Climate change mitigation through landscape planning
Podcast on climate change mitigation through landscape planning
Landscape factors, both human and non-human, influence climate change and can be managed to mitigate adverse consequences. Human factors include agriculture, forestry, urbanisation, power generation and transport. Natural factors include changes in the sun, volcanoes, the Earth’s orbit and the composition of the atmosphere.
Climate scientists investigate the physics, chemistry, geology, biology etc our changing climate. Landscape architects should focus on practical measures relating to land planning, management and design. There is much that can be done and more that may become possible. To date, there has been an imbalance between the necessary research on why our climate is changing and the equally necessary research on how urban and rural landscapes can be adaptated to mitigate the the consequences of climate change.
The examples of multi-objective landscape planning discussed in this podcast are in Upland Britain, London, Egypt and Ladakh. There is a transcript of the text below and a Youtube video will follow in due course. The landscape measures will, I believe, be significantly more effective than a ban on single-use plastic shopping bags. But for other reasons I am a great believer in recycling plastic and designed Gyre Island as a contribution to the de-plasticization of the ocean environment.
A landscape planning approach to mitigating climate change: transcript of the podcast + links
There’s widespread scientific agreement that human use of fossil fuels has become a primary cause of global warming – and that a transition to renewable energy is therefore necessary. We need to reduce the overall demand for energy and we need to increase the supply of non-carbon fuels. I agree with this. But if carbon dioxide is not the only cause of global warming, which it isn’t, then other solutions, will also be necessary.
William Ruddiman, a geologist and palaeo-climatologist, put forward the Early Anthropogenic Hypothesis and it’s been raised to the level of a Theory. He argues that human influence on climate change began at least six thousand years ago and was caused by emissions of the three main greenhouse gases:
- Levels of Carbon Dioxide, CO2, were raised by forest clearance in the ancient world and by the use of the cleared land by early farmers
- The release of Methane, CH4, was increased by livestock rearing and rice cultivation, also in the ancient world
- The release of Nitrous Oxide, N2O, increased with the use of artificial nitrogenous fertilizers, particularly after 1960. Nitrogen now pollutes rivers, lakes and water supplies
William Ruddiman’s theory of anthropogenic climate change is based on graphs showing cooling and warming in previous interglacial periods. The graphs show that, geologically, the Earth is nearing the end of a warm interglacial period, called the Holocene, which followed the Pleistocene glaciations. Also known as The Ice Age, the Pleistocene lasted for 2.6 million of the Earth’s four and a half billion year lifetime. That’s not much. Previous extinction events are associated with geological processes, including plate tectonics, volcanoes and meteors.
Earth’s climate was much hotter before the Pleistocene and in 90% of the preceding 500 million years, the north and south poles had no permanent ice.
Typically, a Pleistocene glaciation lasted for 90 thousand years, and interglacial periods for about 10,000 years. The cycles, of glacials and interglacials, coincided with changes in the Earth’s orbit known to geologists as eccentricity, obliquity and precession. Since the current interglacial period began about 12,000 years ago, we are believed to be approaching the next glacial period – and global temperatures ‘should’ be falling. But human activity appears to be delaying the advance of the ice.
The geological era in which we live is therefore described as the Anthropocene, derived from the prefix ‘anthropo’, meaning ‘human’. It is defined as: ‘the period during which human activity has been the dominant influence on climate and the environment’. If Ruddiman’s Theory is correct, the Anthropocene results:
- in part from the Neolithic Revolution, when agriculture began
- and in part from the Industrial revolution, when we came to rely on fossil fuels
We therefore need measures to deal with the adverse side effects of two revolutions on the Earth’s climate.
The measures discussed in this podcast are examples of Sustainable Landscape Planning. Humans could migrate from coastal areas and the tropics towards the north and south poles. But if global warming continues, and we want to stay where we are, then in both urban areas and rural areas we will need plans:
- For reducing our use of fossil fuels
- For reducing the output of methane and other greenhouse gases
- For sequestering the carbon we have already released into the atmosphere during the past 6000 years
The examples I’m going to discuss of how to plan for this come from areas where I have lived and worked: three are in Britain, one is in Egypt and one is in India.
