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This blog is expressly directed to readers who do not have strong training or backgrounds in science, with the intent of helping them grasp the underpinnings of this important issue. I'm going to present an ongoing series of posts that will develop various aspects of the science of global warming, its causes and possible methods for minimizing its advance and overcoming at least partially its detrimental effects.

Each post will begin with a capsule summary. It will then proceed with captioned sections to amplify and justify the statements and conclusions of the summary. I'll present images and tables where helpful to develop a point, since "a picture is worth a thousand words".

Friday, January 6, 2012

Drastically Reducing California’s Greenhouse Gas Emissions by 2050

Summary:  California’s Global Warming Solutions Act and Executive Order S-3-05 establish the goal of reducing emissions of greenhouse gases economy-wide in the state by 80% below the level of 1990 by 2050.  The California Science and Technology Council, a non-official group, issued its report, “California’s Energy Future: The View to 2050”, providing a detailed analysis of the state’s current energy landscape, and proposed bold measures to attain the 80% reduction goal.

They found that a 60% reduction was attainable using technologies currently available or ready for scale-up.  A major contributor to this goal is enhancing the energy efficiency of the economy, including fixed buildings and transportation.  Additional components include a) replacing the end use of fossil fuels with electricity and the concomitant elimination of carbon dioxide emissions using carbon capture and sequestration, b) commissioning new nuclear power plants, and c) using renewable energy sources.

CCST found, however, that attaining the full 80% reduction goal was beyond the capability of currently deployable technologies.  This requires extensive research to identify and/or implement fully innovative technologies.

Because of the ever-increasing rate of emission of greenhouse gases and the resulting increase in earth’s long-term average temperature, it is important to implement initiatives such as that in this Report.  Strong support from government funding is needed and appropriate in order to embark on such programs.
Introduction.  The need to curtail emissions of greenhouse gases (GHG) around the world has led some nations and regions to develop ambitious programs to limit emissions in coming decades.  The European Commission has developed a plan, currently being implemented by the nations of the European Union, to limit emissions by 20% below the levels of 1990 by 2020, and by at least 80% by 2050 (see this earlier post)

In the U. S., California enacted similar legislation, its statute AB32, the Global Warming Solutions Act, in 2006 (see this earlier post).  AB32 enacts statutory limits on greenhouse gas emissions only until 2020, requiring reduction to the level of 1990 by that date.  Yet, recognizing that climate scientists have determined that more drastic reductions in greenhouse gas emissions are required in order to minimize global warming, the Governor of California at the time, Arnold Schwarzenegger, issued Executive Order S-3-05, establishing the goal of reducing greenhouse gas emissions by 80% below the level of 1990 by 2050.  The California Air Resource Board’s Climate Change Scoping Plan envisions the bold, novel initiatives that are required to achieve this long-term objective.

California has had a long history of developing programs to conserve energy and limit greenhouse gas emissions, even before passage of AB32 and the Governor's executive order.  Starting in the 1970's, an extensive program of energy conservation (see, for example, “Real Prospects for Energy Efficiency in the United States”, prepared by America’s Energy Future, Panel on Energy Efficiency Technologies (National Academies Press, 2010))  and development of renewable energy has been put in place.  As a result, while the rest of the country continued to expand its use of fossil fuels, and of total consumption of energy, the trend for California remained relatively constant, i.e., it did not increase in tandem with the rest of the country.

The California Science and Technology Council (CCST), a non-official group of academic and government officials, recently issued a thorough analysis of the energy landscape accessible to the state, “California’s Energy Future: The View to 2050” (Summary Report, May 2011).  Its objective was to assess the nature and extent of measures needed that might be used to achieve the objectives of S-3-05.  This post summarizes the Summary Report.

CCST points out a significant hurdle in achieving the goal in S-3-05.  Between 2005 and 2050 California’s population is expected to grow by almost 50% to 55 million people.  Furthermore, assuming no major initiatives are taken to curb emissions beyond those already in place, and assuming moderate economic growth the  state will need about twice as much energy by then than at present.

