As urban migration increases, cities are increasingly searching for ways to provide more greenery.
A 11.4 million-euro project, Connecting Nature, which runs until 2022, is developing ‘nature-based solutions,’ such as street trees, parks, and green roofs and walls, across 11 European cities.
….Cities are increasingly looking for ways to provide more greenery, as migration to urban areas rises and a growing body of scientific evidence indicates that being close to nature is good for people.
Vegetation also sucks up planet-warming carbon dioxide, and is key to efforts to combat climate change.
Some 750 climate scientists and urban planners are gathered in Canada this week at a United Nations-hosted conference to discuss how to help cities reduce their greenhouse gas emissions and become more resilient to extreme weather and rising seas.
Vertical forests in Milan, Italy 2017 Luca Bruno AP
The proportion of the global population living in urban areas has risen from half in 2000 to 55 percent now, and is predicted to reach two-thirds by 2050….
Connecting Nature is an innovation-oriented partnership of 32 institutions from 18 countries. It brings together urban local authorities and communities, Small and Medium Enterprises, voluntary organisations, and diverse academic partners in order to scale-up nature-based solutions for building resilient and sustainable cities. Connecting Nature is working with 11 European cities who are investing in the large-scale implementation of nature–based solutions. As an innovative action, part-funded by Horizon 2020, Connecting Nature is mapping nature-based solution exemplars and measuring measuring the efficacy and impact of these initiatives on climate change adaptation, health and well-being, social cohesion, and sustainable economic development. We are also devising new business models and novel mechanisms for financing nature-based solutions as well as identifying key performance indicators. This will foster the creation of commercial and social enterprises for scaling-up nature-based strategies, processes, and products.
A new decision-making model — a social choice model — adds additional criteria to the economic– including environmental, cultural, or recreational, through public discussion.
By using a social choice model, the city would have a richer source of options and ideas to work with. Something that puts all available options on the table and requires that they be evaluated with a more comprehensive and long-term perspective.
In the research study, the option of relocating coastal infrastructure would likely provide the most benefit to the city in the long-run, as it would protect both the beach and vulnerable infrastructure.
US cities facing sea level rise need to look beyond traditional strategies for managing issues such as critical erosion and coastal squeeze, according to new research. Civil society initiatives must now play a crucial role in adapting society to climate change, the study argues.
The three options that have been considered in Flagler Beach are: constructing a sea wall, beach re-nourishment, or relocation of coastal infrastructure…
….The study instead proposes, that from a scientific, environmental and societal perspective, it is the option of relocating coastal infrastructure that would likely provide the most benefit to the city in the long-run, as it would protect both the beach and vulnerable infrastructure. Relocation has been promoted as the only viable long-term sustainable approach to beach management by coastal scientists; since it would provide for the beach to naturally adapt to sea level rise. Implementing this solution, however, is not likely to be an easy task.
…The study argues that a new decision-making model — a social choice model — could be one way forward. By taking primarily economic criteria into account, a wide variety of other concerns citizens have, including those of far-away tax payers and future generations, are left out. Therefore additional criteria, whether environmental, cultural, or recreational, should be identified through reasonable public discussion.
This would require not only more effective collaboration between federal, state and local governments, but also the ceding of more decision-making power to citizens and civil society organizations.
“By using a social choice model, the city would have a richer source of options and ideas to work with. Something that puts all available options on the table and requires that they be evaluated with a more comprehensive and long-term perspective.”…
It has long been known that installing white roofs helps reduce heat buildup in cities. But new research indicates that making surfaces more light-reflecting can have a significant impact on lowering extreme temperatures – not just in cities, but in rural areas as well.
There can be unintended consequences, both on temperature and other aspects of climate, like rainfall. Even local geoengineering needs to be handled with care
….Keith Oleson of the National Center for Atmospheric Research in Boulder, Colorado looked at what might happenif every roof in large cities around the world were painted white, raising their reflectivity — known to climate scientists as albedo — from a typical 32 percent today to 90 percent. He found that it would decrease the urban heat island effect by a third — enough to reduce the maximum daytime temperatures by an average of 0.6 degrees C, and more in hot sunny regions such as the Arabian Peninsula and Brazil.
Other studies suggest even greater benefits in the U.S. In a 2014 paper, Matei Georgescu of Arizona State University found that “cool roofs” could cut temperatures by up to 1.5 degrees C in California and 1.8 degrees in cities such as Washington, D.C….
…But things might not always be quite so simple. Reducing local temperatures would, for instance, limit evaporation, and so potentially could reduce rainfall downwind. A modeling study by Irvine found that messing with the reflectivity of larger areas such as deserts could cause a “large reduction in the intensity of the Indian and African monsoons in particular.” But the same study concluded that changing albedo in cities or on farmland would be unlikely to have significant wider effects. ..
