As a climate change expert at the World Bank, Arame Tall is deeply familiar with the facts and figures of global warming. She understands how rising seas and changing weather cycles are affecting her home country of Senegal — from a retreating coastline in the city of Dakar where she grew up, to her mother's hometown of Diourbel, where drought and floods have forced people to abandon their peanut farms.

But even with all that knowledge, Tall was still shocked when her own nephew attempted to flee the country for a better life in Europe. "To the whole family's astonishment, he disappeared one night, and we looked for him," she told me. "He couldn't be found."

Earlier this year, 18-year-old Amadou had reached the boat that was supposed to smuggle him out of Senegal and into Spain. The captain warned of heavy rain that was forecast at sea and said the trip might not be safe. Afraid for his life, Amadou disembarked.

"Everybody else who got on that boat never came back," Tall told me. "And they were confirmed to have sunk in the Atlantic. So he escaped. But you always wonder, what if he had actually taken that boat?"

There is an expression in Wolof, one of Senegal's main languages: Djawou bou soppekou. It literally means, "The weather is changing."

Today, we are launching a project to look at how the ripples of climate change are radiating outward. Beginning in Senegal, my team and I are setting out to connect the dots on three major stories that I have often covered as distinct issues over the years. ...