Climate System and Human Health Initiative

Disease and climate are inextricably tied. Changes in climate will therefore inevitably affect disease patterns in both natural and man-made ecosystems. Immediate concerns include changes in air quality that influence respiratory diseases and expansion in the natural ranges of parasites and infectious disease vectors, such as mosquitoes and ticks. Relatively little attention has been paid to how the ecology of microbial pathogens and arthropod vectors will evolve in response to global warming. The public health threat from new and emerging infectious diseases has increased in recent decades; studies have already attributed some of these increases to climate change. Surprisingly, very few resources have been devoted to studying the relationship between climate change and disease threats. A major goal of this initiative is to identify areas where early research funding could make a large difference.

Given the current imperative, the mission of the Climate System and Human Health Initiative is to expand climate science research, with a focus on the key uncertainties in regional and global climate simulations, and further promote the advancement of human health science as it relates to anthropogenic climate forcing. YCEI recognizes both the independence and interdependent nature of these topics and will structure a nexus for research collaborations and discussions that inform the public and policymakers of risks to human health posed by climate change.

Topics addressed include research on:

  • Climatic change in polar regions involving sea ice, Arctic hydrologic cycles, coastal erosion, and their cultural impacts
  • Droughts in dryland environments, and how changes in atmospheric circulation influence high altitude glaciers and freshwater supply
  • The impact of aerosols on radiative budgets and climate sensitivity
  • Geoengineering and carbon sequestration strategies

Faculty at the Yale School of Public Health have a long standing interest in the environmental determinants of disease, including:

  • Vector-borne infectious diseases such as Lyme disease, West Nile virus and dengue fever
  • Zoonotic diseases such as rabies, Hantavirus, and leptospirosis
  • Avian influenza virus
  • Dynamic and spatial epidemiological modeling of infectious agents
  • Asthma and other chronic diseases with a link to air quality and climate  


Global mean-annual temperatures this century are projected to rise up to 4°C if greenhouse gas emissions continue unabated. Even if COconcentrations do not continue to rise, there may be as much as 2°C of warming caused by interaction between the atmosphere and the ocean’s large thermal inertia. It is inevitable that temperature change associated with rising CO2 levels will impact hydrologic cycles and consequences of these changes would likely have immediate effects on weather and global patterns of precipitation. Sea-level rise, weather extremes, and sea-ice evolution have direct cultural, demographic, and public health impacts that are presently unfolding. Constraining the extent of future warming requires an improved understanding of factors that amplify or dampen radiative effects of greenhouse gas concentrations, as well as other climate forcers and their future evolution. While global simulations broadly agree across different institutional climates models, regional simulations of future climates differ substantially. Understanding the disparities in regional models is key to future forecasting and planning across all aspects of society, including human health.