Storms of My Grandchildren (21 page)

The Constitution grants Congress the power of the purse strings. Although the executive branch has found ways to gradually assume increasing authority, Congress never would have acceded, knowingly, to the decimation of earth science research and analysis. But the budget cut was inserted via a clever stealth maneuver. When the proposed budgets for the upcoming year were sent to Congress and reported in the media, NASA earth science had a change of only a percent or two, typical of other programs and nothing that would raise any eyebrows.

Here was the trick. In a little-noticed “operating plan” for the current year, which the administration submitted to Congress just prior to the budget for the upcoming year, there was a cut of about 20 percent in planned expenditures for earth science research and analysis retroactive to the beginning of the current year. More than a third of the way into the fiscal year, NASA earth science managers were told to rebalance their books with a draconian cut.

It turns out that the change to NASA’s mission statement was slipped into this same operating plan. A change in the budget inserted in the operating plan is something that would have been worked out between the White House Office of Management and Budget and the NASA Administrator’s Office. As for the removal of the mission statement, Mark Bowen reported in his book: “A high insider at headquarters told me that Michael Griffin rewrote the mission statement and the agency’s strategic plan basically on his own.”

But may it be that this is all a bad dream? I will stand accused of being as wistful as the boy who cried out, “Joe, say it ain’t so!” to the fallen Shoeless Joe Jackson of the 1919 Chicago Black Sox, yet I maintain the hope that NASA’s dismissal of “home planet” is not a case of either shooting the messenger or a too-small growth of the total NASA budget, but simply an error of transcription. Those who have labored in the humid, murky environs of Washington are aware of the unappetizing forms of life that abound there. Perhaps the NASA playbook was left open late one day, and by chance the line “to understand and protect our home planet” was erased by the slimy belly of a slug crawling in the night. For the sake of our children and grandchildren, let us pray that this is the true explanation for the devious loss, and that our home planet’s rightful place in NASA’s mission will be restored.

Protection of our home planet, I suggest, is intimately related to protection of our democracy. The American Revolution launched the radical proposition that the commonest of men should have a vote equal to that of the richest, most powerful citizen. Our forefathers devised a remarkable Constitution, with checks and balances, to guard against the return of despotic governance and subversion of the democratic principle for the sake of the powerful few with special interests. They were well aware of the difficulties that would be faced, however, placing their hopes in the presumption of an educated and honestly informed citizenry.

I have sometimes wondered how our forefathers would view our situation today. On the positive side, as a scientist, I like to imagine how Benjamin Franklin would view the capabilities we have built for scientific investigation. Franklin speculated that an atmospheric “dry fog” produced by a large volcano had reduced the sun’s heating of Earth, causing unusually cold weather in the early 1780s; he noted that the enfeebled solar rays, when collected in the focus of a “burning glass,” could “scarce kindle brown paper.” As brilliant as Franklin’s insights may have been, they were only speculation, as he lacked the tools for quantitative investigation. No doubt Franklin would marvel at the capabilities provided by Earth-encircling satellites and supercomputers that he could scarcely have imagined.

Yet Franklin, Jefferson, and the other revolutionaries would surely be distraught by recent tendencies in America, specifically the increasing power of special interests in our government, concerted efforts to deceive the public, and arbitrary actions of government executives that arise from increasing concentration of authority in a unitary executive, in defiance of the aims of our Constitution’s framers.

I believe there is a straightforward way to address these issues. I made some suggestions before a congressional committee with a name that sounded promising: the House Committee on Oversight and Government Reform. I thought my suggestions were substantive. I was disappointed that the committee members basically ignored them. Their interest seemed to be partisan posturing, not reform or solutions. The public needs to be aware of these matters and put pressure on government to fix the problems. Here are my suggestions.

First, abolish the practice of placing political appointees in Public Affairs Offices of the science agencies. Science and its reporting to the public should not be political. Public Affairs Offices should be staffed by career professionals protected from political pressures by civil service regulations. What’s so hard about that? If political appointees are placed in Public Affairs it is prima facie evidence that the administration wants an office of propaganda.

President Barack Obama has drawn attention to the censoring of science that occurred under the Bush administration and has promised to correct the problem. However, if political appointees are still placed in the Public Affairs Offices of the science agencies, any paper changes in the rules or safeguards are practically meaningless. In my experience, there is no qualitative difference between Democratic and Republican administrations. Public Affairs does fine on most scientific results, because most do not have political overtones. But on a sensitive topic such as global warming, there is interference. The most political interference that I had on a press release was late in the Clinton-Gore administration, with our alternative scenario paper, which tried to draw attention to the importance of climate forcings other than carbon dioxide.

The Public Affairs problem could be fixed by a law that prohibited political appointees in those offices. Or the president could fix it immediately, by inserting no political appointees into Public Affairs. If a later president reinserted political appointees, the public could be promptly informed that these offices were again functioning as propaganda offices.

