Overpopulation is usually defined as the state of having more people in one place that can live there comfortably, or more than the resources available can cater for. By that measure, Dhaka is a textbook example.
If we managed urbanisation properly, we could nearly remove ourselves from a considerable percentage of the the planet’s surface. That would be good for many of the threatened species we share this planet with, which in turn would be good for us, because we are completely enmeshed in Earth’s web of life.
High-tech companies should—out of self-interest, if for no other reason—embrace a shift to a kind of urbanism that allows many more people, especially blue-collar and service workers, to share in the gains of urban development. The superstar cities they’ve helped create cannot survive when nurses, EMTs, teachers, police officers, and other service providers can no longer afford to live in them.
Living in a city could significantly increase young people's vulnerability to psychotic experiences. Adolescents growing up in threatening neighbourhoods could develop maladaptive cognitive responses, such as hypervigilance (e.g. becoming excessively aware of potential threats) and attributing negative intentions to people, which might lead them to become paranoid about those around them.
Results of a new study using US national data add to evidence that living in inner cities can worsen asthma in poor children. They also document persistent racial/ethnic disparities in asthma.
Being surrounded by tall buildings produces a “substantial” negative impact on mood.
Man-made noise can have a detrimental impact on an animal’s use of scent – putting them at greater risk of being attacked by predators. What’s becoming increasingly clear is that a lot of other species – mammals, birds, fish, insects and amphibians – are also impacted in all sorts of ways by anthropogenic, or man-made, noise.
A research team has identified urban expansion as the reason for the low amounts of bio-available oxygen in numerous European lakes in past centuries.
Cropland losses will have consequences especially for Asia and Africa, which will experience growing food insecurity as cities expand. By 2030, it’s estimated that urban areas will triple in size, expanding into cropland and undermining the productivity of agricultural systems that are already stressed by rising populations and climate change. The emerging mega-cities will rely increasingly on industrial-scale agricultural and supermarket chains, crowding out local food chains.
By the end of this decade it may be too late to limit global warming to scientifically guided limits, if the infrastructure built in the next four years is constructed along the same lines as currently planned.
Drivers have been urged to close windows and turn off fans while in traffic jams to avoid breathing in dangerously high levels of air pollution.
The link between psychosis and city living was first noticed by American psychiatrists in the early 1900s who found that asylum patients were more likely to come from built-up areas.
The total area covered by the world’s cities is set to triple in the next 40 years – eating up farmland and threatening the planet’s sustainability.
The sheer numbers of people affected by noise pollution mean that it is now right to start intensive efforts towards effective prevention of traffic noise.
Birds that live in suburban areas exhibit significantly higher levels of territorial aggression than their country counterparts. A possible reason for this is that these birds have less space but better resources to defend.
With more than half of the world's population now living in cities, urban sprawl is a growing problem -- particularly in North America, where single-family homes and two-car garages are common. But it's also an increasing concern in various European countries, where living large is becoming more and more attractive.
Adolescents in urban communities may have less aggressive behaviors if they live in neighborhoods with more greenery, such as parks, golf courses, or fields.
There is a growing tension between the arguably necessary role urban areas play in society and the numbing, even debilitating, aspects of cities that disconnect humans from the natural world. As we build bigger cities, we're not aware how much and how fast we're undermining our connection to nature, and more wild nature -- the wellspring of our existence. There's an enormous amount of disease largely tied to our removal from the natural environment
Lower social cohesion among neighbors and higher crime rates contribute to higher rates of psychotic symptoms among urban children. Many studies have found a two-fold increase for psychosis in adults and children raised in urban areas, which is concerning given that more than two-thirds of the world's population is expected to live in cities by 2050.
Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health. Outdoor air pollution causes more than 3m deaths a year - more than malaria and HIV/Aids - and is now the biggest single killer in the world. The toll is expected to double as urban populations increase and car numbers approach 2bn by 2050.