The incidence of childhood cancers has increased in the developed world over the last four decades. In the United States alone, childhood cancer rates in children under 15 increased by nearly 40% between 1975 and 2014. Environmental exposures have been associated with childhood cancers such as leukemia. Those same exposures are simultaneously both causing and resulting from the climate crisis.
The following air pollutants have been demonstrated as carcinogenic to humans:
Traffic-related air pollution
We are what we eat, as the old adage goes. Meat consumption has a far higher carbon footprint than do plant-based diets. Meat consumption also carries a higher carcinogenic risk for children. Studies have found that maternal consumption of cured meats during pregnancy can lead to increased risk of childhood brain tumors. Red meat has been classified as a probable carcinogen. Diets that include high quantities of fruits and vegetables and low quantities of red and cured meats, such as those proposed by the American Cancer Society, have been shown to reduce an individual's risk of cancer.
See the Further Reading section for sources.