Global Greenhouse Gas Emissions Continue Increasing

Carbon dioxide (CO₂) emissions from sources all around the globe are estimated to be increasing at a renewed, distressingly rapid, rate for 2018 to date, 2.7% for the year, after having been determined to be lower, about 1.6% for the full year of 2017. This evaluation is part of a detailed accounting of all sources of CO₂ emissions and of planetary processes that remove CO₂ from the atmosphere.  The study is undertaken now an annual basis and reported in the “Global Carbon Budget 2018” (C. Le Quere and 70 coauthors, Earth Syst. Sci. Data, 10, 2141-2194, 2018).  The main sources of CO₂ emissions are use of fossil fuels (coal, oil and gas) and the manufacture of cement.  The two largest factors that remove CO₂ are absorption into the waters of the ocean, and plant and soil incorporation of CO₂.  The net balance between all emitting and absorbing factors leads to the increase in man-made atmospheric CO₂ that is the main concern when considering global warming.  The authors present the increasing trend of atmospheric CO₂ in the following graphic:

 

 

Direct measurement of atmospheric CO2 concentration from 1958 to 2018. This graphic represents the difference between man-made sources of CO2 in the atmosphere and its removal by natural earth processes. The authors’ analysis shows that humanity’s use of fossil fuels is a main contributor to increased CO2, and is a main contributor to global warming.
Source: C. Le Quere and coauthors, Earth Syst. Sci. Data, 10, 2141-2194 (2018)

 

 

Why is CO₂ emission such a problem?  This gas persists in the atmosphere for centuries, if not longer.  So the coal that was burned when the industrial revolution began produced CO₂ that is still part of the atmosphere today, and the aggregate amount of fossil fuels we consume at present produces CO₂ that will last for centuries.  The excess accumulation of CO₂ shown above cannot be removed economically on the massive scale needed with currently existing technology: the annual growth of atmospheric in 2017 was 4.6±0.2 billion metric tons measured as carbon/yr (or 16.8 billion metric tons measured as CO₂/yr).

The increased heat-trapping ability of the additional atmospheric CO₂ has alarmed scientists in the past couple of months.  They have issued two dramatic calls to action by the nations of the world (here and here) urging humanity to limit the overall rise in the long-term global average temperature to less than 1.5°C (2.7°F) by 2040 or 2050.  Voluntary national commitments were made by the members of the United Nations to reduce annual emission rates when the Paris Agreement was reached in 2015.  Even at that time, analysis of the commitments recognized that they were seriously insufficient to accomplish the limitation needed.  And in the succeeding three years, even those commitments have not been met.  This is made worse by President Trump’s intention for the U. S. to leave the Paris Agreement; the U. S. remains one of the three top annual emitters of CO₂ in the world and its emissions would increase under the president’s policy.

Global warming depends on the total accumulated greenhouse gases (GHGs), not the annual emissions rate.  The heat-trapping effect of GHGs depends on their total accumulated amount in the atmosphere.  A goal of simply reducing the annual emission rate does not replace the need to stabilize the total accumulated amount as soon as possible at as low a level as possible.  As long as the emission rate is above zero, GHGs continue accumulating in the atmosphere, thereby raising the long-term global average temperature.  Only achieving zero GHG emission rates as fast as possible stabilizes the total GHG burden at the low level needed.  

This is shown in the model image below.  It assumes that we start at a value of 100 for the atmospheric GHG level.  From year 0 to year 10 the annual emission rate, shown in blue, is 4% of the amount of the previous year (in the image the rate is multiplied by 25 to scale it to 100).  Over this period the cumulative GHG amount, shown in orange, rises by the 4% amount based on the previous year’s level, resulting in a line curving upward: 

 

 

Magically, after year 10 all net atmospheric emission rates fall to zero (blue) – including those originating from electricity generation, transportation, heating and cooling, and cement manufacture. No new GHGs are added to the atmosphere.  As a result, the total accumulated GHG burden (orange) flattens out, stabilized at the year 10 level.  It’s important to note that reducing the annual emission rate to zero cannot lead to a reduction in the total atmospheric GHG level.  This idealized model illustrates the important fact that the sooner annual emission rates approach zero, the lower the stabilized GHG level will be, with the result that the long-term global average temperature likewise will stabilize at a lower value.

