Next week, a body of scientists is expected to present ironclad evidence that links humanity's fossil-fuel burning and forest-clearing ways to rising temperatures, shrinking glaciers, bulging seas and ferocious bouts of weather. The evidence could nudge global policymakers to reach a grand bargain to overhaul how we live in a bid to stabilize the global climate. But it probably won't, experts say.

Nearly four years ago, thousands of scientists, diplomats, non-profit workers and activists converged in Copenhagen with hopes that the then most recent version of the Intergovernmental Panel on Climate Change's assessment report would lead to such a deal. Instead, the world received a non-binding agreement to limit warming to 3.6 degrees Fahrenheit above pre-industrial levels.

The climate summit "was widely perceived as a failure because there were unrealistic expectations for it," Elliot Diringer, the executive vice-president of the Center for Climate and Energy Solutions in Arlington, Va., told NBC News.

But since then, he noted, more than 90 countries have submitted pledges under the Copenhagen accord. The pledges fall short of what's needed to meet the goal of limiting warming to below 3.6 degrees Fahrenheit, but they are a sign of progress, he said.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Diringer writes in an essay published today in the journal Nature that this patchwork of individual national pledges "is at once encouraging and underwhelming." Given the circumstances of reality, however, it may be the foundation of the best hope to "substantially advance the global climate effort."

The trick, he explained to NBC News, is to reach an international agreement overseeing this patchwork of pledges "that does more than simply add up the national efforts. You want an agreement that actually raises the overall level of ambition." This could be achieved via a peer-pressure type system where countries scrutinize each other's pledges, encouraging them to stretch the realm of possibility.

If this sounds like an attempt to make lemonade out of lemons, it's because it is. "This thinking reflects in part the stubborn political reality that, despite the rising toll of extreme weather and other climate impacts, governments remain much more preoccupied with flagging economies than with climate disruption," Diringer writes in Nature.

What's more, he added, the thinking reflects what the United Nations Framework Convention on Climate Change can realistically achieve at the international level. The real work on climate change must be done at the local, regional and national levels, he said.

"The reality is that a big, global agreement is not in the cards, so pragmatically working from the bottom up, perhaps loosely coordinated, is simply where the issue is at," Roger Pielke Jr., a climate policy analyst and professor of environmental studies at the Center for Science and Technology Policy Research at the University of Colorado at Boulder, told NBC News in an email.

Diringer's argument, he noted, makes sense, adding that the type of change needed at the national level is a massive investment in technological innovations to move the world "from getting 13 percent of its energy from carbon-free sources to more than 90 percent, all by 2050" if the world aims to meaningfully stabilize greenhouse gas levels in the atmosphere.

"All of the talk of ambition and agreements is great, but at some point how we motivate and pay for energy innovation has to come into the discussion explicitly," Pielke said.

His payment plan hinges on a carbon tax that is too small to disrupt economies, but large enough to pay for energy-related research and development along the lines of the current U.S. $40 billion budget for health research or the $150 billion spent on defense-related research. Today, the federal budget for energy research, including on fossil fuels, is about $5 billion.

John Roach is a contributing writer for NBC News. To learn more about him, visit his website.