Sir Martin Holdgate CB, Emeritus President of Friends of the Lake District and renowned environmental scientist and international conservationist, presents a future vision for the Cumbrian landscape. This illuminating talk was presented at our annual open day and AGM on Saturday 15 June 2019.

"Hard to imagine a better lecture, setting out initial thoughts on climate change and Cumbria, than Martin Holdgate's"  - Audience member at original lecture.


Oh no! Not another talk on climate change!

Well, yes. But I don’t see it as yet another variation on the theme of “we’re all doomed”. But it is true that our species – that ‘clever fellow’, Homo sapiens, has achieved greater dominance than any other species in the history of the Earth. We are now altering the global climate to our own potential detriment.

I want to start by reminding us of how climate is caused and how we are influencing it. I then want to look at what is likely to happen in Britain – and especially in Cumbria. That will lead me to some down-to earth points about the actions we may need to take, and what this may mean for the landscape and communities we all value.

So – theme one. What is climate and how is it caused?

Climate and weather are not the same thing. Weather consists of the day to day atmospheric events we all experience – heat and cold, rain and drought, wind and calm. Climate is the aggregate of weather – what all those day to day events add up to over the years. Because climate is an average it inevitably smooths out the extreme variations in weather – yet these are what hit us most. But both climate and weather change because their causes change.

We all know that the climate affecting this block of land we call Cumbria was dramatically different long ago. Look at our rocks. The Penrith red sandstone began in the dunes of a hot Permian desert, and the limestone that overlooks us here in Newbiggin started as a limy ooze in a warm Carboniferous sea. The differences between the climates of around 300 million years ago and those of a chillier today arise because in those distant epochs this block of land lay in the tropics. It has been moved north by continental drift. But the signs of more recent climate change when England was in its present latitude are all around us. Between 80,000 and 15,000 years ago or so, glaciers scraped our crags, lake basins and valleys. And climate change and sea level oscillations have gone together – just after the last ice age the sea was maybe a hundred metres lower than it is now, so that you could walk from Blackpool to the Isle of Man and the whole southern North Sea was a vegetated lowland. The sea has risen because vast masses of ice have melted. Melt the remaining Greenland ice cap and it would rise another 8 metres. Melt the 3000 metres or so of ice piled over the Antarctic continent and it would rise a lot more.

Why these natural changes? Obviously if blocks of land are moved around by continental drift they will experience different climates as they go. Changes in the sun’s heat are another factor – although it hasn’t changed all that much over millions of years. But this doesn’t explain the recurrent icy periods of the past two million years. Cycles in the Earth’s orbit are another factor. It makes a difference if the Earth is at its nearest to the sun in the northern summer, or (as now) in our winter. The tilt of the Earth’s axis also varies slightly. But the warmth at the Earth’s surface depends especially on the atmosphere. Incoming solar radiation passes through that easily enough and warms the ground, but the planet does not get impossibly hot because heat is also radiated back into space. But certain gases – especially water vapour, carbon dioxide and methane - absorb some of the energy. They act like the glass of a greenhouse which lets the radiation from the sun through, but traps the longer wavelengths radiated back from the soil. As a result of this natural greenhouse effect the Earth is much warmer than it would otherwise be. If the atmosphere lacked these greenhouse gases mean world temperature would be between - 6˚C and - 15˚C and there would be ice almost everywhere. It is the greenhouse effect that makes the Earth the abode of life as we know it. And what is surprising is that these so-called ‘greenhouse gases’ make up under 1% of the air.

The concentrations of greenhouse gases in the air do vary naturally. Volcanic activity, the extent of ice sheets and the vigour of plant growth all have effects. But today a new actor has appeared on the global stage. That ‘clever fellow’ – us!

We, of course, are part of the natural carbon cycle. Like all animals, we emit carbon dioxide as we breathe. Fortunately, green plants take it in – and replenish the oxygen we use. For millions of years the natural cycle has been more or less in balance. Carbon dioxide concentrations in the air have oscillated – especially in step with alternate warm periods and ice ages – but human impact has been slight. But now…..

