What environmental factor can exacerbate emissions problems from vehicles?

High temperatures can significantly exacerbate emissions problems from vehicles due to several interrelated factors. When the temperature rises, several chemical reactions occur in the atmosphere that lead to an increase in ground-level ozone, which is a key component of smog. This is particularly relevant during hot days when sunlight is strong, as higher temperatures facilitate the transformation of volatile organic compounds (VOCs) and nitrogen oxides (NOx) into ozone.

Additionally, warmer weather can affect the efficiency of vehicle emissions control systems. For instance, as engines run hotter, they may produce higher levels of certain pollutants, especially if they are not functioning optimally. Furthermore, high temperatures can contribute to increased fuel evaporation, resulting in more VOCs being released into the atmosphere. Therefore, under hot conditions, emissions from vehicles can significantly increase both in quantity and in the formation of harmful secondary pollutants like ozone, highlighting the negative impact of high temperatures on air quality and public health.