Skip to content

Global Warming’s Terrifying New Math

Rolling Stone, 19 July 2012

If the pictures of those towering wildfires in Colorado haven't convinced you,
or the size of your AC bill this summer, here are some hard numbers about
climate change: June broke or tied 3,215 high-temperature records across the
United States. That followed the warmest May on record for the Northern
Hemisphere – the 327th consecutive month in which the temperature of the entire
globe exceeded the 20th-century average, the odds of which occurring by simple
chance were 3.7 x 10-99, a number considerably larger than the number of stars
in the universe.

Meteorologists reported that this spring was the warmest ever recorded for
our nation – in fact, it crushed the old record by so much that it represented
the "largest temperature departure from average of any season on record." The
same week, Saudi authorities reported that it had rained in Mecca despite a
temperature of 109 degrees, the hottest downpour in the planet's history.

Not that our leaders seemed to notice. Last month the world's nations,
meeting in Rio for the 20th-anniversary reprise of a massive 1992 environmental
summit, accomplished nothing. Unlike George H.W. Bush, who flew in for the first
conclave, Barack Obama didn't even attend. It was "a ghost of the glad,
confident meeting 20 years ago," the British journalist George Monbiot wrote; no
one paid it much attention, footsteps echoing through the halls "once thronged
by multitudes." Since I wrote one of the first books for a general audience
about global warming way back in 1989, and since I've spent the intervening
decades working ineffectively to slow that warming, I can say with some
confidence that we're losing the fight, badly and quickly – losing it because,
most of all, we remain in denial about the peril that human civilization is

When we think about global warming at all, the arguments tend to be
ideological, theological and economic. But to grasp the seriousness of our
predicament, you just need to do a little math. For the past year, an easy and
powerful bit of arithmetical analysis first published by financial analysts in
the U.K. has been making the rounds of environmental conferences and journals,
but it hasn't yet broken through to the larger public. This analysis upends most
of the conventional political thinking about climate change. And it allows us to
understand our precarious – our almost-but-not-quite-finally hopeless – position
with three simple numbers.

The First Number: 2° Celsius

the movie had ended in Hollywood fashion, the Copenhagen climate conference in
2009 would have marked the culmination of the global fight to slow a changing
climate. The world's nations had gathered in the December gloom of the Danish
capital for what a leading climate economist, Sir Nicholas Stern of Britain,
called the "most important gathering since the Second World War, given what is
at stake." As Danish energy minister Connie Hedegaard, who presided over the
conference, declared at the time: "This is our chance. If we miss it, it could
take years before we get a new and better one. If ever."

In the event, of course, we missed it. Copenhagen failed spectacularly.
Neither China nor the United States, which between them are responsible for 40
percent of global carbon emissions, was prepared to offer dramatic concessions,
and so the conference drifted aimlessly for two weeks until world leaders jetted
in for the final day. Amid considerable chaos, President Obama took the lead in
drafting a face-saving "Copenhagen Accord" that fooled very few. Its purely
voluntary agreements committed no one to anything, and even if countries
signaled their intentions to cut carbon emissions, there was no enforcement
mechanism. "Copenhagen is a crime scene tonight," an angry Greenpeace official
declared, "with the guilty men and women fleeing to the airport." Headline
writers were equally brutal: COPENHAGEN: THE MUNICH OF OUR TIMES? asked one.

The accord did contain one important number, however. In Paragraph 1, it
formally recognized "the scientific view that the increase in global temperature
should be below two degrees Celsius." And in the very next paragraph, it
declared that "we agree that deep cuts in global emissions are required… so as
to hold the increase in global temperature below two degrees Celsius." By
insisting on two degrees – about 3.6 degrees Fahrenheit – the accord ratified
positions taken earlier in 2009 by the G8, and the so-called Major Economies
Forum. It was as conventional as conventional wisdom gets. The number first
gained prominence, in fact, at a 1995 climate conference chaired by Angela
Merkel, then the German minister of the environment and now the center-right
chancellor of the nation.

