CHAPTER 1
Closer Than You Think
We are evaporating our coal mines into the air, adding so much carbon dioxide into the air as to change the transparency of the atmosphere. With each passing year, air must be trapping more and more dark (infrared) rays more and more earthlight. Eventually this change might very well heat the planet to heights outside all human experience.
— Svante Arrhenius, 1896
Loud pounding on the apartment door awakened me. Before I could get dressed to answer, the pounding returned. This time it was louder and more aggressive. Throwing my pants on, I raced to discover a firefighter standing in a smoke-filled hallway warning that our building was on fire. He sternly demanded that I leave the building immediately. I did not ask if he was a Republican or Democrat; I did not question his professional judgment or explore for any hidden agenda; I did not seek a contrarian's opinion about the potential of the neighbor's kitchen fire to spread to my unit; nor did I take a wait-and-see attitude about the fire: I followed his advice and got out as fast as I could.
I share this because I see a sharp contrast between how we respond to news of a dangerous structural fire and how we respond to the even greater dangers of global warming. We have been warned about the grave dangers of global warming for a long time. Yet, somehow, the language of scientists has become dangerously obscure, foreign, and unreadable to the average American.
Many talented scientists have done all that they can to get our attention. Great science voices such as James Hansen, Bob Corell, Rosina Bierbaum, Camille Parmesan, Henry Pollack, Tim Flannery, Virginia Burkett, Thomas Lovejoy, Heidi Cullen, Stephen Schneider, Susan Solomon, Katey Walters, George Woodwell, John P. Holdren (the new science advisor to President Obama) and many others referenced in this book have spoken repeatedly, (even very frankly, for scientists) but their urgent messages are not easily reduced to thirty-second soundbites and therefore have not penetrated the nearly impervious American television screen that harbors millions of viewers.
Starting in 1970 with the Study of Critical Environmental Problems conference in Williamstown, Massachusetts, climate scientists have issued multiple warnings with increasing intensity, all saying that we must curb emissions of heat-trapping gases that cause global warming. In 1986 and again in 1987, the Senate Committee on Environment and Public Works invited a number of leading climate scientists from around the world, including top US scientists, to testify at hearings aimed at gaining a better understanding of the state of atmospheric science related to human emissions. In one of those groundbreaking hearings, Wallace S. Broecker, then a geochemist at Columbia University, warned:
The inhabitants of planet Earth are quietly conducting a gigantic environmental experiment. So vast and so sweeping will be the impact of this experiment that were it brought before any responsible council for approval, it would be firmly rejected as having potentially dangerous consequences. Yet, the experiment goes on with no significant interference from any jurisdiction or nation. The experiment in question is the release of carbon dioxide and other so-called greenhouse gases to the atmosphere.
Broecker's warning of grave and immediate danger got my attention. His blunt assessment should have prompted elected leaders to act, and act fast. However, it did not. Here we have an esteemed member of the National Academy of Sciences, a geochemist who has authored eight textbooks in the field and published more than four hundred journal articles, issuing an urgent warning to all inhabitants of planet earth and almost nothing happens.
It's one thing to ignore one author, but the Intergovern-mental Panel on Climate Change (IPCC), involving thousands of scientists, has issued four separate reports during the past fifteen years, with the latest report concluding with a "very high confidence that the net effect of human activities since 1750 has been one of warming." Humankind is causing the bulk of global warming with emissions of carbon dioxide (CO2), methane, and other greenhouse gases. By all reasonable accounts, the core climate science is in, with more than enough published studies pointing to ominous threats in the United States and the world around.
A High-risk Experiment: Massive and Growing CO2 Emissions
Broecker's assessment at the hearings was right. It is now painfully clear that we are conducting a high-risk, high-consequence planetary experiment outside the range of human experience and competence. Through fossil fuel emissions and through alterations of nature's carbon storage systems, we have elevated atmospheric CO2 levels by more than 37 percent since the beginning of the Industrial Revolution.
We have all felt radiant heat from an asphalt parking lot baking in the sun. It is that kind of heat that is being blocked from escaping the atmosphere by CO2 and other global warming pollution. Because CO2 and other pollutants absorb outgoing long-wave radiation, small amounts of CO2, nitrogen oxides, or even trace amounts of methane can have a large effect on the planet's heat balance. CO2 concentrations in the atmosphere have grown from about 281 parts per million (ppm) in the preindustrial age to 387 ppm today, adding a heavy blanket onto the climate system.