…Solar panels “cool daytime temperatures in a way similar to increasing albedo via white roofs,” according to a study by scientists at the University of New South Wales. The research, published in the journal Scientific Reports last year, found that in a city like Sydney, Australia, a city-wide array of solar panels could reduce summer maximum temperatures by up to 1 degree C. …
…The urban heat island can be a killer. Counter-intuitively, the biggest effects are often at night. Vulnerable people such as the old who are stressed by heat during the day badly need the chance to cool down at night. Without that chance, they can succumb to heat stroke and dehydration. New research published this week underlines that temperature peaks can cause a spike in heart attacks. …
…A combination of rising temperatures and high humidity is already predicted to make parts of the Persian Gulf region the first in the world to become uninhabitable due to climate change. And a study published in February predicted temperatures as much as 10 degrees C hotter in most European cities by century’s end. No wonder the calls to cool cities are growing….
…Whitewashed walls, arrays of photovoltaic cells, and stubble-filled fields can all provide local relief during the sweltering decades ahead. But policymakers beware. It doesn’t always work like that. There can be unintended consequences, both on temperature and other aspects of climate, like rainfall. Even local geoengineering needs to be handled with care.
A new analysis finds that city planners have been under counting greenhouse gas emissions from the products they import.
Wealthy cities have reduced emissions but when emissions associated with consumption of goods and services are included, emissions have grown substantially and are among the highest in the world on a per person basis.
Cities should use consumption-based/supply chains GHG inventories alongside their sector-based GHG inventories.
by Stephen Leahy
The carbon footprint of some of the world’s biggest cities is 60 percent larger than previously estimated when all the products and services a city consumes is included, according to a new analysis.
The world’s cities emit 70 percent of the world’s carbon dioxide—and that’s likely higher when consumption emissions are included, says report author Michael Doust, program director at C40 Cities, a network of the world’s megacities committed to addressing climate change….
…Wealthy “consumer cities” such as London, Paris, New York, Toronto, or Sydney that no longer have large industrial sectors have significantly reduced their local emissions. However, when the emissions associated with their consumption of goods and services are included, these cities’ emissions have grown substantially and are among the highest in the world on a per person basis, the report says. Meanwhile, “producer” cities in India, Pakistan, or Bangladesh generate lots of industrial pollution and carbon emissions in the manufacture of products that will be sold and consumed in Europe and North America….
..Cities that have high consumption-based GHG emissions are recommended to use consumption-based GHG inventories alongside their sector-based GHG inventories, or incorporate key supply chains into the latter. This would encourage more
holistic GHG emissions assessments; enable decision-makers to consider a wider range of opportunities to reduce global GHG emissions; and provide an additional perspective with which to engage other stakeholders in climate action….
After a three-year drought, Cape Town is now at serious risk of becoming one of the few major cities in the world to lose piped water to homes and most businesses.
As far back as 2007, South Africa’s Department of Water Affairs warned that the city needed to consider increasing its supply with groundwater, desalination and other sources, citing the potential impact of climate change….
New water supplies have been part of the city’s plans but “it was not envisaged that it would be required so soon.”
Cape Town’s problems embody one of the big dangers of climate change: the growing risk of powerful, recurrent droughts
CAPE TOWN — It sounds like a Hollywood blockbuster. “Day Zero” is coming to Cape Town this April. Everyone, be warned.
The government cautions that the Day Zero threat will surpass anything a major city has faced since World War II or the Sept. 11 attacks. Talks are underway with South Africa’s police because “normal policing will be entirely inadequate.” Residents, their nerves increasingly frayed, speak in whispers of impending chaos.
The reason for the alarm is simple: The city’s water supply is dangerously close to running dry.
If water levels keep falling, Cape Town will declare Day Zero in less than three months. Taps in homes and businesses will be turned off until the rains come. The city’s four million residents will have to line up for water rations at 200 collection points. The city is bracing for the impact on public health and social order.
“When Day Zero comes, they’ll have to call in the army,” said Phaldie Ranqueste, who was filling his white S.U.V. with big containers of water at a natural spring where people waited in a long, anxious line.
It wasn’t supposed to turn out this way for Cape Town. This city is known for its strong environmental policies, including its careful management of water in an increasingly dry corner of the world….
But after a three-year drought, considered the worst in over a century, South African officials say Cape Town is now at serious risk of becoming one of the few major cities in the world to lose piped water to homes and most businesses.
Hospitals, schools and other vital institutions will still get water, officials say, but the scale of the shut-off will be severe.
Cape Town’s problems embody one of the big dangers of climate change: the growing risk of powerful, recurrent droughts. In Africa, a continent particularly vulnerable to the effects of climate change, those problems serve as a particularly potent warning to other governments, which typically don’t have this city’s resources and have done little to adapt.
