Rising global temperature is causing major physical, chemical, and ecological changes across the planet. There is wide consensus among scientific organizations and climatologists that these broad effects, known as climate change, are the result of contemporary human activity. Climate change poses threats to human health, safety, and security. Children are uniquely vulnerable to these threats. The effects of climate change on child health include physical and psychological sequelae of weather disasters, increased heat stress, decreased air quality, altered disease patterns of some climate-sensitive infections, and food, water, and nutrient insecurity in vulnerable regions. Prompt implementation of mitigation and adaptation strategies will protect children against worsening of the problem and its associated health effects. This technical report reviews the nature of climate change and its associated child health effects and supports the recommendations in the accompanying policy statement on climate change and children' s health.Global climate change is a leading public health threat to all current and future children. Rising global temperature, known as "global warming," is causing major physical, chemical, and ecological changes in the planet. The term "climate change" is used in this report to include these broader effects. There is now broad consensus among the world's leading scientific organizations and approximately 97% of climate scientists 1-4 that these changes are the result of human-generated greenhouse gas emissions.Rising greenhouse gas concentrations and climate change are part of a larger constellation of change resulting from contemporary human activity. Exponential increases in human population, habitat transformation, energy production and consumption, and climate change 5 are putting unprecedented pressure on the earth, resulting in physical, chemical, and ecological changes that are fundamentally altering the planet. 6 These accelerating changes threaten the biological systems on which the life, health, and prosperity of all children depend.There is wide recognition of climate change among scientific bodies, 7 international agencies, [8][9][10] and world religions, 11 and it is important for pediatricians to be aware of the effects of climate change on the health and security of individuals, families, and communities. Children are a uniquely This document is