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3. Civility: Treat other members with respect. Do not post personal attacks against other members of this discussion forum.

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Oil is used primarily in vehicles, where it is impractical to capture CO₂ emerging from tailpipes. The large pools of oil remaining in the ground are spread among many countries. The United States, which once had some of the large pools, has already exploited its largest recoverable reserves. Given this fact, it is unrealistic to think that Russia and Middle East countries will decide to leave their oil in the ground.

A carbon cap that slows emissions of CO₂ does not help, because of the long lifetime of atmospheric CO₂. In fact, the cap exacerbates the problem if it allows coal emissions to continue. The only solution is to target a (large) portion of the fossil fuel reserves to be left in the ground or used in a way such that the CO₂ can be captured and safely sequestered.

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We should also urgently pursue R&D for carbon capture and sequestration. Here too this may be done most expeditiously and effectively via cooperation with China and India. Note that, even if it is decided that coal can be left in the ground, carbon capture and sequestration with other fuels still may be needed to draw down the amount of CO₂ in the air. An effective way to achieve drawdown would be to burn biofuels in power plants and capture the CO₂, with the biofuels derived from agricultural or urban wastes or grown on degraded lands using little or no fossil fuel inputs.

Opponents of nuclear power and carbon capture must not be allowed to slow these projects. No commitment for large-scale deployment of either 4th generation nuclear power or carbon capture is needed at this time. If energy efficiency and renewable energies prove sufficient for energy needs, some countries may choose to use neither nuclear power nor coal. However, we must be certain that proven options for complete phase-out of coal emissions are available.

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Well, yeah. I think a lot of leading businessmen are saying: just give us a clear pathway and signal for what has to be done, and we can deal with it. What they don’t like is jumping back and forth – you’ve got a regulation, then you remove it. That’s why I say what you want to a gradual rising price on carbon – and if you tell the business community this is going to happen then they will make the investments. But they don’t like to make investments if the policies may flip again.

Interesting you say that. Because I’ve generally seen energy companies as being more interested in carbon sequestration than environmentalists – who have tended to treat CCS (carbon capture and storage) more as greenwash than as science. Do you see clean coal as being a false hope, or a genuine hope ?

Well so far at least in the United States – and perhaps other places – its been more of a gimmick for allowing coal use to continue while trying to create the perception that there will be a clean-up in the future. But that’s the sort of thing we should be deciding based on a price on carbon, rather than on giving money to develop the (CCS) project…I don’t know if it can contribute or not, to clean energy in future. I think energy efficiency via other clean energies are likely to win out over clean coal but not necessarily. If we can find a way to do it cheaply enough, it might be a competitor..

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My position is very simple. A carbon tax : that is a carbon fee which rises over time, and will either cause carbon capture and storage to be part of the utilities business or else it will lead to different energy sources…. I don’t think we should try to prescribe which one. The marketplace should make that decision.

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Wind Energy Myths

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4 Wind energy is unpredictable and must be “backed up” by conventional generation.

No power plant is 100% reliable. During a power plant outage—whether a conventional plant or a wind plant—backup is provided by the entire interconnected utility system.

The system operating strategy strives to make best use of all elements of the overall system, taking into account the operating characteristics of each generating unit and planning for contingencies such as plant or transmission line outages. The utility system is also designed to accommodate load fluctuations, which occur continuously. This feature also facilitates accommodation of wind plant output fluctuations. In Denmark, Northern Germany, and parts of Spain, wind supplies 20% to 40% of electric loads without sacrificing reliability. When wind is added to a utility system, no new backup is required to maintain system reliability.

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Wind Energy Myths

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4 Wind energy is unpredictable and must be “backed up” by conventional generation.

No power plant is 100% reliable. During a power plant outage—whether a conventional plant or a wind plant—backup is provided by the entire interconnected utility system.

The system operating strategy strives to make best use of all elements of the overall system, taking into account the operating characteristics of each generating unit and planning for contingencies such as plant or transmission line outages. The utility system is also designed to accommodate load fluctuations, which occur continuously. This feature also facilitates accommodation of wind plant output fluctuations. In Denmark, Northern Germany, and parts of Spain, wind supplies 20% to 40% of electric loads without sacrificing reliability. When wind is added to a utility system, no new backup is required to maintain system reliability.