The authors assessed various technologies usable in reducing greenhouse gas emissions, and categorized them into four groups, as shown in the following table.

Technology Bin
Bin 1
Deployed and available at scale now
Bin 2
Demonstrated, but not available at scale or not economical now
Bin 3
In development, not yet available
Bin 4
Research concepts

Source: “California’s Energy Future: The View to 2050”

By focusing only on technologies in Bins 1 and 2, CCST established that reduction in emissions by 60% was achievable by 2050.  This goal required the following four main courses of action.

1. The building stock in the state should be “aggressively” upgraded to be as energy efficient as possible.  (Increasing the efficiency of buildings has been called “the low hanging fruit” in greenhouse gas reduction programs, summarized in this earlier post).  This includes designing new building codes that optimize energy efficiency in building construction and operation.  It also includes, to the extent possible, retrofitting existing buildings to increase the efficiency of their consumption of energy.  As part of their normal life cycle, buildings not susceptible of retrofitting at reasonable cost should be destroyed and replaced.

2. Generation of electricity should move toward operation that releases as little carbon dioxide to the atmosphere as possible, i. e., use of fossil fuels for electric power should be drastically reduced.  This includes development of renewable sources of energy such as a wind power (see this earlier post) and solar power, the use of biofuels which is essentially carbon-neutral, implementation of carbon capture and sequestration technology (
CCS; see the preceding post on this blog) for fossil fuel-driven generation plants, and expansion of  nuclear power generation in the overall energy mix.  The preceding post  characterized CCS as capable of removing 80% of the CO2 in the flue gas of power plants, while the Summary Report relies on removing up to 90% with the current state of the technology.

Non-stationary sources of carbon dioxide emissions (primarily transportation and freight), and industrial users of energy, should move away from primary (i. e., direct) reliance on burning fossil fuels, and become electrified, to the greatest extent possible.  This entails a major shift for passenger cars away from internal combustion engines toward hybrid electric or pure electric propulsion systems.  Similarly, where feasible, industrial consumers of energy  should also seek to employ electric power for their needs.

3. In order to maximize use of electricity and minimize use of fossil fuels, first, overall electric generation capacity will need to double; second, “aggressive” steps must be taken to have minimal emissions of CO2 from this expanded generation of electricity; and third, since renewable energy sources such as wind and solar power provide electricity only intermittently while demand persists undiminished, load balancing technology will have to be developed and implemented that itself minimizes further greenhouse gas emissions. This is referred to as zero-emissions load balancing (ZELB).   It is necessary to fill in the short-term variability in supply of power by generating additional electricity using responsive generation.  Technologies useful for ZELB include pumped water storage, thermal storage, and battery storage.  In addition, digital circuitry should be installed to monitor and optimize power usage at individual sites of demand (smart-grid technology).  The Report supports a significant growth of nuclear power as a technology that emits virtually no CO2, while recognizing that public opinion may oppose it and that current state law prohibits new nuclear plants as long as the U. S. has no plan for permanent storage of nuclear waste.

4.  Energy usage in industries and sectors where electricity is not a convenient source, such as heavy trucks, airplanes, and those needing high heat, should also be shifted to sources that avoid the net release of greenhouse gases.  Principal sources of such energy are various forms of biomass, which represent a cycling of carbon between absorbing CO2 during growth of biomass products and release of CO2 when the biomass is burned.

CCST visualized the concepts identified above in the following chart.

