Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


World Energy Outlook 2011: “The door to 2°C is closing”

Posted on 16 November 2011 by Andy Skuce

If we don’t change direction soon, we’ll end up where we’re heading

These words come from the Executive Summary of the World Energy Outlook 2011 (WEO11), just published by the International Energy Agency (IEA). The study incorporates the most recent data on global energy trends and policies, and investigates the economic and environmental consequences of three scenarios over the 2010 to 2035 time period. This is an important document that should be widely read but, unfortunately, the full report costs €120 for a single-user 650-page pdf.  Some key graphs and fact sheets are provided for free.

The WEO11 report is a commentary on the assumptions and output of the World Energy Model (WEM) in the IEA's words: a large-scale mathematical construct designed to replicate how energy markets function and is the principal tool used to generate detailed sector-by-sector and region-by-region projections for various scenarios.  A detailed description of the WEM is available here. The IEA updates their model and analysis every year, since important and unpredictable developments — a tsunami in Japan, the Arab Spring, new technologies in natural gas production — change the model’s boundary conditions significantly. In 2012, we can look forward to: an election in which the world’s largest economy may elect a government that denies the urgency and even the reality of climate change; further unrest in the Middle East; developments in renewable and fossil-fuel technology; and an unfolding economic crisis in Europe. And those are just some of the more foreseeable events that will make a new WEO study needed next year. In comparison, climate modellers have it easy.

In the 2011 Outlook, the IEA explored three scenarios.

  • The New Policies Scenario. This is used as a reference case. It assumes that governments will follow through on the (non-binding) pledges that they have made to reduce emissions and deploy renewable energy sources.

  • The 450 Scenario. This is an outcome-driven scenario, which lays out an energy pathway designed to limit the long-term concentration of greenhouse gasses to 450 ppm CO2 equivalent. Achieving this would provide a 50% chance of limiting global temperature increases to 2°C. Some climatologists, such as James Hansen, argue that a more aggressive 350 ppm target is required to avoid the possibility of “seeding irreversible catastrophic effects”.

  • The Current Policies Scenario.  This projection models a future in which only those climate and energy policies actually adopted in mid-2011 are incorporated.

To summarize: the IEA base case imagines a ideal world in which governments do what they say they will do; the optimistic case explores what needs to be done if we heed the advice of the more conservative climatologists; and the pessimistic case shows what happens if our governments just carry on doing what they have always done.

Where’s our energy going to come from?

Figure 1, taken, like all the figures in this post, with permission from WEO2011, shows the projection for the energy mix for the New Policies Scenario.  Note that the values are the proportions of the energy shares and not the absolute amounts of energy, the absolute amounts of oil and coal demand continue to climb over the period.


Figure 1: Shares of energy sources in world primary energy demand in the New Policies Scenario.

The graph shows that the relative importance of coal and oil will decline, while the use of natural gas rises. Non fossil-fuel energy sources gain slowly, but steadily, in importance. The relative changes reflect the influence of the policy assumptions in this scenario (among them, applying carbon taxes of $30-45 per tonne of CO2 before 2035).  However, mainly because of assumptions of population and economic growth, total energy consumption rises over the 2009-2035 period by approximately 40%, despite modelled increases in energy intensity (energy used per dollar of GDP).

The IEA does not foresee any major problems associated with depletion of fossil fuel resources over this time period. New technologies for the extraction of natural gas from shales herald what the IEA refers to (notwithstanding concerns about aquifer contamination and other environmental impacts) as a “Golden Age of Gas” Unconventional oil production (bitumen sands) and emerging light-tight oil production technologies will make up for declines in conventional oil production that result from resource exhaustion and underinvestment in the major oil producing areas.

The New Policies Scenario would result in an atmospheric concentration of CO2 equivalent of about 650 ppm, which is expected to result in equilibrium warming of more than 3.5°C. Once warming has reached these levels, according to authors cited by the IEA, the world will be committed to disruptive climate changes, a damaging sea-level rise and greatly increased probabilities of triggering feedbacks in the global carbon cycle (for example, in the Arctic and the Amazon Basin).