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The Second Generation Canadian Earth System Model (CanESM2): An Overview

Gregory Flato
Canadian Centre for Climate Modelling and Analysis
Contact: greg.flato@ec.gc.ca

An Earth System model goes beyond a conventional coupled global climate model by including representations of important biogeochemical processes that feedback directly on the physical climate. Of particular note are representations of the carbon and sulphur cycles. The former directly affects the extent to which carbon dioxide, emitted by human activities, is taken up by the land and ocean, and hence affects the amount remaining in the atmosphere and altering the radiative budget. The latter directly and indirectly affects the energy budget by altering the amount of sulphate aerosols in the atmosphere. This presentation will provide an overview of CanESM2 and a survey of results obtained from both historical simulations and future climate projections. In particular, we will show results comparing historical simulations to observations, allowing evaluation of model performance, and will discuss how the future projections differ from those made with earlier climate models. The development of CanESM2 represents the culmination of many years of work by a large group of scientists at CCCma, along with university colleagues who have been involved in various research networks. The results from this model constitute the core Canadian contribution to the multi-model ensemble that will underpin the IPCC Fifth Assessment Report. …

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The Canadian Earth System Model (CanESM) is based on the CCCma Canadian global coupled Climate Model (CanCM3.5) and includes dynamic models of the ocean and terrestrial carbon cycle. The current version CanESM2.0 contains a simple NPZD-Chl ecosystem model plus carbon chemistry …

The First Generation Atmospheric General Circulation Model

Canadian Centre for Climate Modelling and Analysis

The first generation atmospheric general circulation model (AGCM1) is no longer used at CCCma. The following details about the model are listed here for historical purposes and to help the reader understand how our various models have evolved from their predecessors.

1. Model features

The first generation atmospheric general circulation model evolved from an earlier 5–layer version discussed by Boer and McFarlane (1979). The spectral formulation in the CGCM makes use of a truncated expansion in spherical harmonics to represent model variables in the horizontal.

Other features of the numerics include semi–implicit time–stepping (Robert et al., 1972) with a weak time filter (Asselin, 1972). The basic structure of the model is similar to that of the spectral forecast model of Daley et al. (1976), although some improvements have been made in the procedure for implementing the spectral algorithms and, of course, important additional physical processes have been included.

The equation governing horizontal motion are written in terms of vorticity and divergence of the horizontal wind. The remaining basic prognostic equations include the themodynamic equation written in terms of a function of geopotential height, the moisture equation written in terms of dew–point depression, and the surface pressure equation. Temperature is determined diagnostically from the geopotential via the hydrostatic equation, and the vertical motion variable is determined from the mass continuity equatiovia the hydrostatic equation, and the vertical motion variable is determined from the mass continuity equation.

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The Second Generation Atmospheric General Circulation Model

Canadian Centre for Climate Modelling and Analysis

1. The atmospheric model

The basic features of the atmospheric and land surface parts of AGCM2 are similar to those of the earlier version (The First Generation Atmospheric General Circulation Model, described in some detail in Boer et al., 1984). In particular, the spectral formulation for representation of the horizontal variation of prognostic variables is retained. Important differences between the models are briefly described in the following subsections.

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The Third Generation Atmospheric General Circulation Model

Canadian Centre for Climate Modelling and Analysis

The third-generation AGCM(McFarlane et al. 2005, Scinocca et al. 2008) shares many basic features with the CCC second generation model The Second Generation Atmospheric General Circulation Model(McFarlane et al. 1992). As in AGCM2, the spectral transform method is used to represent the horizontal spatial structure of the main prognostic variables while the vertical representation is in terms of rectangular finite elements defined for a hybrid vertical coordinate as described by Laprise and Girard (1990).

The spectral representation currently used in AGCM3 corresponds to a higher horizontal resolution than that used in AGCM2, being comprised of a 47 wave triangularly truncated (T47) spherical harmonic expansion. The vertical domain of AGCM3 is deeper than in AGCM2 and the vertical resolution is also higher. The third-generation model domain extends from the surface to the stratopause region (1hPa, approximately 50km above the surface).This region is spanned by 32 layers. The mid point of the lowest layer is approximately 50 meters above the surface at sea level. Layer depths increase monotonically with height from approximately 100 meters at the surface to 3km in the lower stratosphere.

The treatment of many of the parameterized physical processes in the third-generation model is qualitatively similar to AGCM2. However, the are some key features that are new to the third generation model. These include the introduction of CLASS, a new module for treatment of the land surface processes (Verseghy et al, 1992). This new land surface scheme is considerably more comprehensive than the simple single soil layer scheme used in AGCM2. In particular, the new scheme includes 3 soil layers, a snow layer where applicable, and a vegetative canopy treatment. Both liquid and frozen forms of soil moisture are carried as prognostic variables. Soil surface properties such as surface roughness heights for heat and momentum (which differ from each other in general), and surface albedos are taken to be functions of the soil and vegetation types and soil moisture conditions within a given grid volume.

