Dr. Roger Pielke Sr. points out on his weblog this interesting press release from IGBP (from March 2012) that we all apparently missed until now. One of the points worth noting is that there were fewer than 20 cities of 1 million or more a century ago, there are 450 today. Yet, the keepers of climate data tend to discount these effects on temperature measurement.

Cities expand by area equal to France, Germany and Spain combined in less than 20 years

Press release |

Urbanization choices to be fundamental to environmental sustainability, say experts; Equivalent of a city of 1 million needed weekly given population growth trend; Four-day Planet Under Pressure Conference in London attracts 2,800 participants Unless development patterns change, by 2030 humanity’s urban footprint will occupy an additional 1.5 million square kilometres – comparable to the combined territories of France, Germany and Spain, say experts at a major international science meeting underway in London.

UN estimates show human population growing from 7 billion today to 9 billion by 2050, translating into some 1 million more people expected on average each week for the next 38 years, with most of that increase anticipated in urban centres. And ongoing migration from rural to urban living could see world cities receive yet another 1 billion additional people. Total forecast urban population in 2050: 6.3 billion (up from 3.5 billion today).

The question isn’t whether to urbanize but how, says Dr. Michail Fragkias of Arizona State University, one of nearly 3000 participants at the conference, entitled “Planet Under Pressure”. Unfortunately, he adds, today’s ongoing pattern of urban sprawl puts humanity at severe risk due to environmental problems. Dense cities designed for efficiency offer one of the most promising paths to sustainability, and urbanization specialists will share a wealth of knowledge available to drive solutions.

How best to urbanize is one among many “options and opportunities” under discussion by global environmental change specialists today, Day 2 of the four-day conference March 26-29, convened to help address a wide range of global sustainability challenges and offer recommendations to June’s UN “Rio+20” Earth Summit.

Other leading options and opportunities being addressed include green economic development (Yvo de Boer, former Executive Secretary, UN Framework Convention on Climate Change), securing food and water for the world’s poorest (Bina Agarwal, Director, Institute of Economic Growth, Delhi University, India), and planetary stewardship: risks, obstacles and opportunities (Georgina Mace, Professor, Imperial College, London). For a full list of “options and opportunities” conference sessions and topics, see conference website.

Cities responsible for 70% of CO2 emissions

Shobhakar Dhakal, Executive Director of the Tokyo-based Global Carbon Project, says reforms in existing cities and better planning of new ones offer disproportionately large environmental benefits compared with other options.

“Re-engineering cities is urgently needed for global sustainability,” says Dr. Dhakal, adding 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.”

Over 70% of CO2 emissions today relate to city needs. In billions of metric tonnes, urban-area CO2 emissions were estimated at about 15 in 1990 and 25 in 2010, with forecasts of growth to 36.5 by 2030, assuming business as usual.

Addressing climate change therefore demands focusing on urban efficiencies, like using weather conditions and time of day-adjusted toll systems to reduce traffic congestion, for example. Congestion worldwide costs economies an estimated 1 to 3% of GDP – a problem that not only wastes fuel and causes pollution, but time – an estimated 4.2 billion hours in the USA alone in 2005. Estimated cost of New York City’s congestion: US$4 billion a year in lost productivity.

An “Internet of things” is forming, he notes – a fast-growing number of high-tech, artificially intelligent, Internet-connected cars, appliances, cameras, roadways, pipelines and more — in total about one trillion in use worldwide today.

High-tech ways to improve the efficiency of urban operations and human health and well-being include:

Rapid patient screening and diagnostics with digitalised health records;

Utility meters and sensors that monitor the capacity of the power generation net-work and continually gather data on supply and demand of electricity;

Integrated traveller information services and toll road pricing based on traffic, weather and other data;

Data gathering and feedback from citizens using mobile phones;

“Our focus should be on enhancing the quality of urbanization – from urban space, infrastructure, form and function, to lifestyle, energy choices and efficiency,” says Dr. Dhakal. Care is needed, he adds, to avoid unwelcome potential problems of dense urbanization, including congestion, pollution, crime, the rapid spread of infectious disease and other societal problems – the focus of social and health scientists who will feature prominently at the conference. Says Prof. Karen Seto of Yale University, who with colleagues is organizing four of the 160 conference sessions at Planet Under Pressure: ”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.” For these reasons, “the planet can’t afford not to urbanize,” says Seto. “People everywhere, however, have increasingly embraced Western styles of architecture and urbanization, which are resource-intense and often not adapted to local climates. The North American suburb has gone global, and car-dependent urban develop-ments are more and more the norm.” How humanity urbanizes to define the decades ahead Fragkias notes that while there were fewer than 20 cities of 1 million or more a century ago, there are 450 today. While urban areas cover less than five per cent of Earth’s land surface, “the enlarged urban footprint forecast is far more significant proportionally when vast uninhabitable polar, desert and mountain regions, the world breadbasket plains and other prime agricultural land and protected areas are subtracted from the calculation.”

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Read the full press release here

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Dr. Pielke writes:

This land use change not only affects local and regional climate, but also results in a time varying effect on surface temperatures that have been used by the IPCC and others as the iconic metric of global warming. As we reported on in

Montandon, L.M., S. Fall, R.A. Pielke Sr., and D. Niyogi, 2011: Distribution of landscape types in the Global Historical Climatology Network. Earth Interactions, 15:6, doi: 10.1175/2010EI371

GHCNv.2 station locations are biased toward urban and cropland (>50% stations versus 18.4% of the world’s land) and past century reclaimed cropland areas (35% stations versus 3.4% land).

This bias is only going to increase in coming years as urban areas continue to expand.

Recently, I did an essay about the disparity of warming in Texas, and this IGBP press release along with Dr. Pielke’s commentary lends credence to what I found.

The differences between temperature trends between Texas as a whole (which is largely rural by area) and some of its fastest growing cities, such as San Antonio, is quite striking:

The data from San Antonio:

At 0.41 Fahrenheit per decade, it is four times larger than the statewide trend from 1948 to 2011. The population of San Antonio looks like a hockey stick, especially after 1940:

According to the Wikipedia entry on San Antonio: “It was the fastest growing of the top 10 largest cities in the United States from 2000-2010, and the second from 1990-2000.”. So I suppose it is no surprise to find it having such a large temperature trend compared to other Texas cities and the state itself.

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