Two hundred years ago this planet had only around a billion human inhabitants. Today there are over 7.5 billion of us. We heat our houses, have vast industries and have mechanised transport systems. The energy these systems use comes largely from the burning of so-called fossil fuels – coal, oil and natural gas – whose carbon has been locked up in the rocks since before the days of the dinosaurs. Human expansion has brought other pressures as well. Large areas of forest have been cleared to make way for farmlands and cities and bogs have been drained. The carbon the trees and peat contained has been released into the air. Cows and other ruminants burp and vent methane and it’s also released when permanently frozen ground in the Arctic melts. Some of the added carbon dioxide is taken up again by vegetation and more has dissolved in the sea – but about half the CO2 released to the atmosphere every year stays there.

Annual global temperatures from 1850-2017

The colour scale represents the change in global temperatures covering 1.35°C [data]

Sampling air bubbles trapped in polar ice has shown that in the 1850s, at the start of the industrial revolution, the atmosphere contained some 280 parts per million by volume of carbon dioxide. By the start of the present century it had risen to about 370 ppmv and it is now over 400 ppmv. If present trends continue, by the end of the century it could reach 550 ppmv – twice the pre-industrial level. That would be a higher concentration than at any time in the past 35 million years.

Adding this carbon is like putting another pane of glass on the global greenhouse – or another blanket on the bed, if you prefer. Records show that between the 1850s and the 1990s the Earth warmed by about 0.7 degrees Celsius. This world map summarizes what happened, showing that the continents warmed more than the oceans, and the polar regions and tropics more than the temperate zones. By 2100 global mean temperature is likely to have increased by another 1.0 to 2.0˚C, depending on what actions the world community takes. Most climate scientists believe that this warming will cause major changes in the weather, bringing more violent storms, heavier torrential downpours and more and worse droughts. Because warmer climate means both more ice melt and the expansion of warmer oceans, sea levels will rise by between 30cm and 70cm and the rise will continue for a couple of centuries whatever we do, with a probable final figure of between 1.2 and 2.3 metres above present levels. This is bad news for some low-lying island nations like the Maldives and Vanuatu, whose very existence may be at risk. Because half the added carbon dioxide is going into the sea, and when it dissolves in water it forms a weak acid – carbonic acid – the sea is becoming less alkaline as well as warmer – both bad news for sensitive coral reefs.

Even if world mean temperature only rises by another degree or so on top of the 0.7 degrees of warming since the industrial revolution, this will add to the immense pressures already being piled on the natural world. High temperatures and droughts may over-stress many species, while the fragmentation of habitats creates barriers to dispersal. If an area warms by 2˚C, that is equivalent to a 240 kilometre pole-ward shift in the limits of tolerance of a species. Suppose the change takes 80 years, migration at a rate of 3 kilometres a year is needed to stay in the same thermal regime. This is faster than many species of plant are likely to be able to achieve – even if there is no obstacle to their migration in the shape of sea, mountains – or farms and towns. Many animals, of course, can go faster – but plant-eating insects can only colonise new habitats if their food plants are already there, and birds and mammals also depend on finding the right kind of habitats. It seems almost inevitable that a lot of species will lag behind the change. And if places like North Africa, southern Spain, the Middle East and parts of Australia get more arid, forests are likely to give way to scrub, dry grassland, or even desert. These changes are being piled on top of processes like the destruction of tropical rain forests and the conversion of wild lands to farms, pastures, oil palm plantations and human settlement. They could lead to a loss of 15% to 35% of species world-wide.

The social and economic pressures underlying all this global transformation are deeply rooted in human attitudes and behaviour. The massive increase in our demand for energy and raw materials is a consequence of economic growth, urbanisation and industrialisation throughout the world – and let us recognise that this has brought great benefits in terms of quality and length of human life. Unfortunately, the conversion of a widening area throughout the globe to human use has brought disbenefits as well. According to United Nations reports, a third of the world’s arable land has been lost to erosion, salinization and pollution in the past 40 years. Some of this has been the sad consequence of desperate poverty. Some has arisen through inappropriate development. Some has been the consequence of incompetent government at local or even national level. As long ago as 1970s expert hydrologists were forecasting that shortage of fresh water would become a serious constraint on human economic growth. We are now beginning to see this prophecy coming true in several parts of the world and this has only a small amount to do with climate change. And it all puts us on the sharp horns of a dilemma. Economic growth and development are urgently needed to lift many poor peoples in many countries out of social misery. Moreover, history shows that the best way to slow human population growth and stabilise our numbers within the carrying capacity of the Earth is economic growth linked to universal education, employment opportunities for all but especially for women, and stable, secure, peaceful prosperity. We need sustainable development. It’s pointless to curb climate change unless we also prevent land degradation.

