I agree with Barry's assessment of the dire environmental consequences of modern civilizations current economic and social choices. We are indeed going to ecological-hell-in-a-handbasket and taking uncountable species down with us. But is the "earth" dying as a result of our actions, as Barry claims? I think not. Oh, I think we humans are capable of destroying "the earth" -- we have enough nuclear weapons stockpiled, which if strategically placed and detonated all at once might create forces capable of causing the earth to break up and become a new asteroid belt, or destabilize earth's orbit and send us out careening into the sun, or spinning out in to the cold blackness (yeah, I did love Space 1999). But to accomplish that would require a level of international organization and cooperation that humans have never shown any indication we possess.
Let me clarify. The planet Earth and life (any kind of life) on planet earth, is extraordinarily resilient, and has withstood destructive forces far greater than those currently commanded by human societies. The natural destructive forces of the earth are such that no trace exists of the original earth's surface from four and a half billion years ago. The oldest rock identified on the surface of the earth is just under four billion years old, some grains of zircon have been discovered that have been dated to 4.2 to 4.3 billion years ago. Since that time the planet's surface has been made and remade, abducted and subducted, and moved about over and over again. There have been periods of time vastly warmer than our man-made global warming is likely to create in the next few hundred years, and periods of time colder than the last ice age during which humans evolved.
The first evidence of life on earth dates to three and a half to possibly 3.8 billion years ago -- meaning that planet earth existed for nearly billion years before there was life. There may have been life before that, but we have no evidence because no trace of the earth's surface older than 3.9 million years ago exists. The oldest fossils are 3.5 billion years old.
This three and a half billion year record of fossils tells us a story of change and extinction, new species, growth, change and new extinctions. During this incomprehensibly long period of time, continents rose and crashed into each other and were torn apart, by unfathomable tectonic forces. To quote from one of my favorite books (J. D. MacDougall A Short History of Planet Earth, John Wiley and Sons, 1996):
"Throughout the earth's history species and families have arisen, prevailed for a time, and then disappeared. But at times, for reasons not wholly understood, rapid and wholesale destruction of large fractions of the plant and animal kingdoms has occurred. Usually, after these crises, there was a rapid proliferation of new and sometimes quite different species. Such abrupt changes in floral and faunal assemblages are reflected in the fossil record. It is only quite recently that geologists have begun to examine these mass extinctions in terms of periodic catastrophes such as the collision of comets or asteroids with the earth, or dramatic changes in the global climate."Let us be honest. Planet earth, and life on planet earth are not at stake. Earth is not dying, life will not cease to exist as the result of human action.
What is at stake is human life and human civilization, and the life of species of plant and animal that sustain human ecosystem ecosystems. We can't destroy the earth, and we can't destroy life on earth, but we sure as hell can destroy ourselves and most of the species we rely upon for our lives. Moreover, anthropogenic climate change, pollution and all the other environmental problems spawned by modern society, will first and foremost kill societies long before impacting the presence of the human race. I'm a Jew, so the New Testament is not one of my religious books, but I've been thinking quite a bit about Jesus' Sermon on the Mount in which he say "blessed are the meek for they shall inherit the earth." It occurs to me that this might end up being literally true -- if one defines "meek" as those simple societies where people live in small bands or tribal groups subsisting by foraging or horticulture (farming with hand tools).
Talking about killing Earth, is not only hyperbole, it is counter productive. What we want is to change human behavior, especially the behavior of those who are rich enough and powerful enough to determine the direction of business and industry, and national policy. At a secondary level we want to change the behavior of millions of consumers in affluent, industrial nations. Most people, including those whose behavior need to change, operate most of the time out of self-interest. Talking to them about a dying earth isn't going to change their behavior. Appealing to their altruism for other species is not going to change their behavior. Making poster children of polar bears is not going to change their behavior. But possibly change will occur if we can get the message through to the rich and powerful that the complex society on which their profits depend is at risk (notice that at least some of the oil companies have figured out that the future of profit is in renewables); and the message to the average consumer that the food and beer will disappear from their local grocery shelves, and the gas for their ATV's will be gone, and the nice cushy life they value is endangered.