The vast majority of environmentalists are progressive. They are pro-human, pro-science and pro-free enterprise. They not only differ with the reactionaries on tactics and style, they also hold fundamentally different values. The following is a brief summary.
A Realistic View of the Past. Progressives are under no illusion that American Indian communities were Gardens of Eden or that the Indians lived "at one with nature." Alston Chase has described how Indian tribes set fires in order to drive herds of frightened buffalo over cliffs, killing far more than the Indians could ever consume.: So extensive was the Indians' use of fire that they virtually created the treeless prairies of the Midwest long before the white man arrived, and their zeal for hunting often decimated the quarry they depended upon to survive.  For example, once Indian tribes acquired horses and rifles, I they almost wiped out the buffalo herds in some parts of western America.  Some tribes were more environmentally responsible than others, but on the whole Indians, like other people, appear to have used nature to their own ends – constrained only by the technology available to them.
Nor are progressives under the illusion that medieval communities were good for the environment or for humans. The use of livestock in agriculture and of animal power in agriculture, trade and transportation led to increased animal waste and significant water pollution, contributing to the high rate of human mortality from infectious diseases. In the 13th and 14th centuries, navigation on the Thames was greatly impeded by human, horse and industrial wastes. Air pollution was so bad that England made coal burning for home heating punishable by death.  The replacement of the horse by the automobile was universally and correctly viewed as a major environmental improvement. The modern city has different forms of pollution. But it is "certainly ... an improvement on the relatively tiny, but incredibly filthy, streets and waterways of medieval and Renaissance cities." 
Unlike the reactionaries, progressive environmentalists look to the future. They hope to use human intelligence, creativity and technological prowess to solve problems that have never been solved before.
A Realistic View of Man and Nature. Progressive environmentalists recognize that nature is not all good or all bad – from a human point of view. Nature produces marvelous wonders, such as the Grand Canyon and the tropical rain forests. But it also produces earthquakes, volcanic eruptions and hurricanes. For the future, nature almost certainly has another ice age in store for us and very probably a cataclysmic collision with a large meteorite – unless we can figure out ways to avoid these catastrophes. The challenge is to use science and technology to preserve the good and avoid the bad.
Unlike the reactionaries, the progressives know that we do not have the ability to turn the earth into a "lifeless planet." We do have the ability to destroy ourselves and most animals and plants with which we currently share the planet, however.
Suppose the worst happened. Suppose a nuclear war wiped out all human life and most animal and plant life as well. What would the world look like beyond that point? According to Harvard scientist Stephen Jay Gould, we don't have the ability to kill all insects and bacteria. So the process of evolution would begin again. Fifty million years from now (a short period on the geological scale), the earth would be teeming with life. Perhaps a new species of dinosaur would ultimately appear. Or perhaps other life forms would emerge that are beyond our ability to imagine.  Progressive environmentalists prefer the current state of the world not because it's the best, but because it's the one in which we happen to live. Progressives want to preserve the current environment precisely because they are pro-human as well as pro-nature.
The Benefits of Technology. Far from being enemies of technology and the industrial base that produces it, progressives realize that technology is the single most important weapon environmentalists have. Technology has allowed us to clean up rivers and lakes, improve the quality of air in our cities [see Figure I], and reduce the impact of oil spills. For the future, reliance on technology, not its avoidance, will allow us to meet the challenge of global warming – if that really does turn out to be a serious problem.
To progressives, the development of cold fusion (a cheap, nonpolluting source of energy) would be a welcome event – as would any other technological breakthrough that allows us to meet human needs with less environmental harm. To the Green question, "Industry or a Livable World?", progressives respond that industry is what makes a livable world possible.
The Benefits of Economic Growth. In response to the development of reactionary environmentalism in the 1950s, C. P. Snow wrote:
"It is all very well for us, sitting pretty, to think that material standards of living don't matter all that much. It is all very well for one, as a personal choice, to reject industrialization – do a modern Walden, if you like, and if you go without much food, see most of your children die in infancy, despise the comforts of literacy, accept twenty years off your own life, then I respect you for the strength of your aesthetic revulsion.
But I don't respect you in the slightest if, even passively, you try to impose the same choice on others who are not free to choose. In fact, we know what their choice would be. For, with singular unanimity, in any country where they have had the chance, the poor have walked off the land into the factories as fast as the factories could take them. 
