The UN climate summit highlighted a massive divide

Dueling plotlines dominated the UN climate summit: Newly revealed ambition from countries and companies, and palpable anguish — distilled in teen activist Greta Thunberg's speech — that it's not nearly enough.

The big picture: The summit brought a burst of new commitments and initiatives. These include dozens of nations pledging to strengthen their plans under the Paris deal, new commitments to the multilateral Green Climate Fund, and asset managers committing to carbon neutral portfolios by 2050.

• Reuters has a tally here, and the UN's summary is here.

But, but, but: Several of the world's largest nations either did not bring new pledges — including China, by far the world's largest carbon emitter — or didn't go as far as advocates hoped.

• The Union of Concerned Scientists' Alden Meyer accused most large nations of "dodging their responsibility to step up action as is essential to address the climate emergency we now face."
• "Advocates and diplomats who have been following climate talks for years said they were disappointed," the New York Times reports.

Of note: At midnight, President Trump mocked Thunberg in a tweet that puts a highlighter pen over the split between the U.S. government — which offered no pledges — and advocates.

The intrigue: The chasm between the summit and advocates' goals was apparent when Big Oil CEOs defended their strategies at a rare, invite-only forum on the event's sidelines.

Driving the news: The CEOs of ExxonMobil, Shell, BP, Chevron and others gathered under the umbrella of the Oil and Gas Climate Initiative, an industry group investing in emissions-cutting tech. 

• A common theme at the nearly 3-hour event: Tackling climate change is more complicated and slower than the urgent message radiating from activists and world leaders nearby at UN headquarters.

• Exxon CEO Darren Woods typified the industry's steady-as-she-goes view of energy transition that activists call wholly at odds with the seismic changes needed. “I don’t see [the transition] as a threat,” Woods said. “It’s an evolution of the industry."

Between the lines: The execs largely agreed natural gas will play a key role for decades to come, which is increasingly at odds with what climate scientists say is needed to aggressively curb emissions.

• “It’s likely to play an even larger role in the future,” Chevron CEO Michael Wirth said. “For the foreseeable future the realistic scalable and affordable way to build out a reliable grid growing renewable power is likely to be with natural gas.”

Go deeper ... Greta Thunberg to world leaders: "You are failing us" on climate change