Reducing CO2 Emissions

       [Contribution to the Reimagining Society Project hosted by ZCommunications]

In the 19th century Marx eschewed "utopia socialist" visions of an ideal society, arguing essentially that we could not know what it will look like until after the revolution which would make it possible. But, in the 21st century, due to the ecological crisis, we face a unique situation in which we do not have the luxury of waiting until history unfolds to find solutions. Indeed, without knowing and finding the solutions, we will have an end to history.

The Belem Ecosocialist Declaration, drafted by leading radical ecologists, eloquently encapsulates a general vision for an ecologically sustainable society. (1) To put flesh on that vision, it is vital to be as quantitative and specific as possible. First, it is difficult to mobilize people for a vision that is not clear to them in practical, every-day terms. Second, such a quantitative approach is also vital for an effective critique of plans now in the public domain which purport to solve the problem.

My goal in this essay is to stimulate discussion of how to construct such a quantitative model. What would worldwide standards of living that can stave off the most grievous forms of global warming look like, concretely? As well, I would like to hear ideas about workable political strategies to move the various key governments to make the necessary changes before it is too late.

By way of background, for 40 years I have worked as an oil and energy economist, specializing in consulting to Third World governments. But in recent years I have become increasingly concerned with the implications of oil and energy usage on the environment, particularly as regards climate change. In 1989,  Dr. James Hansen, the "father" of global warming, first identified the problem and its clear relation to carbon emissions into the atmosphere from human activity, particularly those related to burning of fossil fuels.

In 1992 the UN sponsored a major international conference on environment and development, (UNCED), which took place in Rio de Janeiro. I had the opportunity to attend this historic conference, as a correspondent for the Oil, Chemical and Atomic Workers Union (OCAW) and Monthly Review magazine. What I concluded from that experience is summed up in two articles I wrote then. What I described in 1992 is eerily similar to the present situation in the run-up to the December Copenhagen conference.

"I want to locate the Earth Summit within the context of an international capitalism that is stagnating.... (2)  

"The much bally-hooed United Nations Earth Summit in Rio de Janeiro this June was supposed to bring the world's political leaders together to deal with the international environmental crisis. There is general agreement among reputable independent scientists that global warming, the growing ozone hole in the atmosphere, toxic spills and radiation releases have a sufficiently high chance of leading to irreversible catastrophes that urgent steps need to be taken....(3)

  "...the focus of political leaders was on the whole extremely shortsighted. The worst villains, of course, were the United States and George Bush...

"But it would not be accurate to portray the U.N.C.E.D. conference as a tussle between a villainous United States and a virtuous community of nations. The other industrial nations were seeking only marginal improvements in environmental conditions...

"[And] some of the Third World countries also were jockeying
for their own narrow interests..." (4) 

Seventeen years later, the environmental situation is far worse. The emasculated Kyoto treaty, which finally emerged after UNCED in 1997, targeted a reduction for the leading industrial countries of about 8 percent of their 1990 carbon emissions by 2010. They only achieved a 5% decrease by 2006 (the latest data available). (5)  For the world as a whole, with rapidly growing Third World economies like China and India leading the way, there was actually a huge (30%) increase. (6)

Let's put these figures in context. New CO2 emissions add to the CO2 already existing in the atmosphere, and the total is measured in parts per million (ppm). The pre-industrial revolution figure was 280 ppm. Today's (2008) level is 386, and is increasing at about 2 ppm per year. (7)    This ppm is already dangerously close to the 400 level many scientists warn about and beyond the 350 ppm that Hansen considers a sustainable maximum. Not coincidentally, the average annual global temperature has increased from 14.1 C in 1980 to 14.3C in 1990 to 14.5C in 2005. 

We are all familiar with the almost daily reports of the effects of this global warming, from species disappearing to glaciers melting to agriculture being disrupted. For example, there were major droughts in the Amazon in 2005, 2006 and 2007, and scientists believe that a drought of more than three years in the Amazon carries the danger of turning the rainforest into a Savannah.  Again, "by 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%. Agricultural production, including access to food, in many African countries is projected to be severely compromised." (8)
 
To avoid these scenarios and worse, environmentalists like Lester Brown and George Monbiot have argued that we need to cut CO2 current emissions by 80% by 2020 and by 90 percent by 2030. (9)

But, back in the real world, the leading polluting countries have no such goals in mind. Most notably, among the developed countries, the U.S. under Obama has only now agreed in principle to setting mandatory goals for emissions, with Obama proposing a cut of only 20% by 2020. At the other extreme, UK leaders have talked about "considering" an 80% reduction, but only by 2050; if we interpolate this UK goal, it would mean a 25% reduction by 2020 and only a 45 % cut by 2030. Among the countries of the South, and most significantly China, which is the fastest growing source of CO2 emissions and has overtaken the U.S as the world's leading polluter, most are taking the position that their priority must be economic growth, and the developed countries must shoulder the burden of most of the needed cuts.