Some context: So far, we've raised the average temperature of the planet just
under 0.8 degrees Celsius, and that has caused far more damage than most
scientists expected. (A third of summer sea ice in the Arctic is gone, the
oceans are 30 percent more acidic, and since warm air holds more water vapor
than cold, the atmosphere over the oceans is a shocking five percent wetter,
loading the dice for devastating floods.) Given those impacts, in fact, many
scientists have come to think that two degrees is far too lenient a target. "Any
number much above one degree involves a gamble," writes Kerry Emanuel of MIT, a
leading authority on hurricanes, "and the odds become less and less favorable as
the temperature goes up." Thomas Lovejoy, once the World Bank's chief
biodiversity adviser, puts it like this: "If we're seeing what we're seeing
today at 0.8 degrees Celsius, two degrees is simply too much." NASA scientist
James Hansen, the planet's most prominent climatologist, is even blunter: "The
target that has been talked about in international negotiations for two degrees
of warming is actually a prescription for long-term disaster." At the Copenhagen
summit, a spokesman for small island nations warned that many would not survive
a two-degree rise: "Some countries will flat-out disappear." When delegates from
developing nations were warned that two degrees would represent a "suicide pact"
for drought-stricken Africa, many of them started chanting, "One degree, one

Despite such well-founded misgivings, political realism bested scientific
data, and the world settled on the two-degree target – indeed, it's fair to say
that it's the only thing about climate change the world has settled on. All
told, 167 countries responsible for more than 87 percent of the world's carbon
emissions have signed on to the Copenhagen Accord, endorsing the two-degree
target. Only a few dozen countries have rejected it, including Kuwait, Nicaragua
and Venezuela. Even the United Arab Emirates, which makes most of its money
exporting oil and gas, signed on. The official position of planet Earth at the
moment is that we can't raise the temperature more than two degrees Celsius –
it's become the bottomest of bottom lines. Two degrees.

The Second Number: 565 Gigatons

estimate that humans can pour roughly 565 more gigatons of carbon dioxide into
the atmosphere by midcentury and still have some reasonable hope of staying
below two degrees. ("Reasonable," in this case, means four chances in five, or
somewhat worse odds than playing Russian roulette with a six-shooter.)

This idea of a global "carbon budget" emerged about a decade ago, as
scientists began to calculate how much oil, coal and gas could still safely be
burned. Since we've increased the Earth's temperature by 0.8 degrees so far,
we're currently less than halfway to the target. But, in fact, computer models
calculate that even if we stopped increasing CO2 now, the temperature
would likely still rise another 0.8 degrees, as previously released carbon
continues to overheat the atmosphere. That means we're already three-quarters of
the way to the two-degree target.

How good are these numbers? No one is insisting that they're exact, but few
dispute that they're generally right. The 565-gigaton figure was derived from
one of the most sophisticated computer-simulation models that have been built by
climate scientists around the world over the past few decades. And the number is
being further confirmed by the latest climate-simulation models currently being
finalized in advance of the next report by the Intergovernmental Panel on
Climate Change. "Looking at them as they come in, they hardly differ at all,"
says Tom Wigley, an Australian climatologist at the National Center for
Atmospheric Research. "There's maybe 40 models in the data set now, compared
with 20 before. But so far the numbers are pretty much the same. We're just
fine-tuning things. I don't think much has changed over the last decade."
William Collins, a senior climate scientist at the Lawrence Berkeley National
Laboratory, agrees. "I think the results of this round of simulations will be
quite similar," he says. "We're not getting any free lunch from additional
understanding of the climate system."

We're not getting any free lunch from the world's economies, either. With
only a single year's lull in 2009 at the height of the financial crisis, we've
continued to pour record amounts of carbon into the atmosphere, year after year.
In late May, the International Energy Agency published its latest figures –
CO2 emissions last year rose to 31.6 gigatons, up 3.2 percent from
the year before. America had a warm winter and converted more coal-fired power
plants to natural gas, so its emissions fell slightly; China kept booming, so
its carbon output (which recently surpassed the U.S.) rose 9.3 percent; the
Japanese shut down their fleet of nukes post-Fukushima, so their emissions edged
up 2.4 percent. "There have been efforts to use more renewable energy and
improve energy efficiency," said Corinne Le Quéré, who runs England's Tyndall
Centre for Climate Change Research. "But what this shows is that so far the
effects have been marginal." In fact, study after study predicts that carbon
emissions will keep growing by roughly three percent a year – and at that rate,
we'll blow through our 565-gigaton allowance in 16 years, around the time
today's preschoolers will be graduating from high school. "The new data provide
further evidence that the door to a two-degree trajectory is about to close,"
said Fatih Birol, the IEA's chief economist. In fact, he continued, "When I look
at this data, the trend is perfectly in line with a temperature increase of
about six degrees." That's almost 11 degrees Fahrenheit, which would create a
planet straight out of science fiction.