Scripps Institute of Oceanography (SIO) scientist Charles Keeling first started tracking this buildup by taking actual measurements at the Mauna Loa Observatory in Hawaii in 1958. In 1970, Charles L. Hosler, then dean of the College of Earth and Mineral Sciences at Penn State University, provided my first exposure to the threat. Back then, when humans were adding about 0.7 ppm of CO2 into the air each year, Hosler warned, "We are putting astronomical quantities of materials into the atmosphere and there is no question it's affecting the weather. I am afraid the changes are already greater than most people suspect and there may be a threshold beyond which small changes in the weather could bring about a major shift in the world's climate."
CO2 emissions are not stabilizing or going down as anticipated, but are running far higher than the worst-case scenario anticipated at this stage in "Climate Change 2007," the Fourth IPCC Assessment Report. Perhaps the underestimation was caused by a failure to foresee the growth in Asian emissions, which are increasing 5 to 10 percent per year. (Based on the number of coal plants under construction, this will continue for at least another decade.) The underestimation was also caused by the US failure to cut its pollution or even participate in the Kyoto agreement. Black carbon from China's many new and unregulated coal-fired power plants is also amplifying the melt. Soot from China is falling on Arctic and Himalayan ice and snowpack, creating "dirty snow" that increases energy absorption. # The records since 1970 show atmospheric CO2 readings have been climbing year by year. Since the dawn of the Industrial Revolution, the total burden of CO2 in the atmosphere has increased as a direct result of coal, oil, and natural gas usage, deforestation, unsustainable agricultural practices, and other misdirected human activities on the landscape. Collectively, humans are now adding about 2.1 to 2.4 ppm of CO2 pollution into the sky each year. In other words, human activities are netting three times as much additional atmospheric CO2 buildup each year as we were forty years ago.
Reliable estimates of atmospheric CO2 concentrations have been made by drilling and extracting cores from various ice sheets around the world and analyzing the compressed atmospheric bubbles trapped in the annual layers of ice. A compilation of ice bubble data demonstrates that there were about 280 ppm of CO2 in the earth's atmosphere prior to 1800, and the CO2 levels varied between 180 and 300 ppm consistently for as far back as ice records extend.
The synthesis report of the IPCC has made it clear that worldwide carbon emissions must be stabilized by 2015 and brought down from current levels in order to make it possible to stabilize CO2 somewhere between 445 and 490 ppm. To do that and much more, we need to act now. Existing elevated levels of greenhouse gases will continue to trap additional energy, causing future ice melting and ocean warming. Through human alteration of the relationship between incoming solar energy and outgoing radiant energy, the planet continues to warm over time, and the earth is now locked into some rather severe, yet not fully expressed, climate consequences from the thermal blanket that we have already added. In fact, with all of the human-induced changes to the climate system, we should stop calling extreme weather events "acts of God," pretending that we had nothing to do with them.
Fast-moving climate change may soon trigger dire consequences for much of nature and for humankind. World-renowned climate scientist James Hansen of the National Aeronautics and Space Administration (NASA) is known for his straight talk on the matter: "We're toast if we don't get on a very different path." The director of the Goddard Institute for Space Studies (and often called the godfather of global warming science), Hansen warned the Associated Press in 2008 that "this is the last chance." He has repeatedly warned that we must act now before we tip the climate system so far out of balance that we create a fundamentally "different planet."
As Hansen warns, small imbalances can cause big problems. When mechanics build a race car engine, they carefully balance the engine's moving parts to yield maximum horsepower in the form of revolutions per minute (rpm). Depending upon the precision of the balance and other clearance factors, the mechanic rates each engine with an upper rpm limit on the tachometer so the driver knows not to exceed the redline and risk blowing the engine. The earth's tachometer is trying to tell us to take our foot off the gas pedal.
The climate system is out of balance by about 0.5 watt to 1 watt per square meter per year. For every square meter of the earth's surface, excess energy continues to be trapped and eventually either melts ice or accumulates largely as heat in the oceans' waters. In 2007, Hansen warned in testimony before Congress that "if humanity wishes to preserve a planet similar to that on which civilization developed ...CO2 will need to be reduced from its current 385 to at most 350 ppm." If Hansen is correct that 350 ppm CO2 may be the upper limit, or redline, for the planet, the atmosphere is now over the redline at 387 ppm. If we overshoot that target for very long, we will irreversibly damage life on the earth. Hansen's number makes sense, since it is clear that at 387 ppm, the planet is behaving very badly by shedding ice, killing forests, and releasing methane previously frozen beneath the Siberian Sea and in Arctic tundra into the atmosphere. If anything, Hansen's proposed target may be high, because in the 1940s and 1950s, at much lower CO2 concentrations, Rachel Carson was already seeing glaciers melting, birds migrating farther north, currents shifting, and fish altering their ranges. Unless we act quickly to stop polluting, to end carbon emissions from oil, coal, and natural gas, CO2 will continue to accumulate and block additional heat from escaping the atmosphere.
