Role of remote sensing in decarbonising cities

Role of remote sensing in decarbonising cities

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Municipalities these days are faced with the challenge of reducing carbon emissions in the cities. The potential of satellite measurements and remote sensing to assist local authorities in planning, mapping, modelling and developing low carbon infrastructure is discussed.

The population of cities is growing at an unprecedented rate. Fifty percent of the world’s populations now live in urban areas, and this figure is rising progressively. Demographers expect that by 2050, 5.3 billion people, or 70% of the human race, will reside in cities. This rapid urban growth threatens to contribute to many environmental disasters—massive habitat loss and species extinction, depletion of the Earth’s finite resources, such as potable water and minerals, extreme pollution and build-up of waste, as well as soaring carbon emissions and global warming. ‘Smart’ development of our cities promises to minimise humankind’s impact on the environment. Because it is imperative for our survival that humanity live harmoniously on Earth, cities must work to become part of the solution through attention to their design, function, and governance.

Space agencies’ measurement of urban carbon emissions
Space agencies are helping resolve some of the ambiguity surrounding the contribution of cities to global carbon emissions. Satellite technology is being deployed to assess city greenhouse gas emissions so that these emissions can be measured and monitored more accurately. NASA’s Jet Propulsion Laboratory Megacities Carbon Project is measuring multi-year emission trends of carbon dioxide, methane (CH4), and carbon monoxide (CO) attributed to several megacities and selected major sectors. After this pilot project’s three year trial, NASA in coordination with its international partners, such as the Japanese Space Agency, may expand it to other cities.


Monitoring urban greenhouse gas emission from space

Remote sensing satellite technology is extremely useful not only for measuring city greenhouse gas emissions but also for gaining an initial perspective on the impact that these growing metropolises are having on global carbon emissions. However, the challenge is to account for those emissions generated outside a city’s boundaries for which a city is nevertheless responsible and which should be included in calculating its carbon footprint. These activities in space could be extended further to assist cities with calculating the emissions inherent within the totality of their energy, water, and waste systems and with providing guidance on which portions of carbon emissions they should be responsible for attempting to mitigate.


Megacities observing system for Los Angeles

Decarbonising of city precincts
Municipalities are not simply measuring their carbon emissions; they are also taking dramatic action to decarbonise by implementing new and innovative low carbon strategies intended to reshape the way cities are designed, built, and powered. This process requires local governments to re-examine their urban infrastructure systems, identify the key sources of carbon emissions inherent in the urban fabric, and reconstitute their infrastructure networks accordingly to be less carbon intensive and more resource efficient. If cities are to successfully respond to 21st Century urban challenges and reduce emissions measured from space, they need greater access to remote sensing tools.

Creating low carbon precincts
Recently, the reduction of carbon emissions at the national level, and to a lesser extent at the building scale, has been the topic of much discussion. However, far less attention has been given to low carbon development at the precinct scale. Neighbourhoods are based on precincts, and new developments within brownfield and greenfield areas are often planned at this finer scale. Moreover, the precinct scale has been recognised as an excellent starting point for initiating carbon-mitigating action within a city.


Cockburn Coast, Western Australia, low carbon urban development (Copyright: Hassell)

Planning and developing low carbon precincts – a role for remote sensing
Municipal governments are often responsible for major precinct-planning decisions that directly affect a city’s carbon footprint. However, to make decarbonisation really work at a precinct level, precinct communities, including councils, local business investors, and community stakeholders, require greater access to the appropriate remote sensing tools for planning, developing, and monitoring their low carbon urban systems.

Insufficient technical and financial resources too often hamper local authorities’ decision-making abilities and efforts to implement low- or zero-carbon development. Remote sensing software tools and applications that could perhaps help municipalities model or map various scenarios are often expensive, insufficient and not readily available at this scale. Or, Geographical Information Systems (GIS) technology is presented as a ‘black box’ to protect commercial interests, so users have limited access to manipulating data, configuring scenarios and hence, being in control of making important assumptions linked with urban planning decisions.

Local authorities need remote sensing tools to help them identify where to prioritise their carbon- mitigating actions and to understand the impacts and trade-offs of certain decisions and the investment costs involved in choosing one strategy over another. For example, the majority of a precinct’s emissions may be driven by unsustainable modes of transport or high-energy usage in commercial buildings. If a council can see that energy usage in a central business district drives the bulk of emissions, the council can then determine which energy efficiency measures will have the greatest effect in reducing its precinct’s emissions.

