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By Charli Shield
Not too long ago, many people weren't sure if trees had a place in cities. People, cars, houses and buildings made up urban areas — there wasn't much room for nature.
Trees now have a fundamental place in many big cities around the world, says Sonja Dümpelmann, landscape historian at the University of Pennsylvania — though in most of them, they are still vying for space.
If we want to reap the benefits of urban treescapes, ecologists say it's vital trees are seen as more than just an aesthetic addition to cities. That's especially true now that half the world's population live in cities and a further 2.5 billion are projected to live in them by 2050.
As Cities Evolve, Trees Keep Us Grounded.
Trees are powerhouses when it comes to regulating city microclimates — filtering air pollution, providing shade, absorbing CO2, helping prevent flash flooding, as well as acting as an important antidote to the urban heat island effect that makes cities far hotter than surrounding rural areas.
"Trees can make a huge difference to a city's temperature," says Tobi Morakinyo, an urban climatologist whose research into the cooling effect of trees in Akure, southwest Nigeria, showed using trees to shade buildings could cool them down by up to five degrees Celsius.
In hot sub Saharan African cities like Akure — where average maximum summer temperatures can reach 38 degrees (100 degrees F) — Morakinyo says trees' cooling effect is an important tool councils can wield against both heat stress and cooling costs.
Alongside the eco-services urban trees provide, there are also the qualities "that we can't put monetary value on," adds Cris Brack, a forest ecologist from the Australian National University and director of the National Arboretum in Canberra.
Those are "biodiversity, aesthetics and our visceral, gut-need to experience nature," Brack told DW, referring to the concept of 'biophilia' — the idea that humans have an innate desire to connect with nature. Mounting evidence shows that people who live in places with more trees experience lower levels of stress and mental illness, even when controlling for socio-economic factors.
Trees Make Us Feel Good — Do We Return the Favor?
Though our need for trees in cities appears to only be becoming greater, they often battle oppressive urban environments. Street trees are "in a constant struggle" for space in cities, says Brack, where below ground their root systems can be choked by water pipes, roads and underground car parks, and above ground by pollution, power lines and traffic.
They also face mechanical damage from cars, battering from increasingly extreme weather conditions and regular uprootings to make way for construction sites.
Perhaps the most damaging modern challenge for city trees, though, says Somidh Saha, urban forest ecologist at the Karlsruhe Institute of Technology in Germany, is drought. Following Europe's unprecedented heatwave in 2018, a study co-authored by Saha found 30% of the trees planted in Karlsruhe in southwestern Germany over the previous four years had died — both directly and indirectly because of a lack of water.
"Without enough water, trees become weak and that makes them vulnerable to disease," Saha told DW. At the same time, declining city populations of birds and arboreal mammals, such as bats, leaves insect populations unchecked, and local trees susceptible to their growing numbers.
Seeing the Forest for the Trees
Ambitious greening projects have cropped up in several megacities around the globe in recent years. New York City planted a million trees between 2007 and 2015, London mayor Sadiq Khan hopes to green more than half the capital by 2050 to make the world's first "National Park City," while Paris announced it would build four inner-city urban forests throughout 2020.
But outside the Global North, in places such as Saha's native India and Morakinyo's native Nigeria, where they cite a lack of resources and political will as big barriers to making urban greenery a priority, trees in cities are much scarcer.
As climate change brings hotter temperatures and unpredictable downpours, cities are demanding a new kind of resilience from urban trees. For many cities in the world, ecologists say that means planting more exotic species of trees.
While many people are opposed to the idea of planting non-native species, ecologists Brack and Saha say alternative species are usually better adapted to the artificial environment of a city — especially in the face of increasing heatwaves.
The three-toothed Maple, native to China, Korea and Japan, is one species that could appear in greater numbers in other parts of the world as temperatures rise.