Perhaps most symptomatic of the general head-in-the-sand thinking are the scenarios of  the International Energy Agency, the main international body  which  makes projections on CO2 emissions in relation to economic development and energy use. Under its business-as usual "Reference Scenario", global energy-related CO2 emissions in 2030 will increase by 45% over current levels. But, even under its most radical "450 PPM Policy Scenario," global emissions would still be only 10% lower than today. (10)

So, clearly there is a huge disconnect between what science tells us we need to do, and what is presently being planned by world leaders.

Economic Changes Required to Avoid Disaster

Let us now turn to what the world really needs in terms of economic change, in order to give humanity at least a fighting chance at a future.

Energy is obviously the most crucial area. Table 1 shows annual CO2 emissions in 2005, by type of fuel, for the leading 20 countries. Oil, which is predominantly used for transportation, accounts for about two-fifths of all emissions.  Another two-fifths comes from coal and one-fifth from natural gas, both of which are crucial for electricity production. However, some countries have very different mixes. Two-thirds to three-quarters of India's and China's emissions come from coal, while over half of Russia's stem from natural gas.  Therefore, it is clear that we have to move as rapidly as possible towards carbon free methods of transport, such as electric or hydrogen-based cars, and electricity production based on solar, wind and tidal power.



                TABLE 1        
    CO2 EMISSIONS: MAIN SOURCE, TOP 20 COUNTRIES
               ( million metric tons)    

                                                       2005                              Percent     Cty Total
                                                       Natural                           Natural        
                                      TOTAL*       gas         OIL      COAL     gas      OIL    COAL
WORLD                            29,305    5,446    11,362    11,127    19%    39%    38%
  1 US                                5,847    1,168      2,464      2,158    20%    42%    37%
  2 PR CHINA                      5,631         88         914      4,095      2%    16%    73%
  3 RUSSIA                         1,517       802         332         334     53%    22%    22%
  4 INDIA                            1,425        51         313          988      4%    22%    69%
  5 JAPAN                            1,301      162         637          468     12%    49%    36%
  6 GERMANY                         804       185         291          311     23%    36%    39%
  7 UK                                   554       195        193          156      35%    35%    28%
  8 CANADA                           560       185        256          109      33%    46%    19%
  9 SOUTH KOREA                  475         63        188          198      13%    40%    42%
 10 ITALY                               471       162        224           64     34%    48%    14%
 11 IRAN                                436       184        204            5     42%    47%    1%
 12 MEXICO                           430        101        283           24     24%    66%    6%
 13 SOUTH AFRICA                409            8          42         352       2%    10%    86%
 14 FRANCE                          395          94        234           56     24%    59%    14%
 15 SAUDI ARABIA                367        117         237           -        32%    64%    0%
 16 AUSTRALIA                     366         53          98         210     14%    27%    57%
 17 BRAZIL                           350         38        236           53     11%    67%    15%
 18 SPAIN                             357         68        182           81     19%    51%    23%
 19 INDONESIA                     331         68        170           69     21%    51%    21%
 20 UKRAINE                         328       155          38         128     47%    12%    39%
Subtotal (top 20)              22,355     3,947     7,536      9,859     18%    34%    44%
REST OF WORLD                 6,950     1,500     3,827     1,268     22%    55%    18%
WORLD                             29,305     5,446    11,362    11,127    19%    39%    38%
Source: CDIAC. Oak Ridge Laboratory                    
http://www.epa.gov/climatechange/emissions/downloads/08_CR.pdf
* Includes emissions from gas flaring and cement production.        

