According to the latest CRS report in 2018, the diminishment of Arctic sea ice has led to increased human activities in the arctic, and has heightened interest in, and concerns about, the region’s future. The US is an Arctic country and has substantial interests in the region. Changes to the Arctic brought about by warming temperatures will likely allow more exploration for oil, gas and minerals. However, increased oil and gas exploration and tourism (cruise ships) in the Arctic increase the risk of pollution in the region. Additionally, changes in sea ice can directly affect the health of Arctic ecosystems. Mammals such as polar bears and walruses rely on the presence of sea ice for hunting, breeding and migrating. These animals face the threat of declining birth rates and restricted access to food sources because of reduced sea ice coverage and thickness (EPA, 2016). Although there is significant international cooperation in the Arctic issues, the Arctic is increasingly being viewed by some observers as a potential emerging security issue. Some of the Arctic coastal states, particularly Russia, have announced an intention or take actions to enhance their military presences in the high north. US military forces have begun to pay more attention to the region in their planning and operations. The Congressional Research Service (CRS) reports and Environmental Protection Agency Report (EPA) included in this book provide the readers with the issues, challenges and effects we face today due to Arctic climate changes.