In addition to the fact that economic growth is the only antipoverty program that works, progressive environmentalists have another reason for favoring it. They know that economic growth is what makes environmentalism possible. People who are struggling to meet basic needs rarely show much concern about the environment. Only when their basic needs are met can people become environmentalists.
The Benefits of Free Enterprise. With the opening of the communist countries to the Western media, we have been treated to a litany of environmental horror stories from behind the iron curtain. Mikhail Bernstam has shown that these are not isolated cases of misdirected policies. Higher levels of pollution are inherent in all socialist economies. Because they are so inefficient, socialist economies necessarily use more resources and emit more pollutants than market economies to produce a given amount of goods and services. Take energy use, for example: 
The per capita use of energy in socialist economies is at least as high as, if not higher than, in market economies, even though their per capita GNP (the amount of goods and services produced) is only 40 percent as high.
Per dollar of GNP, socialist economies use almost three times as much energy as market economies. [See Figure II.]
This comparison holds not only for socialist and capitalist economies in general, but also for countries that are very similar except for their political systems. For example: 
North Korea consumes 70 percent more energy per person and three times as much energy per dollar of GNP as South Korea.
What was formerly East Germany consumes 40 percent more energy per person and 3.5 times as much energy per dollar of GNP as West Germany.
Measures of specific types of pollutants tell a similar story. For example: 
Discharges of air pollutants per capita in socialist economies are as much as 2.3 times as high as in Western market economies.
Per dollar of GNP, socialist economies produce from three to six times as much air pollution. 
Reactionary environmentalists tend to assume that pollution increases in proportion to economic growth. The facts say otherwise. From the start of the Industrial Revolution in 1786, to 1986, the world's GNP has expanded 110-fold. But human emissions of carbon dioxide have increased only 12-fold. Industrialization allows us to produce more with less. 
In the 20th century, a remarkable divergence took place between socialist and market economies. Bernstam calls it "the most important reversal in economic and environmental history since the Industrial Revolution."  In market economies a steady decline in the resources needed to produce a given level of goods and services led to a decline in resource use per person (even though the economy kept growing) and to a decline in total resource use (even though the population kept growing.) For example: 
In the United States, the amount of energy needed to produce a dollar of GNP (in real terms) has been declining steadily at a rate of 1 percent per year since 1929.
By 1989, the amount of energy needed to produce a dollar of GNP was almost half of what it was 60 years earlier.
Moreover, since the 1970s there has been a steady decline in the amount of energy used per person. [See Figure III.]
The total amount of coal and electricity used in the United States continues to rise. But the use of many other resources in the production process has been declining for some time – even though the economy has been expanding at a brisk rate. The lower absolute use of resources is apparent for oil and gas, iron ore, iron-originated materials and outputs, and the stock of farm animals.  This trend is reflected in the measurements of pollutants in the United States and in other market economies: 
During the 1970s and 1980s, the annual pollutant discharges from fuel combustion and industrial processes fell between 12 and 37 percent, depending on the country.
By 1986, annual emissions in the United States were 13 percent lower than in 1940, although the U.S. population rose by 82 percent and real GNP rose by 380 percent over the time period.
These reductions were so significant that the total concentration of pollutants in the air over U.S. cities began to decline after 1977. [See Figure I.]
Quite the opposite has occurred in socialist countries, where per capita energy consumption has continued to rise. [See Figure III.] While the use of steel and many other production inputs has declined in absolute terms in the West, in socialist economies resource use has been constrained only by economic collapse. 
Socialist economies use ever more resources just trying to maintain the status quo, giving little thought to the environmental consequences. For example, when East and West Germany merged, it was discovered that half the towns and villages in the former communist country either lacked sewage treatment plants or had ones that did not work properly. To bring East German sewage treatment up to West German standards will cost an estimated $36.3 billion – about $2,420 for every East German resident. 
In market economies, an "environmental invisible hand" is at work: competitive pressures to reduce costs cause a reduction in the use of resources and a reduction in pollution. For example, in the 1960s, 164 pounds of aluminum were needed to make 1,000 soda cans. Today it takes only 35 pounds.  Bernstam has accumulated a wealth of data showing that developed countries cannot continue to grow unless they continue to economize on resources – thus contributing to environmental improvement. [See Figure IV.]
Progressive environmentalists favor free markets not only because markets deliver the goods and meet human wants, but also because market economies are much better for the environment. It is increasingly clear that environmental improvement, economic growth and market economies go hand in hand. But having a market economy isn't enough. Within the context of a market economy, we need intelligent public policies to help us reach specific environmental goals.