“We conclude that a CO2 level exceeding about 450 ppm is dangerous….“

Both Climate Progress and the Center for American Progress strongly endorse the need for a target near 450 ppm — or a total warming from preindustrial levels not to exceed 2°C.

Considering that we have already warmed 0.8°C, we can’t risk another 1°C more — a challenging goal since the Earth will warm another 0.6°C even if we stop all carbon dioxide emissions tomorrow. Nonetheless, James Hansen et al. very much believe the goal is achievable if we act quickly and focus on all greenhouse gases, not just carbon dioxide. (I share this view, and indeed they cite a Science article I coauthored on emissions reductions.)

The 1992 UN Framework Convention on Climate Change (signed by President Bush’s father and ratified unanimously by the Senate) identified an objective–”to achieve stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.” But it never answered the obvious question– really the central question of the century — what is that “safe” level?

The nation’s top climatologist is nothing if not prolific. He and nearly four dozen co-authors answer the question in a masterful article for Atmospheric Chemistry and Physics, “Dangerous human-made interference with climate.”

They look at the “potential criteria for dangerous climate change assuming that humanity wants to preserve planetary conditions similar to those in the period of civilization.” They are especially concerned about the risks posed by an ice-free Arctic, tropical storm intensification, “the potential for accelerating sea level rise [from the disintegration of the Greenland and Antarctic ice sheets], and future positive feedback from methane release.” They warn:

If the [additional] warming is less than 1°C , it appears that strong positive feedbacks are not unleashed, judging from recent Earth history. On the other hand, if global warming gets well out of this range, there is a possibility that positive feedbacks could set in motion climate changes far outside the range of recent experience.

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Tim Wirth, Vinod Khosla and John Podesta have written a piece for Grist on how “new energy rules could unleash an economic boom and help quash climate change.” What do they mean?

Consider the recent case of Xcel Energy, a Minnesota utility that wanted to build a new coal plant. When the state utility commission asked Xcel to recalculate the cost of running the plant with an $8-per-ton cost for carbon emissions, the company did so — and then abandoned its plan for the coal plant. Instead, it will rely on wind generation and hydropower. A spokesperson said that the prospect of a carbon fee helped prompt the decision, and the company now advocates mandatory standards for reducing greenhouse gases.

In this case, just the anticipation of a rule change created a market incentive for Xcel to make its next investment in a way that favored new technology.

They propose five rule changes:

• Put a price on carbon.
• Set “carbon efficiency” standards for vehicles.
• Make energy efficiency the business of utilities.
• Modernize the electric power grid to be more efficient and better deliver clean energy.
• Increase government support for clean energy.

What could this accomplish?

Climate change and oil dependence are pushing us toward a clean, renewable, efficient energy future. The profits to be made in making and selling these technologies are pulling us in the same direction. With one strategic leap, we can wipe out two of the biggest threats to our children’s well-being while creating the high-tech industries that will employ them in the future.

If we just change the rules.

Despite the statements of coalitions made of highly recognized businesses, industries, and military officials from all over the country, President Bush continues to ignore the pleas to cap carbon dioxide emissions or even use the authority he has to tighten CAFE standards.

In December 2006, the Energy Security Leadership Council (ESLC) released a report calling for heavy strides to reduce our dependence on foreign oil. The ESLC includes top names from FedEx, Southwest Airlines, Dow Chemical, and the U.S. Navy, Air Force and Marines.

In January 2007, a handful of utilities and manufacturers joined to advocate a limit on carbon dioxide emissions. The list of supporters includes General Electric, PG&E in California, BP, Alcoa, Caterpillar, and DuPont.

And equally important, a good deal of American citizens have expressed concern over global warming.

So why does our President tell us we are “addicted to oil” and ignore the findings of every peer-reviewed study from 1993-2003 that confirm the scientific consensus of anthropogenic global warming?

We can begin to fight both threats at once – through energy efficiency and renewable fuels and more. We just have to start.