Arctic Melt
The Arctic has been relentlessly melting since the late 1950s. It has lost 40 percent in seaice draft, for an overall melt of more than four feet of ice. The data used to make some of these determinations originally came from US Navy submarines, and was gathered using upward-looking sonar to map the extent and thickness of the Arctic ice for purposes of identifying missile launch sites. Now, satellites are able to take ice measurements on a daily basis.
Accelerating Arctic melt may also be caused by changing ocean currents that are sending warm water under the sea ice, altered cloud cover with increased heat-trapping water vapor, or northern transportation of more energy through variable atmospheric transport mechanisms, including more potent cyclones.
Whatever the exact causes of unexpected melt, this vicious cycle is rapidly overheating the region beyond predictions. Soon disappearance of the ice, once seen as impossible, may be an important cause of increased temperature amplification that could alter weather patterns all over the world as its energy-reflecting surface is replaced by a vast expanse of energy-absorbing open Arctic sea.
Rapid Arctic sea-ice melting may be spawning a spiral of related changes that scientists call "positive feedback loops." While scientists understand the phrase positive feedback loops, those who use this terminology are not effectively communicating to the public. Calling something positive when it is actually negative baffles people. I much prefer "Arctic amplification" or "dangerous feedbacks" to describe the chain reaction or snowballing that is now occurring.
From the eight-hundred-thousand-year-old ice record, we know that CO2 and the earth's temperature travel parallel paths. As increased CO2 warms the planet, a warmer planet emits more CO2 and methane, which further warm the planet. The spiral is brought on by rather small increases in temperature sufficient to trigger changes in the climate system, which in turn cause more warming.
The increased warming leads to retreating ice, for example, which then leads to additional warming. Melting Arctic ice is an accelerant on other temperature-forcing mechanisms such as permafrost melt, which in turn releases more methane and CO2, further feeding the vicious cycle.
Scientists can track and project change when it occurs in a straight line or even when it follows a line that curves. Abrupt changes are rarely predictable. The unrepentant melting of the Arctic over the past few decades suddenly accelerated during the summer of 2007. In six days during September 2007, an area the size of Florida melted from the Arctic. The extent and speed of Arctic sea-ice loss reported during the 2007 melt season shocked the world's Arctic and climate scientists, as it set a new modern-day record by shrinking more than 30 percent below previous averages. On December 13, an Associated Press story reported that Mark Serreze, a senior research scientist at the National Snow and Ice Data Center (NSIDC) at the University of Colorado at Boulder, warned that "the Arctic is screaming." Just a day earlier, Wieslaw Maslowski, a research professor at the Naval Postgraduate School, warned scientists that the Arctic will be ice-free sometime during the summer of 2013. According to his analysis, Maslowski warned that warm water is moving into the Arctic Ocean from the Pacific and Atlantic oceans at much greater rates than the earlier IPCC models predicted.
This rapid melt was not predicted by the Fourth IPCC Assessment Report; they projected summer Arctic ice loss to move more slowly than it has and that the Arctic would be ice-free sometime between 2080 and 2120. The IPCC models were based on reasonable assumptions that the melting of Arctic ice would be more linear, the capacity of natural carbon storage mechanisms such as forests and oceans would be larger and more resilient to saturation, and that nations like the United States would ratify and comply with the Kyoto treaty. Updated predictions of Arctic ice melt now lie outside of the forecasts in the Fourth IPCC Assessment Report by nearly a hundred years. We need to understand the limits of science and be prepared for more climate surprises, because we will have to live with the somewhat unpredictable but undoubtedly dark realities of the feedback loops we've set in motion.
After the dramatic melt in 2007, ice cover remained thinned and weakened in the spring of 2008, with evidence of extensive formations of polynyas in the ice pack. Polynyas are areas of open water surrounded by Arctic sea ice, and they are more abundant in thin and weak ice. Arctic ice has disappeared or become thinner and much more fragile, with a loss of about 70 percent of dense and more durable perennial ice and an increase in the rate of spring and summer melt of vulnerable and thin annual ice.
By the end of the 2008 melt season, NASA and the NSIDC issued the following statement: "The Arctic sea ice cover appears to have reached its minimum extent for the year, the second-lowest extent recorded since the dawn of the satellite era. While slightly above the record-low minimum set in 2007, this season further reinforces the strong negative trend in summertime sea ice extent observed over the past thirty years."