For now, political leaders here talk of coming together to “defeat Day Zero.” As water levels in the dams supplying the city continue to drop, the city is scrambling to finish desalination plants and increase groundwater production. Starting in February, residents will face harsher fines if they exceed their new daily limit, which will go down to 50 liters (13.2 gallons) a day per person from 87 liters now…
…As far back as 2007, South Africa’s Department of Water Affairs warned that the city needed to consider increasing its supply with groundwater, desalination and other sources, citing the potential impact of climate change. Mike Muller, who served as the department’s director between 1997 and 2005, said that the city’s water conservation strategy, without finding new sources, has been “a major contributor to Cape Town’s troubles.”
“Nature isn’t particularly willing to compromise,” he added. “There will be severe droughts. And if you haven’t prepared for it, you’ll get hammered.” Ian Neilson, the deputy mayor, said that new water supplies have been part of the city’s plans but “it was not envisaged that it would be required so soon.”…
….So far, only 55 percent of Cape Town residents have met the target of 87 liters per day. Helen Zille, the premier of Western Cape Province, which includes Cape Town, wrote in The Daily Maverick last week that she considers a shut-off inevitable. The question now, she said, is, “When Day Zero arrives, how do we make water accessible and prevent anarchy?”
Cutting back is a difficult message to convey in one of the world’s most unequal societies, where access to water reflects Cape Town’s deep divisions. In squatter camps, people share communal taps and carry water in buckets to their shacks. In other parts of the city, millionaires live in mansions with glistening pools….
Researchers found an increasing density of migratory birds as they get closer to cities due to light pollution, which is increasing with more LED use;
They also found that suburban areas, such as people’s backyards and city parks, ….harbor some of the highest densities of birds in the northeast, potentially increasing their risk of mortality due to domestic cat predation.
A new study has examined how light pollution lures birds into urban areas during fall migration, a trend that poses risk for the fowl that often fly into buildings and has increased with the addition of brighter LED lights. The researchers were interested in seeing what factors shape the birds’ distributions and why they occur in certain areas.
We found an increasing density of birds the closer you get to these cities. The effect goes out about 200 kilometers [about 125 miles]. We estimate that these flying birds can see a city on the horizon up to several hundred kilometers away. Essentially, there is no place in the northeastern United States where they can’t see the sky glow of a city.”
…The researchers also found that suburban areas, such as people’s backyards and city parks, such as Fairmount Park in Philadelphia, harbor some of the highest densities of birds in the northeast.
…”Domestic cats could be the largest anthropogenic source of mortality for birds. If birds are being drawn into these heavily developed areas, it may be increasing their risk of mortality from anthropogenic sources and it may also be that the resources in those habitats are going to be depleted much faster because of competition with other birds.”
Another concern: light pollution created in these cities has been increasing in recent years with the advent of LED lights, which are much brighter than the incandescent lights they replaced. “The transition of street lighting from incandescent to LED continues to increase the amount of light pollution”….
James D. McLaren, Jeffrey J. Buler, Tim Schreckengost, Jaclyn A. Smolinsky, Matthew Boone, E. Emiel van Loon, Deanna K. Dawson, Eric L. Walters. Artificial light at night confounds broad-scale habitat use by migrating birds. Ecology Letters, 2018; DOI: 10.1111/ele.12902
Planting 20 percent more trees in our megacities would double the benefits of urban forests, like pollution reduction, carbon sequestration and energy reduction. The authors of the study say city planners, residents and other stakeholders should start looking within cities for natural resources and conserve the nature in our urban areas by planting more trees….
T. Endreny, R. Santagata, A. Perna, C. De Stefano, R.F. Rallo, S. Ulgiati. Implementing and managing urban forests: A much needed conservation strategy to increase ecosystem services and urban wellbeing. Ecological Modelling, 2017; 360: 328 DOI: 10.1016/j.ecolmodel.2017.07.016
Jakartans are digging illegal wells, drip by drip draining the underground aquifers on which the city rests — like deflating a giant cushion underneath it. About 40 percent of Jakarta now lies below sea level.
And it has to deal with mounting threats from climate change which exacerbates scores of other ills— runaway development, a near-total lack of planning, next to no sewers and only a limited network of reliable, piped-in drinking water — all posing an imminent threat to the city’s survival.
Hydrologists say the city has only a decade to halt its sinking. If it can’t, northern Jakarta, with its millions of residents, will end up underwater, along with much of the nation’s economy.