The 450 Scenario

Stabilizing atmospheric CO2 levels at 450 ppm is only achievable with the application of policies that are more aggressive than the policies in the base case. For example, the 450 Scenario envisages developed-country carbon taxes in the range $20-45 per tonne in 2020, rising to $95-120 for all countries by 2035.

Figure 2: World energy-related CO2 emissions per year by scenario.

The 450 scenario assumes that global emissions will decline to 1990 levels by 2035, with approximately 67% of the reductions, relative to the other scenarios, coming from non-OECD countries. Over the 2010-2035 period, the 450 scenario involves a 141 GT reduction in cumulative emissions relative to the New Policies Scenario and a 212 GT reduction relative to the Current Policies Scenario.

Figure 3: World energy-related CO2 emissions abatement in the 450 Scenario relative to the New Policies Scenario.

The IEA path to 450 is shown in Figure 3. Large contributions to abatements arise from efficiencies and renewable energy sources but large impacts come from nuclear energy and carbon capture and storage (CCS). After the accident at Fukushima, public acceptance of nuclear energy has fallen, for example, leading Italy to abandon its plans for building new nuclear plants and Germany to accelerate its plans to phase out its nuclear plants. If this trend away from nuclear energy persists, then its contribution to the 450 plan will not be realized. The IEA prepared an additional case, The Low Nuclear Case, to model this eventuality. To reach the 450 target without more nuclear power will require bigger increases in efficiencies, greater deployment of renewables and a very wide deployment of CCS to make up for increased uses of gas and coal in power generation.

Although CCS has been demonstrated as a feasible technology in pilot projects, there are doubts about the scalability, safety and the degree of public acceptance of the technology. The large carbon taxes envisaged in the 450 Scenario should help overcome the problem of the economic viability of CCS, but many other obstacles remain, any one of which could easily delay, restrict or prevent the widespread deployment of CCS, rendering the IEA’s path to 450 unfeasible.

Figure 4: Energy-related CO2 emissions per capita in the 450 Scenario by region.

Emissions per capita will decline everywhere, but the biggest relative and absolute per capita reductions occur in the USA. Developing country per-capita reductions generally start declining after 2020. The biggest source of abatement in the 450 Scenario in all countries is in the electrical power sector.

Energy for all

Concerns about the interactions between energy supplies and human welfare are not just confined to climate change. Chapter 13 of WEO is devoted to the problem of providing energy to the poorest people on the planet, the 1.3 billion without access to electricity, as well as to the 2.7 billion people, nearly 40% of humanity, who do not have clean cooking facilities in their homes. Electricity brings light, communications and refrigeration, benefits that those of us in prosperous counties have taken for granted for many decades. But perhaps the biggest environmental welfare issue of all is the use of biomass (wood, charcoal and dung) as cooking and heating fuels.

A recent article in Science Magazine estimates that primitive household fires contribute to nearly two million deaths annually from indoor air pollution, making this a worse health problem than malaria. The IEA report estimates that by 2030, biomass smoke will result in more premature deaths than HIV/AIDS. This is a problem that can be dealt with the deployment of simple and cheap technology—efficient stoves—albeit on a massive scale. As this article by Stephen Leahy shows, not only would resolving this problem lead to fewer deaths from respiratory illnesses, but it would result in a big reduction in black carbon pollution and help reduce climate change.

If not now, when?

Even though they are expressed as round-number integers, climate and emission targets can't really be defined with any precision: a little more than 450 ppm might be safe; a little more than two degrees of warming might not lead to climate disaster; we might still have a decade rather than the IEA's five years to dither around. On the other hand, perhaps 350 ppm, a limit that we have now passed, should have been our target; carbon cycle feedbacks may have started to kick in already (e.g., the  Amazon, Arctic). Perhaps we had five years to act twenty years ago.

What we do know is that we are near or past the limits. We also know that deploying the policies and the technologies that we need will take time to bear fruit. And that the bad infrastructure choices we make today will be with us for many years.

Figure 5: Typical lifetime of energy-related stock.