 

The relationship between the accumulated GHG level and the  global average temperature.  The Fifth Assessment Report of the Intergovernmental Panel on Climate Change, issued in 2013-2014, modeled the relationship between total accumulated CO₂ in the atmosphere and modeled temperature increases (referred to the value during the early industrial revolution (1861-1880)).  The modeling included four “scenarios”, ranging from the most stringent (zero annual emission rate after 2030-2040; shown in navy blue in the image below), to a “business as usual” scenario (no meaningful policy to reduce emission rates; shown in red below).

 

Historical (black; 1870-2010) and modeled (2010-2100) temperatures (°C) projected for four “scenarios” of differing trends for man-made CO₂ concentrations with greatest to essentially no limitations on annual emission rates.  Data point dots are given every 10 years.  The most stringent (navy blue) falls to a near zero emission rate by 2030-2040; the light blue and orange lines are progressively less stringent, and the red line models the absence of meaningful constraints on emission rates.

 

 

Three important conclusions emerge from the modeling shown.  First, the amount of CO₂ in the atmosphere at any point along the horizontal axis does not depend on the scenario, that is, it is independent of the annual emission rate.  Second, all four scenarios follow more or less the same path along the CO₂-temperature relationship.  This dependence is nearly a linear one: the higher the CO₂ level in the atmosphere, the higher the projected temperature.  Indeed, the most stringent scenario (navy blue) shows no significant increase in CO₂ level between 2050 and 2100 (those points are all bunched together in the image) and consequently no further increase in projected temperature in those decades.  This projection mirrors the results in the model image shown further above.  Conversely, the unconstrained scenario (red) continues to emit CO₂ to 2100, leading to a drastic temperature increase of more than 4.5°C (8.1°F) by the end of the century, a truly frightening possibility.
 
Third, bringing annual emission rates to near zero does not reduce the accumulated CO₂ level after reaching a plateau, nor does this lower the projected global average temperature.  It only keeps the CO₂ level and the temperature stabilized.  

Many countries in the world are not fulfilling the pledges they made under the Paris Agreement.  The New York Times reports,  based on the most recent evaluation by the International Energy Agency, that major emitting countries around the world, including China and India, are continuing to build new coal-fired electricity plants instead of migrating to renewable energy on the scale needed. In fact, China and Japan are exporting them, building new coal plants in many developing countries.  The United States is reneging on its emissions-reducing policies put in place under former President Obama, and is opening federal lands to new fossil fuel extracting leases.  France is showing how difficult  the political scene is for pursuing policies to address global warming; rioting citizens are opposing a small, scheduled increase in taxes on vehicle fuels.

Conclusion 

This post demonstrates that continuing to emit GHGs at high annual rates inexorably adds to higher CO₂ levels in the atmosphere, which leads to higher long-term global average temperatures in a straight-line fashion.  Currently there are no technologies ready to be deployed at scale to remove CO₂ from emitting facilities or from the air, and permanently to store it away from the atmosphere.  Only reducing annual emission rates to near zero in the coming two decades, according to the two reports cited at the outset, (some advocate an even shorter schedule) will keep the world from entering a regime of unacceptably high global average temperatures.  All stakeholders need to coalesce around this objective to achieve this goal. 

© 2018 Henry Auer

 

 

Coal Fuels Developing Countries, but We Need to Decarbonize Energy Right Away

Summary.  Coal is the worst of the three principal fossil fuels in terms of the amount of carbon dioxide, the main greenhouse gas, emitted into the atmosphere on burning.  Whereas annual rates of emission from developed countries are projected to remain steady, the emission rates from developing countries are predicted to rise by almost 3% per year as they burn more and more fossil fuels, mostly coal, each year.

Consequently, according to a growing group of leading climate scientists, the goal of limiting the long-term global average temperature rise to less than 2.0ºC (3.6ºF) likely will not be met.  This will have serious negative consequences on humanity and the planet. 

We conclude that every new investment in energy infrastructure starting “now” should construct renewable energy sources and institute energy efficiency instead of extending fossil fuel-based energy infrastructure.  The principal emitters of greenhouse gases, including the U. S. and China, should reach a “few-party” agreement to decarbonize their energy economies among themselves as soon as possible.

 

Introduction.  Coal is the worst of the three principal fossil fuels in terms of how much carbon dioxide (CO₂), the main greenhouse gas, is emitted into the atmosphere for a given amount of heat produced on burning.  This is shown in the following table. 

It is seen that, on the basis of carbon-atom-to-carbon-atom in the various fuels,  coal emits almost twice as much CO₂ per unit of heat obtained relative to natural gas.  This makes coal the most offending of the fossil fuels in contributing to the worsening of global warming. 

In view of this situation, it would be highly sensible to set policies in place that discourage expansion of coal-burning energy sources.  Yet coal is also highly abundant throughout the world, and readily mined at the scale needed to satisfy energy demand.  Indeed, use of coal for energy continues not merely at a level pace, but at an ever-growing rate, as energy demand around the world keeps increasing.

Growth in energy use and in emissions of greenhouse gases in China and other developing countries has been historically high, and is expected to continue growing in future decades (see Details at the end of this post).  China is the country with the greatest demand for energy sources, coupled with a very high rate of growth in its energy demand.  A large portion of its energy demand is provided by coal.  Use of coal for energy in China grew at an average rate of 8.8% per year from 2000 to 2011, while the rate for the rest of the world was 1.1% per year.  Overall, China’s total energy use more than doubled over this time period, closely tracking the growth in its economy.  Clearly, energy is needed to power expansion in production and infrastructure.

The U. S. Energy Information Administration (USEIA) foresees continued rapid growth in energy consumption in China, as well as in India, in the future decades from 2008 through 2035.  Most of this energy continues to be derived from coal and other fossil fuels, so their projected emissions of the greenhouse gas carbon dioxide likewise grow rapidly during this period. 

Energy use by India, though lower in absolute magnitude than that of China, also grows at a comparable rate, since its energy economy is also being developed with a strong reliance on coal.  In contrast, the growth in energy use among developed countries, and their corresponding annual rate of growth of greenhouse gas emissions, is much lower than that for China, India and other developing countries of the world.

Analysis

China, India and other developing countries of the world have relied on coal and other fossil fuels to provide the energy needed to power their economic growth (as have most developed countries as well).  Coal is the most offensive of these fuels, for on burning it releases almost 50% to about 90% more carbon dioxide, the major greenhouse gas, than other fuels.  This unremitting reliance on fossil fuels has resulted in a dramatic growth in the emissions of CO₂, and is expected to continue without significant change in future decades (see Details, below), in the absence of new energy policies curtailing greenhouse gas emissions.

CO₂ released into the atmosphere is rapidly distributed into the air all around the globe; it does not remain restricted to the air space over the region of the emitting source.  For this reason greenhouse gas emissions at any point on the planet exert their greenhouse effect on all humanity.  Every source of greenhouse gas emissions contributes to the climatic consequences of global warming inflicted across the face of the entire planet.  The developing countries of the world, for example, are continuing to expand their energy infrastructures by installing still more electric generating plants, industrial facilities, and motor vehicle fleets, mostly powered by fossil fuels, as seen in the projections for future fuel use and CO₂ presented in this post.  We must understand, however, that every new facility made operational today cements a commitment to continue emitting CO₂ throughout its operational lifetime: up to a century for housing and commercial structures, about 40-50 years for electric power plants, and 10-20 years for motor vehicles.  The actions our policymakers take today have decades-long consequences.

CO₂, once emitted into the atmosphere, remains airborne indefinitely for at least 100 years, if not much longer (after a fixed, known fraction, about one-third, is absorbed by oceans).  Humanity has been adding new CO₂ to the atmosphere since the industrial revolution began, and is doing so as shown in the Details at an ever-increasing rate.  The extent of increase of the global average temperature is determined by the total accumulated level of GHGs, not by the annual rate of emissions. The present level has already raised the long-term global average temperature by 0.7ºC (1.3ºF).  This increase is continuing higher as the CO₂ concentration continues to increase. 

The Intergovernmental Panel on Climate Change (IPCC)  has set a target of limiting emissions such that the overall global average would not increase more than 2.0ºC (3.6ºF).  But climate scientists, examining current trends in the use of fossil fuels, now realize that humanity will fail to meet this target (these include Sir Robert Watson, former Chair of the IPCC; James Hansen, climate scientist at the National Aeronautics and Space Administration’s Goddard Institute for Space Studies ; Glen Peters and coworkers, Nature Climate Change vol. 3, pp. 4–6 (2013), doi:10.1038/nclimate1783; and Greenpeace “Point of No Return, The massive climate threats we must avoid”, January 2013).  

Recent annual conferences held by the United Nations Framework Convention on Climate Change (UNFCCC), including those in Copenhagen (2009), Cancun (2010) and Durban (2011), have striven unsuccessfully to supplant the Kyoto Protocol on its expiration at the end of 2012.  At the Durban conference it became clear that agreement on a global warming treaty would be seriously delayed.   As confirmed at the Dubai conference in 2012, the objective now is to conclude negotiating a new treaty by 2015 for adoption by the nations of the world and implementation by 2020.

But this is most likely too late.  As seen in the projections shown in this post, representing trends in the absence of policies to reduce emissions, annual emission rates by developed countries will continue at a constant level, while annual rates by developing countries will rise indefinitely.  Neither of these trends points to reduced emissions.  Yet this is what is needed.  Moderate abatement measures instituted a decade or two ago would have been relatively easy to implement.  But in the meantime, in their absence, global emissions have raised the CO₂ content of the atmosphere, so now more drastic abatement measures have to be implemented as soon as possible. 

Thomas F. Stocker, a climate scientist at the University of Bern, Switzerland, calculates (Science2013: Vol. 339 pp. 280-282; doi: 10.1126/science.1232468)  that the longer the delay the more stringent the mitigation policy must be to attain a goal of any given maximum temperature increase over the preindustrial temperature.  As of now, for example, an ambitious goal of a limiting rise of 1.5ºC (2.7ºF) would need a relatively stringent abatement rate of more than 5% per year, while a higher limit of 2.0ºC (3.6ºF) would need a lower abatement rate of over 2% per year.  But if we wait until 2020, for example, a limiting rise of 1.5ºC would require almost a 10% per year abatement rate, and a limiting rise of 2.0ºC would require about a 3% abatement rate.  Dr. Stocker concludes “…even well-intentioned and effective international efforts to limit climate change must face the hard physical reality of certain temperature targets that can no longer be achieved if too much carbon has already been emitted to the atmosphere. Both delay and insufficient mitigation efforts close the door on limiting global mean warming permanently” (emphasis added).

This post concludes that every investment in energy infrastructure undertaken from this date forward should construct decarbonizing energy facilities and implement energy efficiency instead of extending fossil fuel-based energy infrastructure.  These measures can be initiated unilaterally, but in addition the principal emitters of greenhouse gases, including the U. S. and China, should reach a “few-party” agreement to decarbonize their energy economies among themselves as soon as possible, outside of the UNFCCC process.  Our climate future and that of coming generations demands nothing less.

 Details

The historical use of coal by China, and by all other countries, is shown in the following graphic.