1. Let’s start with the landscape planning Britain’s Uplands
By international standards, they’re not high. Most of the area is under a thousand meters in elevation. It’s character is bare hills with expanses of heathland and blanket bog. These Uplands constitute 38% 38% of Britain and are much influenced by public policy. Without human intervention most of the upland area would be woodland, as indeed it used to be before we cut down the trees for fuel and replaced them with hill sheep farms.
Today, we subsidise sheep farming, which stops trees growing on the hills, and we subsidise conifer plantations behind high fences, to keep out sheep and deer.
With climate change objectives now centre stage, we need landscape plans for redirecting public investment in the uplands to public goods. These plans are likely to centre on multi-objective land management, including rewilding, reinstating woodland habitats, accumulating biomass in trees scrub and soil, detaining water, and managing livestock in woodland pastures. IQ2 hosted a great debate on this issue with arguments for and against re-wilding.
2. Landscape planning for London’s Green Belt.
There are several videos and blog posts about this on the Landscapearchitecture.org.uk website.
The original Green Belt idea, as put forward by Ebenezer Howard, had two main aims: to constrain London’s growth and to create a public amenity for residents of the metropolis. In practice, the first aim has greatly outweighed the second.
As it exists today, the Green Belt is a mainly rural area three times the size of London. Its small towns and villages are dominated by the metropolis and getting permission for new building is really difficult. Agriculture survives without prospering. The belt has a lot of horses and horse grazing, a wealth of golf courses, many small badly managed woods, some country parks, not very well managed, and a few good routes for walking and cycling.
Most of the Green Belt is not in public ownership and provides few public goods. But this could change, and the feasibility of managing the London Green Belt to help combat Global Warming should be thoroughly investigated.
Medieval castles and palaces were surrounded by great hunting parks, which belonged to their rulers. 21st century cities could have comparable green belts in which public money is used to create landscape public goods.
Natural capital should be developed with a full awareness of its potential contribution to climate change objectives. The Wikipedia entry on Natural Capital explains the idea as follows:
“It is an extension of the economic notion of capital to goods and services provided by the natural environment. For example, a well-maintained forest or river may provide an indefinitely sustainable flow of new trees .. or fish… Natural capital also provides people with essential services, like water catchment, erosion control and crop pollination by insects, which in turn ensure the long-term viability of other natural resources”
In the Green Belt, public money should be used to develop natural capital, instead of giving financial support to intensive agriculture. This would contribute to the costs of carbon sequestration, wood pasture, foraging, rewilding, aquifer recharge, water supply, recreation, scenic beauty and other public goods.
With regard to food supply, the quantity would be reduced and the quality increased. Wild food provides a wider range of nutrients than the products of industrial agriculture and intensive food processing. This fits with the dietary advice to eat less meat, but higher quality meat. Other nutritious possibilities include the use of woodland to supply Walnuts, Hazelnuts, Chestnuts, Berries, Fruit and Fungi – including Truffles. Their prices are rising because they are important to vegans and veganism is growing. The Sweet Chestnut, Castanea sativa, is well suited to London’s green belt. I did an optimistic post about this on the Gardenvisit.com website in 2011 but now see collecting chestnuts is more of a healthy hobby than a commercial enterprise.
Brazil, said to have the world’s best Dietary Guidelines, advises everyone to ‘Make natural or minimally processed foods the basis of your diet’. Green belts rich in natural capital can help improve our diets.
3. My third set of examples of planning to combat climate change, are for Greater London
‘Could landscape planning reduce the city’s impact on global warming?’
Like other cities, London can become more sustainable by reducing its inputs and reducing its outputs. Stuff needs to be recycled and reused.
There’s a diagram to illustrate this principle in the book from which I took the title for this set of podcasts: City as landscape. It’s on page 91. Water, energy and materials are shown as examples of inputs to be reduced. And as examples of outputs to be reduced, I used water, wastes and pollution.
Let’s take water first, because it’s both an input and an output.
