It would be possible to think all these gabbing candidates (of both parties) are what's important. That would be a mistake.
What's more important is the push by the incumbent president is to do all he can to lower the danger of civilization-destroying war and increase the chances of peace. This species can kill ourselves (and most everything else) off much more quickly with our weapons than we can by allowing carbon pollution to increase.
(There may come a moment when that balance of danger tips. Certainly moving now to mitigate climate change is the stuff of survival. But if we allow unchecked warming to continue, we're not likely to be able to do much about a climate that won't support our kind of life.)
That venerable interpreter of political doings, reporter Elizabeth Drew, tries to fix our attention on what's vital:
The signing of this agreement is a concrete step toward choosing life over death. The chances seem good that the naysayers will not be able to block it. Now that's "one small step ..."