Call it the Starbucks Effect.

When Colorado scientists wanted to figure out how much humans are directly contributing to the long-standing nitrogen pollution problems in our high mountain lakes, they needed a new tracing method.

For decades, researchers have calculated the environmental damage done by nitrogen that rises from Front Range smokestacks, and from human and animal waste-treatment ponds, then falls down on Rocky Mountain National Park in rain or snow.

Now they wanted to know how much the various animals who are overrunning the park and peeing in the watershed were contributing to the stubborn nitrogen problem. They had already sorted out the contributions of the pesky elk herds by following them around with clipboards and tracking how often nature called.

But how to distinguish between human pee and elk pee?

It’s the triple-shot espresso.

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