Diagram representing steps in achieving reductions in greenhouse gas emissions by 2050. 
Source: “California’s Energy Future: The View to 2050”

In all panels of the chart, the vertical axis represents greenhouse gas intensity, i.e., the emissions produced per unit of energy consumed.  The horizontal axis is divided between fossil fuel-derived energy (gray-green, left) and electricity (off-white, right) as the primary energy source used in a particular facility or device.  Multiplying the two directions gives the total energy, the area inside a bounded box.  The full box, surrounded by the purple line, represents the total energy projected to be used in California in 2050. 
Panel a) shows this as the starting point (BAU, business-as-usual), before measures are taken to reduce emissions. 
Panel b) shows the effect of implementing efficiency in all uses of energy (symbolized by the compact fluorescent bulb and the light gray arrows). 
Panel c) shows the effect of using more electricity, produced in ways that limit greenhouse gas emissions, and less fossil fuels (symbolized by the plug-in car and the blue arrows).  Panels b) and c) reduce energy usage, compressing the horizontal axis, and shifting the energy area to the right, toward electrification. 
Panel d) shows the effect of moving away from greenhouse gas-emitting fuels by use of biofuels or biomass for combustion (symbolized by the green leaf and the green arrow) and renewable energy for electricity (symbolized by the yellow lightning flash and yellow arrow); these lower the greenhouse gas intensity (vertical axis). 
Panel e) summarizes the results of the steps in panels b), c) and d).

CCST assessed the effects of implementing efficiency measures economy-wide, expanding the use of electricity for providing energy, reducing the use of fossil fuels or use of CCS to generate electricity with reduced emissions, and reducing use of fossil fuels in generating heat energy (items 1-4 above).  They sought to determine which ones singly, or in combinations of two, three or all four measures, were needed to achieve 60% reduction from 1990 emission levels.  None of the simulations based on only one, two, or three measures was adequate for this purpose.  Only implementation of all four technologies sufficed to achieve the desired 60% reduction.  (The reader may turn to the Report for details on the analysis leading to this conclusion.)

Significantly, however, these technologies, drawn from bins 1 and 2 in the table above, were not effective to achieve 80% reduction of emissions.  This means that major investments in research, development and deployment (RD&D) of technologies currently at a seed stage, and of entirely new technologies, have to be undertaken to attain the objective of Executive Order S-3-05.

Strategies for Attaining 80% Reduction in Emissions.  The Summary Report considers eight technologies, many of which currently are classed in bins 3 and 4, above to reach a reduction of 80%.

  1. Achieve economical 100% removal of CO2 with CCS. 
  2. Totally remove use of fossil fuels with CCS from generating electricity.  This may be counterproductive if 100% capture of CO2 were achieved.
  3. Develop 100% ZELB.  This could be highly advantageous to attain the emissions goal.  Several technologies requiring extensive RD&D could potentially be applied.
  4. Use of biofuels with no net GHG emissions could make a significant contribution to achieving the 80% reduction goal.  However, full life-cycle emissions may be greater than zero.  In addition, land and resource constraints in California may preclude large scale use of biofuels, even if harvested from waste and marginal land sites.
  5. A significant contribution could be made by eliciting population-wide changes in behavior and life-style, including use of smaller homes and cars, greater use of public transportation, and comparable changes in the commercial realm as well.
  6. Burning biomass when combined with CCS results in net negative emission of CO2, i.e., the combined result is to remove CO2 from the atmosphere.  This may be a more advantageous use of biomass than converting it to a biofuel.
  7. Hydrogen fuel can be prepared in a few different ways, currently known.  The principal barrier to use of hydrogen is lack of adequate distribution networks, and lack of ways to incorporate hydrogen storage and release in vehicles, for example.  Furthermore, currently fuel cell technology for burning hydrogen is costly.
  8. The greatest impact could be achieved by doubling the amount of biofuels.  The technology is accessible; this alternative is hindered only in its negative impact on food production.

By combining many of these technologies the Report assesses that California could actually attain a negative emissions rate, i.e., a net removal of CO2 from the atmosphere (see Figure 9 and related discussion in the Report). 

The Report relies strongly on CCS for both the 60% reduction target and the 80% target.  Achieving the 80% target with CCS includes “reforming” natural gas (methane) to provide hydrogen gas as a fuel and CO2 as a waste product.  The report recognizes that CCS remains an unproven technology (see the previous post).


