After a first-day blur of rare quick action and agreement, negotiators at a critical United Nations climate summit on Wednesday finished up their first week in a more familiar place for them: the murky middle where momentum and roadblocks intertwine.

Amidst record-high temperatures, deluges, droughts and wildfires, leaders are convening for another round of United Nations climate talks later this month that seek to curb the centuries-long trend of humans spewing ever more greenhouse gases into the atmosphere.

Wedged between the southwestern town of Bridgwater and the Severn estuary is a 430-acre site where some of the U.K.'s future electricity hopes are pinned.

On a thermometer, a tenth of a degree seems tiny, barely noticeable. But small changes in average temperature can reverberate in a global climate to turn into big disasters as weather gets wilder and more extreme in a warmer world.