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Much of the US is experiencing extreme cold temperatures. But we should not read too much into this when it comes to climate change; its both not an unusual day for global temperatures, and there is not much evidence that climate change is making cold extremes more common.
We can see that while the US and part of Russia are exceptionally cold at the moment, other parts of the world have much warmer than average temperatures. A warming world is still one with regional weather variability!
At the same time, there has been a strong decrease in the number of extreme cold events in many parts of the world. Today's event feels so extreme in part because its become much rarer in recent decades. ( @RARohde has a good graph of this, but I can't seem to dig it up)
We expect on average that local variability will decline in a warming world. Its what we've observed over the past few decades globally, and what our climate models tend to project: https://www.nature.com/articles/nature12310
At the same time, there is an extremely lively academic debate about whether changing conditions in the Arctic – particularly loss of sea ice – is making Arctic Oscillation-driven mid-latitude cool events more likely: https://www.carbonbrief.org/qa-how-is-arctic-warming-linked-to-polar-vortext-other-extreme-weather
As mentioned earlier, we have little evidence in our observational data that cold snaps like the one we are experiencing in the US right now have become any more common. And some recent articles have pushed back against the hypothesis: https://www.nature.com/articles/s41558-020-00954-y
One of the challenges of being on the frontier of science in complex systems is that we have to live with a lot of uncertainty. For the time being we could all use a bit more restraint around arguing either that occasional cold weather disproves or is caused by global warming.
Hmm, that image ended up being a bit fuzzy; here is a higher-resolution version:
