Yes, that is basically true. Methane persists for a couple of decades, but packs a very powerful punch while it's here. (And methane levels are skyrocketing lately, which absolutely has to be addressed. Much of the warming we've seen in the last decade or two is due to methane alone.)

CO2 is longer-lived -- for centuries and millennia -- but warms much more gradually.

Both are important. In our lifetime, current methane emissions will be hugely important. Longer-term, CO2 dominates.

We need to address both, for different and complementary reasons.

In this summary, we showed methane in terms of it's "equivalent" heating impact for the next 100 years. The so-called GWP100 calcluation used by the IPCC and the UNFCC. It glosses over some of these issues, though, and it's useful to have a more nuanced view.

I think methane should be getting *MUCH MORE* attention, as a massive reduction in methane (and black carbon) emissions today could buy us a decade or two to figure out how to decarbonize other parts of the economy that pollute CO2. It would be like tapping the brakes on the climate system today, and we may need to do that.