It is always good when debates can be resolved by appeals to data, because it helps to eliminate ambiguity.

Joe Romm expressed concern that I had shown a graph of energy intensity of the global economy to suggest that the overall decarbonization of the global economy did not decrease over the poeriod 1890-1970. That was this figure:

Romm explained to his readers how serious a mistake I had made:

Obviously carbon per GDP can go in a completely different direction than energy per GDP. If Pielke’s analytical mistake isn’t crystal clear to anyone reading this blog, please let me know. So my problem with him isn’t semantics. Pielke’s argument is simply wrong. His analysis is flawed.

OK Joe, lets look at carbon per GDP over the same time period:

Readers are now in a position to judge for themselves whether or not the argument I made is materially affected in this case by using one figure over the other. The alternative perhaps is that Joe Romm is trying to make a mountain out of a molehill. As I said, thank goodness for data.

Joe Romm is someone who I’ve never met, but he has taken on a somewhat odd obsession with attacking me over the past few weeks, and I have come to the conclusion that he is dishonest and uninterested in constructive discussion.

I have come to this conclusion after reading his most recent diatribe, which takes a semantic issue, inflates it with a lot of heated rhetoric, and pretends that it is something meaningful when it is not.

The molehill that Romm seeks to make a mountain out of is over the difference between “decarbonization of the economy” versus “decarbonization of primary energy supply.”

The difference between the concepts, and their relationship, is easily explained by the Kaya Identity, which is the basis for all emissions scenarios, including those used by the IPCC. The Kaya Identity holds that four factors can be used to develop scenarios of future emissions:

P = Population
GDP/P = Per capita wealth
Total Energy/GDP = Energy intensity
Carbon/Total Energy = Carbon intensity

Carbon emissions = P * GDP/P * TE/GDP * C/TE

You can see from the cancellation of the terms that the units match on both sides. If you take carbon intensity and energy intensity together, you get C/GDP which is often referred to as “carbon intensity of the economy” to avoid confusion with “carbon intensity of primary energy.” Because total energy of the economy is dominated by fossil fuels, trends in “energy intensity” and “carbon intensity of the economy” are very closely related.

A close look at the Kaya Identity shows that carbon emissions can go down by only one of several ways:

Reduce P
Reduce GDP/P
Reduce TE/GDP
Reduce C/TE

In our Nature article we stated quite clearly that:

Decarbonization of the global energy system depends mainly on reductions in energy intensity and carbon intensity. These result from technological changes that improve energy efficency and/or replace carbon-emitting systems with ones that have lower (or no) net emissions.

In other words, we do not think that either population is going to decrease or per capita wealth, so the focus must be on carbon intensity and energy intensity, which we clearly define as “decarbonization of the global energy system” (and not decarbonization of total energy). We wrote in exactly this manner to be absolutely clear about our meaning.

Similarly in a blog post I wrote:

During and following the industrial revolution, the world experienced a long period of carbonization of the global economy . . .

Note that I did not say “carbonization of total energy supply” as Romm would have his readers believe. Romm is either horribly sloppy in his reading habits or willfully malicious in his intent.

Joe Romm’s focus on semantics and definitions is the classic approach of someone who feels that they can’t win a debate on substance, and must resort to dissembling and misdirection. I for one will no longer give Joe Romm the benefit of the doubt. His actions may fool a few who wish to be fooled, but ultimately he is just discrediting himself with such behavior.

Here is a link to an excellent summary and thoughtful discussion of our Nature Commentary (PWG) at Green Car Congress written by Jack Rosebro.

Joe Romm, whose voluminous, hysterical attacks on me and my co-authors Tom Wigley and Chris Green have become somewhat cartoonish, has far more in common with my views than he thinks. Here is what he says on a recent Real Climate post on air capture:

But we should surely do a fair amount of research on air capture, since, by not later than the 2020s, we’re going to get desperate for emissions reductions, and by the 2030s, we’re going to be very desperate and willing to pursue expensive options we that aren’t yet politically realistic.

Investment in research to support a potential breakthrough new technology — what a great idea Joe!