So, new data in hand, everyone at the Rio conference renewed their ritual
calls for serious international action to move us back to a two-degree
trajectory. The charade will continue in November, when the next Conference of
the Parties (COP) of the U.N. Framework Convention on Climate Change convenes in
Qatar. This will be COP 18 – COP 1 was held in Berlin in 1995, and since then
the process has accomplished essentially nothing. Even scientists, who are
notoriously reluctant to speak out, are slowly overcoming their natural
preference to simply provide data. "The message has been consistent for close to
30 years now," Collins says with a wry laugh, "and we have the instrumentation
and the computer power required to present the evidence in detail. If we choose
to continue on our present course of action, it should be done with a full
evaluation of the evidence the scientific community has presented." He pauses,
suddenly conscious of being on the record. "I should say, a fuller
of the evidence."

So far, though, such calls have had little effect. We're in the same position
we've been in for a quarter-century: scientific warning followed by political
inaction. Among scientists speaking off the record, disgusted candor is the
rule. One senior scientist told me, "You know those new cigarette packs, where
governments make them put a picture of someone with a hole in their throats? Gas
pumps should have something like that."

The Third Number: 2,795 Gigatons

number is the scariest of all – one that, for the first time, meshes the
political and scientific dimensions of our dilemma. It was highlighted last
summer by the Carbon Tracker Initiative, a team of London financial analysts and
environmentalists who published a report in an effort to educate investors about
the possible risks that climate change poses to their stock portfolios. The
number describes the amount of carbon already contained in the proven coal and
oil and gas reserves of the fossil-fuel companies, and the countries (think
Venezuela or Kuwait) that act like fossil-fuel companies. In short, it's the
fossil fuel we're currently planning to burn. And the key point is that this new
number – 2,795 – is higher than 565. Five times higher.

The Carbon Tracker Initiative – led by James Leaton, an environmentalist who
served as an adviser at the accounting giant PricewaterhouseCoopers – combed
through proprietary databases to figure out how much oil, gas and coal the
world's major energy companies hold in reserve. The numbers aren't perfect –
they don't fully reflect the recent surge in unconventional energy sources like
shale gas, and they don't accurately reflect coal reserves, which are subject to
less stringent reporting requirements than oil and gas. But for the biggest
companies, the figures are quite exact: If you burned everything in the
inventories of Russia's Lukoil and America's ExxonMobil, for instance, which
lead the list of oil and gas companies, each would release more than 40 gigatons
of carbon dioxide into the atmosphere.

Which is exactly why this new number, 2,795 gigatons, is such a big deal.
Think of two degrees Celsius as the legal drinking limit – equivalent to the
0.08 blood-alcohol level below which you might get away with driving home. The
565 gigatons is how many drinks you could have and still stay below that limit –
the six beers, say, you might consume in an evening. And the 2,795 gigatons?
That's the three 12-packs the fossil-fuel industry has on the table, already
opened and ready to pour.

We have five times as much oil and coal and gas on the books as climate
scientists think is safe to burn. We'd have to keep 80 percent of those reserves
locked away underground to avoid that fate. Before we knew those numbers, our
fate had been likely. Now, barring some massive intervention, it seems

Yes, this coal and gas and oil is still technically in the soil. But it's
already economically aboveground – it's figured into share prices, companies are
borrowing money against it, nations are basing their budgets on the presumed
returns from their patrimony. It explains why the big fossil-fuel companies have
fought so hard to prevent the regulation of carbon dioxide – those reserves are
their primary asset, the holding that gives their companies their value. It's
why they've worked so hard these past years to figure out how to unlock the oil
in Canada's tar sands, or how to drill miles beneath the sea, or how to frack
the Appalachians.

Read more: