The 1970s brought the United States a string of fierce winters and a spate of speculation on a cooling climate. Many atmospheric scientists had a different worry: they knew that carbon dioxide in the air had been increasing for decades and that global temperatures should rise before long.

When scientists around the world began planning the most ambitious weather observing study in history, NCAR was a natural partner.

Computer models of global climate became indispensable tools in the last decades of the 20th century as society began to grapple with the impact of human-produced greenhouse gases.

The field known as weather modification grew wildly through the 1950s and 1960s, as aircraft funded by U.S. states and many countries began “seeding” clouds in hopes of stimulating rain and suppressing hail.

Years before it housed aircraft or supercomputers, NCAR was sending balloons into the stratosphere. Bolstered by new space-age technology, this simple but powerful observing strategy gathered critical data from hard-to-reach places.