Having said this, it must also be added that even  moving in these directions as fast as possible is insufficient to prevent global warming catastrophes.  For one thing, introducing  these new technologies will take a considerable period of time. Even the most optimistic projections for use of non-carbon energy sources still see carbon-based energy providing the vast proportion of our energy consumption in the year 2030. For another, the problem is still being envisaged within the framework of individual countries each trying to increase their output of goods and services.

The nub of the problem, which even the advanced thinkers such as Al Gore, Lester Brown and George Monbiot fail to adequately address, is that, particularly in the so-called advanced capitalist countries, we have far too much production of commodities altogether, most of which require vast amounts of energy.  Further, the impact of globalization and production based on market principles means huge amounts of transport are required, which in turn requires energy and generates pollution. Internationally, commodities are imported to the industrial countries from China because they can be produced at low monetary cost, but at a high carbon emission cost. Here at home, Federal Express has pioneered a business model in which it is cheaper to deliver a package from New York to New Jersey by first flying it to a hub in Tennessee-- cheaper in monetary terms but far more expensive in carbon emissions.

Furthermore, virtually none of the advanced thinkers really address the issue of an absolutely essential global redistribution of production and consumption. This redistribution must be based on valuing goods and services in a way that takes full account of their polluting effects.  And this will require painful sacrifices, because among other things, as noted, there are no quick technology fixes which can be widely deployed in the 2020-30 time frame.

Let's look at this issue concretely. From Table 1 we can see that the developed countries, led by the U.S. plus China, are the main polluters, in terms of percentages of global carbon emissions. The U.S., with 5 percent of the world's population, generates about 20 percent of its emissions. And the other OECD countries, with 10 % of total population, generate 16 % of emissions.

China already generates about 20 % of emissions, in line with its share of world population. India emits only 5% of the planet's emissions, far below its 18% share of world population. Thus, more disaster is on the horizon as countries like China and India seek to catch up to the standards of living of the industrial countries.

There are those who believe that this problem can be overcome largely by use of the market.  For example, George Monbiot, in his otherwise  excellent book, Heat: How to Stop the Planet from Burning, has argued for a rationing scheme under which the total global amount of acceptable carbon emissions is divided among countries on the basis of population, in the form of rights to emit carbon—rights which can be bought and sold. This, in his view, would minimize the need for governmental intervention, and hence be politically acceptable.

Let's examine one key industry, oil, to see the drawbacks of such an approach. This will also serve to illustrate the massive political economy barriers to such rationing approaches.

At present, world consumption of oil is about 85 million barrels per day. Hence, to reduce carbon emissions from oil by 90% would require a reduction to about 8 million barrels per day in global consumption. Given that, and since the US has about 5% of the world's population, under such a rationing scheme it would get emission rights to use only 400,000 barrels per day, which is  only 2 percent of its present usage!

Think about the implications of this. We would be devastating the entire U.S. economy, including the politically powerful oil and auto lobbies. Even if the US could help offset this for itself  by buying credits from the poorest countries, which presently emit very little, and even if it bought up all the rest of the world's credits, it would still only be able to use only 40% of its current consumption.

And what about the other countries of the world? China currently consumes about 7 million barrels per day of oil, or 8 % of the world's oil consumption. If global consumption were cut by 90%, even though China has 20% of the world's population, its quota of oil would be less than 2 million barrels per day, or one-fourth of its present level. What would happen to its plans to develop and "automobilize" the country?

And what about the OPEC countries? With global oil consumption cut by 90%, the price of oil would collapse and their economies would be devastated. They would go from relatively affluent to beggar nations. Why then would countries like China and OPEC agree to such a rationing scheme?

Such a plan, based on convergence toward equal amounts of emissions  per capita may  seem fair. but it fails to take into account vastly different starting points. The industrial countries have, by dint of enormous carbon emissions, built up far greater levels of  financial and productive capital than the poorer countries. Hence, they are in a much better position to make the transition to a low carbon economy. They can use that wealth  to both buy up carbon credits from poorer countries and to increase more rapidly  their alternative energy sources.

Instead of such market-based schemes, in my view what is needed is a complete restructuring  of the world economy—and a restructuring which must be perceived by most people as fair in human terms, in order to make it acceptable. Most likely, it will involve a drastic reduction in living standards for those in the wealthy countries; as well as an end to the aspirations of Global South  countries' elites for a Western standard of living, based on automobilization and consumer commodity production. Such a global economy would need to focus on using limited fossil fuels to provide basic food, shelter, health care, education, running water and clothing for everyone in the world.