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Carbon Dioxide and Climate: A Scientific Assessment

Report of an Ad Hoc Study Group on Carbon Dioxide and Climate

Woods Hole, Massachusetts

July 23–27, 1979

to the

Climate Research Board

Assembly of Mathematical and Physical Sciences

National Research Council

NATIONAL ACADEMY OF SCIENCES

Washington, D.C. 1979

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Summary and Conclusions

We have examined the principal attempts to simulate the effects of increased atmospheric CO₂ on climate. In doing so, we have limited our considerations to the direct climatic effects of steadily rising atmospheric concentrations of CO₂ and have assumed a rate of CO₂ increase that would lead to a doubling of airborne concentrations by some time in the first half of the twenty-first century. As indicated in Chapter 2 of this report, such a rate is consistent with observations of CO₂ increases in the recent past and with projections of its future sources and sinks. However, we have not examined anew the many uncertainties in these projections, such as their implicit assumptions with regard to the workings of the world economy and the role of the biosphere in the carbon cycle. These impose an uncertainty beyond that arising from our necessarily imperfect knowledge of the manifold and complex climatic system of the earth.

When it is assumed that the CO₂ content of the atmosphere is doubled and statistical thermal equilibrium is achieved, the more realistic of the modeling efforts predict a global surface warming of between 2°C and 3.5°C, with greater increases at high latitudes. This range reflects both uncertainties in physical understanding and inaccuracies arising from the need to reduce the mathematical problem to one that can be handled by even the fastest available electronic computers. It is significant, however, that none of the model calculations predicts negligible warming.

The primary effect of an increase of CO₂ is to cause more absorption of thermal radiation from the earth’s surface and thus to increase the air temperature in the troposphere. A strong positive feedback mechanism is the accompanying increase of moisture, which is an even more powerful absorber of terrestrial radiation. We have examined with care all known negative feedback mechanisms, such as increase in low or middle cloud amount, and have concluded that the oversimplifications and inaccuracies in the models are not likely to have vitiated the principal conclusion that there will be appreciable warming. The known negative feedback mechanisms can reduce the warming, but they do not appear to be so strong as the positive moisture feedback. We estimate the most probable global warming for a doubling of CO₂ to be near 3°C with a probable error of ±1.5°C. Our estimate is based primarily on our review of a series of calculations with three-dimensional models of the global atmospheric circulation, which is summarized in Chapter 4. We have also reviewed simpler models that appear to contain the main physical factors. These give qualitatively similar results.

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We conclude that the predictions of CO₂-induced climate changes made with the various models examined are basically consistent and mutually supporting. The differences in model results are relatively small and may be accounted for by differences in model characteristics and simplifying assumptions. Of course, we can never be sure that some badly estimated or totally overlooked effect may not vitiate our conclusions. We can only say that we have not been able to find such effects. If the CO₂ concentration of the atmosphere is indeed doubled and remains so long enough for the atmosphere and the intermediate layers of the ocean to attain approximate thermal equilibrium, our best estimate is that changes in global temperature of the order of 3°C will occur and that these will be accompanied by significant changes in regional climatic patterns.

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SCIENTIFIC LEARNING ABOUT CLIMATE CHANGE

Climate science, like all science, is a process of collective learning that proceeds through the accumulation of data; the formulation, testing, and refinement of hypotheses; the construction of theories and models to synthesize understanding and generate new predictions; and the testing of hypotheses, theories, and models through experiments or other observations. Scientific knowledge builds over time as theories are refined and expanded and as new observations and data confirm or refute the predictions of current theories and models. Confidence in a theory grows if it survives this rigorous testing process, if multiple lines of evidence lead to the same conclusion, or if competing explanations can be ruled out.

In the case of climate science, this process of learning extends back more than 150 years, to mid-19th-century attempts to explain what caused the ice ages, which had only recently been discovered. Several hypotheses were proposed to explain how thick blankets of ice could have once covered much of the Northern Hemisphere, including changes in solar radiation, atmospheric composition, the placement of mountain ranges, and volcanic activity. These and other ideas were tested and debated by the scientific community, eventually leading to an understanding (discussed in detail in Chapter 6) that ice ages are initiated by small recurring variations in Earth’s orbit around the Sun. This early scientific interest in climate eventually led scientists working in the late 19th century to recognize that carbon dioxide (CO₂) and other GHGs have a profound effect on the Earth’s temperature. A Swedish scientist named Svante Arrhenius was the first to hypothesize that the burning of fossil fuels, which releases CO₂, would eventually lead to global warming. This was the beginning of a more than 100-year history of ever more careful measurements and calculations to pin down exactly how GHG emissions and other factors influence Earth’s climate (Weart, 2008).

