The carbon footprint of UK Cities: 4M: measurement, modelling, mapping and measurement

Introduction The planet is threatened by the emission of human-made greenhouse gasses, and in particular carbon dioxide (CO 2) from the combustion of fossil fuels. In 2009, average annual CO 2 emissions were 4.1 t CO 2 per person worldwide, although in developed countries this was substantially higher at 11.5 t CO 2 per person (IEA, 2009). Atmospheric CO 2 concentration has reached 380 ppm globally, with levels increasing by 1.9 ppm annually between 1995 and 2005 (IPCC, 2007). The world's population currently stands at 6.8 billion and is set to rise to c.8 billion by 2050 (PRB, 2009). In 2008, for the first time, over half of all people lived in cities and by 2030 this is expected to rise to nearly two-thirds (UNFPA, 2007). The high density of people in cities, who use energy for transport, food, and consumer goods and services, make them major contributors to global greenhouse gas emissions. The need to reduce CO 2 emissions from cities is clear. International negotiations to curb emissions have had mixed outcomes, but notwithstanding, national and sub-national initiatives proliferate. Policies and economic instruments to cut CO 2 emissions need to operate in a manner that preserves, or even enhances, cities' functioning and environment. Transport emissions have to be curbed without impinging on necessary travel, building energy use needs to be controlled without rendering them inoperable , and emission reduction practices need to impact as little as possible on key ecosystem services 1. Importantly, emissions reduction in all of these areas can go hand-in-hand with improvements to lifestyles and well-being: reduced traffic improves air quality and therefore human health, more energy efficient buildings lower fuel costs to occupants , and green spaces can sequester carbon whilst improving the aesthetic environment and human health and well-being. Thus, a low carbon city can be a cleaner, quieter, healthier and more enjoyable city. The 4M project is examining these issues by estimating key components of the carbon footprint (Wiedmann & Minx, 2008) of the city of Leicester in the UK. The project adopts a multi-disciplinary perspective and is being progressed through collaboration between researchers from five UK universities and Leicester City Council. This enables a rounded view of proposed carbon reduction initiatives to be evaluated in the real social and economic context of a functioning and dynamic city. The project has four activities, measuring, modelling, mapping and managing carbon emissions-hence 4M. The project …