[R-G] [BillTottenWeblog] Coal and Climate

[Bill Totten]

by Richard Heinberg

MuseLetter 196 (August 2008)

This month's essay is another chapter from the retitled
book-in-progress, Blackout: Coal, Climate and the Last Energy Crisis.


Recent reports on global coal reserves, surveyed in previous chapters,
generally point to the likelihood of supply limits appearing relatively
soon - within the next two decades (a contrary view is represented
solely by the BGR report) {1}. According to this near-consensus, coal
output in China, the world's foremost producer, could begin to decline
within just a few years.

Since coal is the most significant source of human-generated greenhouse
gas emissions, releasing about twice as much carbon dioxide per unit of
energy produced as natural gas, the news that there may be much less
coal available to be burned than commonly thought should be heartening
to climate scientists and environmental activists, and to policy makers
and citizens concerned about the fate of the planet. Reduced estimates
of future coal supplies should be factored into climate models - which
typically assume that there is enough coal available to permit continued
expansion of usage well into the next century.

At the same time, because global warming has emerged as the central
environmental issue of our era, climate concerns will inevitably impact
how much coal we continue to burn and how we burn it - whether these
concerns come to be expressed through caps on emissions, carbon taxes,
cancellation of orders for new coal-fired power plants, or the promotion
of new carbon sequestration technologies. In any case, the coal industry
will be - indeed, already is being - forced to change.

These two trends are surely destined to interact, and the uncertain
result will shape climate and energy policy in the years to come.

A Tale of Two Crises

The idea that carbon dioxide emissions from burning fossil fuels might
contribute to a greenhouse effect raising global temperatures was
initially floated in the 1950s. The first evidence that global
atmospheric carbon dioxide (CO2) levels and global temperatures were
both indeed increasing appeared in the early 1960s. The 1980s saw the
first calls for international action to limit carbon emissions, with the
first Congressional hearings held in 1988, the same year Margaret
Thatcher delivered a Climate Change speech to the Royal Society. The
UN's International Panel on Climate Change (IPCC) released its initial
report in 1990. In 1992, the Earth Summit in Rio de Janeiro produced the
UN Framework Convention on Climate Change. The third IPCC report, issued
in 2001, stated that global warming, unprecedented since the end of last
Ice Age, is "very likely", with severe surprises possible. By this time,
debate among scientists over the question of whether human activities
were contributing substantially to Climate Change had effectively ended.
In 2003, numerous observations raised concern that the collapse of ice
sheets in West Antarctica and Greenland could raise sea levels faster
than most had believed possible. That same year, a deadly summer heat
wave in Europe riveted public opinion on the issue. Work to retard
emissions accelerated in Japan and Western Europe, and among US regional
governments and corporations. In 2007 the fourth IPCC report warned that
serious effects of warming have already become evident, and that the
cost of reducing emissions would be far less than that of the damage
they will cause. In the same year, the north polar ice cap melted to
such an extent that the northwest shipping passage was opened for the
first time in history.

In short, over the past fifty years anthropogenic Climate Change has
evolved from a mere hypothesis to a robustly documented and widely
researched phenomenon; and from a concern on the part of just a few
climate scientists to a center-stage issue dominating not just
environmental studies, but economic planning and global politics as well.

Yet while Climate Change is the greatest environmental crisis that
humanity has ever faced, it is not the only serious challenge
confronting us. Climate Change is a "sink" problem - the result of
dumping into the environment a waste product from the burning of fossil
fuels. But there is a simultaneous "source" problem arising from the
gradual depletion of the fuels we are burning.

At about the same time the greenhouse hypothesis was first being
proposed, geophysicist M King Hubbert was publishing his first study on
the phenomenon of oil depletion. Previously, supply concerns about
fossil fuels had centered on the question of when they would run out,
and by most estimates that would not happen for a very long time.
Hubbert reframed the discussion by pointing out that the rate of
extraction of fossil fuels within any given region, or the world as a
whole, will reach a maximum and begin to decline long before the
resource is exhausted; further, he suggested that it is this peaking of
production that is critical for economic planning. By the mid-1970s, US
oil production had peaked and begun to decline, as Hubbert had estimated
that it would. By this time, Hubbert and a few other petroleum
geologists were forecasting a peak in global oil production around the
turn of the century. In 1998, Colin Campbell and Jean Laherrere
published a landmark article in Scientific American titled "The End of
Cheap Oil", in which they argued that oil reserves in the Middle East
were overstated, and that world petroleum production would hit its
maximum before 2010. At the time, the world oil price was hovering in
the range of $12 per barrel. By 2000, British oil production from the
North Sea had begun to fall, and it was apparent that about half the
world's other oil producing nations were also in plateau or decline. In
2005, a study for the US Department of Energy concluded that the world
oil production peak would have "unprecedented" social, economic, and
political consequences. In 2008, the International Energy Agency warned
of a severe mismatch between world petroleum supply and demand in the
years immediately ahead. By this time oil's price had risen to nearly
$150 a barrel, and soaring fuel costs were severely impacting the
automobile industry, the airline industry, the trucking industry, and
tourism.