It has taken human society a long time to wake up to the need for action. Why? I think one reason is that people felt that the world environment was so much bigger than us that we could ignore our impacts upon it. Another was the misplaced belief that nature had been given to humanity by a beneficent God who would somehow look after us however stupidly we behaved. Be that as it may, it was only around 1970 that scientists began to think seriously about how our release of greenhouse gases might create problems. The first United Nations Conference on the Human Environment took place in Stockholm in 1972. The first World Conservation Strategy appeared in 1980. The Intergovernmental Panel on Climate Change – a world-wide assembly of expert scientists – was formed in 1988. A global Convention on Climate Change was signed by most of the world’s nations at the UN Conference in Rio de Janeiro in 1992; and the Paris Accord to the UN Convention dates from 2015. But the activists are right that talk has outrun action.

It is now widely agreed that action to reduce fossil fuel consumption is essential, and the goal is to limit the rise in world mean temperature by 1.5 degrees Celsius above the 1880 figure, with 2 degrees as an outside limit. As I said, however, so far action has lagged behind target and world carbon emissions have continued to rise. Output from the three biggest emitters – China, India and the United States – is still upward. The good news for us is that European emissions – including British ones – have headed in the right direction. Ours have been going down over the past six years and the UK only contributes 1% of the global total. Only last week the Government announced a national target of zero net greenhouse gas emissions by 2050. Good – but as pioneers in the industrial revolution we certainly made a disproportionate contribution to the initial problem. That is why developing countries expect countries like us to do – and pay – more today. I know that one powerful world leader disagrees, but his statements are regarded by most scientists as ‘Trumpery nonsense’.

But enough of that background. Let us now zoom in on Britain and consider what all this may mean for communities and countryside in Cumbria. Look again at a global warming map. The British Isles, on the north-west fringe of Europe, are sandwiched between the continental mass, predicted to warm significantly, and the cool Atlantic, which will change far less. Another piece of good news is that a major change in the ocean circulation in the North Atlantic is highly unlikely. The Gulf Stream is expected to go on bringing warm waters to our western shores.

Within Britain the south-north gradient is likely to get steeper. In the south east, we can expect a rise in mean temperature of around 2˚C by the end of the century, with warmer summers and between 10% and 40% less rainfall. Severe droughts that now happen only once a century are likely once a decade.   Hot dry summers like that of 2018 may happen every 5 years or so. Some models suggest storms with very heavy rainfall will become much more prevalent. Winters will certainly be warmer and wetter. By 2080 nearly every year will be warmer than 1997 - which was the third warmest year ever recorded in the UK.

Here in Cumbria things will change less than farther south. Our mean temperature will probably rise by only a degree or a degree and a half by the end of the century. The good news is that our summers will be a bit warmer and a bit drier. Winters will be appreciably warmer but also wetter, with perhaps 20% more rainfall. I said ‘rainfall’ because the number of days with frost and snow is likely to halve. We may never again see great snowfalls like those in 1947 or 1963. The ‘beast from the east’ may be a rarer visitor.

At the same time, some of that 20% increase in winter rain is likely to come in heavy downpours that bring a risk of flooding – as in December 2015. If river flows increase by 20%, streams may need to widen their channels and reconstructed flood defences will become an investment priority. Some house sites may no longer be tenable. Sea level rise may compel ‘managed retreat’, abandoning reclaimed salt marsh to the sea in places like the shores of Morecambe Bay and the Solway, where low-lying pasture is already very expensive to protect and drain.