Progress in scientific understanding, of course, does not proceed in a simple straight line. For example, calculations performed during the first decades of the 20th century, before the behavior of GHGs in the atmosphere was understood in detail, suggested that the amount of warming from elevated CO₂ levels would be small. More precise experiments and observations in the mid-20th century showed that this was not the case, and that increases in CO₂ or other GHGs could indeed cause significant warming. Similarly, a scientific debate in the 1970s briefly considered the possibility that human emissions of aerosols—small particles that reflect sunlight back to space—might lead to a long-term cooling of the Earth’s surface. Although prominently reported in a few news magazines at the time, this speculation did not gain widespread scientific acceptance and was soon overtaken by new evidence and refined calculations showing that warming from emissions of CO₂ and other GHGs represented a larger long-term effect on climate.

Thus, scientists have understood for a long time that the basic principles of chemistry and physics predict that burning fossil fuels will lead to increases in the Earth’s average surface temperature. Decades of observations and research have tested, refined, and extended that understanding, for example, by identifying other factors that influence climate, such as changes in land use, and by identifying modes of natural variability that modulate the long-term warming trend. Detailed process studies and models of the climate system have also allowed scientists to project future climate changes. These projections are based on scenarios of future GHG emissions from energy use and other human activities, each of which represents a different set of choices that societies around the world might make. Finally, research across a broad range of scientific disciplines has improved our understanding of how the climate system interacts with other environmental systems and with human systems, including water resources, agricultural systems, ecosystems, and built environments.

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Climate change, driven by the increasing concentration of greenhouse gases (GHGs) in the atmosphere, poses serious, wide-ranging threats to human societies and natural ecosystems around the world. While many uncertainties remain regarding the exact nature and severity of future impacts, the need for action seems clear. In the legislation that initiated our assessment of America’s climate choices, Congress directed the National Research Council to “investigate and study the serious and sweeping issues relating to global climate change and make recommendations regarding the steps that must be taken and what strategies must be adopted in response to global climate change.” As part of the response to this request, the America’s Climate Choices Panel on Limiting the Magnitude of Future Climate Change was charged to “describe, analyze, and assess strategies for reducing the net future human influence on climate, including both technology and policy options, focusing on actions to reduce domestic greenhouse gas (GHG) emissions and other human drivers of climate change, but also considering the international dimensions of climate stabilization” (see full statement of task in Appendix B). In other words, this report examines the questions, “What are the most effective options to help reduce GHG emissions or enhance GHG sinks?” and “What are the policies that will help drive the development and deployment of these options?”

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Because policy that limits climate change is highly complex and involves a wide array of political and ethical considerations, scientific analysis does not always point to unequivocal answers. We offer specific recommendations in cases where research clearly shows that certain strategies and policy options are particularly effective; but in other cases, we simply discuss the range of possible choices available to decision makers. On the broadest level, we conclude that the United States needs the following:

• Prompt and sustained strategies to reduce GHG emissions.
  There is a need for policy responses to promote the technological and behavioral changes necessary for making substantial near-term GHG emission reductions. There is also a need to aggressively promote research, development, and deployment of new technologies, both to enhance our chances of making the needed emissions reductions and to reduce the costs of doing so.


• An inclusive national framework for instituting response strategies and policies.
  National policies for limiting climate change are implemented through the actions of private industry, governments at all levels, and millions of households and individuals. The essential role of the federal government is to put in place an overarching, national policy framework designed to ensure that all of these actors are furthering the shared national goal of emissions reductions. In addition, a national policy framework that both generates and is underpinned by international cooperation is crucial if the risks of global climate change are to be substantially curtailed.


• Adaptable means for managing policy responses.
  It is inevitable that policies put in place now will need to be modified in the future as new scientific information emerges, providing new insights and understanding of the climate problem. Even well-conceived policies may experience unanticipated difficulties, while others may yield unexpectedly high levels of success. Moreover, the degree, rate, and direction of technological innovation will alter the array of response options available and the costs of emissions abatement. Quickly and nimbly responding to new scientific information, the state of technology, and evidence of policy effectiveness will be essential to successfully managing climate risks over the course of decades.

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