News and Outreach: Henry Jacoby

AP, Seth Borenstein
WASHINGTON (AP) — Heat-trapping greenhouse gases in the atmosphere are building up so high, so fast, that some scientists now think the world can no longer limit global warming to the level world leaders have agreed upon as safe.

New figures from the U.N. weather agency Monday showed that the three biggest greenhouse gases not only reached record levels last year but were increasing at an ever-faster rate, despite efforts by many countries to reduce emissions.

As world leaders meet next week in South Africa to tackle the issue of climate change, several scientists said their projections show it is unlikely the world can hold warming to the target set by leaders just two years ago in Copenhagen.

"The growth rate is increasing every decade," said Jim Butler, director of the U.S. National Oceanic and Atmospheric Administration's Global Monitoring Division. "That's kind of scary."

Scientists can't say exactly what levels of greenhouse gases are safe, but some fear a continued rise in global temperatures will lead to irreversible melting of some of the world's ice sheets and a several-foot rise in sea levels over the centuries — the so-called tipping point.

The findings from the U.N. World Meteorological Organization  are consistent with other grim reports issued recently. Earlier this month, figures from the U.S. Department of Energy showed that global carbon dioxide emissions in 2010 jumped by the highest one-year amount ever.

he WMO found that total carbon dioxide levels in 2010 hit 389 parts per million, up from 280 parts per million in 1750, before the start of the Industrial Revolution. Levels increased 1.5 ppm per year in the 1990s and 2.0 per year in the first decade of this century, and are now rising at a rate of 2.3 per year. The top two other greenhouse gases — methane and nitrous oxide — are also soaring.

The U.N. agency cited fossil fuel-burning, loss of forests that absorb CO2 and use of fertilizer as the main culprits.

Since 1990 — a year that international climate negotiators have set as a benchmark for emissions — the total heat-trapping force from all the major greenhouse gases has increased by 29 percent, according to NOAA.

The accelerating rise is happening despite the 1997 Kyoto agreement to cut emissions. Europe, Russia and Japan have about reached their targets under the treaty. But China, the U.S. and India are all increasing emissions. The treaty didn't require emission cuts from China and India because they are developing nations. The U.S. pulled out of the treaty in 2001, the Senate having never ratified it.

While scientists can't agree on what level of warming of the climate is considered dangerous, environmental activists have seized upon 350 parts per million as a target for carbon dioxide levels. The world pushed past that mark more than 20 years ago.

Governments have focused more on projected temperature increases rather than carbon levels. Since the mid-1990s, European governments have set a goal of limiting warming to slightly more than 2 degrees Fahrenheit (1.2 degrees Celsius) above current levels by the end of this century. The goal was part of a nonbinding agreement reached in Copenhagen in 2009 that was signed by the U.S. and other countries.

Temperatures have already risen about 1.4 degrees Fahrenheit (0.8 degrees Celsius) since pre-industrial times.

Massachusetts Institute of Technology professors Ron Prinn, Henry Jacoby and John Sterman said MIT's calculations show the world is unlikely to meet that two-degree goal now.

"There's very, very little chance," Prinn said. "One has to be pessimistic about making that absolute threshold." He added: "Maybe we've waited too long to do anything serious if two degrees is the danger level."

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The co-director of MIT's Global Change program discusses what to expect from the U.N. Climate Change Conference, and the effects of 'Climategate'

Delegates from around the world began meeting this week in Copenhagen to try to work out a new U.N. pact to address global climate change. Henry Jacoby, co-director of the MIT Joint Program on the Science and Policy of Global Change and professor of management at the Sloan School of Management, talks about what to watch for at the December 7-18 conference, and what the repercussions may be from the recent release of hacked e-mails and other documents from the University of East Anglia relating to climate-change research. Climate-change skeptics have dubbed the affair “Climategate” and say the materials show a scientific conspiracy to exaggerate the risks of climate change. Many in the scientific community, however, say the release of documents represents a smear campaign.

Q: Expectations about the Copenhagen climate meeting seem to have been on a roller-coaster ride. What is your sense at this point of what will come of this meeting?

A: The original objective and expectation, back when the negotiating text for this meeting was agreed in Bali, was that they would have some kind of binding commitments by developing countries, some agreement to actions by developed countries, and agreement on financial transfers. That’s what they were supposed to do. We aren’t going to be able to do that, for a couple of reasons. [More... ]

Q. How serious are the revelations in the so-called “Climategate” release of e-mails, and what effect do you think that may have on Copenhagen or on other attempts to deal with climate-change issues?


A. There are several ways of thinking about that. Is it a serious challenge to the science of this issue? The answer is no. This is kind of a peek under the blanket of a discussion that went on 10 years ago, about the analysis of tree rings and other data, to try to reconstruct temperature histories over the last thousand years. The work led to the conclusion that the current temperature rise over the last 50 years is both unique in its pace, and has produced temperatures higher than we’ve seen in the last thousand years.

There has been a lot of analysis of that issue since, by other groups, reaching similar conclusions. Also, the basis of our work, as we develop our impression of the risk, does not depend on that data. It depends on much more firm temperature information from the last 150 years. So in terms of its effect on the science, I don't believe it's serious.

It is unfortunate, however, that this has an effect on politics in the U.S. It makes it appear that there's some conspiracy of scientists here. Scientists talk to each other in informal ways. A lot of words they use appear different in public than what they were intended to be. And to some degree this email file is being purposefully misinterpreted, creating an impression that's really unfortunate. But it is true that these scientists should have been more careful — they didn't understand, I think, when they were doing this original work, how important this would be in the political discussion. It provides ammunition to people who argue climate is not a problem, and confuses the public. How serious that is, I don't know. [More... ]

Q. How urgent is the need for action on climate change, in your view? That is, if the world fails to adopt specific, binding targets for reduction of greenhouse gases at this meeting, how serious could the consequences of that be?

A. This is a century-scale problem, so it's not exactly a matter of what you do this year. But we've been at this for 20 years, and we haven't done very much yet. What's important is to get started. We have a lot to learn about the costs of mitigation, and we have to learn even more about the climate system, but waiting to find out before taking action can be costly.

We need to do something to reduce the impact of human activities over a timescale of many decades, but the decades are going by. It's not crucial what we do in 2009 or 2010, but it's quite important that we get started on some serious measures to decrease emissions, and create the international structure, and domestic policies, to have some chance for sustained action over many decades. It’s just a matter of lifting one foot to take the first step now. Long-term targets, say for specific reductions by 2050, have their purpose in terms of motivating people. But the main thing is we’ve got to agree to do something in the short run, on critical issues like what the United States is going to do, and what the relationship is going to be between the developing and developed countries. So achievements this year or next year are not crucial, but failing to get the process on track would be very serious.

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Prof. Henry Jacoby participated in a Hearing of the U.S. Senate Committee on Energy and Natural Resources on the Stern Review of the Economics of Climate Change, examining the economic impacts of climate change and stabilizing greenhouse gases in the atmosphere.