CCST has presented a bold, ambitious plan to achieve 80% reduction in greenhouse gas emissions below the levels of 1990 by 2050, in two stages.  First, a reduction of 60% is to be achieved using technologies that are currently either already operating at the commercial scale needed, or that are sufficiently developed that scaling presents no serious problem to implementation.  This stage relies heavily on increased efficiency of energy use in buildings and transportation, and on converting all primary power generation to the generation of electricity and the concomitant capture of CO2 and its long term storage in geologically secure formations deep underground.  It is envisioned that most transportation vehicles and industrial facilities that currently use fossil fuels will be converted to use the electricity to be provided by the expanded generation capacity instead.  A considerable portion of the new electric capacity will be provided by renewable sources that operate only intermittently, such as solar and wind power.  In order to fill in the periods in which renewables are not active, the Report supports development of electric generating capability producing zero emissions of CO2, and grid technology that responds to fluctuations in the electricity supply-demand balance.

The second stage brings California’s emissions rate down to 20% of the 1990 level.  The Report finds that this final stage is not achievable with currently-deployed energy technology.  Considerable RD&D expenditures will be needed to reach this goal because the multitude of innovations are only now being identified and developed.

The CCST Report presents a detailed analysis of the present energy landscape in California and the needs projected for the next four decades.  Its proposal to electrify energy usage as much as possible, coupled with extensive implementation of CCS and ZELB, is a bold new initiative.  The Report does not specifically address the contentious issue of pricing CO2 emissions, other than noting that AB32 operates via a cap-and-trade regime, but does point out that large expenditures of capital are required by the program presented.

It is appropriate to offer state and federal financial incentives for programs such as this one.  Chemical & Engineering News, published by the American Chemical Society, reports on a detailed analysis by Nancy Pfund and Ben Healey of subsidies and tax incentives enjoyed historically by the energy industry.  Subsidies for oil and gas in the U. S. go back as far as 1916 in the form of drilling depreciation and depletion tax breaks.  Average annual subsidies for four energy types are shown below.  (Subsidies for the coal industry were harder to document, and were not presented.)

Source: Chemical & Engineering News, Dec. 19, 2011;

It is seen that for the periods shown, the average annual subsidy for oil and gas was more than 10 times that for renewables, and for nuclear, more than 7 times larger.  During the first 15 years of an industry, when its future is still tenuous, federal subsidies make a big difference for new ventures.  The research found that in this nascent period nuclear energy received 10 times as much government support as renewables, and oil and gas received 5 times as much.   Thus there is a longstanding precedent for federal support for energy in the U. S.

The CCST Report includes many areas that require further RD&D work in order to be serviceable at scale.  In view of the long history of federal support for energy development it is entirely appropriate that federal funding support be provided to aid in the implementation of this emissions reduction program..

California’s Energy Future: The View to 2050” makes a significant contribution to developing a regime that would significantly limit greenhouse gas emissions by 2050.  It points out the feasibility of the various technologies, highlighting those needing more development, and identifying still others that are still relatively conjectural or poorly demonstrated.  It estimates broadly amounts needed for investment to realize the technologies required.  For these and other reasons the Report deserves serious consideration by policymakers and legislators, both for the state of California and as a model for a national policy.

Critically, it must always be kept in mind that reducing annual rates of greenhouse gas emissions does not have the effect of lowering the world-wide concentration of those gases in the atmosphere in the future.  Reducing emission rates merely slows the accumulation of such gases in the atmosphere.  Thus even if a program such as that presented in this Report succeeds in lowering the rate of emissions significantly by 2050, the overall accumulated concentration of greenhouse gases will still be higher than it is today.  This means that the long-term average temperature around the globe will likewise be higher than it is today, bringing with it worse extremes of weather and climate than the world is already experiencing.  Future climate conditions would not, however, be as severe as they would be under a “business-as-usual” regime in which no remedial actions were taken.  For this reason, it behooves this nation, and the nations of the world, to take concrete steps such as presented in the CCST Report at the earliest possible time.

© 2011 Henry Auer

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