Because natural gas and coal are also non-renewable, it is inevitable
that depletion will result in peaks and declines of output for these
fuels as well. However, studies - even unofficial ones -  of Peak Gas
and Peak Coal have lagged behind those of Peak Oil. While some awareness
of coal limits can be traced back at least to the work of Andrew
Crichton in 1948, the discussion of Peak Coal really started with the
appearance of reports from Energy Watch Group and the National Academy
of Sciences, both in 2007. A report from Energy Watch Group on global
natural gas supplies is due later this year.

Meanwhile, though the timing of the global oil, gas, and coal production
peaks is still controversial, the peaking concept has become
sufficiently accepted that its significance for Climate Change has begun
to be explored.

Climate Models and Fossil Fuel Supplies

Models for future impacts of Climate Change must be based on two
essential parameters: the quantity of future greenhouse gas emissions
that can reasonably be anticipated; and the sensitivity of climate to
added increments of atmospheric greenhouse gases. Both of these
parameters are subject to ongoing research and revision.

In its Special Reports on Emissions Scenarios (SRES), the International
Panel on Climate Change (IPCC) has published a series of forty scenarios
for the fossil fuel contribution to future Climate Change. The latest of
these reports, in 2007, was a multi-year effort involving more than
1,000 authors and more than 1,000 reviewers. In the assessment modeling,
limitations in fossil fuel supplies are not considered critically. For
example, in seventeen of the scenarios, world oil production is higher
in 2100 than it was in 2000 - a situation not considered likely even by
OPEC.

In 1996 the European Environment Council had said that the global
average surface temperature increase should be held to a maximum of two
degrees Celsius above pre-industrial levels, and that to accomplish this
the atmospheric concentration of carbon dioxide will have to be
stabilized at 550 parts per million (the pre-industrial level was 280
ppm and current concentration is close to 390 ppm, though the addition
of other greenhouse gases raises the figure to the equivalent of 440 to
450 ppm of carbon dioxide). The European Union has more recently adopted
a target of 450 ppm of carbon dioxide, in line with recommendations from
climate scientists.

However, the IPCC scenarios suggest that if fossil fuel consumption
continues to increase throughout the century, carbon dioxide
concentrations could reach a staggering 960 ppm by 2100, which would
result in six or more degrees of warming, tilting the global climate
into an entirely new regime and triggering an endless list of
environmental horrors.

Jean Laherrere was an early critic of the SRES, arguing in 2001 that
failure to understand realistic limits to fossil fuel supplies and to
incorporate these into climate models was resulting in highly
unrealistic estimates of future atmospheric carbon dioxide
concentrations, future temperature increases, and future effects on
climate, ocean levels, and so on {2}.

In April 2007, James E Hansen, head of the NASA Goddard Institute for
Space Studies in New York City, who has arguably done more than any
other scientist in recent years to both assess and publicize the likely
impacts of Climate Change, co-authored an important paper (together with
P A Kharecha of the Columbia University Earth Institute) that discusses
fossil fuel supply limits. These authors explicitly mention Peak Oil,
and stress that, "[I]t is important to estimate expected atmospheric
carbon dioxide levels for realistic estimates of fossil fuel reserves
and to determine how the carbon dioxide level depends upon possible
constraints on coal use".

In this paper {3}, Kharecha and Hansen discuss five scenarios. In their
Business as Usual base case, "Peak oil emission ... occurs in 2016 plus
or minus two years, peak gas in 2026 plus or minus two years, and peak
coal in 2077 plus or minus two years". Most of the IPCC scenarios show
far higher carbon dioxide concentrations than Kharecha and Hansen's
Business As Usual (BAU) scenario.