There's also an important distinction to be made between "exotic" trees, which just means they aren't local, and "invasive" trees, which are harmful — spreading very quickly and dominating the environment. As for local wildlife, while ongoing studies are being carried out in places like Germany by Saha's team, Brack says in his local Canberra, where almost all tree species in the city are exotic, birds happily eat fruit from non-natives and mammals alike find homes wherever there is an appropriate hollow.
Citizens Pitch In
One solution to preserving city trees that's grown in popularity in recent years is citizen involvement in urban tree caretaking. New York City's citizen pruner program allows city dwellers to take classes to become official city tree carers, and Berlin — a place that has typically excluded citizens from looking after urban flora — is now allowing residents to apply for permits to maintain tree pits and has proposed that they water city trees in summer.
Involving citizens has its pros and cons, Dümpelmann says, and these kinds of programs may or may not be effective depending on the culture of the city – but even watering trees alone "has been shown to be a really relevant maintenance effort."
While planting trees in urban spaces is an effective and fairly efficient way to adapt to climate change, Dümpelmann stresses that it isn't a holistic solution.
"It's something we should work on while at the same time addressing the root causes of climate change," she said.
Beyond using trees as geo-engineering fix, urban ecologists point out that more trees in cities could change perspectives on urban living and give people a greater understanding of how to value nature as part of a sustainable, livable city – not separate from it.
That means seeing trees as living, growing beings, Brack says – not fixed in time, or immune to the stressors of living in harsh urban environments.
Reposted with permission from Deutsche Welle.
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EcoWatch Daily Newsletter
By Joe Roman and Taylor Ricketts
The COVID-19 pandemic in the United States is the deepest and longest period of malaise in a dozen years. Our colleagues at the University of Vermont have concluded this by analyzing posts on Twitter. The Vermont Complex Systems Center studies 50 million tweets a day, scoring the "happiness" of people's words to monitor the national mood. That mood today is at its lowest point since 2008 when they started this project.
The Hedonometer measures happiness through analysis of key words on Twitter, which is now used by one in five Americans. This chart covers 18 months from early 2019 to July 2020, showing major dips in 2020. hedonometer.org<p>These same tweets also indicate a potential salve. Before pandemic lockdowns began, doctoral student <a href="https://scholar.google.com/citations?user=0P0ZYbIAAAAJ&hl=en" target="_blank">Aaron Schwartz</a> <a href="https://doi.org/10.1002/pan3.10045" target="_blank">compared tweets before, during, and after visits to 150 parks, playgrounds and plazas</a> in San Francisco. He found that park visits corresponded with a spike in happiness, followed by an afterglow lasting up to four hours.</p><p>Tweets from parks contained fewer negative words such as "no," "not" and "can't," and fewer first-person pronouns like "I" and "me." It seems that nature makes people more positive and less self-obsessed.</p><p>Parks keep people happy in times of global crisis, economic shutdown and public anger. Research has also shown that transmission rates for COVID-19 are <a href="https://www.sfchronicle.com/news/article/Is-risk-of-coronavirus-transmission-lower-15287602.php" target="_blank">much lower outdoors than inside</a>. As scholars who study <a href="https://scholar.google.com/citations?user=yFzb2EUAAAAJ&hl=en" target="_blank">conservation</a> and how nature <a href="https://scholar.google.com/citations?user=CCnUeN8AAAAJ&hl=en" target="_blank">contributes to human well-being</a>, we see opening up parks and creating new ones as a straightforward remedy for Americans' current blues.</p>
