Think of a place.
How will it change in the next 1,000 years?
The lake at the University of East Anglia (Norwich, UK) is a suitable subject. Created from old floodplain meadows and fenland at Earlham Park in 1977, it is now an asset for leisure and wildlife enjoyed by locals as well as students. But what does the future hold for the lake and surrounding Park in a globally warming world?
I was asked to think about this question for the Art and Biodiversity Summer School 2013 at the Sainsbury Centre for the Visual Arts, I was asked to lead a guided walks for tutors and young students, focusing on the changes to the environment in the years 1000, 2000, and 3000 AD.
The first two dates were easy enough to do. I started by reconstructing life in the Yare valley at Earlham in late Saxon times using historical and palaeo-environmental information. I then went on to look at present day environmental features. Making projections for the year 3000 was more of a challenge. I extrapolated from present trends, and was fascinated - and a bit shocked - by what I found.
See what you think.
Changing landscapes in the Yare Valley, Earlham Park
1000 – 2000 – 3000 AD
An exercise in environmental reconstruction, analysis and conjecture
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The valley in 1000 AD
This is the late Saxon period in Norfolk. To reconstruct life at this time we can use environmental information contained in sediments from the Broads area as well as a archaeological evidence and a variety of historical sources. Many Norfolk people are direct descendants of those living here a thousand years ago.
- England has an agreeable climate. Research shows we are in the time of the Mediaeval Climatic Optimum (950 – 1100 AD; caused by a variation in solar output), although the temperatures were not quite as warm as the 20th century (see http://en.wikipedia.org/wiki/Medieval_Warm_Period).
- Relative sea levels have been falling since about 400 AD; in the seaward areas of the Broads the Upper Peat is being deposited in freshwater conditions over estuarine Middle Clay, while freshwater peat continues to be deposited up-river, as in this part of the Yare valley. This is related to the Great Estuary story (see http://www.enjoythebroads.com/discover/videos/great-estuary-story).
- The floodplain of the River Yare is likely to have been wider than it is today, including tracts of wet pasture, alder carr woodland, fen and probably also areas of natural open water (meres). Springs welling from the Chalk bedrock supply calcareous groundwater into the valley floor, promoting plants which favour alkaline conditions, including stonewort and watercress.
- This is the Anglo-Scandinavian period in Norfolk. Society is based on an agricultural subsistence economy within a manorial system which maintained a distinction between freemen and slaves. Most people are employed on the land. The villages of Earlham (Herela’s Estate), Bowthorpe (Boi’s Farm), Cringleford (Ford by the Round Hill), Colney (Cola’s Island) and Eaton (Farmstead by the River) had been founded by this time, with a mixture of English and Scandinavian elements in their names (Ekwall 1960). Vikings had settled in East Anglia after 870 and the Kingdom of East Anglia was under Danish control as part of the Danelaw until 920. Norwich was not a happy place at this time, being sacked and burned in 993, 1010 and 1014 during Danish invasions (Wade Martins 1984). These immigrants left traces of their settlement in local place names, such as Bowthorpe, Ashby and Kirby Bedon, and words such as ‘gate’ for street (e.g. Pottergate.). Danish settlement was a major spur for the development of Norwich (Rogerson 1998).
|An Anglo-Saxon village at West Stow, Suffolk. Image courtesy St Edmundsbury Borough Council|
- It is likely that the area of what is now Earlham Park would have been a mosaic of farmland, grazing land and woodland on the valley slopes. The Domesday Book (1086) recorded 29 acres of meadow land in Earlham. Natural resources of the valley floor would have included fish and wildfowl, reed, withies, fibre plants, wood, peat, medicinal plants, and their exploitation would have contributed to shaping local biodiversity. Fishing was carried out with nets, spears and basket traps. Plants and animals were subjects of much folklore and popular superstition.
- There would have been peat cutting in the fen, which creates rectangular pools. Norwich was the 5th largest city in England at this time (Rogerson ibid), and so would have been a thriving market place for locally sourced peat for fuel.
|Early growth of reeds amid alder carr woodland, at Blo’ Norton Fen, Norfolk.|
The reed will be harvested later in the year.
- The wildlife would have had high biodiversity. Local species are likely to have included bittern, crane and osprey (Stevenson & Southwell 1890; Whitman 1898); beaver and wild cat (Yalden 1999); trout and eel. Wolves and bears had probably been exterminated in East Anglia by this time (Yalden ibid). There would have been highly diverse flora in the valley, particularly in open areas where reed and peat was cut (see Blo Norton and Thelnetham Fens SSSI today). Moths and butterflies, such as the swallowtail, are likely to have been abundant because of the ecological richness and lack of pesticides in the environment. The name of the River Yare itself has links with wildlife, as it was derived in Saxon times from the Romano-British Gariennus, which may be derived from a Celtic word Garannos, meaning heron or crane (Ekwall ibid).
