The "arrogance" of rich countries at the Copenhagen climate summit in December contributed to the negotiations' "disappointing" outcome, a leading economist has told the BBC.

Nicholas Stern, a Briton who authored an influential 2006 report on the cost of tackling global warming, said Tuesday the United States and European Union nations failed to properly understand concerns of poorer countries.

"[There was] less arrogance than in previous years -- we have, I think, moved beyond the G8 world to the G20 world where more countries are involved," he said.

"But [there was] still arrogance and it could have been much better handled by the rich countries."

Stern recognised that the talks were "disappointing" but said he believes they were part of a wider process that is going in the right direction.

"The fact of Copenhagen and the setting of the deadline two years previously at Bali did concentrate minds, and it did lead... to quite specific plans from countries that hadn't set them out before," he said.

"So this process has itself been a key part of countries stating what their intentions on emissions reductions are -- countries that had not stated them before, including China and the US."

The talks failed to yield a hoped-for treaty on tackling carbon emissions blamed for disrupting the climate system, sparking a fierce international row about who was to blame.

As the end of the talks approached, it was left to a small group of around two dozen countries, including big carbon emitters, to haggle through the final night to craft a compromise.

The so-called Copenhagen Accord sets a goal of limiting warming to two degrees Celsius (3.6 degrees Fahrenheit) but does not detail when or how this goal should be achieved, nor does it commit its signatories to binding pledges.