The aquifers aren’t being replenished, despite heavy rains and the abundance of rivers, because more than 97 percent of Jakarta is now smothered by concrete and asphalt. Open fields that once absorbed rain have been paved over. Shores of mangroves that used to help relieve swollen rivers and canals during monsoons have been overtaken by shantytowns and apartment towers
…With climate change, the Java Sea is rising and weather here is becoming more extreme. Earlier this month another freakish storm briefly turned Jakarta’s streets into rivers and brought this vast area of nearly 30 million residents to a virtual halt….But global warming turned out not to be the only culprit behind the historic floods that overran Rasdiono’s bodega and much of the rest of Jakarta in 2007. The problem, it turned out, was that the city itself is sinking.
In fact, Jakarta is sinking faster than any other big city on the planet, faster, even, than climate change is causing the sea to rise — so surreally fast that rivers sometimes flow upstream, ordinary rains regularly swamp neighborhoods and buildings slowly disappear underground, swallowed by the earth. The main cause: Jakartans are digging illegal wells, drip by drip draining the underground aquifers on which the city rests — like deflating a giant cushion underneath it. About 40 percent of Jakarta now lies below sea level.
Coastal districts, like Muara Baru, near the Blessed Bodega, have sunk as much as 14 feet in recent years….
…Climate change acts here as it does elsewhere, exacerbating scores of other ills. And in Jakarta’s case, a tsunami of human-made troubles — runaway development, a near-total lack of planning, next to no sewers and only a limited network of reliable, piped-in drinking water — poses an imminent threat to the city’s survival….
…The aquifers aren’t being replenished, despite heavy rains and the abundance of rivers, because more than 97 percent of Jakarta is now smothered by concrete and asphalt. Open fields that once absorbed rain have been paved over. Shores of mangroves that used to help relieve swollen rivers and canals during monsoons have been overtaken by shantytowns and apartment towers.
There is always tension between immediate needs and long-term plans. It’s a similar story in other sinking giants like Mexico City. Here, all of the construction, combined with the draining of the aquifers, is causing the rock and sediment on which Jakarta rests to pancake….
….JanJaap Brinkman, a hydrologist who for decades has been studying Jakarta for the Dutch water research institute Deltares, sympathizes with residents of communities like Akuarium and Tongkol. Eviction isn’t a cure-all, or even possible, he said, considering how many countless thousands of Jakartans now live atop the canals and rivers in informal developments. At the same time, Mr. Brinkman stressed, moving people is necessary, and bungled evictions squander a meager reservoir of good will and precious time.
“We need big steps now,” he said. “If all the discussions get tied up with fishermen and development, there will eventually be a massive calamity and deaths and no choice but to give up on whole parts of Jakarta.”
….The most ambitious move by the city is the construction of what’s called the Coastal Wall, now rising like a black cliff from Jakarta Bay. It’s a quasi-temporary barrier to hold back the rising sea and compensate for subsidence — built extra high because, like the rest of North Jakarta, it is expected to sink, too. With subsidence at the current rate, the Coastal Wall itself may be underwater by 2030.
….Tokyo was in a similar predicament after World War II, he likes to point out. It had sunk about 12 feet since 1900. But the city poured resources into new infrastructure and established stricter rules about development, and within a decade or two made itself a global model of urban innovation, better able to cope with the effects of climate change.
“Jakarta could become a 21st-century version of Tokyo in the 20th century, an example for urban redevelopment,” Irvan Pulungan, the climate change adviser to the city’s new governor, imagined.
But “a city that can’t deliver basic services is a failed city,” he added. ”On top of conventional issues like flooding and urbanization we now have climate change, tipping the scale. And at this rate, people will be fighting in the streets for increasingly limited resources like clean water and safe living spaces.”
Like Tokyo half a century ago, Jakarta is at a turning point, he said: “Nature will no longer wait.”
Includes 22 no-regrets actions that nearly every city should take to start the journey to becoming carbon-free. Disciplined application of four primary selection criteria helped cut through hundreds of possibilities to define a focused list for cities. The selected recommendations are:
Immediately Actionable: could be launched by city staff within one year
Achievable: recently proven and economically viable, with compelling examples of successful city implementation
Impactful: leading-edge solutions that either make immediate, significant impact or enable large, long-term carbon reductions
Broad Relevance: applicable for most cities globally (population: 100,000+
The end result of ambitious 100% goals paired with aggressive action is the same: transformational change mitigating climate impacts. It is about significant, rapid change on a short time frame, rather than slow, incremental change.
The Carbon-Free City Handbook (pdf), launched at COP23 [at the UN 2017 climate conference in Bonn, Germany], helps city staff implement climate policies and actions that resolutely place their communities on an aggressive path toward sustainable, low-carbon economies.
Cities are at the forefront of climate change risk and opportunity. Nearly 600 cities making climate commitments, but they will only get us so far and must be substantiated with on-the-ground solutions that enable cities to make rapid progress toward near-term decarbonization, and put them on a path to full climate-neutrality.