The headline conclusion of the WEO11 report is that, while the 450 target is still achievable, our chances of success are decreasing with every year of delay, and that, by 2017, the target could be out of reach.  Countries have been ready to announce targets but less ready to agree to binding commitments and, faced with the recent economic turmoil, have tended to push climate-related issues down their priority lists. Policy  procrastination has consequences:

  • Every year of delay in implementing policy leads to delays in deployment of low-emissions technology.
  • Every coal-fired power station and bitumen mine that gets opened will be with us for forty years or more. Refitting these projects for CCS will be expensive and sub-optimal.
  • Energy-inefficient buildings may be around for a century.
  • Every delay makes the goal of ensuring a stable climate less likely to be achieved and will make future mitigation and adaptation efforts more expensive.

Our limits are uncertain. Our models and best-laid plans won't survive unscathed from their first contact with reality. But, as the WEO11 report makes clear, we do know exactly when to act: now.

0 0

Printable Version  |  Link to this page


Prev  1  2  

Comments 51 to 75 out of 75:

  1. The door has closed on 2C and is barely ajar on 4C by 2100. We have sown the seed of our own destruction and are busily nurturing it with greenhouse gas emissions. The harvest we shall reap will be one which brings about socio-economic collapse and the loss of much that we have painstakingly built up because we persist in burning fossil fuels to meet our energy needs. We do so in pursuit of short term financial gain at the expense of long-term survival. Instead of moving to renewable energy sources, governments and industry cling to the hope that CCS technology will enable continued safe burning of fossil fuels to meet our energy needs. In so doing they ignore the fact that the capital and recurrent costs of CCS technology are such that it makes cost of energy produced by burning fossil fuels more expensive than energy produced from renewable sources. In short, CCS is neither a commercial or environmental option. Sustainability is not a question of curtailing use of energy or limiting access to it. It is a matter of ensuring that energy needs are produced from renewable sources. We already have the basic technology needed to achieve this and in coming years it will be improved, made more efficient and cheaper to use. It is not more widely deployed because: • burning fossil fuels is the cheapest way of producing energy and • the most promising alternative technology is at a developmental stage and neither urgency or finance are attached to its development and • vested interests seek to prolong the use of fossil fuels. To its credit, the Australian government is one of the few to enact legislation providing for rapid and sustained investment in clean energy alternatives, a move which is likely to prove more far-sighted than its proponents realize. Even so, the need for urgency in development and application of clean technology and its rapid global deployment is fiercely resisted, not so much by electricity generators per-se, as by the oil, gas and coal mining industries. How much longer will our species survive on this planet if we pursue business as usual or policies aimed at placating vested interests and failing to limit CO2 emissions to a dangerous 450ppm? Beyond 2100?
    0 0
  2. Agnostic #51 : I agree with you, notably about conservative short-termism of the fossil-based energy system. But some observations: you say CCS is costly (it is), and seem to exclude it can improve (we don’t really know). But you adopt a double standard for RE energy : Sustainability is not a question of curtailing use of energy or limiting access to it. It is a matter of ensuring that energy needs are produced from renewable sources. We already have the basic technology needed to achieve this and in coming years it will be improved, made more efficient and cheaper to use You can’t be arbitrarily optimistic with RE and pessimitic with CCS : at least, you must explain why there would be progress in one field and stagnation in another. As I expose precedently when discussing with Tom Curtis (first page), we are not sure at all that renewable sources can meet energy needs of 9 billion humans in 2050 without seriously curtailing the use. The best estimate for RE supply in 2050 seems to be approx 250 EJ/y (IPCC SRREN median estimate), but we actually consume rather 500 EJ/y for 7 billion humans (492 EJ in 2008, IPCC source). For an order of magnitude, if you assume 9 billion in 2050, you would have to supply 640 EJ/y anything else beeing equal. If you have a 2% target of world growth, you need a 2% energy intensity gain each year for stabilizing this level (in fact, energy intensity gain are actually between 1% and 1,5% on 1980-2010). You can play with these numbers of course : a 3% economic growth with just 1,5% energy intensity gain would imply a huger energy production in 2050 ; a 1% economic growth with a 3% energy intensity gain would considerably lower the energy demand, etc. I think it would be misleading to suggest our readers that energy transition is an easy