As world leaders gear up for what is being billed as an historic climate meeting in Copenhagen, scientists offer a grimmer outlook on the outcome that is supposed to replace the last major global climate deal, drawn up in 1997.

"I don't have high hopes," said Josefino Comiso, a senior scientist at NASA Goddard Space Flight Center in Greenbelt, Md. "But I hope that the participants could get to a good plan on how to minimize greenhouse gas emissions."

Comiso told LiveScience that more research is needed to convince the public and "climate skeptics" that greenhouse gas emissions are causing global warming. Other scientists say the United States needs to take more of a leadership role.

In addition, the climate-change problem is complex and deeply rooted in multiple sectors, including the economy and its push for consumption along with population growth, according to one climate scientist, who also thinks human nature and our love of material goods could need a fix.

"We need to change our mind frame — our values," said Rasmus Benestad of the Norwegian Meteorological Institute. "Perhaps quality time, love, family values, friendship and respect are preferable to material goods and status? Or maybe we humans are too vain. In this problem, I think we are seeing the worst of ourselves in the mirror. We see power struggle and corruption."

Still hope

Even with these drawbacks, including the monumental need to change human nature, Comiso and others see this meeting as a step in the right direction.

"I am personally hopeful that the upcoming summit can result in agreement on a framework to guide further negotiation and decision-making," said Peter Backlund of the National Center for Atmospheric Research (NCAR) in Boulder, Colo. "I don't think it likely that the summit will result in an agreement that legally binds nations to specific emission reduction goals."

The results could just set the stage for next year, establishing "a strong process so that a binding treaty can be achieved in COP 16," said Kevin Trenberth of NCAR. (The Copenhagen meeting, also known as COP 15, is the 15th Conference of the Parties to the United Nations Framework Convention on Climate Change.)

In fact, the 11-day talks in Copenhagen have already upped the Kyoto Protocol, which was adopted in 1997 (though didn't go into effect until 2005). The United States, India and China will be at the table this time.

That's big, scientists say.

"With key countries like the U.S., China and India declining to participate because of the requirements, there was no way such a protocol would work," Comiso said, referring to the Kyoto Protocol.

While both China and India have ratified Kyoto, neither country is subject to emissions limits under the terms of the treaty, according to the Energy Information Administration (EIA), and the United States never signed the agreement.

But is increased participation this time around enough?

"Not really, because I do not see too many of the brave and intelligent leaders. Barack Obama — although perhaps promising — is not enough," Benestad said. "The climate issue is so complex and has tentacles into so many different issues."

Act locally

For those who believe actions speak louder than words, a key to curbing climate change would be for the United States to make real strides in cutting emissions domestically.

"In the case of the U.S., I believe that domestic legislation on targets and timetables for emission reductions must be agreed and enacted before the U.S. can agree to a legally binding international agreement," Backlund said.

Some of those changes are easier said than done, however.

"I think that in principle there are technological and infrastructure fixes to the problem," Benestad said, citing one example as TGIF (Thank God It's Friday). Four-day workweeks have been shown to result in less energy use. "But the problem is deeply rooted in how our economy works, based on ever-increasing consumption (an irrational concept), he said. "It's also closely related to the human population growth on Earth, and common justice."

Too many people

More than 6.8 billion people breathe in the air and otherwise consume resources across the globe. That number is projected to hit 9 billion by 2043.

"Population is a major issue and not being addressed," NCAR's Trenberth said. "China and India talk about the disparity in emissions per capita. They are correct but it is total emissions that count."

China's coal-related carbon dioxide emissions are projected to reach 9.3 billion metric tons — or 52 percent of the world's total — by 2030. India's emissions are projected to reach 7 percent of the world's total that same year, with the United States expected to come in at 14 percent of the world's total by 2030, according to the Energy Information Administration.

The technology fix

Perhaps the back-and-forth between politicians is just that, some figure.

"My view is that the problem is more likely to be solved by technological innovation than by the political process, not that they are entirely independent, since, for example, politicians can decide to promote innovation," said Kerry Emanuel, professor of atmospheric science at MIT. 

One idea off the bat is nuclear energy, Emanuel said in an e-mail interview.

"The solution to the problem is greatly retarded by the lack of scientific and technological awareness in certain societies, notably the U.S, where superstitions and political passions often trump sound reasoning," Emanuel said. "For example, we could make great strides toward energy independence and reduction of greenhouse emissions by undertaking a serious program of nuclear energy, which can easily supply our energy needs for 100 years. This, coupled with innovation in electric vehicles, would solve much of the problem."

But even if we were to stop emitting greenhouse gases all together, many of their effects would still emerge, say many scientists. And for that, adapting to such an environment is necessary.

"I am also pleased to see the increased attention being paid to adaptation," Backlund said. "Commitments to help developing countries with adaptation funding would be very helpful, as would commitments by developed nations to increase funding for the research that is needed to support effective adaptation."

An example of adaptation would be building up beaches to prevent sea level rise from inundating low-lying coastal areas.

Senior Writer Andrea Thompson contributed reporting to this article.