Investing in the Planet Is an Investment in Brain Health

On April 21, 2023, the White House issued a “Proclamation on Earth Day, 2023,” highlighting the Biden Administration’s initiatives to advance green energy, preserve biodiversity, and executive actions to defray the advancing deleterious impacts of climate change.

But this year’s Earth Day follows prior warnings by the United Nations’ Intergovernmental Panel on Climate Change Workgroup that climate change is a "code red for humanity" needing more. The emphasis on worsening drought, hurricanes, wildfires, and other calamities is well-placed, but this should not be the only cause for action. The lesser-known impact of climate change on brain and mental health is just as relevant.

“Eco-anxiety,” often used to refer to the “mental distress or anxiety associated with worsening environmental conditions or ecological crisis,” is now increasingly recognized as a contributor to adverse mental well-being. Worries about environmental distress are especially prevalent among children.

A 2021 analysis of 10,000 children and young adults between 16 and 25 years old surveyed in ten different countries demonstrated that 59 percent were “very or extremely” worried about climate change and that 84 percent were at least “moderately worried.” More than half of respondents identified accompanying feelings of guilt, powerlessness, and helplessness, and 45 percent described negative feelings that interfere with daily functioning. Research also indicates that adolescents feel climate change is not just a cause of anxious distress but one that is tangible and “worth worrying about,” suggesting that many may expect they will be personally affected during their lifetimes.

There is increasing evidence that the effects of climate change raise the incidence of neurological disorders. The increased ambient temperature associated with climate change increases the risk of stroke death. One Korean study showed a 4 percent increase in death following ischemic stroke for every one degree Celsius elevation in ambient environmental temperature. Heat stroke correlates with a greater risk of long-term neuronal damage, even among those with no prior history of brain disease.

For those already diagnosed with neurodegenerative conditions, warmer seasonal temperatures lead to worsening severity of their illness. In a large community-based study assessing the effects of temperature on New England Medicare beneficiaries with dementia, each 1.5-degree Celsius increase in summer mean temperature increased the chances of a dementia-associated need for hospitalization by 12 percent.

Climate extremes can exacerbate epileptic seizures. Emotional stress, like that associated with eco-anxiety or forced displacement from storm-related events (e.g., floods or tornadoes), can trigger seizure events. Sleep loss is a common precipitant for seizure activity in at-risk individuals, and studies of extreme weather events such as wildfires and hurricanes support that sleep disturbances are pervasive following these incidents, as are mood and traumatic stress disorders.

I am an emergency psychiatrist who practices in a busy metropolitan university hospital. Climate anxiety – two words that never appeared in a textbook in medical school over twenty years ago – has directly changed my practice. Several weeks ago, I met a young mother needing a medication refill. Her chronic anxiety disorder was well-controlled on her antidepressant, and she understood the value of continuing it. But as our conversation progressed, she shared her struggles with her eight-year-old son’s anxiety.

The first week of warmer spring weather had recently arrived with milder temperatures. And while the warmth of spring and summer may be received as a welcome break from Colorado snow for many, it was also a reminder for her son that wildfire season was fast approaching. She spoke tearfully of the December 2021 Boulder County Marshall fire and her son’s worry that a similar event could happen to him. Neither had directly witnessed the fire, however. But their lived experience highlighted a disturbing realization: climate anxiety can be vicarious, and its transmission cross-generational.

To be sure, climate change remains a divisive topic. Although a recent Pew Research poll showed that three-quarters of Americans support U.S. participation in global efforts to address climate change and that the majority agree with carbon neutrality, climate change ranked 17^th out of 21 national issues of greatest importance to Americans. But the long-term health repercussions noted above make inertia an illogical choice.

The Biden administration’s efforts to advance a climate agenda are necessary. Still, as these initiatives progress, we must also acknowledge that the impetus for such action is more than environmental or economic. On this Earth Day, we should remember that a commitment to the planet simultaneously reflects a commitment to the mental well-being of its inhabitants. Both should remain a steady focus of attention.