I first read about the need and potential for aquifer recharge in Ian McHarg’s book on Design with nature. Later, I discussed it in a book Landscape planning and environmental impact design. This quotation is from Chapter 9 on Rivers and Floods:
“In all the industrial countries, rivers have suffered from forest clearance in the uplands, farm drainage in the lowlands and water-proofing in urban areas. Forest clearance took place on the hills, in the valleys and on the plains. This accelerated water runoff. Ploughing and drainage took place in agricultural areas. This accelerated water runoff. River channels were deepened, widened, straightened and fixed. This accelerated water runoff. Large new urban areas were rendered partially impervious, with roofing and paving materials. This accelerated water runoff. The capacity of washlands and flood plains to accommodate peak volumes was diminished by building upon them. Accelerated water runoff raised flood peaks. It then became necessary to place urban rivers into underground culverts or concrete canals, or to supplement their capacity with ‘flood relief channels’. The net effect of all the changes was a dramatic increase in peak storm discharge. Embankments had to be built to prevent overtopping by floodwater. When these works are viewed together it is clear that they do not constitute a good use of public or private expenditure.”
Large sums of money and megawatts of energy were spent on concreting flood defenses and pumping water from one place to another.
In London, the egregious current example of this approach is the Thames Tideway Tunnel. It’s a vast new sewer being built under the River Thames with the design aim of accelerating the flow of storm water from the land to the sea. The sustainable and climate-friendly solution would have been a low-impact drainage scheme, known in the UK as Sustainable Urban Drainage.
The principle is that storm water should be detained, infiltrated and evapo-transpirated on or near the ground on which it falls. With storm water returned directly to the aquifer, London’s sewer network would not be overburdened in periods of heavy rain and the new tunnel would be superfluous.
What London really needed was a reclamation project for its lost rivers. Engineers buried them. Landscape architects should daylight them.
To feed its rivers and aquifers with clean fresh water, London also needs a network of swales, ponds, channels, rain gardens, living walls and living roofs.
Compared to surface water sewers, they are cheap to build and a welcome addition to the urban landscape.
From a global warming perspective, they would save on the use of fossil fuels to build, operate and extend the stormwater sewer network. The Thames Tideway Tunnel alone will cost £4 billion pounds. Then there will be running costs for ever and ever.
Cycle infrastructure and climate change
Transport is another issue. This sector was responsible for 33% of UK CO2 in 2018. Though being reduced, this is happening at a much slower rate than that achieved by the residential, business and energy supply sectors.
By far the most effective and greenest way for the transport sector to reduce its use of energy is to plan and design for a switch: from motorised commuting to commuting by bicycle and on foot. I’ve made a number of Youtube videos about cycling policy.
In the UK, over 80% of the people live in urban areas and over 60% of the trips they make are done by car. Most of our cycling infrastructure is dreadful and less than 2% of all trips are done by bike. In Denmark and Holland, the cycling infrastructure is good and the urban cycling mode share is approaching 50%. This saves a lot of money, a lot of fuel and a lot of air pollution.
The greenhouse gas emissions from mass bicycle transport are below one eightieth of the emissions from travelling the same distance by car.
And the Benefit:Cost Ratio for building Cycleway Networks is between 2 times and 20 times higher than the typical 2:1 BCR for motorised transport projects.
Cycling is the fastest, cheapest, healthiest, safest and most sustainable transport mode for half of all urban trips.
To get more people travelling by bike, cities should build good cycleway networks. Quantity and quality matter. The key principles are:
First, cycleways must be safe and must look safe. This includes protection from accidents and from air pollution. After dark, cyclists feel safest when there is good lighting and good visual policing.
Second, cycleway routes must be based on desire lines, as they are understood by landscape architects. Commuter cyclists want fast A-to-B connections and are much influenced by the quality of the route. A well-designed greenway, though longer, can attract cyclists from shorter but heavily trafficked routes.
It’s not enough for a cycleway to be ‘engineered’ as a mini-road, using standard design criteria. To attract users Cycleways should also be works of landscape architecture: useful, beautiful and sustainably context-sensitive. The design aim is to design a cycle network routes that persuades cyclists not to use motorised transport modes.
Climate-friendly building is a third issue.
With their acceptance of the Modernist design principle that form should ‘follow function’, architects began making exteriors a consequence of internal use of buildings. So contextual issues were ignored. This was a wrong turn.
