It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Sunday, December 9, 2007

And So Say All of Us

2007 Bali Climate Declaration by Scientists

The 2007 IPCC report, compiled by several hundred climate scientists, has unequivocally concluded that our climate is warming rapidly, and that we are now at least 90% certain that this is mostly due to human activities. The amount of carbon dioxide in our atmosphere now far exceeds the natural range of the past 650,000 years, and it is rising very quickly due to human activity. If this trend is not halted soon, many millions of people will be at risk from extreme events such as heat waves, drought, floods and storms, our coasts and cities will be threatened by rising sea levels, and many ecosystems, plants and animal species will be in serious danger of extinction.

The next round of focused negotiations for a new global climate treaty (within the 1992 UNFCCC process) needs to begin in December 2007 and be completed by 2009. The prime goal of this new regime must be to limit global warming to no more than 2 ºC above the pre-industrial temperature, a limit that has already been formally adopted by the European Union and a number of other countries.

Based on current scientific understanding, this requires that global greenhouse gas emissions need to be reduced by at least 50% below their 1990 levels by the year 2050. In the long run, greenhouse gas concentrations need to be stabilised at a level well below 450 ppm (parts per million; measured in CO2-equivalent concentration). In order to stay below 2 ºC, global emissions must peak and decline in the next 10 to 15 years, so there is no time to lose.

As scientists, we urge the negotiators to reach an agreement that takes these targets as a minimum requirement for a fair and effective global climate agreement.

If you are familiar with the science you will recognize some of the signers of this declaration. The Nature blog has a bit more on this.

3 comments:

Zowish said...

Surely a "simple" calculation would tell us the maximum number of automobiles and power plants the world could afford to achieve these CO2 levels.

- HR

Michael Tobis said...

It's almost that simple (there are a few other sources but the idea is sound).

What's not simple is deciding which coutry gets which part of that allocation. There has never been a global rationing program and a lot of folks aren't comfortable with the idea.

AK said...

IMO Bali is the wrong way to go about it. Emission caps and reductions come across as trying to halt the growth in per capita energy usage, which is like getting in front of a moving train and trying to push it to a stop. Not only is there tremendous momentum, but the effort is directly opposed to the interests of the passengers and crew, who will actively oppose you (as they are).

The answer, IMO, is to start by forbidding the word "sustainable" and accept an increasing worldwide per capita energy usage until, at least, the rest of the world enjoys the same level as the US.

The train needs to be switched onto a track that leads to reduced CO2 emission for power, ideally reduced footprint. It needs to be a reasonably gentle curve, not a screeching halt.

The way I would prefer would be a gradually increasing carbon tax, starting with a light burden and reaching highly punitive levels 25-30 years on. The proceeds should be entirely given over to subsidies on carbon-free power, both vehicular and stationary. If done right (a major issue in itself), this could produce massive private investment in R&D towards carbon-free energy sources and storage.

Because the research would be privately paid for and administered, there wouldn't be the growth of massive bureaucracies to oversee research spending. Because the subsidies were clearly defined and did not specify what technology is used, the field is wide open for multiple innovative solutions.