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Monday, February 18, 2008

Light Vs. Carbon

Stabilizing Climate Requires Near-zero Carbon Emissions

ScienceDaily (Feb. 18, 2008) — Now that scientists have reached a consensus that carbon dioxide emissions from human activities are the major cause of global warming, the next question is: How can we stop it? Can we just cut back on carbon, or do we need to go cold turkey? According to a new study by scientists at the Carnegie Institution, halfway measures won’t do the job. To stabilize our planet’s climate, we need to find ways to kick the carbon habit altogether.

In the study, to be published in Geophysical Research Letters, climate scientists Ken Caldeira and Damon Matthews used an Earth system model at the Carnegie Institution’s Department of Global Ecology to simulate the response of the Earth’s climate to different levels of carbon dioxide emission over the next 500 years. The model, a sophisticated computer program developed at the University of Victoria, Canada, takes into account the flow of heat between the atmosphere and oceans, as well as other factors such as the uptake of carbon dioxide by land vegetation, in its calculations.

This is the first peer-reviewed study to investigate what level of carbon dioxide emission would be needed to prevent further warming of our planet.

“Most scientific and policy discussions about avoiding climate change have centered on what emissions would be needed to stabilize greenhouse gases in the atmosphere,” says Caldeira. “But stabilizing greenhouse gases does not equate to a stable climate. We studied what emissions would be needed to stabilize climate in the foreseeable future.”

The scientists investigated how much climate changes as a result of each individual emission of carbon dioxide, and found that each increment of emission leads to another increment of warming. So, if we want to avoid additional warming, we need to avoid additional emissions.

With emissions set to zero in the simulations, the level of carbon dioxide in the atmosphere slowly fell as carbon “sinks” such as the oceans and land vegetation absorbed the gas. Surprisingly, however, the model predicted that global temperatures would remain high for at least 500 years after carbon dioxide emissions ceased.

Just as an iron skillet will stay hot and keep cooking after the stove burner’s turned off, heat held in the oceans will keep the climate warm even as the heating effect of greenhouse gases diminishes. Adding more greenhouse gases, even at a rate lower than today, would worsen the situation and the effects would persist for centuries.

"What if we were to discover tomorrow that a climate catastrophe was imminent if our planet warmed any further? To reduce emissions enough to avoid this catastrophe, we would have to cut them close to zero — and right away," says Caldeira.

Global carbon dioxide emissions and atmospheric carbon dioxide concentrations are both growing at record rates. Even if we could freeze emissions at today’s levels, atmospheric carbon dioxide concentrations would continue to increase. If we could stabilize atmospheric carbon dioxide concentrations, which would require deep cuts in emissions, the Earth would continue heating up. Matthews and Caldeira found that to prevent the Earth from heating further, carbon dioxide emissions would, effectively, need to be eliminated.

While eliminating carbon dioxide emissions may seem like a radical idea, Caldeira sees it as a feasible goal. “It is just not that hard to solve the technological challenges,” he says. “We can develop and deploy wind turbines, electric cars, and so on, and live well without damaging the environment. The future can be better than the present, but we have to take steps to start kicking the CO2 habit now, so we won't need to go cold turkey later.”

Journal reference: Matthews, H. D., and K. Caldeira (2008), Stabilizing climate requires near-zero emissions, Geophysical Research Letters, doi:10.1029/2007GL032388, in press.

Adapted from materials provided by Carnegie Institution.

Monday, February 4, 2008

Tipping into the light?

February 4, 2008

The Final Tipping Point

by Christopher Flavin, President, Worldwatch Institute

There are good reasons to think that the world may be on the verge of a major transformation of energy markets. The powerful interaction of advancing technology, private investment and policy reform have led to a pace of change unseen since men like Thomas Edison and Henry Ford created the last great energy revolution a century ago. But is it enough? Will the coming years bring the accelerated change and trillions of dollars of investment that Nicholas Stern estimates is needed to reverse the tide of climate change?

The answer to that question will likely be found not in the messy world of economics but in the even messier world of politics. Can the enormous power of today's industries be set aside in favor of the common good? Time is growing short. In the United States alone, 121 coal-fired power plants have been proposed. If built, they could produce 30 billion tons of carbon dioxide over their 60-year lives. China is building that many plants every year.

There were growing signs in 2007 that the years of political paralysis on climate change may be coming to an end, spurred by the warnings of scientists and the concerns of citizens. One sign of the changing times is that many of the planned coal plants are under attack by local and national environmentalists, and some have already been scrapped. Germany recently announced that its centuries-old hard coal industry will be closed by 2018.

Several potentially game-changing political developments in 2007 are worth noting:

  • Twenty-seven major U.S. Companies — from Alcoa and Dow Chemical to Duke Energy, General Motors, and Xerox — announced support for national regulation of CO2 emissions.
  • The European Union committed to reducing its carbon dioxide emissions 20 percent below 1990 levels by 2020, and member states are ramping up their energy efficiency and renewable energy programs in order to achieve these goals.
  • China announced its first national climate policy, pledging to step up its energy efficiency and renewable energy programs and acknowledging that earlier policies were not sufficient.
  • Seventeen states in the United States moved toward adopting regulations on CO2 emissions, increasing pressure on the U.S. Congress, which was considering national legislation.
  • Brazil recognized the threat that climate change poses to the country's economically crucial agriculture and forestry industries and signaled a new commitment to strengthening international climate agreements.

As negotiations begin on the international climate agreement that will supplant the Kyoto Protocol after 2012, the world's political will to tackle climate change will be put to an early test. The politics of climate change are advancing more rapidly than could have been imagined a few years ago. But the world has not yet reached the political tipping point that would ensure the kind of economic transformation that is required. And the divide between industrial and developing countries over how to share the burden of action must still be resolved.

As people around the world come to understand that a low-carbon economy could one day be more effective than today's energy mix at meeting human needs, support for the needed transformation is bound to grow. Urgency and vision are the twin pillars on which humanity's hope now hangs.

Christopher Flavin is President of the Worldwatch Institute. This piece was excerpted from the WorldWatch State of the World 2008. For more information, please visit

The information and views expressed in this article are those of the author and not necessarily those of or the companies that advertise on its Web site and other publications.

Reader Comments (1)

Jonathan Cole

Date Posted:
February 4, 2008

I have been a fan of Worldwatch Institute since its inception. But I must say that if we wait for the political will to make these changes, it may be too late. The way the world works is the old "king of the hill" technologies (i.e. railroads, petroleum energy systems), are defeated by upstart technologies (automobiles, ([solar energy systems?]) that give the customer what they want at a price they can afford. Solar is already affordable, it is just not packaged efficiently. It is not the politicians we are waiting on, it is the intelligent financiers!! The Henry Ford of solar energy is awaiting the financial means to mass produce the right product!