The Industrial Revolution had significant, long-lasting impacts on the environment. Air and water pollution affected the health of people living in the rapidly growing urban areas. Entire landscapes were destroyed as humans cut down timber for railroad ties, stripped hills and mountains for ores, and denuded areas of vegetative cover for farming. This increase in deforestation exacerbated desertification in some areas and flooding and mudslides in others. The invention of dynamite in 1867 opened the way to more effective removal of earth and stone, particularly for mines and tunnels. Mechanical methods of hunting made fishing and whaling more effective, with the result that many areas were significantly depleted even by the early twentieth century. Many whale species were in danger of becoming extinct until the discovery of petroleum products made whale oil less valuable. Improved firearms made hunting easier, often with disastrous results as animals like the bison of the North American plains were hunted almost to extinction.
Improvements in medicine, along with better diets resulting from more food production, led to a dramatic rise in population as well as to an increase in the average life expectancy. The Earth's population in 1750 was 790 million. By 1900, the population had doubled. Urbanization increased even faster than population growth because new methods of transportation (most notably railroads and steamships) led to increases in both internal migration within a country and external migration. Cities were some of the most dramatic examples of human changes to the environment during this period.
It was also during this era, however, that concern for the environment, beyond the need to conserve for a nation’s resources, first began to assert itself. Many nations formed forestry services, initially based on the French and then the American model. National parks and nature preserves were created to keep areas from being developed. Western curiosity and scientific observations began to note the interconnectedness of nature and man’s impact upon it. Scientific methods in medicine and chemistry began to find and then develop cures and preventative measures like sanitation systems, use of soaps and disinfectants, and vaccinations for many of the diseases that have plagued mankind throughout the centuries.