World’s climate experts lay out ‘severe,’ ‘irreversible’ alternatives to a global treaty cutting CO2 emissions

Source: Gayathri Vaidyanathan, E&E reporter • Posted: Tuesday, November 4, 2014

Pressure for a new global treaty on climate change grew yesterday after the completion of a landmark U.N. science report that warned of “severe, pervasive and irreversible impacts” unless global warming is tackled immediately.

“This global system of our Earth is having really a high temperature,” said U.N. Secretary-General Ban Ki-moon, speaking at a press conference announcing the report. “So when your child is sick with a temperature, you have to take all medication and, if necessary, bring to doctors. This is what we have to do now.”

The synthesis report by the Intergovernmental Panel on Climate Change (IPCC) was released in Copenhagen, Denmark, where representatives from more than 100 nations met last week behind closed doors to distill three sweeping scientific reviews into a short “summary for policymakers” (ClimateWire, Oct. 28). The synthesis report is meant to be a scientific road map for policymakers and is the most urgent statement yet on climate change issued by the IPCC.

The synthesis report warns of irreversible damage to ecosystems if the world continues emitting greenhouse gases at present day levels.

But it also sounds a hopeful note that warming can be limited to 2 degrees Celsius (3.6 degrees Fahrenheit) above preindustrial levels by 2100 if nations begin cutting emissions immediately. By midcentury, emissions have to be reduced by 40 to 70 percent below preindustrial levels. And by the end of the century, the world would have to remove more carbon dioxide from the atmosphere than it is emitting.

“We need to start moving as quickly as possible,” said Rajendra Pachauri, the chairman of the IPCC. “The good news is we’ve got plenty of options available today, which can be implemented effectively and in an economically viable manner.”

Upon release of the report, officials and lawmakers from the United States, Europe and other nations called for climate action transcending national interest.

“The longer we are stuck in a debate over ideology and politics, the more the costs of inaction grow and grow,” said U.S. Secretary of State John Kerry in a statement. “Those who choose to ignore or dispute the science so clearly laid out in this report do so at great risk for all of us and for our kids and grandkids.”

Rhetoric has so far not been matched by action, but Secretary-General Ban said negotiators will have a working draft of the climate deal ready when they meet next month in Lima, Peru.

Limits to adaptation

The negotiators would be guided by the clarity of language in the IPCC synthesis report. For instance, a tussle has developed between developing and developed nations, with the poorer countries preferring targets focused on adaptation and climate finance, while developed countries prefer greenhouse gas reduction targets.

The IPCC report stresses that both are needed in the long term.

“Adaptation can reduce the risks of climate change impacts, but there are limits to its effectiveness, particularly if greenhouse gas emissions are not reduced,” the IPCC report states.

It stresses that emissions reductions would promote sustainable development in poorer nations and would have co-benefits such as improvements in air quality, said Navroz Dubash, a co-author of the synthesis report from India and senior fellow at the Centre for Policy Research.

In fact, development would be unsustainable unless climate change is tackled, the report states. If the world fails to act, climate change could reverse progress on reducing poverty and endanger the livelihoods of the world’s poor, the report states.

The IPCC synthesis lays out an alternate framework for negotiators to think of the 2-degree-Celsius target. In order to meet the target, the world can emit 2,900 gigatons of CO2, of which two-thirds has already been used up, the report states. If the world continues to emit at present-day levels, the carbon budget will be used up by midcentury, it says.

This implies that the world cannot burn fossil fuels indefinitely without carbon capture and storage (CCS). The IPCC calls for a complete revamp of electricity generation by midcentury such that low-carbon sources make up 80 percent of the energy mix. By 2100, fossil fuels cannot be burned in power plants without CCS.

The report was welcomed in the usual manner by U.S. lawmakers, with Democrats like Sen. Edward Markey of Massachusetts welcoming the IPCC report while deriding their Republican colleagues.

“When U.S. politicians refuse to act on climate change by claiming that they are not scientists, this report is the answer to their evasion,” Markey said. “Our world’s best climate scientists are saying climate change is dangerous, it is here, and it will get worse if we sit idly by and make excuses not to act.”

On the opposite side of the spectrum, Rep. Lamar Smith (R-Texas), chairman of the House Science, Space and Technology Committee, called the IPCC report “re-packaged rhetoric.”

“America cannot afford to drive its economy over a cliff with the hopes that the rest of the world will make the same mistake,” he said in a statement.

Experts keep buildup of CO2 as primary target

The atmosphere was more conducive to compromise in Copenhagen than on Capitol Hill. Last week, hundreds of experts crammed together to debate terminology and the implications for a global climate deal. The fate of the planet, and billions of dollars, hung in the balance.

One of the bigger controversies focused on a graph that shows man-made CO2 emissions rising between 1850 and the present day. According to the graph, emissions increased exponentially following World War II, and again after China’s rapid development in the 2000s.

“Although the figure is obvious, it does speak to past and current responsibility to climate change, including recent increases in emissions,” said Piers Forster, a professor of physical climate change at the University of Leeds, who took part in the discussions.

China called for more discussion, and this graph and its caption were furiously debated for nearly 15 hours. Some nations wanted greenhouse gases other than CO2, like methane and hydrofluorocarbons, represented in the graph. These gases, called short-lived climate pollutants, are easier to mitigate than CO2. If these short-lived pollutants make it into a global climate deal, nations could choose to mitigate these low-hanging fruit rather than CO2.

The scientists wanted only CO2 represented in the graph, since it has had the biggest impact on climate change. Adding the other gases would only confuse things, they said.

Finally, after four days, at 5 a.m. on Saturday, most nations (except one) agreed to allow the figure into the report.

Forster said he had become increasingly pessimistic about getting an international agreement on climate change, but the debate this time made him an optimist. China and European nations favored the figure, and “opposition turned to sand,” he said.

At the end, the Chinese delegation said, “‘China respects the science and the judgment of the authors and we appreciate their hard work. We accept this figure,'” Forster recalled. “[It] gives me huge hope for the future.”