Yes, the weather has gotten weirder lately, but since we're getting used to it, we think it's normal.

Who cares? Well, this means we may not recognize how dramatically and how fast the climate is changing around us, a new study suggests.

“There’s a risk that we’ll quickly normalize conditions we don’t want to normalize,” said study lead author Frances C. Moore of the University of California - Davis. “We are experiencing conditions that are historically extreme, but they might not feel particularly unusual if we tend to forget what happened more than about five years ago.”

It's similar to the "boiling frog" metaphor, which describes a frog not jumping out of slowly warming water, even though the increasing heat eventually kills him.

Moore and his research team analyzed more than 2 billion weather-related tweets and found that people have very short memories when it comes to weather: On average, people base their idea of "normal" weather on what's happened in just the past two to eight years.

"We estimate that it takes five years for changes in temperature to become completely unremarkable," Moore and her co-authors wrote in the Washington Post.

In the Twitter posts, which were written between March 2014 and November 2016, scientists found that people tweet a lot when temperatures are unusual: a strangely warm March or unexpectedly freezing winter, for example.

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But if that same unusual weather repeated for several years, fewer posts appeared on Twitter.

Thus, the study concludes that people quickly began to view it as normal in a very short amount of time.

"Even if it keeps getting warmer, people appear to adjust their expectations relatively quickly, almost as quickly as the warming itself," said study co-author Flavio Lehner, a scientist at the National Center for Atmospheric Research. "This goes for both heat waves and cold snaps: people today might tweet about a winter day being exceptionally cold, even if the data show that this would have been a perfectly normal temperature a few decades ago," he said.

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This is "alarming" news as to how this relates to climate change, the authors wrote in the Post. "If emissions are not rapidly cut, warming over the next century will exceed that of the last half-million years. But if we ignore weather and climate events that happened more than five years ago, even the changes we notice will seem small."

The study was published Monday in the peer-reviewed journal Proceedings of the National Academy of Sciences.