Politics and eagle's nests
In order to appreciate the place of Ruskin in the modern environmental arena we first have to consider environmentalism in relation to the model of global industrialisation, to which he was responding when it was surging ahead in mid- Victorian Britain. Environmentalism, like industrialism, was not a completely new phenomenon to the Victorians, but rather the culmination of tendencies going back to the seventeenth century. Its roots extend deep into the beginnings of the industrial revolution, from where it became entangled in social criticism, public health Acts, and landscape appreciation. 
All that has happened in recent years has been an explosive realisation that natural resources, landscape heritage and the global commons of sea and air, are being destroyed irreversibly on an ever increasing geographical scale.  This has occurred alongside a sharpening of public awareness of environment, through the media and its popularisation of new divisions of applied biological sciences, such as ecotoxicology. The rapid decline in 'environment health is now seen by nearly everyone as a major threat to the survival of humanity. 
The key to understanding this vast interdisciplinary area of knowledge lies in the synthesis between two eighteenth century primary divisions of knowledge, political economy and natural economy.  These subjects were the birthplace of the many specialisms which produced the compartmentation of scientific information which is now an impediment to civic understanding of environmental issues. 
It is appropriate at this point to give Ruskin's words which sets the tone for the interaction between politics and wildlife.
"And of all essential things in a gentleman's bodily and moral training, this is really the beginning - that he should have close companionship with the horse, the dog, and the eagle.  Of all birthrights and bookrights - this is his first.  He needn't be a Christian, - there have been millions of Pagan gentlemen; he needn't be kind - there have been millions of cruel gentlemen; he needn't be honest - there have been millions of crafty gentlemen.  He needn't know how to read, or how to write his own name.  But he must have horse, dog, and eagle for friends. 
If then he has also Man for his friend, he is a noble gentleman; and if God for his Friend, a king. And if, being honest and kind, and having God and Man for his friends, he then gets these three brutal friends, besides his angelic ones, he is perfect in earth as for heaven.  For to be his friends these must be brought up with him and he with them.  Falcon on fist, hound at foot, and horse part of himself - Eques, Ritter, Cavalier, Chevalier.
Yes; - horse and dog you understand the good of; but what's the good of the falcon think you?
To be friends with the falcon must mean that you love to see it soar; that is to say, you love fresh air and the fields. Farther, when the Law of God is understood, you will like better to see the eagle free than the jessed hawk.  And to preserve your eagles' nests, is to be a great nation.  It means keeping everything that is noble; mountains and fields, and forests, and the glory and honour of them, and the birds that haunt them. If the eagle takes more than his share you may shoot him, - (but with the knight's arrow, not the blackguard's gun) - and not till then"    
Political Economy and Natural Economy
Ruskin's writings were frequently concerned with what he called "political economy". Political economy was one of the two major interdisciplinary themes that unified the gathering and presentation of knowledge about European development for about 200 years.  The other was natural economy.  Natural economy dealt with the organisation of natural resources for human production.  Political economy, as a distinct body of knowledge, is complementary to natural economy.  In Ruskin's day, it dealt with questions about how production is socially organised, the factors that determine the pattern of jobs in different production systems, and the social and economic relationships between workers.  Ruskin would be pleased to see that, increasingly, it now deals with the planning constraints governing the utilisation of natural resources for sustained production.  These questions are usually analysed in relation to different kinds of monetary policies, and economic value-systems.
The distinction between the "natural' and the "political" aspects of industrialism were put in the following way by John Ruskin in the 1870s, "It is one question, how to get plenty of a good thing, and another whether plenty of it will be good for us."  In the context of modern world development, political economy is the launching pad for laws and plans governing development and conservation, whilst natural economy delineates the technological innovations for the exploitation and management of natural resources by which laws and plans can be realised. 
Having said this, Ruskin did not define natural economy as being separate from political economy. But, some of his contemporary readers could dimly perceive a distinction from his writings.  For example, Mr Dixon, a cork-cutter in Sunderland, to whom, in 1867, Ruskin wrote a series of letters stressing how important is was that working people should clearly define their aims in social reform, tells Ruskin of a pamphlet he has read. This "gives an account of how it is the poor Indians have died of Famine simply because they have destroyed the very system of Political Economy, or one having some approach to it, that you are now endeavouring to direct the attention of thinkers to in our country".  In fact, the American march into the West had destroyed the delicate balance between Indian society and the natural economy of its renewable resources, an example of the interdependence of political and natural economy.    Again, Dixon writes, after reading Sesame and Lilies "I cannot help directing your attention to that portion where you mention or rather exclaim against the Florentines pulling down their Ancient Walls to build a Boulevard.  That passage is one that would gladden the hearts of all true Italians, especially men that love Italy and Dante!"   It can be argued that since then the British have lost, proportionately more of their architectural heritage than the whole of Europe.                    