- Malaria (known as ague or marsh fever) was endemic to the swampy parts of East Anglia.
1000 AD references and resources
o Ekwall, E (1960): The Concise Oxford Dictionary of English Place Names; 4th Edition, Oxford
o George, M (1992): The Land-use, Ecology and Conservation of Broadland; Packard, Chichester
o Greenoak, F (1981): All the Birds of the Air: Names, Lore and Literature of British Birds; Penguin
o Lacey, R & Danziger, D (2003): The Year 1000: An Englishman’s Year; Abacus
o Lambert, JM et al (1960): The Making of the Broads; Royal Geographical Society / John Murray.
o Open Domesday: The Domesday Book – see http://www.domesdaymap.co.uk/place/TG1908/earlham/
o Regia Anglorum: Fishing in Early Medieval Times – see http://www.regia.org/fishing.htm
o Rogerson, A (1998): Vikings and the new East Anglian towns; British Archaeology, vol.35 – see http://www.archaeologyuk.org/ba/ba35/ba35regs.html
o Stevenson, HS & Southwell, T (1890): The Birds of Norfolk; Gurney & Jackson.
o Wade Martins, S (1984): A History of Norfolk; Phillimore
o Whitman, CH (1898): The Birds of Old English Literature; Illinois – see http://archive.org/details/cu31924031439544
o Yalden, D (1999): The History of British Mammals; Poyser.
The valley in 2000 AD
To understand the present day environment in the valley we need to trace its changes over the last few centuries and relate them to present day biological records and environmental information. We are in the opening phase of the Anthropocene Epoch, in which human activities are intentionally and unintentionally modifying natural processes. The start of the Anthropocene may be dated to 1784, with the invention of James Watt’s steam engine which powered the Industrial Revolution and has led to escalating fossil fuel use.
- In 2000 AD, carbon dioxide levels in the atmosphere measured 370 parts per million (ppm), driven by burning of fossil fuels and emissions of methane which been rising since the beginning of the industrial period (global pre-industrial C02 levels were 280 ppm).
- The impact of land drainage over the past 200 years has lowered water levels in the valley, leading to progressive drying out and wastage of peat land on the floodplain. This means that land levels in the valley are lower and the floodplain is somewhat narrower than it used to be.
- The water levels in the river are now artificially regulated by weirs and dams, for example downstream at Cringleford Mill and Keswick Mill.
- Springs and seeps from chalk bedrock supply calcareous groundwater into the valley floor. However the impact of pesticides (fungicides, herbicides, insecticides), artificial fertilisers and sewage effluent has altered the chemical composition of the ground and surface water in the Yare valley over the last 60 years, leading to elevated nutrient levels and diffuse systemic poisoning which is thought to be affecting biodiversity. See for example http://www.thelocal.de/sci-tech/20130618-50367.html.
- This is the post-industrial period in Norfolk. Society is organised within a consumer-capitalist economy, and most of the industrial activity which supports it takes place abroad. Mechanisation means that very few people are employed in agriculture; most are employed in service industries. The Lake is maintained as a leisure amenity area, notably for walking, recreational angling and exercising dogs; it is not used as a subsistence resource for the local population. The 2011 census shows that 12.9 % of the Norwich population (17,094 people) were recorded as having been born outside the UK.
- The 1st edition OS map shows us what the area was like a century ago. The land where the Lake now is was fen land or damp grazing meadows subject to seasonal flooding. This is similar what we see today west of the Heronry (UEA Marsh CWS 1447), across the river in Cringleford meadows and upstream at Earlham Marsh (CWS 1451) and Bowthorpe Marsh nature reserve.
|The site of the Lake, from a first edition Ordnance Survey map c.1888, showing tracts|
of fenland and carr woodland in the Yare valley. There is evidence of artificial straightening
of the river channel. Image courtesy Norfolk Heritage Explorer.
- Alder and willow trees are fringing the Lake. These are typical of the carr woodland seen on parts of the Yare floodplain nearby, as on the other bank of the river at Cringleford Wood. Areas of such woodland may have been more extensive in past centuries. Grazing meadows and fens tend to become woodland if neglected or the ground is allowed to dry out.
