In our region and county, the average temperature is expected to increase significantly in coming decades. In the past 50 years, local average annual temperatures have already increased nearly three degrees.

This temperature increase will impact our transportation system in many ways. Shorter, warmer winters might mean less snow plowing, but more time hovering around the freezing point will likely exacerbate freeze-thaw cycles that can damage roads—especially since we can expect greater precipitation during our winter months.

According to the Union of Concerned Scientists’ report on Climate Change in the Northeast, we can expect to see greater precipitation in the coming decades, but that precipitation will not be spread evenly over the year. The increase is likely to come during the winter months, while spring, summer, and fall precipitation levels are expected to remain the same. We can also expect greater fluctuation on a month-to-month or year-to-year basis: more extreme precipitation events and more droughts. Droughts have limited direct impacts on transportation (though a shallower shipping route in the Hudson could pose problems for maritime freight), but they have several indirect impacts, including an increased likelihood of fires and the creation of hard-soil conditions that lead to floods and mudslides when it does rain.

Weather event-related flooding will likely be one of the greatest impacts of climate change on our region. As noted, we expect to see increased rainfall, and that rain is likely to be concentrated at certain times of the year. A longer and more severe hurricane season also has the potential to bring flood-inducing storms northwards. All of this puts our transportation system at risk: about two thirds of our bridges and about 150 miles (5 percent) of our roadways travel over or through a flood zone.

Fortunately, flooding may be one climate change byproduct with the highest potential for mitigation. By developing responsibly, protecting and enhancing important natural spaces, and upgrading key infrastructure, we can substantially lessen the impact of inevitable flood events.

The National Oceanic and Atmospheric Administration (NOAA) maintains the Coastal Flood Mapper application, which shows the impact of sea level rise from one foot to 10 feet. In Dutchess County, sea level rise will need to reach several feet before having a direct impact on our transportation system, with the Metro-North Hudson Line the first critical infrastructure to be affected.

However, any rise in the Hudson’s water level will make it easier for flooding to occur during a storm. Storm surge is one of the primary concerns for the MTA, particularly along the Hudson Line—which already suffered storm surge damage during Hurricane Sandy in 2011. According to the NOAA Mapper, there are points along the line throughout Dutchess County that are susceptible to storm surge, and there is an even greater risk further south. A disruption at any point along the line would impact service for the county.

Climate change is likely to cause substantial migration away from susceptible areas. Available research focuses on sea level rise and movement away from coastal areas, though desertification and drought could also alter migration patterns in the US. Research suggests that the changing climate will not alter American migration pathways—we will still go where we have familial, cultural, or geographic ties—but it will change how many people migrate to and from a given place. One study estimates that Dutchess County is likely to see a net increase of a few thousand residents from sea level rise. If existing migration pathways do remain, many of those migrants would come from New York City, Long Island, and Westchester. The number is small enough that it is unlikely to have a major impact on our transportation system in the near-term, but the strong link between the New York/New Jersey coast and Dutchess County means that a major event (like a hurricane) could dramatically alter that prediction.

While climate change is obviously a global challenge, we can address this critical issue by collecting information, educating decision makers, and advocating for policies and projects that counter the causes and effects of climate change. There is a great deal of data on potential climate impacts that we simply do not have, which is where our role begins:

• Expand our understanding
  • Conduct a transportation infrastructure vulnerability study, measuring the risk of flooding and other climate-related hazards to our roads, bridges, and culverts.
  • Map the impact of future flood events on our transportation system, potentially contracting with a mapping service to provide accurate data in the immediate aftermath of a flood event.
  • Use DARTE data, which estimates transportation emissions at a one kilometer scale, to monitor emissions patterns across the county.

• Reduce transportation’s climate impact
  • Support municipalities’ efforts to implement climate-sensitive land use regulations.
  • Promote smart land use policies to help reduce vehicle travel and congestion, and support transit, walking, and bicycling.
  • Encourage the use of public transit, park-and-rides, and other alternatives to reduce single occupancy vehicle travel.
  • Support technological innovations that can reduce greenhouse gas emissions, including electric vehicles, automated vehicles, and cashless tolling.

• Incorporate climate into road and bridge projects
  • Consider climate change in any bridge and culvert replacement projects.
  • Explore ways to improve monitoring of roadsides for proper ditching, tree-trimming, and erosion control.
  • Encourage communities to prohibit dead-end roads in flood-prone areas and evaluate possible connections for existing roads without multiple access points.