The US has a slow growth, nearly stable population. Germany and other European countries have declining populations. These people will provide large population increases as they become reproductive. US is experiencing net population growth due to baby boomers now having children. Immigration is also increasing US population size increasing at 1 million people per year.
People migrate for better jobs, living standards, and to escape oppression and war.
Compare human population increases with the Paramecium population increase example in your book. Environmental problems related to industrialization have been caused by a small percentage of people on the earth. As populations in developing countries burgeon, pressure on the environment will increase tremendously. EPA grants to remediate brownfield sites. Land use policies must address these problems.