B CMBR: Is It Constant or Changing Over Time?

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The Cosmic Microwave Background Radiation (CMBR) is not constant; it is gradually cooling and becoming more redshifted due to the universe's expansion. Fluctuations in the CMBR are expected to change over time, with significant alterations predicted in about one billion years. Small changes may be detectable within a century. A 2013 WMAP conference highlighted these findings, emphasizing the evolving nature of the CMBR. Overall, the CMBR's characteristics are dynamic and subject to change as the universe continues to expand.
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My question is this: is the CMB constant or might it be changing with time?
 
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Bill McKeeman said:
My question is this: is the CMB constant or might it be changing with time?
It's cooling. Very slowly, but it's cooling. It's the glow emitted by the Big Bang, more and more redshifted due to the expansion of the universe. It used to be really, really hot.

I expect the fluctuations will change over time too, but I don't know the timescale.
 
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It is not constant. At some WMAP conference in 2013 it was estimated that the CMBR map will look totally different in about 1 billion years.
Very small changes might be detectable on the order of 100 years.

Link to blogpost about that conference.

It includes an animation of how those changes could look over time.
 
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