The effect flows from climate to body, not the reverse
The idea that human body temperature could drive climate change reverses cause and effect. The heat released by human bodies is negligible compared with the energy trapped by greenhouse gases. The research instead asks whether a warming climate is reshaping human physiology. One hypothesis proposes that increasing global temperatures, driven by human activity, are resetting the body's thermoregulatory set points, leading to lower average core body temperature [1]. This is framed as a possible short-term physiological adjustment rather than genetic evolution [1].
That hypothesis is explicitly speculative. The authors note that reduced infections and modern lifestyles have likely also contributed to the observed decline in core body temperature, and they acknowledge limitations in historical temperature measurements [1]. So even the climate-to-body link is not established; it is a proposed explanation that needs more evidence.
Climate change affects human heat stress and work capacity
While body temperature does not change the climate, climate change clearly affects human thermal stress. An empirical model projects how heat waves and climate change will reduce human physical work capacity, using factors such as air temperature, humidity, and skin temperature [2]. This is about the environment acting on people, not people acting on the environment.
The health consequences of warming are also well recognized. Research on global warming and human health has examined heat-related mortality and the spread of disease under climate change scenarios [4]. Again, the direction is climate influencing human health, not human body heat influencing climate.
Even subtle body temperature differences may relate to brain structure
A pilot study in healthy adults found that core body temperature was negatively correlated with whole-brain gray matter volume: higher body temperature tended to go with lower gray matter volume [5]. The correlation was moderate (r = -0.496) and became only trend-level significant after adjusting for covariates, and the sample was small (27 participants), so the authors describe it as preliminary and hypothesis-generating [5].
The study situates this finding in the context of global warming, suggesting that understanding individual differences in body temperature could offer clues about the neural health consequences of rising environmental temperatures [5]. Possible mechanisms include heat-induced inflammation, oxidative stress, and increased metabolic load on neural tissue, but these are proposed possibilities, not confirmed causes [5].
Why the question can seem plausible
The confusion may come from the fact that both body temperature and climate involve heat, and some papers discuss them together. For example, research on floating solar panels examines how these installations affect water body temperature and stratification, with implications for mitigating climate change impacts [3]. That work is about water temperature and energy technology, not human body temperature, but the shared vocabulary of 'temperature' and 'climate change' can blur the distinction.
In short, the evidence supports a one-way influence: climate change may affect human physiology and health, but human body temperature is not a meaningful driver of climate change.
Sources used in this answer
Climate change and the decline in human core body temperature: A hypothesis of physiological adaptation
Average human core body temperature has declined over two centuries, and the authors hypothesize that rising global temperatures from human activity may be driving a physiological reset of thermoregulatory set points, though other factors and measurement limitations are acknowledged.
An advanced empirical model for quantifying the impact of heat and climate change on human physical work capacity
An empirical model quantifies how heat and climate change reduce human physical work capacity, using factors including skin temperature and humidity.
Floating photovoltaics could mitigate climate change impacts on water body temperature and stratification
Floating photovoltaics can alter water body temperature and stratification in complex ways, potentially mitigating some climate change impacts on water bodies or causing deleterious effects depending on design and coverage.
The impact of climate change on human health: some international implications
Global warming may affect human health through heat-related mortality and disease spread under climate change scenarios.
Core Body Temperature Negatively Correlates with Whole-Brain Gray Matter Volume: A Pilot Study in the Context of Global Warming
In a small pilot study, core body temperature was negatively correlated with whole-brain gray matter volume, a preliminary finding that may offer insights into neural health consequences of rising environmental temperatures.