Sea Turtles in a Warming World: How EPI Teaches Climate Change in Costa Rica
- Luis Diego Molina
- Oct 16
- 5 min read
Updated: Oct 24
This post is the first in a series exploring how EPI addresses climate change in its field-based environmental education courses. We begin with Costa Rica, and upcoming editions will cover Belize, the Galapagos, Yellowstone, and Baja California Sur. Climate change is one of the greatest—if not the greatest—challenges of our time, and education is vital to confronting it.
When Climate Change Shapes Life Itself
What happens if an entire species of animals begins producing only females? This isn’t a hypothetical question or science fiction, it’s a real consequence of climate change.
Climate change is undeniable. It’s already here, affecting all of us to varying degrees. Wildfires, floods, and droughts dominate the news almost daily. And it doesn’t just affect humans, it threatens all life on the planet.
Sea turtles are no exception. In Costa Rica, EPI manages Pacuare Reserve, home to the fifth most important nesting beach in the world for the endangered leatherback turtle. There, we witness firsthand how global warming impacts this remarkable species.
Heat, Sand, and Survival
For sea turtles, the temperature of the nest determines the sex of the hatchlings. If the temperature rises above 29.5°C (85.1°F), females will predominate. Extreme feminization can severely disrupt reproduction, putting the species’ survival at risk.
At even higher temperatures, many eggs fail to hatch at all. In Costa Rica, beach temperatures have already surpassed 35°C (95°F), posing a serious threat to hatchling survival.
Coastal erosion adds another layer to the problem. As polar ice melts and global sea levels rise—currently by about 3 mm per year—beaches are changing shape.
Female turtles return to the same coasts where they were born to lay their eggs. When beaches erode, recede, or flood more frequently, turtles struggle to find safe nesting areas. This often leads to failed nesting attempts or migration to less protected sites.
For example, according to an reportage by the University of Costa Rica, in Gandoca, on Costa Rica’s southern Caribbean coast, once a prime nesting site for leatherbacks, nest counts dropped from around 1,000 per season in 2007 to just over 100 before the pandemic, largely due to coastal erosion caused by rising seas.
Climate change also affects the marine ecosystems turtles depend on for food and migration.
As oceans absorb more carbon dioxide, they become more acidic, leading to massive coral bleaching. This disrupts food chains, impacting not only leatherbacks but also hawksbill and green turtles, both of which feed on reef-associated species and are frequently encountered at Pacuare Reserve.
Teaching Climate Change Through Experience
For EPI, as an educational organization, addressing climate change is essential. Our very first student group 25 years ago visited Pacuare Reserve, and we continue to bring students there today. This sanctuary allows them to understand the real-world impacts of the climate crisis on critical species like sea turtles.
Each night, guided by moonlight and mission, students at Pacuare Reserve join the Sea Turtle Monitoring and Conservation Program, learning the protocols and taking part in nightly beach patrols from March to July.
They accompany research assistants, walking six kilometers in complete darkness. When they encounter a nesting turtle, they help collect biometric data, such as carapace size, and carefully relocate eggs to the hatchery, where the hatching success rate rises from 9% to 78%.
Alongside this fieldwork, students learn about the turtles’ life cycle and how climate change affects their survival.
From Data to Understanding
“As educators, we challenge students with questions,” explains Ana Beatriz Hernández, EPI staff member. “What happens if a population has only females? And this is a species that needs both sexes to reproduce. It helps them understand the urgency of protecting an endangered species.”
The goal isn’t just to provide data. It’s to help students grasp that climate change isn’t a matter of opinion, but of evidence and science.
“Everything about forming an opinion on climate change has to come from evidence,” says Ana Beatriz. “It’s not about personal belief. It’s about looking at trends and understanding that, yes, there are changes, and yes, they’re affecting us.”
Simulating Real-World Challenges
To bring sustainability to life, EPI uses a role-playing simulation where students take on the roles of community members in a fictional town facing an environmental crisis. Participants may be a farmer, a politician, or a business owner, each with different interests and responsibilities. At first, students focus on their own goals, often creating conflicts over land, energy, and resources.
Example (fictional): Banana plantation owners might try to expand monocultures into forested areas, while other students argue for protecting water and wildlife. These decisions are mapped on the town map, making the trade-offs visible.
Afterward, students learn about the SDGs and Project Drawdown — a set of science-based strategies to reduce greenhouse gases and strengthen natural carbon sinks — and redesign their town on the map to balance economic growth with nature’s conservation.
Example (fictional, second phase): Teams may limit plantation expansion, introduce agroforestry, or protect forests as carbon sinks. The updated map reflects sustainable production and cooperation.
Through this activity, students experience how compromise and creative thinking shape sustainable solutions and gain ideas they can apply in their own communities.
Inspiring Lasting Change
“What made this course so great was that it really made me aware of what we have in this world. I learned about biology and the ecosystem alot and it also inspired me to become an engineer to help combat climate change”, commented Mark, a ST. Andrew's Episcopal School student that participated in an EPI course in 2023.
And that is what EPI courses are about. As Ana Beatriz explains:
“If climate change isn’t presented in an engaging way for young people, it’s a topic they’ll likely overlook. And that makes it harder for it to become relevant later in life.”
EPI’s goal is not only for students to gain knowledge but also to develop skills and change behaviors, in their daily lives and in their communities. That’s why EPI created the Alumni Leadership Award, which funds student-led sustainability projects.
One recent example came from Instituto Experimental Bilingüe de Pococí — a high school in the Costa Rican Caribbean — where a student named Andrés led a project to collect plastic waste and transform it into tables and other school furniture.
“His interest came from seeing the link between plastic waste and the ocean,” explains Ana Beatriz. “As plastics degrade into microplastics on beaches, they combine with rising sand temperatures, intensifying heat in turtle nests and increasing the risk of sex ratio imbalance in hatchlings.”
Building Climate Awareness, One Field Course at a Time
At EPI, climate change—and humanity’s broader impact on ecosystems—is a cross-cutting theme in every field course. The goal is to awaken curiosity, help students understand how their daily actions contribute to the causes of climate change, and inspire them to take community-level action to mitigate its effects.
Through science, experience, and reflection, students leave not just informed, but empowered to be part of the solution.
👉 Learn more about our Costa Rica Ecology Program and how you can experience conservation in action: https://www.ecologyproject.org/costa-rica-ecology-program