Buildings should look green, in the sense of vegetated, and they should be green, in a broad environmental sense.
NO DEAD SKIN is a good climate-friendly policy for relating buildings to contexts. In addition to their traditional roles, exteriors should support vegetation, detain and transpire water, generate energy and let buildings make friends with their neighbours, socially, aesthetically, climatically and ecologically.
Most building skin should be designed to support vegetation. Plants and substrates can insulate interiors from heat loss and from heat gain. Vegetation sequesters carbon, supports wildlife, absorbs noise and lessens surface water discharge. Living roofs can be gardens, open to the sun, isolated from traffic noise, free from fumes. Or they can be wildlife habitats, contributing to biomass and biodiversity.
Other parts of the building skin should allow for interiors to be naturally lit and naturally ventilated. This is sweeter and healthier than energy-consumptive heating and ventilation systems. South-facing walls are good places for solar arrays to generate electricity.
Tall buildings should be designed with special attention to their impact on microclimates. Towers can reflect sunlight into dark corners and gloomy alleys. In hot countries, buildings can provide shade and ventilation, as they did in the ancient South, East and West Asia. In cold countries, groups of buildings can be designed to provide shelter from strong winds.
Singapore has a really good ‘landscape replacement’ policy for vegetating buildings and their surroundings. Launched in 2009, it requires all new developments to provide: “Landscape Replacement Areas which in total are at least equivalent in size to the development site area.” So a hundred square meters of land must have at least a hundred square meters of vegetation. In 2017, the policy was extended
- To include vertical greenery and green roofs
- To support rooftop urban farming, and other sustainability-related features; and
- To set Green Plot Ratio standards for private developments
Singapore has a great acronym for its policy: LUSH. The letters stand for Landscape for Urban Spaces and Highrises.
Most cities need to do much more than ‘replace’ habitats destroyed by current development and redevelopment projects. They also need to replace the natural habitats which were built over when the land was first urbanised. Their pre-industrial lushness can and should be restored.
4. My fourth example of landscape planning to combat global warming is from Egypt.
I worked there in 1975 on a UNDP financed Regional Plan for the Suez Canal Zone. The project team leader was Jac Smit, who later became known as ‘the ‘Father’ of ‘Urban Agriculture’. My responsibility was for the environmental section of the plan.
Having studied landscape architecture at Harvard, where he was inspired by Jaqueline Tyrwhitt and Patrick Geddes, Jac Smit was a great believer in landscape planning. With a broader view than mine, he argued that Egypt’s agricultural land should be protected and that its fast-growing population should be housed on the desert land which fringes Egypt’s delta. His policy was not followed. Instead, Egypt has reduced its carbon sequestration by building on farmland, destroying topsoil and removing vegetation. This is also being done in India, China and most of the developing world. It’s a climate-unfriendly and most unwise policy.
In 2015, forty years after publication of the Suez Canal Regional Master Plan, Egypt took Jac Smit’s advice and began construction of a new city in the desert between Cairo and the Suez Canal. In design terms, the plan looks like an unhappy marriage of northern Baroque and Modernist design principles. Who would ever guess that this is a desert city in a hot arid environment? It looks as though it was designed by a Chinese company – and it was.
5. My fifth example of landscape planning to combat global warming, is from Ladakh
It is a part of Northeast India where I’ve been helping to make a garden for a Buddhist-influenced school. It illustrates the point that different places require different approaches to planning for climate change.
Ladakh is a Himalayan region. It borders Tibet, with a similar language and even less rain – about 100mm per year. The elevation of the garden is three and a half thousand meters above sea level. Without water from melting snow, agriculture would not be impossible. Its glaciers are retreating and its snowfields contracting. The weather is always sunny, warm in the summer and very cold in the winter. Geographically, it’s classified as a cold desert and it’s river valleys are oases.
Ladakh has been called ‘the canary in the coal mine’ for global warming. When the snowfields have melted the region will become uninhabitable.
The region’s travel sector is booming but tourists are less environment-friendly than the local people. They like their hotels to be built on Ladakh’s very-scarce agricultural land. For everyday living, they use much more water and much more energy than the Ladakhis.