way, only blocked by fossil lobbies (de facto, we do know they tried and try to block any policy agenda detrimental to their interest, but it is not the whole picture). As I said, European countries met since the 1990s some favourable conditions : few denialism in public opinion, strong comitment of policymakers, modest economic growth (when compared to emerging countries), high level of scientific and technological knowledge… but the real progress in decarbonization are still modest, and the budget is even negative if you account for the carbonized goods we import from Asia instead of producing them in Europe (Peters et al 2011, see reference in page 1). In contrast, I would say an efficient energy policy in the USA would have very good results, because you start at a very high level of energy consumption (far higher than Europe in the 1990s or at any recent decade), with few private or public effort to change the fossil addiction of your economy.
    0 0
  3. "You can’t be arbitrarily optimistic with RE and pessimistic with CCS: at least, you must explain why there would be progress in one field and stagnation in another." It's not arbitrary. The glaringly obvious difference between them is that RE is being deployed right now. And the costs are reducing all the time. Plummeting in the case of solar PV. CCS has not yet been shown to produce CO2 free power at commercial scale. There's a lot of R&D still to be done. And the costs are not yet known, especially for a complete rather than partial sequestering process.
    0 0
  4. adelady, in fairness, you also need to note that CCS has only just started to have serious research. RE has been around for a long time. Disclaimer: my department (though not me personally) is involved in CCS research. I do not think that we know the answer to enough questions to say with any certainty whether CCS has a role to play or not. Hence the research.
    0 0
  5. adelady : "It's not arbitrary. The glaringly obvious difference between them is that RE is being deployed right now. And the costs are reducing all the time. Plummeting in the case of solar PV." Well, "all the time", it depends. I take this 2009 document from a wind energy association (so, at least, we can suppose that it should be fair to wind, not a competitor-funded critics). If you look at the figure 0.3 p. 10, you can observe that wind costs are not really reducing in the most recent years (example of Denmark, whose aggressive policy and reknown savoir-faire is leader in Europe). Note also the 7.5% discount rate. Same is true in this 2010 Wind Technologies Market Report from US Dept of Energy / Lawrence Berkeley National Laboratory. Look at the figures of pp 45-47, particularly figure 28 : costs are up if anything from 2001-2003 to 2011. (In the previous 2009 report, they announced that costs could drop in 2010, but they don't. In this 2010 report, they say costs could drop in 2011... and we'll see). IPCC SRREN 2011, in the chapter 7 dedicated to wind energy, don't give a decade trend for wind cost. But it emphasis that a deeper penetration (20%) would imply higher balancing costs (see 7.17, figure and explanations), even if there is also a hope for further technological improvement downing costs (no estimation, no date, as far as remember). So this is not a "all-the-time decreasing cost" for wind energy, even if it is presently mature and competitive in many conditions. It would be better to document such assertions when firstly introduced in the discussion, if possible from serious sources. scaddenp : "I do not think that we know the answer to enough questions to say with any certainty whether CCS has a role to play or not" I agree with you. That's why IEA scenario, and all energy-economy models' scenarios, should be taken with some caution. Unbiased skepticism is healthy in the energy debate.
    0 0
  6. "...wind costs are not really reducing in the most recent years..." Well, according to this report the best windfarms are now competitive with coal, gas and nuclear. And they expect that by 2016 the average wind farm will be cost competitive. When we're looking at choices for investors, I'd not be putting my money into one that looks to be declining in competitiveness within the industry.
    0 0
  7. I suppose I should add that I live in a state that gets 20% of its power from wind already.
    0 0
  8. adelady, this state?
    0 0
  9. I have described the problems associated with development of CCS technology and its use in CCS: Investment in Futility at Since 2008, very large sums of money (public and coal industry) have been allocated to overcoming these problems. Progress has been made on capture of CO2 but not on reducing overall cost of using the technology. In Australia, the only attempt at commercial application ended in the 2010 bankruptcy of the proponent company. The exercise did at least confirm earlier expressed views that use of CCS technology was prohibitively expensive, preventing its commercial use. During the same period, the cost of RE has fallen and continues to fall as technological improvements in this area made by the private sector in Australia (with limited public funding) and overseas. In Australia, legislation pricing carbon establishes an independent