Park Visits Are Up During the Pandemic<p>According to the Hedonometer, sentiments expressed online started trending lower in mid-March as the impacts of the pandemic became clear. As lockdowns continued, they registered the lowest sentiment scores on record. Then in late May, effects from George Floyd's death in police custody and the following protests and police response once again could be seen on Twitter. May 31, 2020 was the saddest day of the project.</p><p>Recent surveys of park visitors around the University of Vermont have shown people <a href="https://osf.io/preprints/socarxiv/sd3h6" target="_blank">using green spaces more</a> since COVID-19 lockdowns began. Many people reported that parks were highly important to their well-being during the pandemic.</p>
<div id="4c7e4" class="rm-shortcode" data-rm-shortcode-id="bc0ac146ab2a94228f32d973fc2ab272"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1289428912879964160" data-partner="rebelmouse"><div style="margin:1em 0">#Goldengatepark #sf #quarantinemood https://t.co/9l3ufnbkt6</div> — Suvd (@Suvd)<a href="https://twitter.com/Suvd19486406/statuses/1289428912879964160">1596258783.0</a></blockquote></div><p>The powerful effects of nature are strongest in large parks with more trees, but smaller neighborhood parks also provide a significant boost. Their impact on happiness is real, measurable and lasting.</p><p>Twitter records show that parks increase happiness to a level similar to the bounce at Christmas, which typically is the happiest day of the year. Schwartz has since expanded his <a href="https://arxiv.org/pdf/2006.10658.pdf" target="_blank">Twitter study</a> to the 25 largest cities in the U.S. and found this bounce everywhere.</p><p>Parks and public spaces won't cure COVID-19 or stop police brutality, but they are far more than playgrounds. There is growing evidence that parks contribute to mental and physical health in a range of communities.</p><p>In a 2015 study, for example, Stanford researchers sent people out for one of two walks: through a local park or on a busy street. Those who walked in nature showed <a href="https://doi.org/10.1016/j.landurbplan.2015.02.005" target="_blank">improved moods and better memory performance</a> compared to the urban group. And a team led by <a href="https://penniur.upenn.edu/people/eugenia-gina-south" target="_blank">Gina South</a> of the University of Pennsylvania showed in a 2018 study that greening and cleaning up blighted vacant lots in Philadelphia <a href="http://dx.doi.org/10.1001/jamanetworkopen.2018.0298" target="_blank">reduced local residents' feelings of depression, worthlessness and poor mental health</a>.</p>
Creative Strategies<p>It isn't easy to create new parks on the scale of San Francisco's Golden Gate Park or the Washington Mall, but smaller projects can expand outdoor space. Options include greening vacant lots, closing streets and investing in existing parks to make them safer, greener and shadier and support wildlife.</p><p>These initiatives don't have to be capital-intensive. In the University of Pennsylvania study, for example, renovating a vacant lot by removing trash, planting grass and trees and installing a low fence cost only about US$1,600.</p><p>Urban green space is most needed in neighborhoods that have lacked funding for parks, especially given <a href="https://www.nytimes.com/2020/04/08/nyregion/coronavirus-race-deaths.html" target="_blank">COVID-19's disproportionate impact on Black and Latinx people</a>.</p><p>Cities can also create parklike spaces by <a href="https://theconversation.com/with-fewer-cars-on-us-streets-now-is-the-time-to-reinvent-roadways-and-how-we-use-them-140408" target="_blank">closing streets to cars</a>. Many cities worldwide are currently retooling their transportation systems for the post-COVID-19 world in order to <a href="https://thecityfix.com/blog/bicycles-slower-speeds-livable-city-paris-mayor-anne-hidalgo-plans-ambitious-second-term-dario-hidalgo/" target="_blank">reallocate public space</a>, widen sidewalks and make more space for nature.</p><p>Urban designers, artists, ecologists and other citizens can play a direct role, too, creating pop-up parks and green spaces. Some advocates <a href="https://www.bloomberg.com/news/articles/2017-09-15/a-brief-history-of-park-ing-day" target="_blank">transform parking spaces into mini-parks</a> with grass, potted trees and seating for just the time on the meter, to make a larger point about turning so much public space over to cars.</p><p>Or cities can invest a little more. Minneapolis, Cincinnati and Arlington, Virginia, have won <a href="https://www.tpl.org/parkscore" target="_blank">national recognition</a> for their ambitious investments in public park systems. These areas could serve as models for neighborhoods that lack access to parks.</p>
