Warren CornwallWhen world leaders celebrated reaching a landmark climate change agreement in Paris in December 2015, the Eiffel Tower and Arc de Triomphe were illuminated with green floodlights and the message “Accord de Paris c’est fait!” (the Paris agreement is done!).
Now, five tumultuous years later, a new slogan might be “travail en cours” (work in progress).That will be the implicit message sent tomorrow when nations gather—virtually—to look back on what the Paris agreement has achieved in its first half-decade and, more importantly, to unveil new pledges to further cut planet-warming emissions.