The need to manage nature to retain a wide range of incompatible benefits was not new in Ruskin's day.  It first emerged in 17th century Europe at a time when information about, rocks, soils, and the particular assemblies of plants and animals associated with them, were under scrutiny as resources for increasing human health and prosperity. From the 16th to the early 18th centuries the term economy was used in a context where we would now use 'management', 'control', or 'regulation'.  It defined the ordering of various systems such as the household, animal and crop husbandry, the human body's physiological systems, the political administration of all the resources of a community or state for production.
To a biologist, economy also means the interactions and interdependence of plants and animals.  The latter area was defined by Linnaeus in the 1740s as 'nature's economy' and it is to Linnaeus and his pupils that we must turn for the approaches to a scientific understanding of the linkages of living things in food chains and habitats, which were taken up later in the 18th century, particularly by Gilbert White and John Bruckner.
Managing nature
Although he never articulated it distinctly, it is probably true to say that Linnaeus saw our role in nature as managers of its resources to maintain the orderly and interdependent interplay between living things and their surroundings.  He certainly saw the need to avoid unnecessary destruction and ensure a continuous supply of environmental resources' for human development.  He was aware that the maintenance of natural resources requires knowledge of natural structures, processes, and systems.
From the diaries he kept on his scientific expeditions in search of new resources to fuel the Swedish economy, it is clear that Linnaeus could also see that the richness of an environment was not just the monetary returns that could be obtained from the use of natural resources.  He also put a great value on the aesthetic riches of an unspoiled landscape.   The problem then, as now, is to define the analytical techniques and social mechanisms by which we may regulate relationships between exploitation and stabilisation to maintain standards of 'environmental richness' when different kinds of riches have to be related to a common monetary currency.
Natural economy gained it's knowledge through analytical topography; the study of the whole landscape and its multipurpose uses.  However, as knowledge about the developing European environment accumulated, it was increasingly delivered into expanding academic educational compartments such as geology, and zoology.  In Ruskin's time, natural economy had lost its prime relationship to the human economy and was split into a range of specialist academic subjects.  Also, nature's economy became much more narrowly defined as a subject dealing with unspoiled nature, and eventually reemerged at the end of the 19th century as the academic, non-applied subject of ecology. 
Humanity has now entered an era where we must return to the broad base of 'natural economy' which, in its original definition was both font and focus of knowledge emanating from a wide range of environmental subjects embracing anthropology to zoology.
Modern natural economy defines the ways in which we now treat most of the planet as a resource.  As a theme, based on a well-defined set of principles governing the relationship of people to nature, it stands in relation to environmental management as physics does to engineering.  Also, it can also be an attitude, and a cause, to sustain human development in that it sets out to systematise knowledge that is necessary to balance human numbers with nature, in dignity and harmony.
National and local perceptions of development have to be related to a world view where human well-being is seen to be limited by the Earth's natural economic order, and planners have to deal with many competing global demands on natural resources. This depends on the "landscape capital" of rocks, soils, water, air and the interdependent communities of animals, plants and microbes. This balance between the uses of physical and biological capital produces the ecological segregation of landscape expressed nationally as the country's biogeographic zones, and locally as a particular pattern of land use and settlement. 
The most dominant of these demands is urbanisation.  Ruskin in his description of the expanding city of Geneva in the 1860s cynically describes the fruits of progress, which will strike a cord with any modern traveler faced with endless miniaturised versions of New York and Los Angeles.  In Ruskin's day the models were London and the industrial cities of northern Britain.
"The town itself shows the most gratifying signs of progress in all the modern arts and sciences of life.  It is nearly as black as Newcastle- has a railroad station larger than the London terminus of the Chatham and Dover-fouls the stream of the Limmat as soon as it issues from the lake, so that you might even venture to compare the formerly simple and innocent Swiss river (I remember it thirty years ago-current of pale green crystal) with the highly educated English streams of Ware or Tyne, and finally, has as many French prints of dissolute tendency in its principle shop windows as if they had the privilege of opening on the Parisian Boulevards".
A holistic knowledge system, based on Ruskin's overview is now necessary to deal with the maintenance of the dynamic equilibrium and global accountancy of natural resources.  We have now become the dominant species on the planet, and the dominant force for change.  By comparison, the earth before mankind changed infinitely slowly.   Now, governments and local communities increasingly have to plan within the natural economics of competitive resource utilisation in order to first to gain, and then to maintain prosperity by setting a dynamic balance of land use.  On the credit side is prosperity; in the debit column of the global account is  the decline of wildlife communities, unclean rivers, unstable climates, and the loss of human well-being through the creation of industrialised agricultural systems. 
