 cities in 31 European countries and found that up to 43,000 premature deaths could be prevented each year if these cities were to achieve the World Health Organisation (WHO) recommendations regarding residential proximity to green space. The WHO recommends universal access to green space measuring at least 0.5 hectares at a linear distance of no more than 300 metres from every home. The Institute's results showed that 62% of the European population lives in areas with less green space than recommended.
Green space is associated with a large number of health benefits, including lower premature mortality, longer life expectancy, fewer mental health problems, less cardiovascular disease, better cognitive functioning in children and the elderly, and healthier babies. It also helps to mitigate air pollution, heat and noise levels, and provides opportunities for physical exerciseand social interaction.
Green space contributes to climate mitigation by reducing urban heat island effects, but it contributes relatively little to carbon sequestration, as cities account for only a small percentage of our land use and CO2 emissions are high. Green space can improve ecosystems and increase biodiversity in cities, particularly through well-designed green infrastructure throughout the city.
Wildfires Can be Avoided by Maintaining Green Spaces
With the latest wildfires in Europe destroying homes as a result of record temperatures, it has made us even more aware of the value of green spaces. A top weather event in Canada brought record-breaking temperatures of 49.6 C to Lytton, British Columbia last year. The following day a wildfire destroyed 90 per cent of the town, killing two people and displacing 1,200 others.
During heat waves, the highest temperatures are often found in urbanized areas. Urbanization is almost always associated with an increase in paved, impervious areas, and often a decrease in greenery. Concrete and asphalt roads, and other built materials readily absorb, store and release heat, raising city temperatures, a phenomenon called the urban heat island. It has been found that human settlements act both to increase wildfire ignition rates and to remove fuel required for fire spread.
A research paper published in Science Direct found that the likelihood of a wildfire occurring at any site is determined by a complex array of factors - those that influence fire ignition and those that influence its subsequent spread. If people act in countervailing ways, both to increase ignition rates and to remove fuel, then it should be possible to separate these effects using measures that reflect one or other of them. The extent of unvegetated land mitigates permanent fuel removal and so affects fire ignition and spread, while property density increases the potential source of ignitions.
Nearly 85 percent of wildfires are caused by humans resulting from campfires left unattended, the burning of debris, equipment use and malfunctions, negligently discarded cigarettes, and intentional acts of arson. Wildfires do sometimes occur naturally, either ignited by the sun's heat or a lightning strike. However, most wildfires are caused by human activities.
With the rise of sustainable urban planning, green space zones designated for recreational use have become a popular requirement.
Oregon's Almeda Fire
The Almeda Fire started as a wildfire in an empty field on the outskirts of Ashland near the southernmost end of the Bear Creek Greenway, but it evolved into an urban conflagration as it hopscotched between wildland vegetation, the Greenway, adjacent fields, and neighborhoods. But in September in southern Oregon, the Bear Creek Greenway turned from a cherished bike path into a force of destruction, as the Almeda Fire travelled along it like a tunnel from its starting point in Ashland, through the towns of Talent and Phoenix, and into the suburbs of Medford, destroying thousands of adjacent homes.
As neighborhoods in southern Oregon rebuilt they restored and fostered fire-resilient native ecosystems to mitigate the risk of fire in the future, as fire seasons continue to grow longer and more volatile as a result of climate change.
They felt that climate change is pouring gas on everything. Things are getting drier and drier, and the window of opportunity for fires to burn is getting longer and longer every year.” The Almeda Fire is only the latest example of an urban conflagration that was aggravated by climate change and spread through well-populated areas. The Camp Fire, which destroyed more than 18,000 structures in northern California in 2018, also spread due to hot and dry weather and strong winds.
Defensible Space
Defensible space is essential to improve our home’s chance of surviving a wildfire. Defensible space is the buffer we create between our building and the grass, trees, shrubs, or any bush area that surrounds it. This space is needed to slow or stop the spread of wildfire and it helps protect our home from catching fire—either from embers, direct flame contact or radiant heat. Proper defensible space also provides firefighters a safe area to work in, to defend our homes.
