We hear and read a lot about our human carbon footprint but what do we know about our urban footprint? According to a new United Nations (UN) report, this urban footprint will expand by another 1.2 million square kilometres if we fail to make changes to our cities' development patterns. This huge increase is the size of France, Germany and Spain combined. The report's highlights were presented at the recent international science meeting, 'Planet Under Pressure', in London, United Kingdom.
Experts say the urbanization choices we make play a key role in the sustainability of the environment. UN estimates indicate that the human population will grow by 2 billion to 9 billion within the next 38 years, and urban centres will absorb the bulk of this increase. In essence, around 1 million more people are expected on average each week between now and 2050. Cities will likely feel more pressure as rural dwellers (another 1 billion people, according to projections) make their way to cities. The data indicate that the urban population will swell to 6.3 billion in 2050, up by 2.8 billion from today's estimates.
Dr. Michail Fragkias of Arizona State University in the United States says it is important to determine how to urbanize, not whether we have to. But it should be noted that today's ongoing pattern of urban sprawl puts humanity at severe risk, triggered by environmental problems, according to the researcher.
For his part, Dr. Shobhakar Dhakal of the Global Carbon Project in Japan points out that we can gain environmental benefits if we implement reforms in existing cities and carry out better planning of new ones. "Re-engineering cities is urgently needed for global sustainability," says Dr. Dhakal, noting that emerging urban areas "have a latecomer's advantage in terms of knowledge, sustainability thinking, and technology to better manage such fundamentals as trash and transportation."
More than two thirds of the planet's carbon dioxide (CO2) emissions relate to city needs. Urban area CO2 emissions were estimated to be around 15 billion metric tonnes in 1990 and 25 billion metric tonnes in 2010. These figures are expected to jump to 36.5 billion metric tonnes by 2030 if no changes are implemented. Dr. Dhakal adds how the focus should be on "enhancing the quality of urbanization - from urban space, infrastructure, form and function, to lifestyle, energy choices and efficiency."
Meanwhile, Yale University's Professor Karen Seto says: "The way cities have grown since World War II is neither socially or environmentally sustainable and the environmental cost of ongoing urban sprawl is too great to continue."
And Professor Sybil Seitzinger, Executive Director of the International Geosphere-Biosphere Programme at the Royal Swedish Academy of Sciences, says: "A truly sustainable planet will require cities to think beyond city limits. Everything being brought into the city from outside - food, water, products and energy - need to be sourced sustainably. We need to rethink the resource flow to cities."
Explore further: Growth of cities endangers global environment