What about the effects on nature, farming and landscape? In Cumbria each 1oC rise in mean temperature would displace the limits of tolerance of a species about 120 kilometres to the north or around 100 metres up the fellsides. We are, of course, fortunate in having strong vertical relief and a great diversity of microclimates, because this will make it much easier for a species to match its required conditions by moving only a short distance. But arctic-alpine species that are clinging on to our highest fells as relicts from the last glaciation may be squeezed out. High mountain birds like dotterel, golden plover, dunlin or ring ousel have worsening prospects here. At the same time species from the warmer south will go on edging north, as various butterflies, dragonflies, other insects and birds are already doing. Little egrets are now familiar on the shores of Morecambe Bay. They weren’t there when I was a boy. Possibly other southern birds like cranes, storks and black kites may arrive. Our lakes are already just at the frontier where the northern cold-water salmonid fishes, including relicts like arctic charr, vendace and skelly, meet southern coarse fish like roach – and warming may mean the advance of the latter. Already roach (possibly translocated by anglers) are showing signs of replacing charr in Windermere. However forestry experts do not think there will be great changes in our tree flora – we may find rather more beech at low levels in the South Lakes and sycamore will also flourish, but we are unlikely to see cork oak and olive groves!

But we simply cannot examine changes in the wild flora and fauna without also looking at the human dimension. The dominant determinant of the pattern of landscape and habitat is human land use. Over the past five thousand years or so, successive generations of farmers have altered the Cumbrian landscape enormously. Way back in the Neolithic they started clearing forests to make way for crops and livestock. When they began, maybe 80% of Cumbria was wooded. By the start of the 20th century forest cover was down to around 5 per cent. It is now about 8 per cent. The bare, sheep-grazed, hills are a human artefact. The sheep are aliens, imported from the Middle East. And future changes, while affected by climate change, will continue to be dominated by the way the land is used – and here the determinants will continue to be economic and social.

For Cumbrian farmers a warmer climate may appear good news. It means a longer growing season, so that pastures will flush earlier and continue later into autumn. First cuts of silage can be made earlier and late cuts later. Pastures and arable will be more productive. Higher atmospheric carbon dioxide concentrations may increase plant productivity. However wetter soils in winter may hamper plant growth and cultivation, and cause a greater risk of poached soils if stock are wintered outside. And the northward movement of wild species is likely to be paralleled by the movement of animal diseases. Bluetongue is already here, carried by native midges. Two years ago, an issue of the New Scientist listed African Horse sickness, West Nile virus, Rift Valley fever and St Louis encephalitis fever as livestock diseases vets should prepare for. Our doctors may have to cope with the return of malaria. More seriously – what about the movement of people?  While ours may well be among the countries that will not suffer too badly, we cannot isolate ourselves from the lands around the Mediterranean, which will probably become hotter and drier. Climate change is very likely to aggravate something we have already seen – economic and environmental refugees, streaming in unprecedented numbers towards the areas more favourable for human life.  These pressures could completely alter the social context within which we operate. Already we see the ethical dilemmas posed by migrants seeking to cross the Mediterranean in unseaworthy boats, while the Governments of low-lying tropical islands like the Maldives or some Pacific archipelagos speak of the total submergence of their countries. Are those of us who live in fortunate areas willing to welcome millions of immigrants? If not, what are we going to do?

Clearly we must act now rather than wait for disaster, and that action must span both measures to end our dependence on fossil fuels and wider action to promote sustainable development around the world. And while Britain – and within Britain, Cumbria – can only make a minor contribution to global needs it is right for us to do what we can. I am not going to speculate about the future of farming, though we clearly face major changes. But there is a fundamental point. A healthy and beautiful countryside depends on a sound rural economy. While tourism is an industry of enormous economic importance in Cumbria it is closely intertwined with farming since this maintains the character of the landscape that people come to enjoy. It follows that action to combat climate change has to be taken within the context of other social policies that maintain the local economy. ‘Public good’ is not just a matter of natural beauty and living diversity. The wider human context – and especially the welfare of the people who maintain the cultural landscape – is also of crucial importance. And because climate change is a global consequence of global human actions overlaid on dynamic nature, we cannot treat Britain – and still less, Cumbria – in isolation. Neither is a self-contained entity. We have to look over our shoulders and over the shoulders of our hills. The biggest drivers of what happens here may not be the climate changes on our doorstep but the social and economic ripples of events far away.

But we must surely accept that the problem is real, that action is necessary, and that we are going to have to adapt to a 1.5 to 2 degrees Celsius rise in mean world temperature above pre-industrial levels and a 30 to 70cm rise in mean sea level by the end of this century. How will this affect the landscape – especially in rural Cumbria?

