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Sentry at the Atlantic Gateway  Experimental mooring monitors
water flow through Hudson Strait   Here’s an easy recipe to
change Earth’s climate: Just add more fresh water to the North
Atlantic Ocean.  In this oceanic part of the world lies a
critical—and sensitive—component of the heating and plumbing
system that regulates the planet’s climate. Messing with it is
like tampering with the thermostat in your house.  Warm, salty,
equatorial waters flow via the Gulf Stream to the North
Atlantic. In winter, they confront cold air and release heat to
the atmosphere, making winters in North America and northern
Europe milder. The waters—still salty and now colder—become
denser and sink to propel a global system of currents called the
Ocean Conveyor.  Adding fresh water throws a monkey wrench into
the system. It is much lighter than, and floats above, saltier
water. The fresh water can form a cap that can block the deeper
warm waters from surrendering their h