I am seeking to develop an analysis which is as quantitative as possible that would allow us to translate the required cuts in emissions into a rough picture of such a world. In this sense I view it as a first step toward reimagining a low-carbon society.

My focus is on two key questions:

1.    which economic sectors are generating carbon emissions today, and
2.    if total emissions were cut by 80-90%, what would the "average" standard of living look like worldwide?

The Economic Sources of CO2 Emissions (11)

Table 2 shows the latest data for the 41 countries which have provided relatively detailed, standardized information to the United Nations. These countries, which are known as the "Annex I" countries, are mostly the high income nations plus Eastern Europe.  They account for more than half of global emissions.

From the table it can be seen that for these mainly developed countries, energy usage is the overwhelming culprit, accounting for almost 90% of their total emissions,, with industrial processes, such as manufacturing of  iron and steel, accounting for less than 10%. The biggest surprise, and a positive one, is just how little agriculture contributes to total greenhouse gas emissions - only five percent of world emissions and only 9% of Annex I country emissions. And transport accounts for less than one-fourth of Annex I emissions.
 

TABLE 2: Annex I Countries
2005 GREENHOUSE GASES EMISSIONS
(Billions of Metric Tons of CO2 equiv.)

         
SECTOR/IPCC Category                                 2005         % of                 % of
                                                                                                  Annex 1 Total     World Total    

Energy/a                                                       18.3          89%               48%    
    Fuel Combustion Activities                            7.0          34%               18%    
    Manufacturing & Construction Industries        3.1          15%                 8%    
    Transport                                                     4.6         22%                12%    
    All other energy                                           3.6          17%                 9%    
Industrial Processes                                          1.6           8%                 4%    
Agriculture                                                       1.8           9%                 5%    
Land use, Land-use Change and Forestry          -1.7           -8%               -4%    
Total 41 Annex I Countries                               20.6          54%    
World                                                             38.3              
Source: UNFCCC, Time Series - Annex I                
http://unfccc.int/ghg_data/ghg_data_unfccc/time_series_annex_i/items/3814.php

(a) Energy: "The energy sector mainly comprises: exploration and exploitation
 of primary energy sources; conversion of primary energy sources into more  
useable energy forms in refineries  and power plants; transmission and distribution of fuels;
and use of fuels in stationary and mobile applications. Emissions arise from these
activities by combustion and as fugitive emissions, or escape without combustion.

Table 3 shows, for the U.S., emissions organized by different economic categories. Electric power generation is the number one offender (33% of total), followed by transportation (28%), and industry (19%). It is important to remember, however, that these data locate emissions in terms of the production sector, rather than final consumer goods and services. Thus, although electric power production creates a large proportion of total emissions, the residential and commercial sectors ultimately are the main users of that energy.

   

                                                        TABLE 3

         U.S. GREENHOUSE GAS EMISSIONS BY ECONOMIC SECTOR    
                                  (Metric tons of CO2 equiv)  
         
                                            2005        % of                
    SECTOR                          Emissions    Total            
    Electric Power                     2,430       33%            
    Transportation                    2,009       28%            
    Industry                             1,353       19%            
    Agriculture                            595         8%            
    Commercial                           431         6%            
    Residential                            381         5%            
    TOTAL                                 7,260                 
Source: U.S. EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006
http://www.epa.gov/climatechange/emissions/downloads/08_CR.pdf

Tables 1 to 3 are useful in beginning to analyze the emissions problem, by identifying the main sources of C02 in terms of countries, fuels and broad economic sectors that produce emissions. However,  in trying to answer the question of what an average standard of living would be under conditions of  cutting present emissions levels by 80-90%, I encountered several major difficulties.

First, there are no systematic data on emissions by economic sector for the non-Annex I countries, which account for close to half of the total. Second, except for the U.K., there are no country-specific data on how the carbon emissions by economic sector translate into carbon emissions from individual consumer goods and services. In short, what is needed is a kind of global input-output table for CO2.  From that, it would be possible to focus changes in goods and services where they would have the greatest CO2-reducing impact.

Table 4 shows the beginning of such an analysis for the British economy, drawn from a break-through study which assigns all carbon emissions to final consumer goods and services. It shows the widespread diffusion of emissions into every nook and cranny of the economy.

