This Earth Day is an important time to reflect on not only climate change, but its effects—including poverty and disease. According to USAID, it is anticipated that the world’s population will increase by 50 percent by 2050; 99 percent of this growth will take place in developing countries, and more than 90 percent of the growth comprises the poorest individuals of these countries.

Organizations such as Population Services International (PSI) are champions in combating the effects of climate change preventing HIV, unintended pregnancies and death from malaria and diarrhea.

Watch Anna Kournikova, former tennis star and PSI Ambassador, as she visits Haiti as part of a public-awareness campaign.

10 Population Health Facts

• Between 1995 and 2005 alone, the urban population of developing countries grew an average of 1.2 million people per week or around 165,000 people per day.
• Evidence from 47 countries on child health outcomes shows higher socioeconomic inequality in urban areas compared to rural areas.
• One in three urban dwellers or 1 billion people worldwide lives in slums.
• Around 32 percent of urban residents in developing regions lack improved sanitation. Globally, it is estimated that 3 percent of all deaths and most diarrheal disease are attributable to the lack of improved drinking water sources, sanitation, and adequate hygiene.
• About 25 percent of city dwellers in developing countries and 70 percent in least developed countries use solid fuels for heating and cooking, causing indoor pollution. This greatly increases the risks of respiratory disease, especially in children, and exacerbates outdoor air pollution.
• Tuberculosis (TB) incidence is much higher in big cities. In New York City, TB incidence is four times the national average. Incidence of TB in some parts of London is as high or higher than in China. The situation is no different in resource-poor countries: 45 percent of TB cases in Guinea live in Conakry; 83 percent of TB cases in the Democratic Republic of the Congo live in cities.
• Developing country cities are particularly vulnerable to health hazards from climate change. In particular, the coastal location of many major cities makes populations more vulnerable to extreme weather and rising sea levels. Heat waves also place cities at risk of the “heat island’ effect, where temperatures may be as much as 41°-52° F (5-11° C) warmer than surrounding rural areas due to dense urban geography and energy sources.
• Prevalence of HIV in generalized epidemics is generally higher in urban areas; population-based household surveys indicate that prevalence is 1.7 times higher in urban than in rural areas.
• The rapid growth of cities has increased the visibility of unequal access to skilled care at birth and to emergency care for urban women.

Source: Knowledge Network on Urban Settings report, the WHO Commission on Social Determinants of Health