Analysis
Christiana Figueres did make a similar statement at COP19, though exact wording varies across reports. While the current generation experiences unprecedented climate impacts, earlier generations also felt climate change, making the "first generation" claim debatable. The idea that we are the "last generation" that can act is a rhetorical warning, not a scientifically proven limit—future generations can still mitigate climate change, albeit with greater difficulty.
Background
Figueres served as Executive Secretary of the UNFCCC and frequently used strong language to emphasize urgency at climate conferences. The quote has been widely circulated in media and advocacy circles, often without precise citation. Climate science acknowledges that impacts are accelerating, but does not set a strict generational cutoff for action.
Verdict summary
The quote is attributed to Figueres but the factual claims about generations are overstated.