 One of the striking revelations of the U.K. data is just how difficult it would be, given the present structure of the economy,  to find cuts adding up to a 90% reduction in CO2 emissions,.  Even if all home heating and transport were eliminated, this would only save 33% of emissions. Stopping the generation of all electricity and water heating would only save another 15 percent. Even if provision of only food, non-alcoholic beverages and housing were allowed, emission cuts would still fall 1% short of the 90% target.

 
    TABLE 4    
             UK: CARBON EMISSIONS OF FINAL CONSUMER CATEGORIES
  
                                               2002 YEARLY
                                         CARBON EMISSIONS    
CATEGORY                           (Million Metric Tons)      % of Total
Space heating(b)                               22.6                    13%
Private transport (direct)                    18.3                    10%
Transport services (indirect)                18.2                    10%
Food and non-alcoholic drink               14.5                     8%
Health and hygiene                             11.4                     6%
Water heating                                      9.1                     5%
Recreation and entertainment               7.6                      4%
Financial and other services                  7.0                      4%
Other personal effects                           5.6                     3%
Education                                             5.3                     3%
Housing                                                5.0                     3%
Public administration and defense           4.8                     3%
household appliances                             4.3                     2%
Electricity (lighting)                               3.4                     2%
Electricity (brown goods)                       3.3                     2%
Electricity (cold appliances)                    3.1                     2%
Holidays                                               3.0                     2%
furnishing and other household               2.9                     2%
Clothing and footwear                            2.6                     1%
Electricity (wet appliances)                     2.4                     1%
Delivered fuels (indirect)                        1.9                     1%
Cooking                                                1.8                     1%
Alcohol and tobacco                               1.7                     1%
Electricity (misc.)                                   1.6                     1%
Post and communication                         1.6                     1%
Water supply and other misc. services     1.5                     1%
Books and newspapers                           1.0                     1%
International and Military Aviation          11.0                     6%
        
Grand Total                                          176.5    100%
Source: Carbon Trust, The Carbon Emissions Generated in all that we Consume, CTC603.

Another way of looking at the problem is to ask the question: If countries cut emissions by 90% of 2005 levels, to what year would their economies return? One hypothetical answer is provided in Table 5, which shows for a number of countries how far back in time they would have to go. The U.K.  would have to return to its economy of 1829, the US to 1898 and China to 1969. In each case, those were years essentially before the industrial revolution had taken hold. In some countries, such as Britain and China, they were times of vast poverty, especially where urbanization was significant. In others, however, the economies were almost entirely rural, small-scale, home-based and agricultural.

TABLE 5      
    TOTAL FOSSIL FUEL EMISSIONS        
(metric tons CO2 equivalent)

COUNTRY              2,005          10%            Year Emissions
                                                               Were 10% of 2005
Australia                 369            37                     1939
Canada                   539            54                     1910
China                   5,556          556                     1969
Denmark                  48              5                     1897
UK                         547            55                      1829
USA                    5,788           579                      1898
Total                 12,847        1,285    
As % World            47%         47%    
WORLD              27,360        2,736     
Source: CDIAC. Oak Ridge Laboratory.        
 "Global CO2 Emissions from Fossil-Fuel Burning,       
  Cement Manufacture, and Gas Flaring: 1751-2005,"
http://cdiac.esd.ornl.gov/ftp/fossilfuel-co2-emissions/global.1751_2005.ems

(a) Emissions have been converted from carbon to CO2
      


Cutting Future C02 Emissions


Despite the limitations in currently available data, there is enough information to draw some perhaps surprising conclusions.

First, as noted earlier, the agricultural sector does not contribute overall to more than about 5% of total CO2 emissions. This is true even in non-Annex I countries where agriculture produces only 9% of all their emissions. This suggests that a "Utopian" model needs to place a heavy emphasis on shifting production from manufacturing to agriculture.
 
Second, from Table 2, we see that the mainly industrial Annex I countries produce 58% of global emissions. What is striking is that even adding China and India to this total, leaves 17% of emissions which come from the rest of the world. Given the present structure of the world economy, reaching the 80-90% reduction target, therefore, would require substantial reductions in emissions from the smaller countries of  the Global South.


Conclusion

Science has told us that reducing CO2 emissions drastically in the next two decades is an urgent task which cannot be delayed. Every day that goes by on the present economic path brings us closer and closer to irreversible "tipping points," from which the planet may not be able to recover.

