The Paris Olympics opening ceremony is a little less than four weeks away.

Organizers have set a lofty goal, generate less than half the greenhouse gas emissions of the last two summer games.

And it's not just the Olympics,

across the sports world there's a new opponent,

climate change.

Jeffrey Brown reports on how the changing climate is changing the game.

The crack of the bat, a throw from the outfield.

On hallowed ground in American sports,

Yankee Stadium in the Bronx, New York, it's time for that great baseball

tradition, the pre-game warm-up. But these days here is everywhere,

warm-up means something much more.

Every professional sports community in the United States

is being affected by climate change.

Alan Hirschkowitz is the Environmental Science and Sustainability

advisor for the New York Yankees, the first

environmental scientist hired by a pro team

across all sports.

At his urging, the Yankees became the first North American pro team to sign a United Nations pledge to bring down greenhouse gas emissions.

Because he says the stakes are too high.

So there is an urgency because guess what?

Children are not going to be able to play baseball outside.

People are not going to be able to play tennis outside.

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