As delegates from around the world descend on Warsaw for talks toward a new climate treaty, scientists are issuing more and more dire warnings that time is running out to avoid dangerous global warming.
In the past week, several new reports echoed the common theme that urgent action is required to reverse emission trends. Otherwise, greenhouse gas accumulations will surely break through the threshold that scientists say will lock in unacceptable warming—with the attendant droughts, floods, storms, sea rise and damage to ecosystems.
Concentrations of greenhouse gases in the atmosphere continue to set records, a Nov. 6 report by the World Meteorological Organization confirmed. The gap between a safe track for emissions and the business-as-usual track continues to widen, another organization's report said on Nov. 5.
Yet another, by the Intergovernmental Panel on Climate Change, foretold consequences including disruption to food supplies and possibly rising violence.
All the reports sounded a common theme: more needs to be done, and faster.
The grim warnings come at a crucial time for the long-running climate talks. The negotiations, under the auspices of the United Nations Framework Convention on Climate Change, seek to achieve a binding treaty in Paris in 2015 that will put the world on course to limit global warming to 2 degrees Celsius above pre-industrial levels by the end of the century.
Decisions in Warsaw and actions in 2014 are considered crucial to achieving any such treaty. But few would contend that the world's emissions trend can be readily reversed.
It's important to try, said Christiana Figueres, executive secretary of the UN convention, in a recent speech in London. "There is no doubt that we have to act and that we have to act now," she said, repeating the phrase "now is the time" over and over.
"It is not tomorrow. It is not the day after tomorrow. ... Now is the time and Warsaw needs to show that we have understood that now is the time."
The reason for the growing sense of urgency, said Michel Jarraud of the World Meteorological Organization, a UN body, is that "time is not on our side."
The WMO issued an annual report showing, to nobody's surprise, that atmospheric concentrations of greenhouse gases increased once again in 2012, building up the blanket of heat-trapping gases at a pace that scientists find alarming.
"Limiting climate change will require large and sustained reductions of greenhouse gas emissions," Jarraud said. "We need to act now."
All the world's climate negotiators know about the bleak latest assessment of the Intergovernmental Panel on Climate Change (IPCC), a UN body whose work represents the consensus on climate science. The report reaffirmed that the world is in serious danger of exhausting the "carbon budget," or the amount of fossil fuels countries can safely burn before Earth's climate patterns are destabilized, triggering irreversible climatic changes.
On Nov. 5, the UN Environment Program issued its own annual report on what it calls the "emissions gap"—the extent to which current emissions will break through the 2-degree safety net.
The gap, it said, will persist for the next several decades, even though some emissions reductions could be achieved through governments' current policies and pledges.
In his foreward to the UNEP report, the organization's executive director, Achim Steiner, said that countries were not showing the will to confront the problem, even as it grows more urgent to do so.
"The challenge we face is neither a technical nor policy one—it is political: the current pace of action is simply insufficient," he wrote. "The technologies to reduce emission levels to a level consistent with the 2° C target are available and we know which policies we can use to deploy them. However, the political will to do so remains weak. This lack of political will has a price: we will have to undertake steeper and more costly actions to potentially bridge the emissions gap by 2020."
The report said that with a carbon cost of between $50 to $100 a ton, nations could cut carbon dioxide emissions by approximately 17 million tons by 2100, enough to avoid the worst climate outcomes.
"This is enough to close the gap between business-as-usual emission levels and levels that meet the 2° C target, but time is running out," the report said.
Without quick action, it said, closing the emissions gap will become less and less likely, and avoiding severe warming will become "more difficult, costlier, and riskier."
The report was authored by 70 scientists from 44 scientific groups in 17 countries.
"Emission reductions in reality have not kept up with the least-cost paths," the scientists warned. "As a result, it is becoming increasingly difficult to achieve the emission levels in 2020 specified by least cost scenarios. This situation has inspired the research community to look into scenarios that explore the impact of later action. While such scenarios can lessen the necessity for short-term emission reductions they come with many additional costs and challenges. To avoid these costs, it is important to increase near term policy efforts aiming at reducing emissions by 2020, even if they do not reach the level of the least-cost scenarios. Without such efforts, the carbon-emission budgets consistent with keeping temperatures below 1.5° C or 2° C are exhausted rapidly, and mitigation challenges in the future are increased."
The unfinished draft of another UN report, which is due to be published in a few months, was leaked on the Internet late last week while still under review. Some of its warnings, too, were grim. And like the other reports, it said the only way the world "can substantially reduce risks of climate change in the second half of the 21st century," is if countries put strict emissions controls in place over the next few decades.
Among the risks it cited was falling agricultural productivity, making it harder to feed the world's growing population. Even though some crops in some regions might thrive amid rising temperatures or other shifts in climate patterns, the tropics would probably be hit hard. As a result, overall global food yields might go down as much as 2 percent every 10 years for the rest of the century, it found.
The problem in all of this—and the difficulty facing negotiators in Warsaw—is that while a few countries are making considerable progress, significant commitments are needed from all nations. This is especially true for developing countries, where emissions are growing fastest and where the need for new energy supplies is especially acute.
The United States has pledged to reduce its emissions by 17 percent by 2020 from 2005 levels, and around 80 percent by 2050. Although challenging, the targets are plausible given recent trends, at least for the short run.
But even for those nations and states that are performing well and have committed to making tough emissions cuts in the coming decade, the kind of steep reductions that are needed may be difficult to guarantee.
Angel Gurría, the secretary general of the Organization for Economic Cooperation and Development, said last month in London that the world needs to reduce carbon dioxide emissions to zero in the second half of the century.
"While governments need to start taking action now to put us on a pathway to achieve zero net greenhouse emissions globally in the second half of this century, our dependence on fossil fuels appears to be unshaken," he said.
"We need to learn from the policies some countries are implementing to drive the investment and technology shift needed to break that dependence, and to highlight the stumbling blocks that will require strong political will to be overcome," he continued.
A new study by the Lawrence Berkeley National Laboratory showed that even governments like California's, which has already enacted rigorous carbon-cutting policies, are going to have to do more to meet ambitious long-term goals. The study found that California may hit its target for 2020, but it is not on track to reduce emissions by 80 percent by 2050, as it promised.
Jeff Greenblatt, a Berkeley Lab researcher said in the study: "This is quite a stringent requirement, and even if we aggressively expand our policies and implement fledgling technologies that are not even on the marketplace now, our analysis shows that California will still not be able to get emissions to 85 million metric tons of CO2-equivalent per year by 2050."