## 1 Introduction  
Canada's Changing Climate Report, published in 2019, presents several crucial facts that can affect the life cycle of airport and road pavements. According to the report, the annual average temperature in Canada increased by 1.7 \({}^{\circ}\)C between 1948 to 2019; however, the most drastic change can be noticed over the winter seasons, found to be warmer by 3.3 \({}^{\circ}\)C [1]. Further to the average temperature changes, an increase in temperature can lead to changes in the timing and duration of winter freezing and spring thawing in cold regions, directly impacting frost and thawing penetration depths [2].  
[PERSON] et al. used an ensemble of climate models to forecast how climate change might affect freezing and thawing processes beneath roadways in New Hampshire and Maine in the United States [2]. The results of the study showed that the duration for which the pavement cross section remains frozen will be significantly shortened over the next 30 years, and that shallower frost depths are projected for the end of the century. Figure 1 shows the predicted frost depth in different sites in New Hampshire and Maine, demonstrating that projected frost depths under emission scenario RCP 8.5 will become shallower at a greater rate than emission scenario RCP 4.5 after 2040. The results also suggested larger changes over time, and larger differences between the low- and high-emission scenarios at the end of the century for the sites with deeper frost penetration.  
Similarly, Canadian pavement conditions will also be impacted by the warming climate. With shorter freezing season lengths in Canada, not only will frost penetration depth decrease, but also the minimum pavement-thickness requirements to cope with frost penetration. While the latter may possibly lower the initial cost of construction, areas underlain by permafrost may suffer from pavement bearing capacity reduction due to melting of the frozen layers.  
Permanfrost temperature in Canada has increased over the past three to four decades. Regional observations have shown warming rates of about 0.1 \({}^{\circ}\)C per decade in the central Mackenzie Valley, and 0.3 \({}^{\circ}\)C to 0.5 \({}^{\circ}\)C per decade in the high Arctic [1]. Such increments might seem modest; however, permafrost layers can be highly vulnerable to thawing, since the soil temperature in these regions is already close to zero [1]. Melting of the permafrost soil will increase the seasonal active layer thickness; that is, the upper part of the ground that freezes and thaws each year. For instance, the seasonal active layer thickness in the Mackenzie Valley has increased by approximately 10% since 2000 [1], making these areas more prone to deformations and distresses caused by freeze-thaw cycling.  
Knowing how climate change can impact airport pavement freeze-thaw conditions is essential for better planning future transportation infrastructure projects in Canada. However, there are few, if any, available studies in the existing literature to inform decision making in this area. To this end, the aim of this study was to analyze how climate change will affect freeze-thaw penetration and frost heave in several locations across Canada. First, frost depth calculations from three methods were compared to the field data with the goal of evaluating the accuracy of the methodologies. Then, freeze-thaw depths and frost heave  
Figure 1: The projected maximum frost depths using actual pavement cross-sections. Adapted from [2].  
predictions for the high emission scenario RCP8.5, in 20 and 40 year time horizons, were made.