<div id="25fd0" class="rm-shortcode" data-rm-shortcode-id="383f0d2df0237e9359c30dcce6cd6c42"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1276558744835379201" data-partner="rebelmouse"><div style="margin:1em 0">Looking to safely get outside? Check out the best parks for social distancing in this year's top ten ParkScore citi… https://t.co/HJjEtDsrTD</div> — The Trust for Public Land (@The Trust for Public Land)<a href="https://twitter.com/tpl_org/statuses/1276558744835379201">1593190296.0</a></blockquote></div>
A New Park Deal?<p>The United States has historically driven economic recovery with major infrastructure investments, like the New Deal in the 1930s and the 2009 <a href="https://www.investopedia.com/terms/a/american-recovery-and-reinvestment-act.asp" target="_blank">American Reinvestment and Recovery Act</a>. Such investments could easily include nature-positive spaces.</p><p>Parks are not panaceas, as evidenced by the widely publicized <a href="https://www.nytimes.com/2020/07/06/nyregion/amy-cooper-false-report-charge.html" target="_blank">racist confrontation between a white woman and a Black birder</a> in New York's Central Park in early July. But Hedonometer data add to a <a href="https://advances.sciencemag.org/content/5/7/eaax0903?utm_source=miragenews&utm_medium=miragenews&utm_campaign=news" target="_blank">growing body of evidence</a> that they provide <a href="https://doi.org/10.1073/pnas.1807504116" target="_blank">clear mental health benefits</a>. Creating and expanding parks also <a href="https://www.nrpa.org/contentassets/f568e0ca499743a08148e3593c860fc5/economic-impact-study-summary.pdf" target="_blank">generates jobs and economic activity</a>, with much of the money spent locally.</p><p>We believe investments in nature are well worth it, offering both short-term solace in difficult times and long-term benefits to health, economies and communities.</p>
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New York State Attorney General Letitia James announced Thursday that she will attempt to dismantle the National Rifle Association (NRA), arguing that years of corruption and mismanagement warrant the dissolution of the activist organization, as CNN reported.
<div id="7eb49" class="rm-shortcode" data-rm-shortcode-id="83819841e380a7072ec66d3186c160e8"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1291705003984510977" data-partner="rebelmouse"><div style="margin:1em 0">🚨RESPONSE to #Mauritius #OILSpill 🚨 “Once again we see the risks in oil: aggravating the #ClimateCrisis, as well as… https://t.co/PBLioZat6X</div> — Greenpeace Africa (@Greenpeace Africa)<a href="https://twitter.com/Greenpeaceafric/statuses/1291705003984510977">1596801446.0</a></blockquote></div><p>"There is no guaranteed safe way to extract, transport and store fossil fuel products. This oil leak is not a twist of fate, but the choice of our twisted addiction to fossil fuels. We must react by accelerating our withdrawal from fossil fuels," Greenpeace Africa Senior Climate and Energy Campaign Manager Happy Khambule said in a <a href="https://www.greenpeace.org/africa/en/press/11864/greenpeace-africa-response-to-mauritius-oil-spill/?utm_campaign=oil&utm_source=t.co&utm_medium=post&utm_content=single-image&utm_term=mauritius-oil-spill-reactive" target="_blank">statement Friday</a>. "Once again we see the risks in oil: aggravating the <a href="https://www.ecowatch.com/tag/climate-crisis" target="_self">climate crisis</a>, as well as devastating oceans and <a href="https://www.ecowatch.com/tag/biodiversity" target="_self">biodiversity</a> and threatening local livelihoods around some of Africa's most precious lagoons."</p>
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By Gianna-Carina Grün
While the first countries are easing their lockdowns, others are reporting more and more new cases every day. Data for the global picture shows the pandemic is far from over. DW has the latest statistics.
What's the Current Global Trend?<p>The goal for all countries is to make it to the blue part of the chart and stay there. Countries and territories in this section reported zero new cases both this week (past seven days) and the week before.</p><p>Currently, that is the case for 14 out of 209 countries and territories. </p>
How Has the Covid-19 Trend Evolved Over the Past Weeks?<p>The situation has improved slightly: 87 countries report more cases this week than last week. </p>
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