- The floodplain was modified by gravel extraction to create an artificial lake in 1977, introducing open water habitat to this part of the Yare valley, and quarry spoil was spread over the floodplain in the area west of the Lake, giving rise to an elevated area of thorny scrub woodland today. There are other examples of pits at Colney and Bawburgh gravel pits upstream. Although the Lake is a County Wildlife Site (CWS 1449 UEA Broad), it is not counted as Biodiversity Action Plan Habitat, unlike others in Earlham Park (e.g Wet Woodland, Lowland Fens, Reedbeds). A shallower lake would be better for biodiversity.
- Biological recording by members of the Norfolk & Norwich Naturalists’ Society is gathering baseline information about species by which future changes to biodiversity can be evaluated.
- Immigrant species have been introduced over the last 1,000 years through deliberate and accidental releases. These include American mink, Canada goose, grey squirrel (native range originally North America), collared dove (western Asia), common carp (eastern Europe), Egyptian goose (Africa), little owl (Europe / Asia), muntjac (South Asia). Immigrant flora include Canadian pondweed (North America) and Himalayan balsam (India). The red-eared terrapin is an immigrant reptile (native to southern North America).
|The Lake, looking from the western end, with White Water Lily in the foreground. |
The water is too deep for water plants to thrive, except close to the edges.
- Migrant bird species recorded at the Lake link it with different parts of the world: overwintering in Africa (swallow, cetti’s warbler, common sandpiper, cuckoo, willow warbler), breeding in the Boreal forest and tundra zone of northern Eurasia (brambling, fieldfare, goldeneye, red-throated diver, shorteared owl, siskin, waxwing, woodcock). Other species move about seasonally as the need arises, e.g. because of bad winters, for example Moorhen (from Holland), Goosander (from Scandinavia).
- Resident species form the core of the Lake’s wildlife assemblage at all times of the year. As ever, local populations are in flux according to habitat loss, weather, predation, pollution and other factors. Small tortoiseshell butterflies used to be common on nettles and are now becoming rare in southern England, thought to be due to predation by an immigrant parasitoid fly. The swallowtail butterfly is now rare because its caterpillars only feed on the plant milk parsley found in fens, now a dwindling habitat. The common frog is threatened by a virus and a fungus whose spread may be linked to global warming.
- Colonisation of this newly created water feature by plants and animals is still continuing. Some native species have returned to the area following persecution and hunting, for example otter, goshawk, little egret.
- Local inhabitants no longer suffer from marsh fever (malaria), because of improved drainage and marsh land reclamation in the C19th and C20th. The nickname of Norwich City football team (The Canaries) is said to have originated in a joke about the jaundiced complexion of Norfolk men caused by this disease.
2000 AD references and resources
o County Wildlife Sites in Norfolk - http://www.norfolkwildlifetrust.org.uk/Wildlife-in-Norfolk/Habitat-explorer/County-Wildlife-Sites.aspx
o Norfolk Emap Explorer – http://www.historic-maps.norfolk.gov.uk/mapexplorer/
o Norfolk Heritage Explorer – http://www.heritage.norfolk.gov.uk/
o Species records for UEA Broad from the Norfolk Biodiversity Information Service - http://www.nbis.org.uk/
o UK Biodiversity Action Plan Priority Habitats - http://jncc.defra.gov.uk/page-5706
o Wildlife sites and species from the National Biodiversity Network Gateway - http://data.nbn.org.uk/
The valley in 3000 AD
A thousand years is very little in geological time, but at least 40 generations in human time. The Yare valley of the year 3000 is likely to look very different from today; we shall clearly be in the Anthropocene Epoch. While we cannot be sure what local details will be like, we can project something of the wider environmental changes which are likely to set the scene for the local ecology. To guess the elements of the biological and cultural environment in the Yare valley at the dawn of the 4th millennium means analysing and extrapolating present trends into a range of potential scenarios. Factors include the burning of fossil fuels (gas, coal, oil), shifts in biodiversity, the impact of human population growth, shifts in land-use, the likelihood of conflict and warfare, technological changes including the growth of biotechnology, growing resource depletion notably soil and water, the possibility of catastrophic events such as volcanic eruptions, and even the possibility of human extinction.
What follows is a conjectural reconstruction based on present trends, enlivened by some imaginative interpretation.
- The closest historical analogue we have for the predicted climate over the next century is the Mid-Pliocene warm period c. 3 million years ago. CO2 values are estimated to have reached 360–440 parts per million, and global mean annual temperatures were approximately 3 deg C higher than today (Salzmann et al 2009).
