**1. Introduction**

Coastal erosion is a worldwide concern, affecting virtually all coastal countries. In some cases, erosion reaches stages where it results in a high rate of environmental degradation. The economic repercussions are diverse, such as damage to the natural environment and loss of public infrastructure and/or private property. These facts can have extremely serious consequences in economy, ecosystems, tourism, and public health.

The main causes of coastal erosion are the rising of sea level that is underway globally and inadequate management of coastal areas. Frequently, it is associated with the installation of urban and industrial equipment or with structures dedicated to leisure, housing, and tourism.

In the state of Ceará, Northeast Brazil, in the 1950s, an industrial harbor was built. The harbor structures, with other factors such as the destruction of dune bypass, produced a large erosive process downdrift. It was responsible for the loss of more than 400 m of beach in six decades. At Canoa Quebrada beach (a nationally and internationally famous touristic area), a recent partial process of collapse of the cliffs occurred as an answer to inappropriate uses and occupation. This fact produced landscape and economic damage. In the northern coast of Colombia, anthropogenic interruption of the longshore transport caused by the construction of groins, as well as some harbors, produced severe beach erosion along the downdrift shoreline.

With the abrasive action of waves associated with rising sea level, these coastal areas in both countries are at risk of more substantial degradation. These environmental situations will be the object of synthetic technical and scientific analysis and discussion in this chapter. Mitigation propositions for both countries coastal areas are also considered.
