Daniel M. Kammen

Discussions of our proximity to a "global tipping point" on climate have now become commonplace.

Today the carbon dioxide concentration in the atmosphere is about 385 parts per million - more than 100 parts per million higher than before the Industrial Revolution. Just when and where the climate will begin to change in large, unpredictable ways remains a threat that all our environmental models say is coming, even if they cannot be forecast with any real accuracy.

James Hansen, the tremendously well-respected climate scientist and director of the NASA Goddard institute for Space Studies, has often been quoted on this topic.

"We don't understand how fast ice sheets can respond," Hansen said in a podcast interview with Earth & Sky. "But what we're learning is that they're responding a lot faster than we realised even a few years ago. So I think that we're getting close to the point of no return, and that's why we have to begin to make changes within the next few years, or we very well may be beyond the point of no return."

These tipping points are not confined to ice, but relate to ocean temperatures and fisheries and coral survivability, severe storms such as Hurricane Katrina (whatever was the climatological origin of Katrina itself), devastating forest fires, and heat waves. Around each of these issues, and indeed many more, the same story can be heard: clear evidence exists that the planet is changing - often unpredictably. What has been clear, however, is that the rate of change is faster than even the most aggressive models indicate.

Two points are of greatest underlying concern. First, the ability of the planetary system - notably the carbon "sinks" of the forests and the 800-pound gorilla in the room, the oceans - are slowing in their ability and capacity to absorb added carbon emissions. That is a problem, to say the least. What is also a problem is that our one collective success story - something termed 'decarbonisation' - has slowed to a halt.

Decarbonisation, the process of making our economic engine more carbon efficient, had been improving globally for decades. This change was largely due to greater industrial efficiency - making products with less waste and less energy inputs is simply good business - and the progression of energy efficiency efforts in a number of cities, states, and nations.

Now, we see that over the last eight to 10 years, that pace of improvement - roughly one per cent per year globally, and as much as 4 per cent to 6 per cent per year in some of the most efficient nations and/or during spells of enhanced innovation - has stagnated. This is a disaster on many levels. First it means that in a world with a growing economy emissions are rising fairly rapidly, and in a global economy that is slowing, few energy policy-makers will have the leeway to implement aggressive new programs - as we need - for fear of contributing to a weak economic system.

This last point, of course, turns out to be factually incorrect (efficiency is good for business), but yet it remains widespread in the psyche of many stewards of energy and industrial policy.

This trend is deeply troubling on its own, particularly in light of the economic benefits of using less materials and fuels to grow the economy. It is equally troubling because of the wealth of technologies and policies available to encourage the deployment of energy efficient practices.

A second lurking issue, however, is what this means for all the individual climate protection plans that are under development or early implementation in individual US states and regions, such as California and the Northeast, and in a number of nations, such as Germany, Japan and New Zealand, among others.

With the rate of decarbonisation slowing or coming to a halt - just when the climatic consensus agrees that we are now truly in the key window of time where our choices will dictate our collective climate future - the ability to "simply " accelerate a slowly evolving trend will weaken.

Policy tipping points may follow, or in some cases lead technological development and deployment tipping points, but what is clear is that the ecological tipping point looms all that much closer when even the positive energy and economic trends slow or stop.

Green-Biz Editor-at-Large Daniel M. Kammen is the Class of 1935 Distinguished Professor of Energy at the University of California. He co-directs the Berkeley Institute of the Environment and is founding director of the Renewable and Appropriate Energy Laboratory.

Kammen has served as a lead author for the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize. He has appointments in the Energy and Resources Group and the Goldman School of Public Policy.

This article first appeared at Greenbiz.com