Second, abolish the requirement for government scientists to have their testimony to Congress reviewed and edited by the White House Office of Management and Budget. Government scientists do not work for the president; they work for the taxpayer. Congress and the public have the right to hear unfiltered testimony. This censorship has no basis in the Constitution. It is just one of the ways that the executive branch has arbitrarily increased its power. If the president continues this practice, Congress should vociferously object, taking the president to court, if necessary.

However, the biggest obstacle to solving global warming is much more difficult than the two specific matters above. The problem concerns the role of money in politics, the undue sway of special interests. But before we discuss this crucial issue, I need to give you some bad news. The dangerous threshold of greenhouse gases is actually lower than what we told you a few years ago. Sorry about that mistake. It does not always work that way. Sometimes our estimates are off in the other direction, and the problem is not as bad as we thought. Not this time. The bad news emerged clearly only in the past three years. That is the story in the next chapter.

I
N 2007, THE ENVIRONMENTALIST AND writer Bill McKibben began bugging me, very politely, to either confirm 450 parts per million as the appropriate target level of carbon dioxide in the atmosphere or else to define a more appropriate one. He was developing a Web site to draw attention to this target limit and was thinking of calling it 450.org. I kept putting him off, though. I wanted a number that would remain valid for policy purposes for the foreseeable future. And I wanted to have a good science rationale—otherwise the number would have little meaning.

By the late 1990s I had begun to work explicitly on the question of what the dangerous level would be. I also wanted to better understand the degree to which there could be a trade-off (“offset”) between carbon dioxide and other human-made climate forcings.

The result of this research was our “alternative scenario” paper, published in 2000. We concluded that carbon dioxide had better be kept to no more than about 450 ppm. And it should be allowed to go that high only if some other gases, notably methane and tropospheric ozone, were reduced below current values, a task that we argued was feasible but not easy. A target of 450 ppm would mean 1 degree Celsius additional warming.

Where did this limit of 450 ppm come from? Not from climate models, although it is easy to understand why the public would believe that—they hear it again and again, from people with a vested interest in covering up the reality and urgency of the climate threat. They know, just as Nazi propaganda chief Joseph Goebbels did, that if you repeat something often enough, many people will believe it. And they know that it is easy to find fault with climate models, which are still very imperfect representations of the real world. So they set up a strawman—pretending that the 450 ppm limit came from climate models. Actually the 450 ppm limit came from looking at Earth’s history—remarkably detailed data showing how Earth responded in the past to changes of climate forcings, including changes of atmospheric composition.

Civilization developed in and is adapted to the climate of the Holocene, the stable, relatively warm period that has existed for about 11,000 years. There have been prior interglacial periods—warm intervals between the ice ages—during the past several hundred thousand years that were warmer than the Holocene; as much as a few degrees Celsius warmer at the poles, but only about 1 degree warmer on global average.

My thesis was that Earth during those interglacial periods was reasonably similar to Earth today. On the other hand, if we go back to the last time that Earth was 2 or 3 degrees warmer than today, which means the Middle Pliocene, about three million years ago, it was a rather different planet. Sea level was about 25 meters (80 feet) higher than today. Florida was under water. About a billion people now live at elevations less than 25 meters. It may take a long time for such large a sea level rise to be completed—but if we are foolish enough to start the planet down that road, ice sheet disintegration likely will continue out of our control.

The target limit of 1 degree warming that we arrived at is relative to the temperature in 2000. Earth warmed about 0.7 degree Celsius between the 1800s and 2000, which made the global temperature in 2000 approximately match the highest level in the Holocene. So the limit on warming that we suggested was 1.7 degrees Celsius relative to the late Holocene, the preindustrial climate, just prior to the warming that began in the late 1800s. Our proposed limit on global warming was only a few tenths of a degree stricter than the 2-degree limit the European Union has been advocating for the past few years and continues to advocate today.

Unfortunately, what has since become clear is that a 2-degree Celsius global warming, or even a 1.7-degree warming, is a disaster scenario. In order to clarify why I can say that with confidence, I need to continue the story of what has transpired in the past several years.

Even when I first suggested a limit of 1 degree Celsius additional warming, and a carbon dioxide limit of about 450 ppm, I was aware of one niggling detail—but I swept it under the rug. That niggling detail was the evidence that sea level during the prior interglacial period, about 125,000 years ago, had probably reached a level about 4 to 6 meters higher than today. A sea level rise of 5 meters (about 17 feet) would submerge most of Florida, Bangladesh, the European lowlands, and an almost uncountable number of coastal cities around the world.

My rationale for sweeping my concerns about sea level under the rug was the belief that ice sheets, and thus sea level, can change only very slowly. If that were true, then humanity might have a thousand years to figure out how to get atmospheric composition back to a safe level or adapt to changing sea level. That tidy rationalization seemed to be supported by ice sheet models and by most paleoclimate records of sea level change.