Let us, in that context accept that with or without Brexit, Government will continue to provide support for farmers, including those who manage the Cumbrian hills. But it is not yet clear what form this support will take – or how markets for farm produce may change? Here we have not only Brexit to think about but also changing public tastes including a current questioning of the red meat content of our diet. But it does seem that support may echo the mantra “public money for public good”. And what is ‘public good’? Certainly the maintenance of natural beauty, biodiversity, cultural heritage and the public enjoyment of the countryside. Flood mitigation has also been mentioned as an object, to be supported by the restoration of peat mires and the planting of trees to slow the flow of water from the hills. But what about food production – after all, the main purpose of farming? Last week the Climate Change Committee argued for a 20per cent reduction in the consumption of beef, lamb and dairy products. Once we leave the Common Agricultural Policy there will be those – including Treasury officials - who will challenge subsidy for agricultural business. Clarity is urgently needed.  

In Cumbria, if climate change and social pressures lead to enhanced agricultural production, this is most likely to affect the lowland areas of the Solway Plain, Eden Valley and Lune Valley. Even if the slightly warmer climate and boost to plant growth from higher atmospheric CO2 levels leads to an increase in upland pasture productivity this is likely to be slight and perhaps offset by the greater saturation of the soil in winter. The best guess is that large tracts of our hills will remain livestock country, but that the details may well change in response to market factors and demands for flood mitigation, biodiversity enhancement and conservation of our internationally famous landscape. The prosperity of Cumbria, and the value of its tourist industry are also important factors. But for the Friends of the Lake District the devils – or angels – may lurk in the detail. How much new woodland, where? Should we replace bracken by trees? Would cattle rather than sheep be better for biodiversity – but how would this fit with public access (and the public’s dogs)? Will the most marginal areas be uneconomic as livestock farms? If so, what about so-called ‘re-wilding’? Would re-introducing beavers help flood control?

Let me end with some prophecies! I think we can be confident that restoring and maintaining peat mires will be one positive policy. Cumbria has about 42,000 hectares of peatland – much of it degraded by draining, burning and over-grazing. It stores the equivalent of 250 million tonnes of carbon dioxide, and the half that is actively growing fixes some 15,000 tonnes of CO2 a year. If we could restore the degraded part, we could double its value as a sink, and surely this would be a worthwhile use of public funds? But there are snags, especially on gently sloping fells, where bog spreads across paths. You can see this very well near where I live, in Hartley, where the Coast to Coast walk has to cross some badly eroded peatland on the west side of Nine Standards Rigg. The County Council as Footpaths Authority has tried board walks and stone dumps, but it’s hard to beat a bog on its own ground in a high-rainfall area! And trampling livestock (and humans) don’t help.

What about woodlands? This is a serious question, for if there is a 20% drop in the market for English lamb or a drop in financial support for hill sheep farming, we could see a lot of upland farms go out of business. Diversification into bed and breakfast, payments to conserve biodiversity and a mix of hardy cattle with hardy sheep may help many survive, especially in National Parks and AONBs, but in areas of lower scenic quality, low ecological interest and limited cultural heritage, commercial afforestation may be the most attractive land use from an economic standpoint, especially if planting and maintenance are generously grant aided. And from a climate change standpoint the attractions are real.   Our Cumbrian woodlands cover less than 8% of the county but they hold the equivalent of some 35 million tonnes of carbon dioxide and fix 650,000 tonnes a year. Once upon a distant time the greater part of our county was forested. Should we not now be encouraging an expansion, maybe to as much as 16%? Double the woodlands and restore the bogs and we would offset the emissions of nearly half the resident population of Cumbria. This would certainly fit with the Climate Change Committee’s call for the planting of 3 billion trees as part of the national strategy.

But what should be planted, where? In 1936 the new-born Friends of the Lake District celebrated its first great triumph – the concordat with the Forestry Commission excluding large-scale commercial conifer afforestation from the central Lake District. I am sure that our organization would fight equally strongly to stop such planting today – and would likewise seek to exclude it from the Yorkshire Dales National Park, including the Westmorland Dales.  But it is a fact that 86% of the UK market is for softwood timber, most of which is imported. Should we object to new native broadleaved woodland, or even sensitive mixtures of broadleaf and conifer, especially in areas where hill farming is no longer economic? One of the great attractions of Borrowdale is its ancient valley-side oakwoods, called by the late Derek Ratcliffe ‘the English rain forests’. Although they are not diverse in terms of tree species, they are rich in associated lesser plants and oak has more invertebrates associated with it than any other British native tree. Some areas of hillside near those woods are stony, and others are covered in bracken which is a good marker of deeper soil and former forest. Might it not enhance the landscape to allow these native oakwoods to spread onto stony and brackeny valley sides in the upper dale towards Seathwaite, along Langstrath, and in similar places? Wouldn’t this be good for biodiversity with scenic benefits and negligible loss to agriculture?

