Energy Literacy 4. How to gauge whether your politicians are faking it on climate change commitments


Saul Griffith is an inventor and entrepreneur. He did his PhD at MIT in programmable matter, exploring the relationship between bits and atoms, or information and materials. Since leaving MIT, he has co-founded a number of technology companies including Optiopia, Squid Labs, Instructables, Potenco, and Makani Power.

On the day before Thanksgiving, while everyone was distracted buying (or pardoning) turkeys, the Obama team announced that the president will go to Copenhagen and promise to try to commit to a carbon reduction schedule for the United States.

(More links if you want to see the news repeat it over and over again: 1, 2, 3)

On one hand, I want to be excited about this because unless the US makes a commitment to CO2 reductions, it's exceedingly unlikely that the rest of the world will bother. On the other hand, no one should be jumping in the aisles till we look at the numbers more carefully.

It's probably useful to first update yourself on the climate science. Here's a well-written, critical, and objective summary of recent scientific results released a few months ago. It was prepared as an update between the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) of 2007, and IPCC AR5, which will not to be completed until 2013. The PDF of the full report is well worth reading.

In summary, the science news isn't so good. Greenhouse gas emissions have increased nearly 40% between 1990 and 2008. The temperature has been increasing at a rate of 0.19 degrees C, (0.34 F) each decade for the past 25 years. Ice-sheets, glaciers, and ice-caps are exhibiting accelerated melting. The existing sea-level rise predictions look to be underestimates by at least a factor of 2. Delaying action risks irreversible damage and we must peak in emissions soon, preferably between 2015 and 2020, if not earlier.

Those who claim recent cooling trends are ignoring the fact that we are currently at a solar minimum, a period of low solar activity that is partially offsetting the long term global heating trend. This is a bit like saying you don't need to change your eating habits because you lost weight while having the flu.

So, in light of this science, how can we understand what Obama's pledge means?

For starters, any public dialogue that talks about "percentage reductions in emissions" by a certain date is misleading. Because of the long residence time of CO2 in the atmosphere, it makes far more sense to talk about the amount of CO2 remaining to be released before we hit a peak CO2 concentration. Let's call this the "remaining cumulative carbon emissions" method. After those emissions, we essentially need to emit zero carbon. This way of looking at the climate was first popularized by Krause, Bach, & Koomey, in an excellent book called "Energy Policy in the Greenhouse" (1992). It was revisited as a tool of understanding the climate challenge in two great Nature magazine articles this year. (Nature magazine is probably the most prestigious, and rigorous, of all the academic journals.) In one of those, Meinshausen et al., used this method of analysis to look at how you would limit the planet to 2 degrees C of warming.

Two degrees is what most industrialized nations see as the upper limit of tolerable climate change, and it has become something like the default target before we see "dangerous levels of climate change." (Incidentally, the least-developed nations and the 43 small island nations of AOSIS are calling for limiting warming to 1.5 degrees.) The Copenhagen Diagnosis Update referenced above summarizes: "Meinshausen found that if a total of 1000 Gigatons of CO2 is emitted for the period 2000-2050, the likelihood of exceeding the 2-degree warming limit is around 25%. Between 2000- 2009, about 350 Gigatons have already been emitted, leaving only 650 Gigatons as the emissions budget for 2010-2050. At current emission rates this budget would be used up within 20 years."

The remaining cumulative carbon emissions is a useful framework by which we can now assess the pseudo-commitment (meaning unratified by Congress) that Obama will present in Copenhagen. According to the New York Times, "Mr. Obama will tell the delegates that the United States intends to reduce its greenhouse gas emissions 'in the range of' 17 percent below 2005 levels by 2020 and 83 percent by 2050, officials said."

The first problem here is that most nations, including Europe, are committing to reductions based on 1990 levels, but the US is basing its reductions on 2005 levels. Here's the historical US data.

And I've put it into a public spreadsheet for you to see. This spreadsheet assumes meeting these targets with a linear fit between 2010 & 2020, and the same from 2021-2050. That is very likely an optimistic assumption.

As you'll note, a 17% reduction over 2005 levels means only a 0.3% reduction over 1990 levels.

What you'll also see is that Obama is making a commitment to emit 59 Gigatons from the US alone from 2010-2020, and a further 88 Gigatons from 2020-2050, for a total of 147 Gigatons of CO2. This is 22.7% of the 650 Gigaton limit implied by Meinshausen. This helps to see why it's hard to get an agreement in Copenhagen. In order to avoid "dangerous levels of climate change" the US is committing to reduce its output to "only" 22.7% of global emissions, despite having only 4.5% of the global population. The other point to note is that even these reductions don't satisfy the "emissions go to zero" aspect of this CO2 budget, as the US would still be emitting a gigaton of CO2 per year in 2050 under this plan.

There are a few things we might hazard a guess at when we look at these numbers:

a) The US government doesn't think that we should bother aiming at even a 25% chance of staying below 2 degrees C.

b) The US government believes the rest of the world won't notice the disproportionality of its emissions based on population.

c) The US government believes that we'll invent a magic technology for sequestering atmospheric CO2 at some low cost powered by a magic new energy source.

d) The US government has lost its ability to make hard choices, and to rise to the urgencies of the moment in a way that is required of a great nation.

I like to think of the modern era as "the age of consequence." We are starting to understand the consequences of our individual and collective actions. Although it's early in the modeling revolution, we are learning to model the results of our actions now as the play out in the future. The upside of the age of consequence, and having the internet out there for lots of people to look ponder it (the age of transparency), is that the general public can analyze policy such as the announcements Obama is making in Copenhagen, and critique it. Perhaps we'll even be able to use this elegant framework of "total CO2 emissions" to quite frankly say, "this is not good enough, your words and commitments don't match up".

I don't think public policy alone, whether from individual government or the entire international community, will meet the climate challenge. Individuals will need to lead by example and make personal reductions by demanding products and services that will meet the real climate challenge. Fundamentally, that means massive installation of zero carbon energy generation technologies, and likely quite large reductions in personal energy use. It would be fantastic if we re-defined the climate challenge in terms of how we do both of those things while increasing the quality of our lives. Unless individuals do this, it is unlikely that governments will see the demand for action and act appropriately.

The main criticisms and resistance to climate action are often because we frame it as a challenge of denying ourselves and negatively impacting our lives and economy. By framing it instead as a "how do we improve our quality of life?" question, more people are engaged in the debate and the actions we need. It's no longer a purely technological fix; we can more accurately frame the problem for what it is: a challenge for us all, where we can win if we think clearly about what we are trying to achieve. That's a better quality of life for all.

ref: Meinshausen, M. et al., (2009) Greenhouse-gas emission targets for limiting global warming to 2°C. Nature 458, 1158-1162.