365 Days of Climate Awareness 262 - Introduction to Central America

Central America is the narrow portion of North America between Mexico and Colombia. It consists of seven countries (Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica and Panama). From Mexico it extends southward along tectonic boundaries between the Cocos and Nazca plates to the southwest, and the Caribbean plate to the northeast. It is entirely tropical, ranging between roughly 13° and 7.5° N latitude, and a population of slightly over 45 million. Central America forms a land bridge between the continental masses of North America (which it is considered part of), and South America, with its narrowest point about 50 km/30 mi wide, occurring at the Isthmus of Panama.

Political map.

Academic debate has seesawed for some time on when Central America became a complete land bridge blocking Pacific from Atlantic water. Consensus thinking is that this led to the formation of the Gulf Stream and the current North Atlantic climatic regime, in addition to the ice ages of the past 2-3 million years tied to the Earth’s Milankovitch cycles. Several different lines of evidence, including fossils and sediment cores from the Pacific and Caribbean leave a fairly wide window for this to have happened, from almost six to about 2.5 million years ago. Currently the Isthmus is crossed by the Panama Canal, though this is of no relevance to ocean currents.

Physical map.

The region is tectonically very active, with two oceanic plates–the Cocos to the north, and the Nazca to the south–moving northeastward and being subducted beneath the Caribbean and South American plates. Volcanoes and earthquakes are regular occurrences there. On top of this, the region frequently receives tropical cyclones, from depressions on up to hurricanes, on an annual basis. Despite the dynamic geological and climatic environment, Central America is one of the most biodiverse spots on earth, estimated to contain 7% of the planet’s entire biodiversity (number of distinct species). 

Tectonic plates of Central America and the Caribbean.

Evidence of human inhabitation stretches back more than 12,000 years. The region came to be dominated by the Maya from the south and the Aztecs from the north, though the arrival of the Spanish in the early 1500’s signaled the era of colonial domination and the forced export of mined precious metals and other products. In the 1800’s local populations began asserting their independence, though they seldom found peace with each other, and the Mexicans to the north made repeated attempts to conquer and control their southern neighbors. The modern-day countries we know largely emerged from the ongoing civil wars and attempts at conquest which continued throughout most of the 19th century. 

Köppen-Geiger climate zones, 1980 - 2016

Tomorrow: climate issues facing Central America.

Be brave, and be well.