Climate change and mental health: a commentary.

Climate change represents a major global challenge. Some hallmarks of climate change that have been connected to human activity include an increase of 0.8-1.2 °C in global temperatures as well as the warming of upper ocean water. Importantly, approximately 500 million people worldwide face the consequences of desertification. Simultaneously, the world population has grown from 1.6 billion in 1900 to 7.7 billion today, greatly exacerbating the human toll of devastating environmental disasters, which result in increasingly larger and more common mass migrations that also fuel human trafficking and modern-day slavery. The mental health outcomes are staggering and include, in the context of chronic stress, addiction, anxiety disorders, post-traumatic stress disorder (PTSD), bipolar disorder, major depression, and suicidality. Mental health practitioners, healthcare systems, and governments across the world need to be prepared to address the mental health sequelae of climate change.