statutory fund for development of RE technology (specifically excluding CCS) and a fund to assist in its commercial application. By imposing a price on carbon emissions, the legislation ensures (and is intended to ensure) that the price of FFE rises and continues to rise relative to the cost of RE producing base load power – geothermal, marine and solar. As the price of FFE rises commercial use of CCS technology also becomes more affordable but it still remains significantly more expensive than RE and seems destined to remain that way – at least that is my assessment. As adalady points out, RE is being deployed in Australia now. Five solar energy power stations have been approved for construction and the first geothermal (hot rocks) electricity is expected to come on line in March 2012. Meanwhile the domestic and global price of coal continues to rise while pricing carbon emissions gives certainty to investors that RE is the way to go and provides for billions to be available for its technological development. Rather than representing a biased (pessimistic) view of CCS v RE, I suggest it is a view based on current realities.
    0 0
  10. Adelady : thanks, I’ll try to charge the Bloomberg report (just access to the press release for now, not the primary source). Agnostic : I’ve problem with your link. In my mind, we are not discussing here if some non-carbon energy sources are competitive (of course they already are in better – sunny, windy, etc. – places, and even more with a carbon price), but at which conditions a 2K / 450 ppm can be targeted (IEA WEO report). It is very different to get, say, 20 % of your total energy mix (not just electricity) and to get 50 or 80% of it from non-carbon sources. A majority of models are unable to rely just on RE (see IPCC SRREN) and that’s why coal with CCS, biofuel, nuclear are supposed to be included in the mix.
    0 0
  11. Suggested reading: “Climate-Control Policies Cannot Rely on Carbon Capture and Storage: That’s My Side of The Economist Debates” by Joe Romm, Climate Progress, Nov 22, 2011 Click here to access this article.
    0 0
  12. The Global Carbon Capture and Storage Institute in Canberra is endowed with >$2 billion and is responsible for producing cost-effective, efficient CCS technology. The last I heard (2010) was that this was not expected before the 2030’s and was unlikely to prove commercially viable until the price of carbon reached $120/tonne. But at that price RE is going to be far cheaper. The Australian coal mining industry does indeed hope that deployment of CCS in countries importing its product will ensure a long-term future. That is simply unrealistic. Those countries will deploy the technology which produces the cheapest energy and by 2030 that will be RE. To suggest that CCS is going to be the technology of the future which enables on-going use of “clean” coal is wishful thinking.
    0 0
  13. It would depend on where you are for getting enough RE at that price. Also, you arent going to find an alternative to coal for steel-making any time soon.
    0 0
  14. My guess is that CCS, if it is ever used on a large scale at all, will likely be deployed as remediation (rather than mitigation) in the latter half of this century, to correct what will almost certainly be an overshoot in any safe or acceptable level of CO2 concentration. See for example the two slides on page 11 of this presentation. The audio for this talk (by Myles Allen) can be accessed here. This is a talk worth watching in its own right, anyway. Given the massive problem we face in decarbonizing our energy supply (and eventually, probably, the atmosphere itself) I don't see why we should write off any potential contribution to a solution at this point. I know, after having paid a fortune to the oil companies for having them extract the carbon from the earth, to have to pay them again for putting it back, is a bitter pill to swallow.
    0 0
  15. Document of interest in the debate: the IEA roadmap for CCS (2009) . About the economic cost of mitigation: "IEA analysis suggests that without CCS, overall costs to reduce emissions to 2005 levels by 2050 increase by 70%." But Joe Romm documents (#61) point to the opposite. Hard to decide. #63 scaddenp : yes, coal as a fuel and reducing agent (coke) in metallurgy is often forgotten. It is also used (for heat) in cement, glass, ceramic or paper industry, so these intensive processes must be included in the RE package if substituting coal rather than capturing CO2 from its combustion is the only option.
    0 0
  16. @65 CO2 emissions from the reduction of steel are a very low percentage of total emissions. They can safely be left until much further into the energy transition. In the long term, coal can be replaced by charcoal for reduction, thus rendering the process carbon neutral. Direct heating is an important use of coal (and oil and gas). However, in all instances it can be replaced by heating using electricity, and in some cases could be replaced by the use of solar furnaces. Further, energy consumption for direct heating in industrial processes is included in estimates of total energy use. Therefore this is not an additional requirement on top of those already being discussed.
    0 0
