What can landscape and urban designers to to limit climate change and global warming?

Alma Grove is a survivor of the Metropolitan Borough of Bermondsey street beautification policies of the 1920s and 1930s. Then such street beautification was seen as part of public health provision, along with backgardens for tuberculosis sufferers, window box competitions, public parks and gardens, municipal bakeries (to combat adulteration of flour) and medical provision under the mayorality of Dr Alfred Salter

Wikipedia has good entries on Global Warming and  the Greenhouse Effect. The Intergovernmental Panel on Climate Change summarizes the arguments, details the scientific data and provides a Summary for Policy Makers. The IPCC was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO).   The greenhouse effect is fundamental to climate change theory. It is the process by which radiation (light and heat) reflected by the surface of the earth is absorbed by atmospheric gases. Greenhouse gases include water vapour and carbon dioxide. They transfer this reflected radiation to other components of the atmosphere and it is re-radiated in all directions, including back down towards the surface. This transfers energy to the surface, so the temperature there is higher than it would be if direct heating by solar radiation were the only warming mechanism.  Nicholas Stern made an authoritative review of the economic arguments for dealing with global warming in 2006: The Stern Review on the Economics of Climate Change and concluded that the benefits of strong, early action on climate change considerably outweigh the costs, so that 1% of global gross domestic product (GDP) per annum should be invested to avoid the worst effects of climate change. Otherwise we risk global GDP falling by 20%.

So what does this mean for urban designers and landscape architects? Here is an unranked list:

  • plan ecological corridors to promote migration of flora and fauna,
  • conserve water,  use drought-tolerant plants and change methods of cultivation,
  • use shade structures (e.g. roadside trees) to promote human comfort,
  • design high albedo (= light reflective) surfaces to combat heat island effects
  • plan landscapes for coastal retreat,
  • install sustainable urban drainage systems (SUDS)
  • restructure agricultural and other landscapes as the tree line moves upwards,
  • plan high density settlements to reduce energy consumption,
  • promote the use of  renewable energy,
  • design afforestation schemes,
  • include for recycling and composting in designed landscapes
  • manage river basins to avoid flooding
  • design green roofs
  • use soil conservation and soil carbon sink policies
  • use good design to promote cycling and walking
  • use low embodied carbon materials, (e.g. use flexible paving not paving with a concrete base course)
  • minimizing the area of paving, and built form,
  • use  low thermal conductivity materials e.g. avoid metal paving with a high thermal conductivity, and prefer timber paving with a low thermal conductivity;
  • avoid smooth surfaces with a high thermal conductivity and prefer rough surfaces such as gravel or small unit paving (eg prefer riven stone setts to sawn stone setts)
  • change the form of urban development (eg to avoid high rise and urban canyon effects),
  • avoid thick pavements with a higher thermal storage capacity: e.g. avoid concrete bases to stone paving,
  • increase the vegetation including parks and gardens, street trees and roof gardens,
  • reduce waste heat emissions from buildings.

This list constitutes either ways to limit the increase in global warming by reduction of use and production of greenhouse gases or by ways to ameliorate the effects of such warming such as planning for river flooding in response to the extreme weather events, which are a characteristic of the warming process. For the discussion of the heat island effect refer to London’s Urban Heat Island: A Summary for Decision Makers Greater London Authority October 2006:  “When a land cover of buildings and roads replaces green space, the thermal, radiative, moisture and aerodynamic properties of the surface and the atmosphere are altered. This is because urban construction materials have different thermal (heat capacity and thermal conductivity) and radiative (reflectivity and emissivity) properties compared to surrounding rural areas, which results in more of the sun’s energy being absorbed and stored in urban compared to rural surfaces. In addition, the height of buildings and the way in which they are arranged affects the rate of escape at night of the sun’s energy absorbed during the day by building materials. The result is that urban areas cool at a much slower rate than rural areas at night, thus maintaining comparatively higher air temperatures. Urban areas also tend to be drier than their rural counterparts because of the lack of green space, a predominance of impervious surfaces and urban drainage systems, which quickly remove water from the urban surface.  This combination of effects alters the energy balance of the urban environment. Consequently in urban compared to rural areas, more of the sun’s energy absorbed at the surface goes into heating the atmosphere and thus raising the air temperature than into evapotranspiration (water uptake and loss by plants), which is a cooling process.” The heat island effect contributes to increased mortality rates for the old and the young such as in the hot summers of 2003 and 2006. See the list of GLA publications on the environment and in particular the GLA report on  Living Roofs and walls, technical report: supporting London’s Plan Policy (2008).  Also  the US Environmental Protection Agency website. http://www.epa.gov/ (e.g. http://www.epa.gov/heatisland/index.htm and see http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/7339/report/0

In summary

  • minimize inputs,
  • minimize outputs


  • promote energy efficiency= densification, transport, sustainable production
  • promote waste efficiency= re-cycling and re-use
  • promote food efficiency= local production.

