The environmental impact of human beings has grown in scale, become more rapid, and changed in character. Whereas we once transformed locales or regions, today we can be said to be transforming the Earth on a global scale. Changes which once took decades or centuries are now taking place over the course of a few years. And whereas we once changed the Earth in relatively small ways (for example by clearing a field of forest cover), we are now able to substantially alter the flows of elements and energy that constitute the planet’s basic life-support systems.
Through burning fossil fuels and industrial processes, we are releasing many pollutants into the atmosphere. Some of these reduce air quality, whilst others are most probably causing a change in the Earth’s climate. Other wastes from the consumption of natural resources can pollute soil and water environments as well.