As climate change progresses, heat waves are projected to become more frequent, longer lasting, and more severe. Extreme temperatures are already the number one weather-related killer in the US, and as these events become more common, their impacts will increase.
Heat stress in humans depends not only on the temperature but also on the humidity. The hottest regions are not necessesarily the most dangerous; the body is remarkably capable of cooling itself as long as the humidity is low enough to permit the evaporation of sweat. However, some of the most densely populated parts of the world can be both hot and humid, presenting a major risk. Recent heat waves have killed tens of thousands of people, caused infrastructure damage and crop failure, and dramatically increased energy demand. Our work has shown that in the coming decades, without rapid emissions reductions, hundreds of millions of people annually could be exposed to levels of heat stress that approach the limits of human tolerance. We aim to identify the most at-risk regions for heat stress, and to understand the dynamics that drive the most extreme events.
Many natural systems are strongly dependent on temperature thresholds. As summers become hotter and winter cold becomes less frequent, ecosystems may experience signficant change.
The Southern Pine Beetle is a well-known threat to pine forests. In recent years, the beetle has been observed in New Jersey and southern parts of New York and Connecticut. Prior work has found that the beetle's spread is constrained by the occurance of cold temperatures and that as climate change has made cold events less likely the beetle has moved north. In our work, we use a bark temperature model and the latest suite of climate models to make the first projection of the time of emergence of a climate favorable to the Southern Pine Beetle in the Northeast United States.
Long distance bird migration may also be negatively affected by higher temperatures, as birds typically end their journies with very little energy remaining, and higher temperatures require more energy to produce the same amount of lift. We are investigating this potential affect on North American migratory birds.
Aircraft takeoff performance is strongly dependent on temperature. As air temperature rises, air density declines, meaning that a wing produces less lift at a given speed. This requires that takeoff speeds be higher on hotter days; for a given airport and aircraft type, there is a threshold above which the airplane cannot takeoff at its maximum takeoff weight and must be weight restricted. We're investigating how the frequency of weight restriction may increase in the future, and what economic impact this may have on the airline industry.