The authors also discuss a "Coal Phase-out" scenario that "moves peak
coal up to 2022". This second scenario "is meant to approximate a
situation in which developed countries freeze their carbon dioxide
emissions from coal by 2012 and a decade later developing countries
similarly halt increases in coal emissions". This Coal Phase-out
scenario shows a peak of atmospheric carbon dioxide concentrations at
about 445 ppm in 2046.

One message from the paper is that climate mitigation efforts should not
focus so much on reducing oil and gas demand, as these fuels are
supply-limited. Rather, they should concentrate on reducing the
exploitation of coal and unconventional fossil fuels, since these are
demand rather than supply limited for the time being. This message is
more explicit in Hansen's June 23, 2008 Congressional testimony:

"Phase out of coal use except where the carbon is captured and stored
below ground is the primary requirement for solving global warming. Oil
is used in vehicles where it is impractical to capture the carbon. But
oil is running out. To preserve our planet we must also ensure that the
next mobile energy source is not obtained by squeezing oil from coal." {4]

However, it appears that Kharecha and Hansen did not take fully into
account the recent coal supply reports surveyed in this book (though
they do mention the NRC report of 2007). The authors write, "[E]ven if
coal reserves are much lower than historically assumed ... there is
surely enough coal to take the world past 450 ppm carbon dioxide without
mitigation efforts such as those described here", but they do not define
what they mean by "much lower". In fact, the EWG, Hook et al, Laherrere,
and Rutledge forecasts cited in this book all show future coal supply
limits that are roughly in accord with Kharecha and Hansen's Coal
Phase-out scenario, and that achieve a target of approximately 450 ppm
carbon dioxide.

A month after the release of the Kharecha and Hansen paper, Kjell
Aleklett, professor of Physics at Uppsala University and President of
Association for the Study of Peak Oil (ASPO), published an article
provocatively titled, "Global Warming Exaggerated, Insufficient Oil,
Natural Gas and Coal" (May 18 2007). Aleklett's main purpose was to take
the IPCC to task:

"The sum of all fossil resources that the industry considers available
is presented annually in BP Statistical Review. According to this rather
optimistic estimate, the total energy of all oil, natural gas and coal
amounts to 36 Zeta joules (ZJ), a gigantic amount of energy. This is
more than what our research group considers likely, but it is still less
than what do the [SRES] scenario families A1, A2, B1 and B2 require ...
Up to 2100, IPCC prognosticates that A2 will need between seventy and
ninety ZJ, that is, twice as much as the industry believes is available
... We need a new assessment of future temperature increases based on a
realistic consumption of oil, natural gas and coal."

David Rutledge published his paper, "The Coal Question and Climate
Change {6}" cited throughout this book, in June 2007. In it, he compared
the results of Hubbert linearization modeling of future coal production
with the IPCC models. He concluded, "Our Producer-Limited Profile has
future fossil-fuel production that is lower than all forty of the IPCC
scenarios, so it seems that producer limitations could provide useful
constraints in climate modeling". More specifically, "The
Producer-Limited Profile gives a peak of 460 ppm in 2070" - which is
only marginally above the widely accepted target of 450 ppm. The
implication is clear: sufficient greenhouse gas reductions will be
accomplished by fossil fuel depletion alone, without any need for carbon
emissions regulatory policy.

In short, the implication of the latest research might appear to be that
Peak Oil, Peak Gas, and Peak Coal will together solve the problem of
global Climate Change, without need for intervention by policy makers.

However, this could be a dangerously premature conclusion.

Climate Sensitivity

Recall that climate models depend not only on future carbon emissions
(which are contingent, as we have just seen, on fossil fuel supplies as
well as on energy policy) but also on climate sensitivity. How will the
global climate respond to a given additional increment of carbon
dioxide? In general, as observations of impacts from Climate Change are
being logged, they are tending to show that past assumptions about
climate sensitivity have, if anything, been too timid and conservative.

Most climate sensitivity models are now being seen as subject to three
problems. First, they tend to assume a linear relationship between
atmospheric greenhouse gas concentrations and global temperature
increase, whereas there is mounting evidence that the relationship is
actually non-linear. Second, they tend to assume a linear relationship
between global temperature increase and actual impacts to ecosystems and
human society, whereas there is mounting evidence that this relationship
is also non-linear. Third, such models have created a questionable basis
for policy: it has been widely accepted that a future temperature
increase of two degrees Celsius (which is assumed to be tied to a
greenhouse gas concentration of 450 ppm) must be our target limit, above
which changes to the climate will be catastrophic, irreversible, and
unacceptable -whereas, in fact, we may already be seeing degrees of
change that are catastrophic, effectively irreversible, and unacceptable.

Non-linearity in the relationship between greenhouse gases and
temperature increase was demonstrated by a 2005 study by researchers at
the Potsdam Institute for Climate Impact in Germany, which concluded
that - to keep the temperature from increasing more than two degrees
Celsius - the atmospheric concentration of carbon dioxide would need to
be stabilized at then-current levels (that is, 380 ppm). Among other
things, the study pointed out that the biosphere's ability to absorb
carbon is being reduced by human activity, and this must be factored
into the equations; by 2030, this carbon-absorbing ability will have
been reduced from the current four billion tons per year to 2.7 billion
tons.

Non-linearity of the consequences of global warming is illustrated by
several self-reinforcing feedback mechanisms that, if triggered, could
result in effects spiraling far out of human control. Perhaps the
scariest of these has to do with the vast amounts of methane (a
greenhouse gas over twenty times more potent than carbon dioxide) locked
in the ocean floor and in the frozen soils of Siberia, Northern Europe,
and North America. Climate warming could trigger a rapid thawing that
would release billions of tons of this stored methane into the
atmosphere. More methane in the atmosphere would create more warming,
which would release still more methane. The ultimate consequence might
be the tipping of the planet into a new climate regime so different from
the current one that many higher life forms (including humans) might
find survival difficult or impossible.

The inadequacy of policies that use 450 ppm and a two degree Celsius
average global temperature increase as targets or limits is illustrated
by evidence that catastrophic Climate Change has already been set in
motion on the basis of a mere one degree Celsius global temperature
rise. For example: Recent observations have established that oceans are
absorbing increasing amounts of carbon dioxide from the atmosphere,
resulting in their gradual acidification. In the last two centuries, the
oceans have absorbed roughly half of the amount of carbon dioxide
emitted by fossil fuel use and cement production. This has caused ocean
pH to fall. Ocean acidity will be devastating to the marine environment
within a short period of time - tens of years instead of hundreds of
years. Seawater undersaturated in calcium carbonate will make it
difficult for shelled organisms to create skeletons and shells. These
organisms form an essential link in the aquatic food chain; thus all
life in the seas will be impacted. Given that the oceans have already
absorbed a substantial amount of carbon dioxide, we are already
committed to an irreversible amount of ocean acidification. It is likely
that rebalancing the ocean pH will take thousands, or even hundreds of
thousands, of years.

Ocean acidification again illustrates the disturbing fact that very
little about "global warming" is simple or linear. Instead, the
consequences of greenhouse gas emissions are complex, mutually
interacting, and far-reaching. Rather than merely having to accustom
ourselves to winters and summers a degree or two hotter, we will see far
more severe storms of all kinds, as well as rising sea levels,
collapsing ecosystems, disease outbreaks, species extinctions, profound
challenges to agricultural production, and more. We may already have
committed ourselves to centuries of overwhelming environmental damage.

If we are already seeing fundamental changes to the world's oceanic food
chain, to the Arctic sea ice, and to glaciers that feed some of the
world's most important river systems, can we afford to commit ourselves
to still higher atmospheric greenhouse concentrations (450 ppm instead
of the current 390), and to a two degree temperature increase above
pre-industrial levels instead of the single degree that has already
produced these impacts?

In a recent paper {7}, James Hansen, along with eight co-authors,
questioned the 450 ppm target and suggested a new one:

"Our current analysis suggests that humanity must aim for an even lower
level of greenhouse gases. Paleoclimate data and ongoing global changes
indicate that 'slow' climate feedback processes not included in most
climate models, such as ice sheet disintegration, vegetation migration,
and greenhouse gas release from soils, tundra or ocean sediments, may
begin to come into play on time scales as short as centuries or less.
Rapid on-going climate changes and realization that Earth is out of
energy balance, implying that more warming is 'in the pipeline', add
urgency to investigation of the dangerous level of greenhouse gases ...
We use paleoclimate data to show that long-term climate has high
sensitivity to climate forcings and that the present global mean carbon
dioxide, 385 ppm, is already in the dangerous zone ... Ongoing Arctic
and ice sheet changes, examples of rapid paleoclimate change, and other
criteria cited above all drive us to consider scenarios that bring
carbon dioxide more rapidly back to 350 ppm or less."


On the basis of this article and the recent findings that prompted it,
climate activists such as Bill McKibben and George Monbiot have also
begun to call for more stringent targets - 350 ppm target for
atmospheric carbon dioxide concentrations and a 100 percent reduction in
carbon emissions by 2050.

This is a far more rapid and drastic reduction in carbon emissions than
can be achieved by fossil fuel resource depletion alone.

Further, relying on fossil fuel depletion to safeguard the world's
climate would entail a serious risk: What if the new lower estimates of
coal reserves turn out to be wrong? Clearly, the world's oil and coal
reserves are a mere fraction of total resources. If somehow a way were
found to transform a significant portion of remaining resources into
reserves, this could entail a significant increase in atmospheric carbon
emissions.

This risk also extends to unconventional fossil fuels such as tar sands,
shale oil, and methane hydrates. While the potential for the development
of these resources is often overstated, since current technology will
permit only a very slow extraction rate for tar sands and perhaps no
commercial extraction at all of oil shale and methane hydrates,
nevertheless there is always the possibility that new technologies will
enable their exploitation on a wide scale. Without a stringent emissions
policy in place, the consequences for the global climate would be profound.

In general, human society faces a conundrum: unless non-fossil sources
of energy are developed quickly, or unless society finds a way to
operate with much less energy, and preferably both, the depletion of
higher-quality fuels (natural gas and oil) will mean that efforts to
obtain more energy will entail burning ever dirtier fuels, and doing so
in proportionally larger quantities in order to derive equivalent
amounts of energy.

Therefore, to the question, "Will coal, oil, and gas depletion solve
Climate Change?", the answer is an unequivocal no.

Will Climate Change Solve Peak Coal?

If some Peak Oil-Coal-Gas analysts suggest that depletion will stop
Climate Change, climate activists look at the matter the other way
around. While peaks and declines in the production of fossil fuels will
undoubtedly have enormous societal consequences, these nevertheless pale
compared to the potential ecological effects of Climate Change. Peak Oil
may result in the collapse of the global economy; Climate Change could
do so as well, while also devastating Earth's ecosystems in a way that
would require millennia, perhaps millions of years, for planetary recovery.

But if we proactively deal with Climate Change by reducing fossil fuel
consumption, the result will obviously be a reduction in dependence on
fossil fuels - and therefore a solution to the problems of Peak Oil,
Gas, and Coal. Therefore all that is needed is a clear, sustained,
vigorous policy focus on reducing greenhouse gas emissions.

There is some evidence to support this argument. Efforts to reduce
carbon emissions are already having an impact on the coal industry,
primarily in the US and Europe (though not nearly to the same degree in
China and India). In the US, nearly ninety percent of all new coal power
plant projects proposed between 2000 and 2006 were delayed or cancelled,
according to an October 2007 report by the US Department of Energy -
many over concerns about future carbon emissions regulations. Of 151
proposals for new plants submitted in early 2007, almost half had been
dropped by year's end, many blocked by state governments or delayed by
court challenges. Most recently, in July 2008 a judge in Georgia threw
out an air pollution permit for a new coal-fired power plant because the
permit did not set limits on carbon dioxide emissions. In Europe new
coal plants are faring better only because higher-efficiency power
plants are being proposed.

Climate mitigation efforts typically center on "cap and trade" (or "cap
and dividend" or "cap and share" - alternative regimes being proposed by
a number of economic equity activists), or on carbon taxes. Any of these
policies to restrict carbon emissions will inevitably reduce fossil fuel
consumption, impacting coal more than other fuels simply because of
coal's higher carbon content. While future coal-burning power plants
could be constructed to capture carbon, which could then be permanently
sequestered underground (a technology discussed in the next chapter),
over the short term reducing carbon emissions simply means using less coal.

If these efforts were to pick up speed, they would reduce demand for
coal (and other fossil fuels), thus heading off shortages and keeping
prices lower.

But will climate concerns succeed in driving policy in the face of
energy scarcity? Currently, global coal consumption is still growing -
faster by volume, indeed, than the consumption of any other energy
resource. Can nations experiencing shortages of oil and battered by high
energy prices be persuaded to forgo the still relatively cheap energy
from coal in order to avert environmental consequences for future
generations?