Hence, pushing off target dates for sustainability into the far future, such as 2050 and 2100, will cause John Maynard Keynes' famous dictum that "In the long run we will all be dead" to come true, literally. Such an approach is a favorite technique of business leaders and politicians, who with their short time horizons have no real interest in what will happen in those far away periods, and happily promise great improvements by that distant future.

Others propose to "solve" the problem in the relevant time frame by making wildly optimistic projections of the time required to replace existing fossil fuel technologies by renewable energy sources, or for making fossil fuels "clean" by means of technologies which are still in the dreaming stage.

What virtually all of these approaches have in common is an implicit commitment to seeking market-based solutions, while also choosing to remain on the path of economic growth.

To confront these plans, and to develop our own, I believe the Left has to go beyond making generalized statements about the need for a change in the way economic life is organized and for a global redistribution of  resources. While this is absolutely true, the fact is that unless people see a way forward that is reasonably concrete, in the face of the unremitting pressure to maintain the status quo, they are unlikely to opt for radical change.

The core of our vision must be based on the principle that the market cannot and will not solve the global warming problem, and that solutions must be based on re-allocation of resources and CO2 emissions negotiated by governments. Such efforts will require massive worldwide pressure by aware and mobilized populations everywhere.

The ultimate solution likely will involve a combination of massive alternative energy expansion, major decreases in the consumption of goods and services that produce CO2 emissions, and  the  restructuring and scaling down of the entire world economy to a basic "needs plus" system. Thinking through and constructing such a quantitative "utopian" model of what a sustainable and just global economy might look like is a huge task. It will require a collective effort of many people around the world. My hope is that others in the Reimagining Society project will be interested in participating in and contributing to such an effort.



* I wish to acknowledge a deep debt of gratitude to my long-time friend and colleague, development economist Dr. Idrian Resnick, who contributed greatly to the research and thinking described in this essay.

Notes

 (1) The Belem Ecosocialist Declaration
http://links.org.au/node/803
"The...Declaration was prepared by a committee elected for this purpose at the Paris Ecosocialist Conference of 2007 (Ian Angus, Joel Kovel, Michael Löwy), with the help of Danielle Follett. It [was] distributed at the World Social Forum in Belem, Brazil, in January 2009."
(2) Michael Tanzer, "After Rio," Monthly Review, November, 1992, p.1.

(3)  Michael Tanzer, "Earth Summit: Implications for OCAW members," OCAW Reporter, November-December 1992, p.10.

(4) Tanzer, "After Rio," pp. 2-3.

(5) Mongabay.com, "Industrialized countries slow to reduce emissions," November 17, 2008. http://news.mongabay.com/2008/1117-emissions.html

(6)  Carbon Dioxide Information Analysis Center (CDIAC). Global Fossil-Fuel CO2 Emissions, Digital Data,
http://cdiac.ornl.gov/trends/emis/tre_glob.html

(7) See: Energy Information Administration. International Energy Annual 2006, December 2008. http://www.eia.doe.gov/pub/international/iealf/tableh1co2.xls; and, US National Oceanic and Atmospheric Administration. http://www.esrl.noaa.gov/gmd/ccgg/trends/
 
The basic equation for estimating the increase in ppm is that for each billion tons of emissions, ppm will rise by .07. Hence, the predicted increase in ppm for the period 1990-2008 would be .07 times 469 billion tons, or 31 ppm,   which is only 1 ppm away from the actual increase.

(8) UNEP. Intergovernmental Panel on Climate Change, Working  Group III, Mitigation of Climate Change, "Climate change and its impacts in the near and long term under different scenarios," This report is now only available for pay at: http://www.ipcc-wg3.de/

(9) See Lester R. Brown, Plan B 3.0, W.W. Norton & Company, New York, 2008, pp. 64ff; and George Monbiot. Heat, Cambridge, MA, South End Press, 2007, p. xii.

(10) International Energy Agency. World Economic Outlook 2008, Executive Summary, pp 11-14. http://www.worldenergyoutlook.org/docs/weo2008/WEO2008_es_english.pdf

(11) Greenhouse gas emissions include CO2, which is generally over 85% of total emissions, and a range of other gases, such as methane, nitrogen and sulfur, which have a CO2 equivalency in terms of effect.