Tag Archive for 'bathtub'

Other bathtubs – capital

Published on May 24, 2010 in Climate, SystemDynamics and energy. 0 Comments Tags: , , , , , , .

China is rapidly eliminating old coal generating capacity, according to Technology Review.

Draining Bathtub

Coal still meets 70 percent of China’s energy needs, but the country claims to have shut down 60 gigawatts’ worth of inefficient coal-fired plants since 2005. Among them is the one shown above, which was demolished in Henan province last year. China is also poised to take the lead in deploying carbon capture and storage (CCS) technology on a large scale. The gasifiers that China uses to turn coal into chemicals and fuel emit a pure stream of carbon dioxide that is cheap to capture, providing “an excellent opportunity to move CCS forward globally,” says Sarah Forbes of the World Resources Institute in Washington, DC.

That’s laudable. However, the inflow of new coal capacity must be even greater. Here’s the latest on China’s coal output:

ChinaCoalOutput

China Statistical Yearbook 2009 & 2009 main statistical data update

That’s just a hair short of 3 billion tons in 2009, with 8%/yr growth from ‘07-’09, in spite of the recession. On a per capita basis, US output and consumption is still higher, but at those staggering growth rates, it won’t take China long to catch up.

A simple model of capital turnover involves two parallel bathtubs, a “coflow” in SD lingo:

CapitalTurnover

Every time you build some capital, you also commit to the energy needed to run it (unless you don’t run it, in which case why build it?). If you get fancy, you can consider 3rd order vintaging and retrofits, as here:

Capital Turnover 3o

To get fancier still, see the structure in John Sterman’s thesis, which provides for limited retrofit potential (that Gremlin just isn’t going to be a Prius, no matter what you do to the carburetor).

The basic challenge is that, while it helps to retire old dirty capital quickly (increasing the outflow from the energy requirements bathtub), energy requirements will go up as long as the inflow of new requirements is larger, which is likely when capital itself is growing and the energy intensity of new capital is well above zero. In addition, when capital is growing rapidly, there just isn’t much old stuff around (proportionally) to throw away, because the age structure of capital will be biased toward new vintages.

Hat tip: Travis Franck

Aerosols and the Climate Bathtub

Published on April 21, 2009 in Aside and Climate. 0 Comments Tags: , , .

From RealClimate:

Over the mid-20th century, sulfate precursor emissions appear to have been so large that they more then compensated for greenhouse gases, leading to a slight cooling in the Northern Hemisphere. During the last 3 decades, the reduction in sulfate has reversed that cooling, and allowed the effects of greenhouse gases to clearly show. In addition, black carbon aerosols lead to warming, and these have increased during the last 3 decades.

For an analogy, picture a reservoir. Say that around the 1930s, rainfall into the watershed supplying the reservoir began to increase. However, around the same time, a leak developed in the dam. The lake level stayed fairly constant as the rainfall increased at about the same rate the leak grew over the next few decades. Finally, the leak was patched (in the early 70s). Over the next few decades, the lake level increased rapidly. Now, what’s the cause of that increase? Is it fair to say that lake level went up because the leak was fixed? Remember that if the rainfall hadn’t been steadily increasing, then the leak would have led to a drop in lake levels whereas fixing it would have brought the levels back to normal. However, it’s also incomplete to ignore the leak, because then it seems puzzling that the lake levels were flat despite the increased rain during the first few decades and that, were you to compare the increased rain with the lake level rise, you’d find the rise was more rapid during the past three decades than you could explain by the rain changes during that period. You need both factors to understand what happened, as you need both greenhouse gases and aerosols to explain the surface temperature observations (and the situation is more complex than this simple analogy due to the presence of both cooling and warming types of aerosols).

Read the rest: Yet More Aerosols

The Acid Bathtub

Published on March 30, 2009 in Policy and Sustainability. 0 Comments Tags: , , , , , , , .

I noticed a few news items on the SO2 allowance market today, following up on the latest auction. Here’s the auction history:

SO2 allowance auction prices

The spot permit price has collapsed, from a high of $860/ton in the 2006 compliance stampede, to $62. That’s not surprising, given the economic situation. What is a little surprising is that the forward price (allowances for use starting in seven years) fell to $6.63 – a tenth of the previous low, spot or forward. What’s going on there? Do plants expect a seven-year recession? Are utilities hoarding cash? Do they expect the whole market to unravel, or to become irrelevant as climate policy imposes a more tightly-binding constraint?

Continue reading ‘The Acid Bathtub’

Climate War Game – Is 2050 Temperature Locked In?

Published on August 4, 2008 in Climate, Clout & Climate Change, Models, Policy and impacts. 0 Comments Tags: , , , , , , , .

This slide became known as “the Angry Red Future” at the war game:
The Angry Red Future

Source: ORNL & Pew via Nature In the Field

After seeing the presentation around it, Eli Kintisch of Science asked me whether it was realistic to assume that 2050 climate is already locked in. (Keep in mind that we were living in 2015.) I guessed yes, then quickly ran a few simulations to verify. Then I lost my train of thought and lost track of Eli. So, for what it’s still worth, here’s the answer.

Continue reading ‘Climate War Game – Is 2050 Temperature Locked In?’