  17. @42, I apologize for this late and limited response. I am very short of time at the moment, and as a result my commentary on more difficult subjects (including this one) has dropped of. Clearly I was in error regarding total energy consumption. That being the case, I would point out that if you are correct that the value of energy is not properly captured by its cost as a percentage of GDP, then expenditure on energy conversion will rise as a shortfall in usable energy develops, meaning conversion to RE will be faster than that suggested by SSREN scenarios. There can be no question that we could make the conversion to a zero carbon economy if we where determined to do so. Available solar energy is 11,000 times our current usage. Available wind energy is 78 times our usage. Available wave energy is 4 times our usage. (Figures from Richard Alley, Earth: The operators manual") Nor is there any question that we currently have all the technical expertise required. Even issues of intermittency are, as engineering problems, easily solved. What is not clear is whether they can be solved with low economic, social and ecological cost. In short, the issue of moving to a carbon free economy by 2050 is not can we, but will we pay the costs of doing so, where the cost is a small percentage of GDP. With regard to food, the IPCC AR4 indicates increases in temperature above 3 degrees C will reduce crop yields world wide. That is in addition to the loss of crop land due to changes in precipitation patterns. There will be similar losses in fishery production as warming water results in arctic (high oxygen) biomes being replaced by temperate and tropical biomes. On top of that there is a significant probability of the destruction of major barrier reefs, and in the long term the generation of anoxic oceans due to ocean acidification coupled with warming seas. It is the later possibility which represents the complete collapse of global fisheries (if they do not collapse before then due to the earlier, smaller effects of global warming coupled with over-fishing). So, from my point of view, the dilemma we face is the choice between a possible slowing of global growth in energy usage vs a probable decline in global food production. Faced with a population growing from 7 to 9 billion, it is the later which is the greater cause for concern. Unfortunately, and again I apologize for this, I will not have the time to argue these points in detail in coming months.
    0 0
  18. Tom : ‘energy consumption for direct heating in industrial processes is included in estimates of total energy use. Therefore this is not an additional requirement on top of those already being discussed’ I agree with that, but often (here adelady or Agnostic), energy transition examples are limited to substitution from gas or coal electricty to RE electricity, although electricity is not the major part of energy end-use in our societies. For industry in particular, IPCC SRREN recalls : 'The potentials and costs for increasing the use of RE in industry are poorly understood due to the complexity and diversity of industry and the various geographical and local climatic conditions.' (Technical Summary, 118). There are opportunities, specially for low-heat demanding industries, but it is uneasy to determine the pace of transition. For example, Germany must presently deal with a problem of this kind, after the nuclear ban. Windy places are located at the North of the country, but industrial regions are rather in the South. So, the cost is not just to install on- and offshore farms in the windy Baltic, but also to build high-voltage lines across the country and modify the grid. All is feasible of course, but as you say, there are 'economic, social and ecological costs' : climate issues are not the sole factor of human decision. There have been much debate about these topics when Nicholas Stern published his report, some years ago : if you take the worst (but still uncertain) trajectories of climate change models' estimates and the lowest discount rate, you conclude that benefits largely exceed costs, even with the most ambitious energy plan ; if you take the best (but still uncertain) trajectories of the same models' estimate and the highest discount rate, you may well conclude that some scenarios of energy transition will cause unuseful harm to present and next generations. For the rest, and notably GDP related to energy choices, I think the debate will continue with the 2nd part of perseus post.
    0 0
  19. @68, although discussion normally focuses on the production of electricity. However, nearly all smelting requirements can be carried out using arc furnaces or plasma arc furnaces, industrial heat requirements can to a very large degree be supplied by electricity, and at a very high efficiency. With regard to Germany, sorry, coming from Australia I find it difficult to believe that running power lines across Germany is a significant cost relative to production and use of the energy. Sorry, I don't know to which post by Perseus you refer.
    0 0
