Territory Profile

Population Adjusted GDP  GDP per capita Major income sources Geography Legal Status
161,785 (July 2015 est.) $4.882 billion (2013 est.) $30,500 (2013 est.) U.S. military, tourism (primarily from Japan), construction An island of volcanic origin in the North Pacific Ocean Organized, unincorporated territory of the U.S.

Part of the Mariana Archipelago, the island of Guam shares an ancient history and culture with other islands in the chain. The Chamorro people, who first settled the archipelago 4,000 years ago, maintain a culture and language unique in the Pacific.

"Sunny day, Tumon Bay, Guam," ©Tata_aka_T 2007, used under a Creative Commons Attribution license

“Sunny day, Tumon Bay, Guam,” ©Tata_aka_T 2007, used under a Creative Commons Attribution license

The island chain has been colonized by successive colonial powers since 1521, when Ferdinand Magellan laid claim to the islands for Spain. In 1898, at the end of the Spanish American War, Spain ceded Guam to the United States. Japan took control of Guam for three years during World War II, marking a violent period in its history. Guam became a U.S. territory in 1950. The U.S. military installations on the island remain some of the most strategically important in the Pacific region for the U.S.

As in Hawai‘i, the cash economy in Guam is highly developed and relatively few people rely on subsistence agriculture and fishing. In addition, the Territory adheres to a western legal system. It is by far the most developed island in the Micronesian region.

Key Climate-Related Stressors and Issues

A high volcanic island, Guam does not experience as many of the impacts associated with sea level rise as do the low-lying atoll islands. Guam has extensive freshwater supplies in an underground aquifer, which have sustained the island through periods of drought. Drying patterns are closely associated with El Niño events, which could become stronger in the future. Dry periods bring wildfires to the island and impact agriculture. Villages that rely on surface water sources have experienced water shortage in past drought events.

Guam lies directly along a tropical cyclone belt, and thus is regularly impacted by major storms. Extreme storm surge events result from wind, wave, and atmospheric forces in tropical storms, resulting in coastal flooding and erosion. Guam and CNMI are more exposed to this threat, than they are to tide-related surge, due to their location in the path of frequent storms. A key issue for climate change impacts on Guam is whether storm tracks and intensities will change under future warming.

Climate stressors on low-lying atolls of nations could become an increasing driver of migration in the future. Guam is currently a main destination for immigrants from the freely associated states of the Federated States of Micronesia and the Republic of the Marshall Islands. Thus, Guam is likely to receive higher numbers of regional migrants in the future.

Adaptive Capacities

In 2015, the Governor of Guam issued an executive order establishing a formal policy to take action on climate change and creating a climate change task force. At a 2015 meeting with U. S. Department of Interior official, the Government of Guam discussed its plans to conduct a vulnerability assessment that will inform a territorial climate change plan.

The U.S. Department of Interior also has announced plans to increase climate change adaptation funding for Pacific Islands, including Guam, in 2016. Secretary of Interior Esther Kia‘aina is encouraging Pacific Islands governments to develop vulnerability assessments and climate adaptation plans.

In 2008, Guam developed a Local Action Strategy on coral reef resilience. As part of that effort, specific resilience action plans are now complete and actions are underway to protect reefs and watersheds from multiple threats, including climate change.

The government is actively working to enhance communications during emergencies with plans to replace land mobile radio with new mobile apps.

Lower poverty rates on Guam would suggest that the territory is more resilient to climate change than many less-developed Pacific Island countries and territories.

The preceding text is excerpted and abridged from the following sources:

“Guam and El Niño” The Government of the Territory of Guam, available from:

Lander, M. A., & Guard, C. P. (2003). Creation of a 50-year rainfall database, annual rainfall climatology,and annual rainfall distribution map for Guam (Technical Report No. 102). University of Guam, Water and Environmental Research Institute of the Western Pacific. Retrieved from

“Guam And Insular Areas Discuss Climate Change Assessments & Adaptation,” Ridgell, C.,  Pacific News Center, 04 June 2015, retrieved from

U.S. Department of Interior, Office of Insular Affairs, U.S. Insular Areas Climate Change Stakeholder Meeting, Tumon, Guam, June 4-5, 2015, available at

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