The Druk White Lotus school was built, as Jac Smit would have liked, on desert land. This saves agricultural land from being lost but exposes the school community to extremes of heat, cold and wind-blown dust.
The architects, Arup Associates, applied sustainable principles to the building design and have won many architectural awards for their work. The building stone, granite, was locally sourced and squared by hand. The heating is passive solar, using Trombe walls. Electricity is generated by solar panels and used to pump water from, we think, a dynamic aquifer. After use, the water seeps into the River Indus.
All the toilets are composting. The planting policy is based on hydrozones and soil development zones. Local plants are being used to establish shelterbelts as protection from dust storms and to shade outdoor areas. Building on deserts is much more sustainable than building on farmland.
The land surrounding the school is being made into a Dragon Garden. The design strategy is secular but Buddhist-influenced. Dragons symbolise compassion and gentle power. The Lotus, as used in the school’s name, is a symbol of enlightenment. It’s a climate-friendly garden – and there’s a good deal of information about it on Youtube. See playlist of Youtube videos on Druk White Lotus School landscape and garden.
Interim conclusions on landscape planning in an era of climate change
Well, having looked at examples of how landscape architects can help combat global warming, I’ll finish with some general thoughts about climate change.
The fundamental point is that you can’t argue with thermometers. If sufficient records say the climate is changing then as far as I’m concerned, the climate IS changing. And if this is going to lead to the flooding of densely populated coastal areas, then effective action should be taken.
Now for a short digression. I remember looking out of an aeroplane window on my first night-flight, in the 1960s, and being amazed at the quantity of artificial lighting in urban areas. My thoughts were that ‘This can’t be good’ and that ‘This can’t last’.
- In the 1970s I didn’t need the Club of Rome to persuade me that, one day, the oil will run out, though I was sceptical about when this might happen.
- In the 1980s, as a London cycle commuter I became ‘interested’ in the air pollution, noise and road safety arguments for reducing car transport.
I should therefore have been an early adopter of the climate change argument for transitioning away from fossil fuels. But I was put off by three aspects of the campaign.
- First, I heard too little discussion of the influence of Nature on climate change. Everyone who’s studied geology knows its importance. Though man’s impact on climate may be greater at present, the influence of non-human factors will surely be greater in the longer term and we are, of course, part of nature
- Second, I dislike the comparison with holocaust deniers implied by the phrase ‘climate change denier’. The comparison is insultingly ill-judged.
Scientists should be sceptical and should welcome criticism. They have weakened their case by becoming politicians and by saying so little about the historic and the non-anthropogenic causes of climate change
- Third, too many proposals for dealing with global warming are un-researched, unrealistic and trivial. I remember asking the checkout lady who first refused me a polythene bag for my shopping if she thought her employer’s policy would ‘save the planet’. ‘Oh no, she said, but it may gie us a few extra minutes’.
These factors have weakened the case for taking effective action on climate change.
My own assumption is that William Ruddiman’s Theory of Anthropogenic Climate Change is correct. So I think man’s influence on climate began with the Neolithic Revolution, became more significant with the Industrial Revolution, and became even more significant with the Oil Power Revolution of the 20th century. Ruddiman’s graphs show that from a geological perspective the past 10,000 years have been most unusual for their relative climatic stability. We’re over-warming the planet now and it could be a wise policy to hold back hydrocarbon reserves until global warming is needed.
Avoiding global cooling without an excess of global warming will require Climate Management, Geo-Engineering and CaLP. That’s Climate and Landscape Planning. The present need is to reverse global warming. But when we have exhausted the world’s hydrocarbons, an opposite policy may be required, just as we switch between central heating and air conditioning between winter and summer.
For this to be possible, we will need much more information on the consequences:
- of a transition from fossil fuels to renewable energy
- of changes in the size of the world’s population
- of landscape planning policies, as discussed in this podcast
- small-scale policies which get a lot of publicity, like banning single-use plastic bags,
Research on the costs, effectiveness and acceptability of policy alternatives should proceed in step with research on the causes of climate change. Policy changes should be evidence-based.