Scientists believe that winters might be milder on the Eastern Seaboard in the future primarily due to the second response: A change in the amount of polar ice will alter how ocean currents move.
As polar ice melts, it can affect the distribution of heat in the ocean and atmosphere, potentially leading to changes in ocean currents. This can have significant impacts on regional climates, including milder winters in certain areas, as altered currents can transfer warmer water and air into regions that previously experienced colder winters.