Further references: (1) the Dutch National Waterplan is an excellent example of landscape architects being effective at a national scale is (2009) (2) Michael D. King, Parkinson Claire L., Partington Kim C. and Williams, Robin G. Our Changing Planet, the View from Space. Cambridge University Press:2007 (3) Mathis Wackernagel and William Rees Our Ecological Footprint Gabriola Island, New Society Publishers: 2007 (4) Robert Kunzig and Wallace Broecker Fixing Climate The story of climate science and How to stop global warming London Profile Books Ltd.:2008 (5) Centre for Alternative Technology Zerocarbonbritain2030 Machynlleth, Centre for Alternative Technology Publication: 2010 http://www.zerocarbonbritain.com/

12 thoughts on “What can landscape and urban designers to to limit climate change and global warming?

  1. Christine

    I am not yet convinced of the arguments for densification as much of this theory relies on ‘New Urbanism’ and is based on sociological and amenity arguments against suburbia (sprawl) and the resulting depopulation of urban centres and cost of infrastructure provision. The purported environmental benefits (reduced pollution and greenhouse gases) of reducing the reliance on the car are incidential to the theory.
    [ http://www.newurbanism.org/density.html ]

    This is not so say that ‘New Urbanism’ does not make valuable contributions to urban theory, nor that selective densification within cities and rationalisation of service provision may not be a highly desirable and beneficial strategy. But this is to consider the effect of using a multi-density strategy within cities.

    Taking the diurnal and nocturnal seasonal temperature of cities (ie. measuring the nett heat island effect) might be a useful start point for a macro study of the effect of density and climate change. These measurements could be longitudinal thus capturing the effect of city growth.

  2. Tom Turner

    I am sympathetic to many of the principles of New Urbanism BUT BUT BUT it should be regarded as a design idea for some locations, as you say, and not as a panacea to be rolled out across the world and thrust down everyone’s throats. New Urbanists call for diversity but their idea ‘diversity’ appears to exclude suburbia. Too many of them have spent too much time sipping red wine under Martini umbrellas. They are the descendants of Mesopotamian palace civilizations and they should spend more time thinking about Genesis 3:19: ‘In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return.’ You can’t grow your veg under a Martini umbrella!

  3. Christine

    I wonder when we will start to understand that we are not the only living thing on the planet? And that animals, even the tiny seemingly inconsequential ones, are not just good for eating?
    [ http://rsbl.royalsocietypublishing.org/content/3/6/638.full ]

    If you rarely see nature in your day to day life you will not even consider it in your designs! (Even when eating duck confit at your favourite restaurant.)
    [ http://www.bioone.org/doi/abs/10.1675/1524-4695(2008)31%5B62:LEOWDI%5D2.0.CO%3B2 ]

  4. Tom Turner

    I am reminded of a previous blog post on Easter Island – and suspect we will only appreciate them when they have gone. I read recently that China has used such large quantities of pesticide in some areas that all the bees have been killed and the peasants must know polinate their fruit trees by hand.

  5. Poppy

    From wiki :”Climate change is a long-term change in the statistical distribution of weather patterns over periods of time that range from decades to millions of years.” It is good and necessary to think about the role of landscape architects to “mitigate” climate change,but I always have a personal view that landscape architects can not “limit” climate change,or nobody is able to limit it,because it is a natural phenomena.

  6. Christine

    Hi Poppy, climate change has two components natural and anthropogenic (human-induced).

    There is currently uncertainty as to the extent of the influence of the two components on our climate system. However, mitigation efforts are directed at our ability to reduce human impacts on climate even though we may not know the full extent of the consequences of human impacts.

    Many of these action such as reducing pollution, ensuring a healthy environment and achieving sustainability (social, economic and environmental) are worth doing regardless of climate change.

    Often climate change will merely impact on the parametres of an existing problem, ie forecasting the future frequency and impact of extreme weather events, determining the availability of water resources, addressing the problem of species decline and extinction etc.

  7. Tom Turner

    I agree with Poppy’s scepticism and Christine’s pragmatism: it is good to have politicians supporting an argument for ‘ensuring a healthy environment’. If the policy changes have no significant affect on climate change they are still worth doing for other reasons.
    Re my scepticism, I can never forget that when the British Isles were re-populated after the last Ice Age the sea level was 50m lower than it is today. If human action raises the level another 1m in the next 10,000 years there could well be other causes of other changes which make this relatively insignificant.

  8. Christine

    In the few nations with alpine environments I have researched there is evidence of climatic warming in the increased formation of warmer climate features ie. glacial lakes. Whether these lakes are forming because of natural or human induced climate change or a combination of the two is more difficult to say.

    There is also (incidential) evidence that when acid rain causing sulphate emissions were reduced from coal fired power stations across the US and Europe there was measurable warming as a result. Thus warming of the climate can be directly linked to coal fired power stations.

  9. Tom Turner

    I am sure humans are contributing to climate change – and if a new ice age were to begin then humans might set their minds to thinking how they can achieve more of it. Life in Scotland would be difficult if there were ever again to be a 500m thick layer of ice.

  10. Christine

    Well yes there are arguments for advocating for warming and arguments for advocating for cooling. The point of adaptation to climate change is to be able to adjust to either situation, particularly since global warming is typified by extremes of weather both hot and cold.


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