LowEmissionAsphalt-136pg-WhitePaper-May2023

P a g e | 33 absorbed and later remitted into the atmosphere, this energy is disorganized and gets trapped. Pavements play a considerable role in this. CO 2 is the leading greenhouse gas (GHG) capable of this trapping effect . Figure 15 – Temperature Change by Impact Relative 1750 61 (Celsius) 62 Source: UN IPCC Report 2022 We will discuss all of the greenhouse 63 impacts or carbon dioxide equivalents (CO 2 e) from the roadway microenvironment throughout the report emphasizing the combined roles of both CO 2 and NO 2 as an indirect GHG, as well as Urban Heat Island 64 intensity due to poor road system reflectivity (i.e., “heat sinks” ). 61 Hegerl H, Zweirs F, et al., United Nations (UN) Intergovernmental Panel on Climate Change Report 2022, Chapter 9 Understanding and Attributing Climate Change . 62 To convert Celsius to Fahrenheit, multiply Celsius by 1.8x. 63 greenhouse gases absorb and emit radiant energy within the thermal infrared range. 64 urban heat island effect is higher temperatures experienced in densely populated areas where built infrastructure absorbs and then reemits excess radiant energy relative to more rural, well vegetated areas.