Then again, would it really harm the landscape to have more woodland in the Haweswater basin where an ancient and beautiful cultural landscape was drowned out of existence by Manchester so that today, to quote our founder, the Revd H H Symonds, “you may neither lodge, drink nor pray – only curse.” People tend to forget that three major catchments in central Lakeland - Ennerdale, the Thirlmere basin and Mardale - now have no ancient villages and few working farms. They are NOT ‘cultural landscapes’ in the positive sense of the term. Could not a sensitive ‘re-wilding’, better than that now taking place in Ennerdale, give the visitor a sight of ancient wild Lakeland alongside the cherished cultural heritage that we all want to preserve in Borrowdale, Wasdale, Langdale, the Vale of St John, Lorton and Buttermere and suchlike ‘landscape plotted and pieced’? Such new woodlands would be valuable as carbon sinks as well as wildlife habitats, and enhance Cumbria’s attractiveness for a tourism that will certainly be boosted by warmer and drier summers. They might also support a more diverse wild fauna – including beavers as good flood managers, red and roe deer, and….possibly wild boar ? But NOT, I think, long-lost large predators! No wolves!

In concentrating on landscape-level actions I don’t want to give the impression of ignoring what all of us should do as individuals and households. While each can only make a tiny contribution to action against climate change, the global whole is the sum of individual parts. We do need to curb carbon emissions, and this means phasing out fossil fuels. The Governments of Europe are setting an example by scheduling an end to petrol and diesel cars. Gas cookers and oil-fired heating will have to go. But last year total world emissions rose by 2.7%, most coming from China, India and the United States. The UK’s total carbon emissions fell by 1.5% last year – the sixth consecutive annual fall – and is now lower than in any year since 1888. Renewable sources – notably from offshore wind farms – are providing a progressively larger part of our electricity. Good – but how we continue to contribute is important. I am against blotting our landscapes with on-shore wind turbines, plastering the hillsides with solar panels, or opening a new coal mine under the Cumbrian coasts on the specious justification that it will only make a tiny contribution to global carbon totals. But would it not make sense to tap solar energy within the ‘urban jungle’? You can now get solar tiles indistinguishable from traditional roofing slates. In less than a day the sun irradiates the Earth with more energy than humanity uses in a year. Make all new buildings carbon-neutral! Make cities generate their own energy, and keep the landscape green! With that linked to doubling the woodlands and restoring the bogs our county could become carbon neutral by 2040 and possibly sooner.

So, to conclude. Climate change is real. It has many causes, but today human actions are behind a rapid increase in global temperatures and this needs to stop. While Cumbria itself looks like being relatively fortunate, the idea that “we’re all right Jack” is dangerous. Although what we do in Britain will not stop desertification in North Africa, droughts in central Australia, the melting of sea ice across the Arctic Ocean, the shrinking of rainforests, or the rising sea levels that may threaten the very existence of low-lying Pacific Island states, unless we and other countries – especially industrialised ones – take enhanced action things will get worse. Climate change is a consequence of human actions across the whole planet.

The important thing is not to shrug and say ‘I can do nothing’ or ‘it’s all someone else’s fault’, but for everyone and every organization to contribute what we can. We must also press for sustainable development and population stabilisation everywhere. Because uncertainty is inevitable we will have to monitor changes as they occur, and be flexible in our policies. We shall have to adapt rapidly to the changes we cannot prevent. Younger generations look certain to live in ‘interesting times’. But Friends of the Lake District and rural Cumbria can act now to improve the landscapes we hand on to them, and these can be heritage-friendly, climate-friendly and wildlife-friendly and continue to delight and refresh mind and body of millions of visitors every year. That must be our goal.

Banner image by © Jill Brown