  20. "I don't know to which post by Perseus you refer" : This one . For Germany, see for example recent articles from Spiegel , either on cost of wind electricity from Baltic or on environmental and aesthetic concern about high voltage lines . Of course, it is not a technical problem per se. But as we translate the 2K/450 ppm objective in real energy decisions, there will be more political debates of this kind. (And, in my opinion, more pressure toward climate modellers and energy-economy modellers for reducing their remaining uncertainties.)
    0 0
  21. An interesting article in Science (Express) by Williams et al. . The abstract : "Reducing greenhouse gas emissions 80% below 1990 levels by 2050 is the subject of vigorous policy debate but there has been little physically realistic modeling of the energy and economic transformations required. We analyzed the infrastructure and technology path required to meet this goal in a specific economy (California), using detailed modeling of infrastructure stocks, resource constraints, and electricity system operability. We find that technically feasible levels of energy efficiency and decarbonized energy supply alone are not sufficient. Rather, widespread electrification of transportation and other sectors is required. Decarbonized electricity becomes the dominant form of energy supply, posing challenges and opportunities for economic growth and climate policy. The transformation demands technologies that are not yet commercialized and coordination of investment, technology development, and infrastructure deployment." Their results from the Californian case (world’s sixth largest economy and 12th largest emitter of GHGs, per capita GDP and GHG emissions similar to those in Japan and Europe), converge with IEA WEO 2011 we're discussing : reducing 2050 emissions 80% below the 1990 level would imply to include nuclear power and CCS in the mix. Their energy scenario needs three steps : "Three major energy system transformations were necessary to meet the target (Fig. 2). First, energy efficiency had to improve by at least 1.3% yr−1 over 40 years. Second, electricity supply had to be nearly decarbonized, with 2050 emissions intensity less than 0.025 kg CO2e/kWh. Third, most existing direct fuel uses had to be electrified, with electricity constituting 55% of end-use energy in 2050, compared to 15% today." As for the IEA WEO scenario, sustained gains in energy efficiency are the necessary condition of success : "The rate of EE improvement required to achieve the target and enable feasible levels of decarbonized generation and electrification—1.3% yr−1 reduction relative to forecast demand—is less than the level California achieved during its 2000-2001 electricity crisis (22), but is historically unprecedented over a sustained period."
    0 0
  22. Tom, you can forge with an arc furnace but it is CO that does the reduction from ferrous oxide to iron. Pretty expensive to do it other ways.
    0 0
  23. scaddenp @72, agreed that it is expensive to do it other ways. However the carbon for the CO can come from charcoal. As trees (the source of charcoal) draw their carbon from the atmosphere, iron reduction using charcoal as the reducing agent is carbon neutral. Again there is likely to be a cost in switching from coal to charcoal. I do not think it will be sufficient to have a major impact. More importantly, CO2 production in the reduction of iron is a small component of total industrial emissions and so can be one of the last areas of significant emissions reduction without significantly setting back the effort to reduce emissions. Just because something has to be done now does not mean everything has to be done now.
    0 0
  24. For charcoal substituting to coal, here a Hanrot et al 2009 study. Iron and steel industry accounts for 5% of total energy use, and 3-4% of GhG emissions according to Xu et Cang 2010 . Not the main issue for mitigation – if oil and coal could be used as commodities where they are strictly necessary in industrial processes rather than as energy sources for transport or electricity, it would be a great leap forward. I must emphasize (for all of us including me!) that if an energy-economy model is needful for simulating energy transitions, it is because in such discussions, we tend to poorly estimate the global quantities (requested for a certain level of production in the future) and furthermore, to add each energy solution in the mix a) without controlling that it is compatible with others in a certain land availability, b) without estimating the equilibrium cost of the energy in question and c) without ensuring that this energy can be implemented specifically where the needs (and workers!) are, or will be in 2050. Even energy-economy models have difficulties to track all the relevant factors, and this is probably one of the reasons for which they diverge in their conclusions about what we can and cannot do from now to 2050.
    0 0
  25. Hi, I'm in a college Environmental studies class and for the term paper I wanted to write about Geothermal Energy and why my city should make the switch. Is there anyway to calculate seattle wa's current use of energy (which is hydropower) and see what the prediction of environmental damage avoided and money saved if we made the switch to relying on Geothermal 20 years from now? I'd appreciate any resonses, Thanks K
    0 0

Prev  1  2  

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us