In the model of industrialisation derived from Ruskin's writings natural economy defines the system involved in our 'social use' of nature through industrialisation.  Expressed as a general model for world development, it represents people drawing living, and non- living, resources from the material environment according to the process of consumerism, which is driven by peoples wants.  These wants are generated within our social environment by education in its broadest context, and are transmitted globally through sophisticated information networks of the media.
People's wants, expressed as 'commodified' foods, goods, services and armaments, are produced as cheaply as possible by industrialisation, which is activated by a combination of science and monetary capital.  Up to a point, human development increases the richness of the landscape, but above a certain population density, and, beyond a certain scale of industrial development, the environment is 'used up' and its riches decrease.
Industrialism no longer means factory production lines;.  Agriculture and tourism are now classed as industries; the one using machines to minimise investment in people to maximise crop output; the other supporting the production of ever larger aircraft and hotels to get economies of scale in transporting people to their holiday destinations, and feeding them with mass-produced food.
Ruskin had his clashes with the embryonic tourist industry.
"In 1862, I had formed the intention of living some years in the neighbourhood of Geneva, and had established myself experimentally on the eastern slope of the Mont Saleve; but I was forced to abandon my purpose at last, because I could not endure the rabid howling, on Sunday evenings, of the holiday-makers who came out from Geneva to get drunk in the mountain villages".
The  products of industrialism, whether it be the latest motor car, long-haul package holiday , or commodified food produced by ranch-type industrial husbandry, change society by increasing peoples horizons for more products.  Industrialism therefore uses up the environment ever more rapidly.  The resultant self-augmenting cycle is an example of positive feedback, which is the most difficult kind of system to control.
Ruskin was right to tell us that control of industrialisation has to exerted through our perceptions of the environment, which are set by moral values (religion), and culture (political philosophy and associated legislation).  Regulatory inputs at one extreme come from the application of collective interest and responsibility (socialism with a small 's'). This is the 'brake" which encourages a balanced or positive use of the environment.  At the other extreme are the corporate and individual interests of capitalism).  This is the "accelerator" which encourages destructive, or negative use of the environment.
If we are to stabilise the natural economy, the year to year stability and riches of regional and local environments first have to be evaluated.  These measured states have then to be compared with desired norms of stability, richness and availability (climate, soil fertility, wildlife diversity, state of industrial resources, and art in the context of our landscape heritage).  Any departures from desirable standards of stability, richness and availability have to be corrected by a change in our attitude towards development.  This correction involves the application of collective interest and responsibility through the social environment so that less is taken from the material environment, and fewer harmful substances are put into it.
Ruskin was concerned with delineating some of the social mechanisms to controlling the use of the environment.  For example, in the 1860s he wrote:
The income of great landowners should be paid to them by the State and,
"So far from their land being to them a source of income, it should be, on the whole costly to them, great part of it being kept in conditions of natural grace, which return no rent but their loveliness; and the rest made, at whatever cost, exemplary in perfection of such agriculture as develops the happiest peasant life;  agriculture which, as I will show you hereafter, must reject the aid of all mechanism except that of instruments guided solely by the human hand, or by animal, or directly natural forces; and which, therefore, cannot compete for profitableness with agriculture carried on by aid of machinery". 
It is a small step across a century of ever-increasing industrialisation of British agriculture, and the destruction of its Georgian patchwork of small fields and woodlands, to see this sentiment expressed in recent legislation to subsidise low-input agricultural systems for maintaining uneconomic agricultural landscapes in so-called 'environmentally sensitive areas'.
In a modern context, education, is required to generate an ecological conscience; legislation, taxation, and commodity pricing, to discourage negative usage of the environment; and the subsidisation of unprofitable use of the environment, to encourage positive management for wildlife and landscape aesthetics.  The latter are global riches that cannot be equated directly with monetary economics
The missing element in Ruskin's work is a firm scientific viewpoint.  Unfortunately, apart from a tourists knowledge of geology, he lacked any scientific understanding, which would allow him to incorporate natural science into the comprehensive knowledge system he was striving to create.  We are occasionally made aware of this difficulty and at the same time see, as in the following passage, where a synthesis between art and science might have led.
He tells us that in 1867, he visited a friend who had been conducting  experiments into the pigments of leaves, each of which he defined by its fingerprint of dark energy absorption bands, or bars, in a spectroscope. 
"My friend showed me the rainbow of the rose and the rainbow of the violet and the rainbow of the hyacinth and the rainbow of forest leaves being born and the rainbow of forest leaves dying. And at last he showed me the rainbow of blood.  It was but the three- hundredth part of a grain, dissolved in water; and it cast its measured bars, for ever recognisable now to human sight, on the chord of the seven colours.  And no drop of that red rain can now be shed so small as that the stain of it cannot be known and the voice of it heard out of the ground.  Then , he characteristically took off at a tangent to define the fulfillment of human liberty in the peaceful inheritance of the treasure of a fruitful earth and not "the ravage of it down the valleys of the Shenandoah".