American Samoa

Quick Facts About American Sāmoa

American Sāmoa has a tropical marine climate moderated by southeast trade winds that blow continually with an annual rainfall averaging about 3m. Although rainfall varies from year to year and location, the rainy season is from November to April followed by a dry season from May to October. Heavy and long periods of rain are common throughout the year, yet typhoons or tropical cyclones are most common from December to March. Due to the sloping landscapes, severe landslides and flooding can occur after heavy rains.

The main island of Tutuila contains 70% of the total land area for American Sāmoa. Areas for development and agriculture are limited. Out of the 34,082 acres of land on Tutuila, only 18,626 acres have less than 45% slope, which makes it difficult for agricultural food production. According to the 2009 vegetation map, approximately 5,960 acres of Tutuila’s land was identified as agriculture and 2,084 acres as developed. For all the islands combined, 21.7% of the land is used for agriculture, with 13.3% arable land and 8.4% ‘permanent crops’ (2011 est. CIA Factbook 2016).

Climate Change in American Sāmoa

Increased Rainfall

Rainfall is projected to increase by up to 10% by mid-century compared with the present, with additional slight increases by the end of the century. Both extreme heavy rainfall events (causing increased runoff, erosion, and flooding) and droughts (causing water shortages) have become more common.
Resource: Fourth National Climate Assessment

NASA radar overview of American Samoa

Sea Level Rise

American Sāmoa faces an additional threat called "subsidence", meaning the island is sinking. The sinking has accelerated since the 2009 earthquake by 1-1.25 feet which is a sea level rise rate of five times the global average.
Resource: Samoa News

coral bleaching

Coral Reef Bleaching

Coral reefs are very valuable because they reduce the strength of waves therefore protecting tropical shorelines from being eroded away. Under projected warming of approximately 0.5°F per decade, coral reefs will experience annual bleaching beginning in about 2040 in American Sāmoa.
Resource: Fourth National Climate Assessment

Additional environmental issues of major concern

Deforestation for agriculture

Portions of the forest habitats have been cleared and replaced by agriculture and development to sustain American Sāmoa’s increasing population. The high demand for lands suitable for growing crops and level lands for building roads, homes, and businesses have significantly increased pressure on the forest.

Limited freshwater resources

Storms and Cyclones

As storms and cyclones become more frequent and dangerous, there are irreversible effects on food resources and land.

Additional Resources