Photo Credit: Onofre Quezada
Scientific Frontline: Extended "At a Glance" Summary: Shifting Climate in Caribbean Tropical Forests
The Core Concept: Despite the conventional assumption that tropical ecosystems possess stable climates, recent data reveals that these regions are experiencing rapid, significant increases in extreme temperature and localized precipitation events. This destabilization is driven by global climate change and is currently affecting even highly protected areas.
Key Distinction/Mechanism: Hydroclimatic responses to global warming in the tropics are not uniform; they are highly localized and can diverge dramatically over short geographic distances. For example, while two closely located Caribbean sites both experienced a severe increase in extreme heat days, one site became significantly wetter with heavy rainfall, while the other experienced prolonged dry extremes.
Origin/History: Researchers identified a decadal warming trend of 0.29°C by analyzing continuous monitoring data collected from 1975 to 2024 in Puerto Rico, and from 1983 to 2024 in Costa Rica. By 2024, the frequency of extreme heat days at these sites had quadrupled compared to historical baselines.
Major Frameworks/Components:
- Hydroclimatic Monitoring: The continuous assessment of air temperature, water temperature, precipitation, and stream water levels using automatic and manual sensors.
- Extreme Event Frequency: The statistical tracking of environmental events that exceed the 95th, 97th, and 99th percentiles for heat and precipitation.
- Localized Divergence: The phenomenon of geographically proximate ecosystems exhibiting contrasting climate impacts, such as wet extremes versus dry extremes.
- The El Niño Southern Oscillation (ENSO): The evaluation of how broader climatic phases, such as La Niña, influence local temperature variations in specific regions.
Branches of Science: Hydroclimatology, Ecology, and Environmental Science.
Future Application: These findings will inform the development of high-resolution climate models and adaptive management strategies, enabling conservationists to design ecosystem protections that account for hyper-local climate divergences.
Why It Matters: This research demonstrates that tropical biodiversity hotspots, long thought to be insulated from anthropogenic climate impacts, are highly vulnerable. Understanding these extreme, localized shifts is critical for predicting ecosystem survival and managing global conservation efforts.
A new study finds that tropical areas, often thought to be safe from the effects of climate change, are experiencing significant changes in rainfall and extreme temperature events.
Researchers studied climate events at the La Selva research station in Costa Rica and the El Verde field station in Puerto Rico. They found that while average temperatures did not change much over time, the two locations experienced significantly more days of extreme heat in 2024 compared to long-term data stretching back to 1992.
“In La Selva prior to 2024, you had an average of eight hot days—days where the temperature exceeded the 95th percentile of temperatures at that site—per year,” said Alonso Ramirez, lead author of the study and a professor in the Department of Applied Ecology at North Carolina State University. “Now that number is up to 30. These spikes in temperature are becoming more severe and more common.”
Notably, the two locations also experienced contrasting precipitation patterns, despite being relatively close to each other. La Selva experienced more heavy rain events and fewer zero-rain days, while El Verde experienced more dry days. At La Selva, instances where rainfall exceeded the 99th percentile rose from around one event per year between 1983 and 1985 to six per year in 2024. El Verde showed no significant increase in heavy precipitation events but saw an increase in dry extremes from 152 to 170 days per year.
“That was surprising, that one is getting wetter and one is getting drier,” said Marcelo Ardon, co-author of the paper and a professor in the Department of Forestry and Environmental Resources and the Center for Geospatial Analytics at NC State. “Given how close they are to each other, we expected to find similar trends across the two sites. This shows how climate change is happening right now, and we can demonstrate that with data that doesn’t stretch that far back.”
These findings demonstrate how climate change affects even areas typically thought to have stable climates.
“A lot of people tend to think of the tropics as being stable and unchanging, especially in protected areas like the ones we’re studying,” said Ramirez. “Conventional wisdom would say that these places should not show much of a change from anthropogenic impacts. Instead, these two sites that are hotspots for research are showing clear changes in climate and in the environment, which then affects the functioning of the ecosystem.”
Reference material: El Niño, La Niña, and a Climate in Flux (revised)
Published in journal: PLOS Climate
Authors: Alonso Ramírez, Marcelo Ardón, Pavel García, Nicholas S. Marzolf, and David Genereux
Source/Credit: North Carolina State University | Joey Pitchford
Edited by: Scientific Frontline
Reference Number: as110226_01