Coal consumption, in billions of tons used per year, from 2000 to 2011 for China (red line) and the rest of the world (black line).

Source: U. S. Energy Information Administration, http://www.eia.gov/todayinenergy/detail.cfm?id=9751&src=email.

 

In all countries of the world not including China (black line), coal use grew from 3.8 billion tons per year to 4.3 billion tons over the eleven years shown.  This works out to an average growth rate of 1.1% per year.  In contrast, coal use in China grew from 1.5 billion tons per year in 2000 to 3.8 billion tons in 2011, for an average growth rate of 8.8% per year.  Use in 2011 grew by 9%, continuing the long-term trend. 

World trends for coal use for 1980 and 2010 are shown in the two images below

 

World use of coal in 1980 and 2010 in billions of tons (Images captured from an animated version tracing year by year changes).   While North American use has expanded slightly, coal use in Europe and the former Soviet Union has actually fallen.  In the same period, coal use in Asia, due primarily to China and India, has expanded dramatically.

Source: U. S. Energy Information Administration http://www.eia.gov/todayinenergy/detail.cfm?id=4390.

 

This link animates the above images year by year between the 1980 and 2010 endpoints.  The two still images and the animation bring home in striking visual impressions the vast growth in Asian coal use, originating mostly in China and India.

The growth in overall energy use by China tracks quite exactly with its economic expansion, as seen below:

 

 

Total energy use by China (in quadrillion British thermal units (aqua bars)) and its economic growth (in 2000 U. S. constant $ (brown line)).

Source: U. S. Energy Information Administration http://www.eia.gov/todayinenergy/detail.cfm?id=8070.

 

About 71% of China’s electricity originates from thermal generation, mostly powered by coal.  Electricity generation doubled between 2005 and 2011, with coal-fired generation growing proportionately.  In some years in this period, China was commissioning 1-2 new coal-fired electricity plants per week. Even though China has the largest coal reserves in the world, it imports additional coal to meet its demand, starting in 2009.  (A detailed accounting of China’s historical energy economy is available at the USEIA).

 

In 2010, China accounted for about 73% of Asia’s coal use.  From 1980 to 2010 Asia’s coal use increased 403% during a period in which total world use increased 94% and North America’s use increased 50%.  In 1980 Asia accounted for 24% of the world’s total use of coal, while in 2010 this share grew to 63%. (Source: U. S. Energy Information Administration).

 

 

USEIA published its International Energy Outlook 2011 in September 2011.  Using a Reference scenario which assumes no further governmental energy policies other than those already in place in 2011 it projects trends in energy production and consumption from 2008, the last year of historical data included, through 2035.  As seen in the graphic below, total energy use in China and in India increases by much higher annual growth rates than does the increase in usage by the U. S.

 

Source: U. S. Energy Information Administration http://www.eia.gov/forecasts/ieo/world.cfm

 

China and India, continuing the historical trend already noted, derive much of their energy in the period projected through 2035 by burning coal.  This contributes to large accumulations of atmospheric CO₂.  This is seen in the following graphic:



Historical emissions of CO₂ from 1990 to 2008, and projections under the Reference Scenario to 2035 for developed countries (OECD, black line) and developing countries (non-OECD, red line). Source: U. S. Energy Information Administration; http://www.eia.gov/forecasts/ieo/emissions.cfm.

 

Emissions for developed countries in the Organization for Economic Development (OECD) increase minimally over the projected period, while those for the non-OECD countries increase 73% from 2008 to 2035, to 28.9 billion metric tons of CO₂.  Emissions originate worldwide mostly from coal, then from liquid fuels (powering transportation), then natural gas.  The growth in emissions from coal originates almost entirely from developing countries, which are dominated by emissions from China and India.  Growth rates for emissions from China and India are 2.6% per year and 2.7% per year, respectively, and the rate for all developing countries is 2.1% per year.  By contrast, the growth rate for emissions from developed countries is only 0.2% per year.

 © 2013 Henry Auer