Seven communes in Greater Concepción would be directly affected as a result of a one-degree Celsius rise in sea temperature off the coast. This increase is explained by abnormal swells and tornadoes, among other phenomena that would cause flooding of more than 21,000 homes in the communes of Talcahuano, San Pedro de la Paz, Tomé, Lota, Penco, Coronel, and Hualpén.

The study “Impact of climate change on the coastal edge of Greater Concepción”, prepared by our laboratory, which concludes, among other points, that Chile is one of the most vulnerable countries to climate change, with the central zone of the country being the most affected territory.

The research, led by Helen de la Fuente and territorial analyst Valeria Araya, warns that the coastline of the Greater Concepción metropolitan area will experience alterations, impacting biodiversity and industrial and residential ecosystems.

Sea level rise by based on

temperature increase

San Pedro de la Paz
In San Pedro de la Paz, wetlands act as buffers to rising sea levels.
Penco
The entire Penco coastline is affected by rising sea levels.

The calculations, projected on this group of communes using the Climate Central study as a data source, indicate that with a 1°C increase in global temperature, communes such as San Pedro de la Paz or Penco could lose 280 and 800 hectares of populated areas, respectively.

Likewise, in communes like Coronel and Talcahuano, this increase can also harm port operations in the area, leaving the Coronel, San Vicente, and Talcahuano terminals severely impacted.

In this last commune, the situation is especially worrisome. According to the latest report from the Intergovernmental Panel on Climate Change, the global temperature is increasing by 1.45°C above pre-industrial levels, putting three early childhood education establishments and two school-level establishments, the ports of San Vicente and Talcahuano, the Naval Base, and five artisanal fishing coves, and at least 13 kilometers of the interport highway at risk of flooding.

The situation is even more critical if the increase is 2°C. The reach of the sea level rise would affect 32 preschools and 28 schools, three fire stations, the second Carabineros police station, two family health centers (Cesfam) and one community health center (Cecosf), the Higueras Hospital, two Biotren stations, and nine kilometers of Avenida Colón. The Carriel Sur Airport is also within this risk zone.

Projection of flooding in Talcahuano. Both ports and the El Arenal and Higueras sectors would be submerged.

In 2021, 45 beaches were analyzed along two thousand kilometers of the Chilean coast, where 80% of them showed signs of erosion in recent decades (Martínez, 2021). In 2024, a study considered 67 beaches between Arica and Chiloé, determining that 86% of the beaches are at risk of disappearing, of which 65% show erosion between -0.2 and -1.5 meters per year.

The impacts of these increases on the coasts of Greater Concepción will have a strong impact on how urban life develops. In Tomé, the effects of increasing the temperature by 1°C would leave the beaches of Dichato, El Morro, Tomé, and Bellavista underwater, as well as six artisanal fishing coves and the Tomé Cemetery. If the increase is 2°C, 206 hectares of populated areas would be flooded, along with eight preschools and eight schools, the fourth fire station, the Bellavista family health center (Cesfam), and the Tomé Hospital.

Fernando Pérez,

principal director

“Based on this, using the data available in the territory, we can anticipate the impact on urban infrastructure, services, equipment, roads, and housing. It is the same methodology that we use to study Greater Concepción and that allows us, with data and technology, to anticipate and prevent, measure future impacts, and provide input to the authorities for decision-making based on science.”

Role of wetlands

Rocuant-Andalién, Rocuant and María Isabel beach in Talcahuano, Boca Maule in Coronel, the Biobío River Estuary Wetland and Los Batros in San Pedro de la Paz, and wertlands Price and Lenga in Hualpén will play a fundamental role in containing the increase in global temperature, by acting as carbon sinks, regulating floods and preventing erosion of coastlines.

According to the conclusions and recommendations made by our team, the communes with the presence of wetlands, Talcahuano, Hualpén, and San Pedro de la Paz, will experience a greater area of impact, since these areas are significant water reservoirs.

A good mitigation alternative is to allow coastal wetlands to expand inland and establish different conservation measures, since these ecosystems function as a protective buffer for infrastructure and water containment.

Helen de la Fuente,
Interim Research Director
(s)

“Our projections are to 2100, using estimated data up to 2035. It is essential to begin implementing the Regional Climate Change Action Plan (PARCC, by its innitials in spanish) of the Biobío Region, which is a regional instrument that establishes measures along with concrete objectives and actions to address and adapt to the impacts of climate change in our region, involving public and private actors to promote resilience and sustainable development. In our laboratory, we will continue to provide more data, more science to contribute to the transformation of urban planning.”

Technical info climate change study

The study “Unprecedented threats to cities from multi-century sea level rise” is used as a primary source of information, in which different scenarios are analyzed and how the increase in temperature would affect the rise in sea level in different coastal sectors by the year 2100.

Climate Central is an independent group of scientists and communicators who research and report the facts about climate change and how it affects people’s lives.

This group specializes in carrying out different global projections on the impacts of climate change in areas of the planet, highlighting sea level rise models, in which it is possible to predict the areas with the greatest impact from future floods caused by these variations in ocean levels (Climate Central, 2024).

The warming of the ocean and the melting of glaciers in Greenland and Antarctica generate impacts that alter sea levels. Some estimates indicate that for each degree of warming, the sea level could rise by up to 2.3 meters (Strauss, 2015 in Benjamin H Strauss et al. 2021) and where long-term projections indicate that the sea level could reach between 2.9 and 8.9 meters for a warming of 1.5°C to 4°C and where in the most severe scenarios they could even reach up to 11 meters (Benjamin H Strauss et al. 2021).

The Intergovernmental Panel on Climate Change (IPCC) 2013 model (IPCC13) is used, which addresses the impact of climate change on sea level considering the thermal expansion of the oceans, the melting of glaciers and polar ice caps, and the loss of mass from the Greenland and Antarctic ice sheets. These components are modeled independently and with parameters associated with each submodel under specific warming scenarios ranging from 1.5°C to 4°C of global temperature increase. All projections use the year 2000 as the reference year for sea level and are based on different warming scenarios up to 2100.

For a more accurate assessment of the areas that will be exposed to coastal flooding, the Coastal DEM, a digital elevation model in raster format, previously developed by the Climate Central group, was used. This is especially relevant in densely populated urban areas, where vulnerability is greater due to the high concentration of population and coastal infrastructure.

Among the findings of the study, they indicate that a drastic reduction in carbon emissions is crucial for all coastal nations. However, even if emissions are reduced, significant adaptation efforts will be needed worldwide to protect coastal populations and preserve urban areas and cultural heritage from rising sea levels. It highlights that the use of these tools is fundamental to understanding climate change and guiding policies and actions for its mitigation.

  • Define the urban infrastructure, equipment, services, and housing that are crucial in the city and how these would be affected in the current urban scenario.
  • Calculate the number of dwellings and inhabitants found in the affected areas, according to the 2017 Census. Additionally, based on INE estimates, estimate the affected population for 2035, under the assumption that settlements will maintain a similar behavior in the future.
  • Present the main conclusions and recommendations to prepare the city for the impacts of climate change in relation to sea level and define areas where it will be necessary to implement key strategies in terms of infrastructure, location of services, and population.

Correction: Helen stated that the projections go to 2035. Projections extend to 2100, based on housing and population estimates for 2035.