I read with interest the report on the importance of good urban design so as to optimise usage of land ("Explore how to house all the world in France"; Dec 18, 2015).
On the other end of the spectrum of urban design are slums in developing countries, where people build haphazard structures that are not only lacking in comfort, but are also sources of pollution, due to raw untreated sewage and rubbish that flow into rivers and taint freshwater supplies.
Singapore has achieved optimal land usage within a very short timeframe, due to the comprehensive masterplan we had in place that allocated permissible land use for each plot of land.
If other governments adopted our urban design methods, perhaps many problems linked with overpopulation and the erosion of natural habitats could be resolved.
The ideal city would be one that has minimal impact on the natural environment by way of pollution, uses energy efficiently and controls a sustainable supply of resources for city dwellers.
A very futuristic view of cities is a city built under the sea. That might be the only way to escape global warming if that phenomenon cannot be reversed in time, especially at the equator.
Currently, much more land is being used for agriculture and the rearing of domestic animals to feed the world than that tied up in cities.
As the world population explodes, exponentially more land must be cleared from forests to set up more farms to meet the demand for food from cities.
To counter this dilemma, an ingenious solution to double the yield for that same amount of land is badly needed.
Perhaps, we should seriously consider growing our meat in the laboratory on petri dishes, or using 3D-printing techniques, rather than keeping livestock that requires large pastures for grazing.
Also, we must bear in mind that we are not the only species dominating the planet Earth. It is shared with a multitude of other animals, and our species has emerged only recently when compared with the hundreds of millions of years of head start some of the other animals have.
We have no right to be the causative perpetrator of the next wave of mass extinction in the years to come, as an inevitable result of our actions ("Dawn of new geological age shaped by mankind?"; Jan 9).
Lee Kay Yan (Miss)