I have noticed lots of people wearing shorts and T-shirts outdoors in the past few days. No wonder. The forecast for our corner of north-central North Carolina predicts a week or more of 70s in the daytime, with occasional dips into the 60s. Great weather for spring, but today is February 21. This isn’t our first warm spell this winter. But for one brief snow episode, we’re having a winter that feels more like a balmy spring. This is confusing flowers and flowering trees. Colds and flu cases are increasing.

Not that I’m complaining, mind you. As one who moved from Baltimore to Miami seeking warmth and remained in South Florida for 20 years, I’m partial to warm weather. It feels good.

But in California, residents are fleeing industrial-strength floods that are destroying their homes. New England is digging out from a heavy snowstorm that shut down highways and cut off electrical power in places. Cape Cod, which experiences milder temperatures than a more inland Boston, was hit particularly hard this time. Other parts of North America are parched, desperate for rain.

Are we seeing the effects of climate change? Most certainly. Sea levels rose about 6.7 inches in the last century, and the rate in the last decade is more than double that, according to the National Aeronautics & Space Administration (NASA). The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost 36 to 60 cubic miles of ice per year between 2002 and 2006, while Antarctica lost about 36 cubic miles) of ice between 2002 and 2005. Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. Glaciers are retreating almost everywhere — in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.

All of this affects weather, leading to such extreme events as flooding, drought, tornado activity, storms on steroids. Some people choose to doubt climate change. Scientists around the world are worried. We should be, too. Our response as a nation depends on those holding political power, and right now, that’s pretty scary.