Councils could also benefit from greater access to remote sensing technology for assessing how their precincts might evolve over time with certain staged planning decisions for low carbon development. This assessment includes the measurement of overall precinct emissions, the impact that infrastructure choices may have on local environmental resources, and the potential cost savings that may be realised for local government and the community by the implementation of any given choice. Greater use of drone imagery integrated within simple, easy-to-use GIS modelling tools would enhance the visual platform and assist municipalities to better conceptualise and thus better understand the potential outcomes of certain modelled scenarios.


Kinesis CCAP Precinct modeling tool (Copyright: Kinesis)

Monitoring low carbon precincts – a role for remote sensing
Precinct communities also need to better monitor the impact of their local carbon-mitigating activities. Remote sensing technology holds great promise for accomplishing this goal. Likewise, satellite imagery and data could provide excellent support for the documentation and visualisation of a precinct’s local environment and for alerting a precinct to any changes that might be occurring because of urban pressures that might affect the resilience of newly implemented infrastructure systems. Remote sensing drone technology could be useful for this purpose also. For example, by measuring atmospheric temperatures, a drone could report the impact that a tall building’s biophyllic landscaping is having on the reduction of a precinct’s heat island effect.


Aerial remote sensing technology (Copyright: PHASEONE Industrial)

Collaboration between space agencies and precinct communities
Fostering greater collaboration between space agencies and municipalities with carbon-mitigating projects could create a win-win situation. Firstly, creating strong linkages at finer scales between cities and remote sensing agencies rather than establishing the linkages between isolated, hierarchical, and generalised governance systems and these agencies, could open doors for cities to obtain the data that are most relevant to their specific urban or climate change challenges. Such challenges are extremely location- specific and complex, and they require many scales of intervention to effectively deal with emissions reduction. Secondly, expertise to use the technology and understand the data is often lacking within local government. If local authorities and their precinct communities work directly with space agencies, they can communicate more easily with remote sensing specialists and therefore achieve a better understanding of the remote sensing data. Local authorities and their precinct communities could in turn provide valuable on-the-ground information to improve the accuracy of space-satellite derived data, which, as mentioned above, can have limitations.

Remote sensing building capacity for local carbon governance
Strengthening the technical resources of municipalities will not only improve governance for low- carbon urban planning and development but also aid in attracting private sector funds for investment in precinct-scale infrastructure projects.

Increasingly, municipalities are working jointly with multiple actors on different levels to implement low carbon development. Partnering with the private sector, creating community ownership models, or involving residents in participatory budgeting are becoming more popular as tactics to attract financing, deal with management, and gain community support for climate change projects. Many organisations—for example, pension funds and insurance companies—are seeking to demonstrate a low carbon profile to their shareholders or board of directors through their investments and operations.


Fremantle, Western Australia involving community in planning of FredZed low carbon precinct (Copyright: J.Green)

Conclusion
Decarbonising cities and subsequently their economies requires many different kinds of innovation and activity. The process can be greatly assisted if precinct level, finer-scale development can be a focus, for precincts are where much new development is taking place and where distributed, low carbon systems can work effectively.

If precinct communities are going to have a substantial impact on reducing carbon emissions, they will need an innovative carbon governance model supported by and linked with the appropriate remote sensing technology. Well-planned cities matched with well-planned governance can help to reduce carbon emissions without sabotaging the population’s quality of life. A new ‘green’ economy accompanied by decarbonised city infrastructure systems will open up new job opportunities, provide clean air to breathe and fresh water to drink, public transportation will be more accessible and efficient, power bills will be lower and active landfills will be replaced with flourishing green areas for food production and recreation.


Renewable energies powering a city (Copyright: iStockphoto.comSi-Gal)

References

  • Un-Habitat and United Nations Human Settlements Programme, State of the world”s cities 2008/2009: harmonious cities. Vol. 11. 2008: Un-Habitat.
  • NASA and Jet Propulsion Laboratory. MegaCities Carbon Project. 2013 [cited 2013 20 January]; Available from: http://megacities.jpl.nasa.gov/portal/.
  • Bunning, J., Beattie, C.,Rauland, V., Newman, P, Low Carbon Sustainable Precincts: An Australian Perspective (unpublished), in Sustainability Journal. 2013, Curtin University Sustainability Policy Institute, (CUSP): Perth.
  • Jones, A., Interview with Jess Bunning, Curtin University Sustainability Policy Institute, (CUSP), 2012, : Perth, Australia.
  • Newman, P. and Kenworthy, J. Sustainability and Cities. 1999, Washington, DC: Island Press.