However, for 3000 AD, the closest climatic analogue we have for the planet is the early Eocene Epoch, c.50 million years ago, when the world was much hotter and there little or no ice at the poles. See https://en.wikipedia.org/wiki/Eocene and https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum/.
- In our imagined scenario, fossil fuel consumption continued through the 21st century, notably coal use in China, although peak oil production occurred as early as 2022. The resulting global warming/heating lasted for five centuries before the climate slowly reached an equilibrium state in the 27th century. It caused deglaciation of the Greenland and Antarctic ice sheets and thermal expansion of the oceans (http://en.wikipedia.org/wiki/Current_sea_level_rise), leading to sea-level rise of over 6 metres. Low-lying coastal areas of Norfolk were inundated and there was a corresponding landward shift of wetland environments. An estuarine environment now extends up the Yare valley as far as Bowthorpe (http://geology.com/sea-level-rise/), with fringing mud flats and saltmarshes.
- The average global temperature in 3000 is over 6 deg C warmer than today. Thus, the average annual temperature in the UK may be comparable with southern Spain today. (http://www.climate-charts.com/World-Climate-Maps.html#temperature). However, in this imagined scenario dangerous exponential global heating has not occurred (c.f. Wasdell 2007). If it had, we would be envisaging a catastrophic scenario.
- Carbon dioxide levels are much higher than today’s levels, at over 1500 parts per million. (In 2013 the Mauna Loa observatory records broke the 400 ppm barrier; global pre-industrial levels were 280 ppm.) At these levels, the area would be experiencing a climate approaching those of the early Eocene Epoch (50 million years ago) see http://www.skepticalscience.com/print.php?n=1380 (n.b. peak Eocene levels were 2000 ppm (http://www.readcube.com/articles/10.1038/35021000?locale=en).
- Atmospheric methane levels are likely to be higher than today. Forcing factors over the 3rd millennium included release of methane hydrates in the ocean and melting of tundra permafrost due to global warming; there was also a volcanic eruption (perhaps in Iceland). This resulted in abrupt shifts in global climatic patterns and amplified positive feedback loops in the weather systems, which lead to several centuries of intense weather instability. Methane levels stabilised after 2400 due to natural attenuation., but remained at concentrations eight times pre-industrial levels (https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum; Sloan et al 2000).
- Unstable weather has become normal, with periods of drought and dust storms alternating with bouts of intense rainfall. This has led to widespread loss of topsoil and extensive gullying of farmland. As a result, much agriculture is now carried out using artificial media under shelter.
- Wildlife is different from that of today. Some Norfolk species were able to respond to the challenges of climate change by shifting their geographical distributions and life-cycles; others became extinct both locally and globally. Heightened temperature and CO2 levels mean that plant growth rates are now enhanced, and fungi, bacteria and algae different from today form the base of the trophic pyramid. Immigrant species typical of Mediterranean, African and Asian habitats today have become established, particularly hardy plants, insects and spiders. These include the malarial mosquitoes Anopheles atroparvus, which breeds in warm, brackish water along river estuaries. However, overall biodiversity has been grossly reduced, with fewer species forming the bulk of the biomass, including those resistant to pesticides and other environmental stresses. Many genetically engineered feral and mutant species are present in the environment.
Drought-resisting Mediterranean plants such as the pistachio
may be at home in Norfolk in 3000 AD.
- Catastrophic changes to marine life occurred in the 3rd millennium, with the cumulative impacts of ocean acidification and warming, over-fishing and pollution contributing to ecosystem collapse in the North Sea, ecological phase shifting, and the rise of algal and jellyfish blooms. The effects can still be seen in 3000 AD in the ecology of the Yare estuary, which has a deeply impoverished fauna compared with 2000 AD.
- Globalised human society has undergone radical transformations. Rapid social evolution and much migration of populations has taken place in step with the forcing effects of environmental change, resource depletion, population growth, disease and an increasingly hostile and unpredictable climate. For instance, an influx of refugees from drought-stricken lands bordering the Mediterranean led to 37% of the Norfolk population being of Spanish and North African descent by 2200. Natural Malthusian processes have acted to control the human population through various decades of disease and starvation; this was particularly true in the aftermath of an Icelandic volcanic eruption in the early 23rd century, which caused a Volcanic Winter lasting nine years and triggered increased global warming feedbacks in the climate system. In 2000 the world population was just over 6 billion, and this climbed to 9 billion by 2040, boosted by continuing use of fossil fuels and genetically engineered foodstuffs. Birth control policies were finally implemented in the 2100s and again in the 2700s, and the world population has now successfully been returned to what it was in the year 1950, and is now artificially maintained at that level.
