Great concept, but after being in the stationary, industrial side of things for many years, find it rather difficult. An industrial process, from plastics to generating electric power, has a potential to emit (PTE). Permits are written as to the "maximum allowable emissions rate" that cannot be exceeded. Actual emission - which you're talking about - may be between 80 and 90 percent of the maximum in the permit, and sometimes much lower in a slow-down or idling of the plant due to economic considerations (and some natural ones like hurricanes).  

Perhaps a stupid example is a good idea. Few or no permits have a PTE for CO2, so using a fuel analysis and some engineering, annual CO2 emissions were 1.0 million tons per year.  In reality, speaking of 2008 calendar activity, actual emissions were 0.8 million tons as measure by stack monitors. Wow, that's like a 20 percent reduction, way cool.

Not so fast. In order to "lock in" that 0.8 million tons, it has to be certified and written into some kind of permit amendment. In other words, you can't have a cap without an enforceable limit and enforcement requires a permitted maximum emissions limit.

The existing industry could very well say that the state and federal governments allowed up to 1.0 million tons, so since we emitted only 0.8, therefore we are entitled to a huge carbon credit!

So slow-downs aren't the answer.  But if some technology known as BART, BACT, and LAER come along (sorry for the alphabet soup), the permit would be amended for perhaps even a lower emissions level such as 0.6 million tons a year, such as with a combination of combustion fuel efficiency and utilization of clean power (waste heat recycling, wind, solar, geo, etc.). The government can do this in many cases, even for old "grandfathered" sources subject to BART *best available retrofit technology).

Now here's the question: did the source reduce emissions from 1.0 million tons of CO2 or from its base year emissions of 0.8? See, there are many complexities about how to certify a baseline and what is the cap - things that politicians, lawyers, and lobbyists will fight about for years.

Sorry to confuse the reader but it is complicated, although very simple in design as compared to mobile sources - which are like herding cats. That's a topic for a different discussion because mobile sources are not permitted and really can't have a "cap." Shame, because mobile sources burn an incredible amount of liquid petroleum fuels made from crude oil (you can regulate the refinery but not the car).

I will say that as I have tried over the years, there is a trade-off between reducing CO2 and possible increases in conventional air pollutants such as NOx and PM in combustion devices. That too is a discussion for a different day ...

David if you meant establishing national targets instead of "caps" during a recession, well that is a different thing, political and not technical. Taking credit for CO2 reductions in a severe downturn in the economy is a very serious no-no, however, since the emissions could zoom right back up during better times, a process designed for failure. That's why I talked about enforceable permit limits, which have penalties under the Clean Air Act of over $25,000 per day per violation. Unfortunately, you have to do it the hard way like this, or "wish on a star."

'Nuff said.
sammie

Onward through the fog

Dripping with sarcasm and innuendo, I loved the above post. But one must be careful to have a nice replacement for electrical base load before shutting sown the old stinker coal-fired generation stations, as they really do put out some major power these days. Bummer having to deal with such details, I know.

I've been through several small hurricanes, Emily and Dolly, and the worst of it was not having electrical power for two weeks. I'm serious, that really sucked. No refrigerator, lights, heater, A/C, stove, hot water, radio, stereo, or computer. I can live without some of that but the freezer blew my mind - we had to have a party and cook all that over a wood fire and give it away, and we were slap out of food in three days.

If I had a plug-in electric car in the garage, of course if would have been dead too.

Be careful about what you wish for, as what we went through was pure hell. We have to start thinking of building 100 to 250 MW replacements for the old col fired generators, and many of them. Even then, I would consider keeping a few for emergency base load just because of a  national emergency. Hurricanes come to mind and let's not think about worse.

How fast can we do this? I've seen a few 50 MW wind farms and such, but that just was treated as peaking, "green account," or export power that was kind of frilly to the base load coal and natural gas generators. If I say 15 years that would be quick unless somebody starts doing something real quick. Yet in 15 years, the CO2 concentration might be beyond reducing due to Joe Romm's feedback loops!  -sammie

Onward through the fog

Its a perfect time to be building green infrastructure like transit, high-speed rail and cycling facilities. Save cap and trade for when the economy recovers.

Now wait just a minute, guys.  Y'all are mixing together the alphabet soup regs (BACT, LAER, BART...) and cap-and-trade, and ascribing all the problems of one to the other.

I've worked on the alphabet soup, and yeah, they're a bureaucratic and legal nightmare.  But look at the acid rain program (SO2 cap-and-trade) -- it works fine, with little litigation and major emission reductions.  That's because it's confined to power plants with continuous emission monitors (CEMs), whose readouts are automatically reported, and because it doesn't require a permit system as messy as the alphabet soup programs.

Carbon cap-and-trade will work fine if it applies to power plants with CEMs.  Let's please at least do that!  Along with the 30-odd state renewable portfolio standards already in effect, it'd encourage big reductions, so long as the cap is set low enough.

Re setting the cap based on the downturn -- we should set the cap at some percentage of emissions below, say, the average of the last few years, and then make it decline over time.  Don't get hung up on the nitty-gritty of where the number comes from -- Congress is going to pull it out of their butts based on who shouts the loudest about what number makes sense.  That's probably ok, though, given who is likely to be in charge now.