Most of the 20th century has been a development on the Industrial Revolution taken to an extreme: people now own more products than ever before; there are enough nuclear weapons to destroy the earth several times over; there is hardly any forest left and pollution has got to the point where we buy water. Within a few years I predict you will be able to buy air (There once was a time when you didn't need to buy food or shelter either.). Important developments in the last century are the breaking down of the class structures left over from the Industrial Revolution stage, bringing with it the empowerment of the "common man": the working day is set by law to only 8 hours a day, everyone has the vote, the media has less obvious government control, people have landed on the moon, sent spacecrafts to Mars and so on. Families have also shrunk drastically ; the nuclear family came about, and especially in the last half of the 20th century, one-parent families are becoming more common. This shrinking in the size of the family shows the increased independence of people--once upon a time people had to live in large groups to survive. As humans have "become the gods", they have realized their individuality and independence and taken their control of the world to an extreme. In many countries the land is almost completely used in the production of food and as living space and they live in small cities which are entirely human constructed, made from materials which are also entirely human constructed(concrete, bricks) with hardly any remains of nature. Weeds are poisoned because they are messy; even parks have trees grown in tidy lines; grass is mowed to keep it short and so on. I think the massive drug "problem" troubling people is a result of too much of this influence, humans needing to escape the stark world they have created by entering fantasy worlds. Over the last 100 years, the 20th century consciousness has spread throughout the world; most of Asia has been thoroughly "Westernized", and most of the Third World is being overrun by Western ways of doing things and living. What's the author most concerned about?
The influence of pollution. Strong effects of development. Changed positions of humans as gods. The process of the Industrial Revolution.