- A variety of technical solutions to the problems of human life have been attempted, which imitate the functional logic of biological systems through biotech engineering, including bio-robotics and chlorophyll technology. The result is sustainable modular hive technology which guarantees human life is tolerable for the majority within certain limits. The recycling of water, nutrients and wastes are key considerations. Fabricated nutrients are an important component of human diet. What happens in the environment beyond the hive is a matter of general indifference to the human population; biodiversity is no longer a meaningful value. Biological entities are now valued in functional terms as sources of useful information and material resources to mitigate the effects of living on the depleted planet.
- Erlem is part of the Hub City of Norrich. The old UEA site was reclaimed in 2287 following the destruction of its buildings in the Third Boreal War a century earlier, which had been fought over the allocation of scarce water resources. The site was then used for hydroponic cultivation, and drew its fluid from the Yeh Estuary. An entry in the Solicon Archive for 2654 shows that the site was used as a location for a new Chlorofusion Reactor to power the Eton Sub. The view of the valley in 3000 is of an estuarine landscape seen through hot, misty air; a series of low buildings and plant growing installations line the valley sides. Biodiversity is dominated by hardy plants and insects; some herbivorous and insectivorous birds and small mammals are able to thrive in set-aside wilderness strips. The few trees permitted living space are those which been designed or selected for their functional value, and they are arranged in plantations sheltered by awnings and irrigated by a water collection system; rainfall is too erratic and violent for unsheltered and untended trees to survive.
Artificial food production, from the film ‘Soylent Green’
(dir. Richard Fleischer, USA 1973). Image courtesy http://www.dvdbeaver.com
- A tall stone monument to Old Earth was erected in the centre of Norrich in 2128, and its remains are still visible in 3000. The stonework has been eroded by acidic rainfall, and the lettering is poorly legible. It shows a vertical scale marked with a series of global CO2 concentration levels linked with dates. The design is topped with a stone ball chiselled in the likeness of the planet, and the side and back panels are carved with a profusion of interlaced plant and animal species, most of which are unfamiliar to the city’s inhabitants.
- Three attempts were made to colonise polar areas of the planet Mars in the 22nd century. Norrich contributed three couples to one of the expeditions. Each colony was abandoned after a few decades because of supply difficulties, psychological problems among the colonists and the adverse environment (Mars Colony II was buried by a dust storm). It is now generally accepted that planet Earth is the only viable home for the human species.
3000 AD references and resources
o International Geosphere-Biosphere Programme: Have we entered the Anthropocene? – see http://www.igbp.net/5.d8b4c3c12bf3be638a8000578.html
o National Geographic (2004): Six Degrees Could Change The World – Video at: http://www.youtube.com/watch?v=TKo4TSq40l0
o Lynas, M (2004): Six Degrees: Our Future on a Hotter Planet; Harper Perennial
o Mitchell, D (2004): Cloud Atlas; Sceptre
o Reiter, P (2000): From Shakespeare to Defoe: Malaria in England in the Little Ice Age; Emerging Infectious Diseases, Vol.6, No.1 – see http://wwwnc.cdc.gov/eid/article/6/1/00-0101_article.htm
o Salzmann, U, Haywood, AM and Lunt, DJ (2009): The past is the guide to the future? Comparing Middle Pliocene vegetation with predicted biome ditributions for the twenty-first century; Phil. Trans. R. Soc. A 367
o Sloan, CL, Huber, H & Ewing, A (2000): Polar stratospheric cloud forcing in a greenhouse world; in: Abrantes, F & Mix, A 2000: Reconstructing the Ocean History; Springer Verlag
o Warrick et al (1990): The greenhouse effect and its implications for the European Community; Commission of the European Communities
o Wasdell, D (2007): Feedback Dynamics and the Acceleration of Climate Change; APPCCG – see http://www.apollo-gaia.org/BaliandBeyond.htm
o World Bank (2012): Turn Down The Heat - Why a 4 deg C warmer world must be avoided – see http://www.worldbank.org/en/news/feature/2012/11/18/Climate-change-report-warns-dramatically-warmer-world-this-century
‘Norwich in AD 2035 - A prophetic fantasy’, by WT Watling
(Norwich Almanac and Record, 1935). Image courtesy Norfolk Record Office
© Tim Holt-Wilson, July 2013
Photos THW, unless otherwise credited