Gwyn Prins, a professor at the London School of Economics who is also a friend and collaborator, has a thoughtful op-ed in The Guardian with his views on the significance of our Nature commentary of last week. Here is an excerpt:

The global economy is not decarbonising – it is recarbonising. This was noticed by the experts in the IPCC but not reported in its Summary for Policymakers, the politically negotiated document mostly read by politicians and journalists. If the free rider of decarbonisation is not available, the challenge to move quickly to a radically different type of global climate policy is all the greater.

What would a materially effective policy do? It would break the link between poverty reduction and carbon emission. It would recognise that the developing world needs to consume – and will consume – more energy, not less. It would recognise that attempting to control human-created carbon emissions by setting binding output targets and relying on artificial carbon markets and dodgy offsets, as Kyoto does, has not and never will work.

Such policy would shift to the input side, and concentrate on radical improvements in the production and use of energy. It would focus first on the sectors of all economies that are the heaviest consumers of energy: power generation, building, cement and metals production. The sectors that western environmentalists have prioritised hitherto, such as road and air transport, should be much further down the list. If all automobile use in the US stopped tonight, the reduction in global emissions would be less than 6%. Instead, there must be a much larger commitment to fundamental energy technology research and development.

Read it here.

Last week BBC4 aired a special on adaptation to climate change, in which I am interviewed along with Richard Tol, Mark Lynas, Tim Flannery, and others. You can read a transcript here.

[Update #4: The guys at Grist Magazine apparently have not yet read our paper, which probably explains why one of their commentators explains that everything we say is right but common wisdom, while another says that everything we say is wrong. At least they have their bases covered. Why don't these guys at Grist actually read the paper before commenting? One wonders.]

[Update #3: Andy Revkin of the NYT provides some comments as well here.]

[Update #2: John Tierney of the NYT times provides excerpts of an extended set of comments that I shared with him here.]

[Update: Here is a short interview I did with Scitizen link.]

Tom Wigley, Chris Green, and I have a Commentary in today’s Nature on the technology challenge of stabilization. It has already generated some discussion and this discussion will be the focus of some of my posts over the next weeks.

Meantime, please have a look at this summary that Tom, Chris, and I prepared:

(more…)

Nature’s Climate Feedback blog provides a nice summary of a correspondence that I authored published today in Nature Geoscience:

Today in a letter to Nature Geoscience (subscription required), Roger Pielke, Jr, questions whether models from that 2001 generation improve on the predictive power of their forbears.

Pielke checks predictions from all four IPCC reports, dating back to 1990, against reality. Each report made a series of ‘if-then’ statements about the likely results of various emissions scenarios; in hindsight, Pielke can pick out which of these possible greenhouse experiments has actually been running on Earth since 1990 and compare the results to the IPCC’s shifting hypotheses.

Whereas the 2001 projections undershot the observed temperatures and sea levels, the 1990 projections overshot them, he concludes. Projections of temperature and sea level fell substantially between the 1990 and 1995 IPCC reports, when aerosols were added to models and carbon-cycle simulations were tweaked. But because they dropped too far, the adjusted post-1995 projections “are not obviously superior in capturing climate evolution”, says Pielke.

Today there are no doubt a plethora of jokes bouncing through the interwebs. Whether this is reflective of the mindset in Washington or an attempt at stealth advocacy, I’ve noted the following from Public Knowledge, a public interest group focused on intellectual property rights.

Public Knowledge Slams New Intellectual Property Legislation

As the title of this post suggests, this is indeed an April Fool’s joke. The execution is a bit subtle, but those who dig into the comments embedded in the associated legislation should figure it out.

At the risk of further ruining the joke, I wonder how effective it is to devise a piece of legislation that cobbles together worst case scenarios for content users and throw it into a gag. It’s worth noting what parts of their gag legislation are reflective of actual legislation, but I’m not sure how many people will read deeply enough into this that weren’t already aware of the issues.

So let me raise this question, independent of the April 1 baggage – how effective can worst-case alarmist scenarios be in evoking meaningful action? Does it depend on the issue?