The human population is a major underlying environmental issue because the large number of people and their impact on the environment has led to significant environmental damage. While population growth has occurred throughout history, the current situation of over 6.6 billion people is unprecedented and poses a threat to long term sustainability of resources. Two key factors that influence the human impact on the environment are population size and the impact of each individual, both of which have increased substantially in modern times due to growth and technology. Addressing population growth through methods like family planning programs will be important to mitigate environmental problems.