Unfortunately, over the past several years, support has crumbled for the tidy belief that ice sheets require millennia to disintegrate.

First, as I argued in my 2005 “Slippery Slope” paper and discussed in chapter 5, it became clear that the ice sheet models fail to incorporate physics components that are critical during ice sheet collapse. This deficiency has been confirmed by the models’ inability to simulate the rapid changes observed on Greenland and Antarctica during the past few years.

Third, evidence has mounted during the past several years that it is not unusual for sea level to fluctuate by several meters within an interglacial period. The most comprehensive study for the immediately prior interglacial period was published by geologist Paul Hearty and several colleagues in 2007. They showed, from sedimentary and fossil evidence on the shorelines of Australia, Bermuda, the Bahamas, and other locations, that sea level was about 2 meters above the present level for most of that interglacial period, but near the end of it, about 120,000 years ago, sea level increased to a maximum between 6 and 9 meters higher than today. The additional water must have come from Antarctica, Greenland, or some combination of the two.

The Hearty study and others show that the sea level stability of the late Holocene cannot be taken for granted. The Holocene’s stable sea level, so far, may be related to the fact that temperature peaked early in the Holocene and at a level slightly cooler than in most interglacial periods—and this peak warming was followed by a slight cooling trend.

Whatever the reason for sea level stability, it helped spur the development of civilization, as mentioned earlier. The stable sea level not only provided early humans with a high-protein marine food supply, but it also made possible grain production in estuary and floodplain ecosystems. With these conditions, food for the human population could be produced by a fraction of the people, thus allowing a transition from the Neolithic way of life to urban social life and the development of complex state-governed societies.

The period of stable sea level is almost surely over. But whether human-caused sea level rise will be a slow bump-up reaching a maximum only on the order of a meter or so, or whether it will be an eventual increase of tens of meters, with disintegrating ice sheets, continual havoc for coastal cities, and a redrawing of global coastlines, depends on policies adopted in the near term. I believe it is possible to keep sea level rise at a small bump-up, but that will require the amount of atmospheric carbon dioxide to peak soon and then begin at least a moderate decline.

Sea level rise is one of the two climate impacts that I believe should be at the top of the list that defines what is “dangerous,” because the effects are so large and because it would be irreversible on any time scale that humanity can imagine. Ice sheets take thousands of years to build up from snowfall. Reasonable “adaptation” to a large sea level rise is nearly impossible, because once ice sheets begin to rapidly disintegrate, sea level would be continually changing for centuries. Coastal cities would become impractical to maintain.

The other climate change impact at the top of my “dangerous” list is extermination of species. Human activities already have increased the rate of species extinctions far above the natural level. Extinctions are occurring as humans take over more and more of the habitat of animal and plant species. We deforest large regions, replace biologically diverse grasslands and forests with monoculture crops, and introduce foreign, invasive animal and plant species that sometimes wipe out the native ones.

Now human-made climate change, with an unnaturally rapid shifting of climatic zones, threatens to add a new overwhelming stress that could drive a large fraction of the species on the planet to extinction. Our understanding of this threat, as in the case of ice sheets and sea level, depends especially on information that we extract from Earth’s history and observations of what is happening today. There is another analogy between sea level change and species extermination: Survival of ice sheets and species both present “nonlinear” problems—there is a danger that a tipping point can be passed, after which the dynamics of the system take over, with rapid changes that are out of humanity’s control.

Indeed, animals are on the run. Plants are migrating too. Earth’s creatures, save for one species, do not have thermostats in their living rooms that they can adjust for an optimum environment. Animals and plants are adapted to specific climate zones, and they can survive only when they are within those zones. In fact, scientists often define climate zones by the vegetation and animal life that they support. Gardeners and bird-watchers are well aware of this, and their handbooks contain maps of the zones in which a tree or flower can survive and the range of each bird species.

Those maps are already being redrawn. Most people, mainly aware of much larger day-to-day fluctuations in the weather, hardly notice that climate, the average weather, is changing. In the 1980s I used a colored six-sided die that I hoped would help people understand global warming at an early stage. Only two sides of the die were red, or hot, representing the probability of having an unusually warm season during the years between 1951 and 1980. By the first decade of the twenty-first century, four sides were red; one side was white, for average 1951–1980 conditions; and one side was blue, for unusually cold. The actual change in the frequencies have almost matched that expectation—the number of unusually warm seasons now averages about 60 percent, while it needs to reach 67 percent to yield four red sides.

Problems are greater for other species. Ecosystems are based on interdependencies—between, for example, flower and pollinator, hunter and hunted, grazer and plant life—so the less mobile species have an impact on the survival of others. Of course, species adapted and flourished during past climate fluctuations. But now the rate of climate change driven by human activity is reaching a level that dwarfs natural rates of change. And barriers created by human beings, such as urban sprawl and homogeneous agricultural fields, block many migration routes. If climate change is too great, natural barriers, such as coastlines, will spell doom for some species.