The tropics are warming faster than we thought, and it's a big deal. A recent study finds that parts of the tropics, specifically the Bogotá Basin in Colombia, may warm more dramatically than previously expected as atmospheric carbon dioxide (CO2) levels continue to rise. This is a big deal because it means that the impacts of climate change may be more severe than we anticipated, particularly for the people living in these regions.
The study, led by Lina Pérez-Ángel from Brown University, analyzed a 585-meter-long sediment core drilled in central Colombia. The core captured millions of years of ancient lake, river, and wetland sediments, providing a detailed temperature record of the region. The researchers used modern dating techniques and temperature proxies to establish the ages and temperatures of the sediment layers.
The findings were surprising. While the timing of temperature change on land was similar to previous studies of sea surface temperature in the tropics, the magnitude of the change on land was greater than expected. Theory predicts that over-land temperatures in the tropics should increase about 1.4 degrees for every 1 degree increase in sea surface temperature. However, this study found that temperatures in the basin increased nearly twice as much during the Pliocene as the tropical oceans.
So, what caused this excess warming? The researchers propose a few possibilities. One is that shifts in the amount of warming at high-altitude regions like the Andes could increase with more CO2. However, this would not explain the entire excess warming. Another possibility is that regional ocean warming during the Pliocene may have driven higher temperatures in this region of the Andes. Whatever the cause, the findings underscore the importance of studying past climate over land and at a regional scale.
In this case, Pérez-Ángel's research suggests that the Bogotá Basin, which is home to more than 11 million people, could face significantly higher-than-expected temperatures as the world's climate continues to warm. This is a big deal because it means that the impacts of climate change may be more severe than we anticipated, particularly for the people living in these regions.
The research was supported by the U.S. National Science Foundation, and the findings were published in the Proceedings of the National Academy of Sciences. The study highlights the need for more research on climate mechanisms at a regional level to better understand and prepare for the impacts of climate change.
