Two weeks ago, I laid the foundations for this post. Yes, there is debate among climate scientists about many things. No, there’s no scientific debate about whether the earth is warming, or whether human activities are driving it. And no, there’s no serious debate about the permanent impact (for the next few hundred years, at least) about the greenhouse gas emissions we will emit in the next decade.
But that doesn’t mean everybody snaps to attention when climate scientists issue new findings about global warming. For example, last November, New Jersey’s straight-talking Gov. Chris Christie told the world that he was skeptical. “But you know – ’cause I’ve seen arguments on both sides of it that at times – like I’ll watch something about man made global warming, and I go, ‘Wow, that’s fairly convincing.’ And then I’ll go out and watch the other side of the argument, and I go, ‘Huh, that’s fairly convincing too.’ So, I got to be honest with you, I don’t know.”
Honesty’s a good thing right? Well, in the seven months since then, Gov. Christie’s learned a thing or two. Last Thursday, in a speech devoted to killing a regional carbon trading compact, the governor admitted what the world’s leaders have been saying since the mid-1990’s: “When you have over 90% of the world’s scientists who have studied this stating that climate change is occurring and that humans play a contributing role it’s time to defer to the experts.” [Click here for full text.]
But even with Gov. Christie on board (in a very strange sense), there are still plenty of folks who imagine all kinds of things. In a striking example, California congressman Dana Rohrabacher last Wednesday stated at a House committee hearing that he believed that we could reduce greenhouse gas emissions by clear-cutting the rain forests. (Really, I’m not making this up. Read for yourself here.)
“Seriously confused”, “crazy” and “whacky” were among the adjectives offered by climatologists and foresters in reaction to the congressman’s statement. The point is, even our leaders still say all kinds of things about climate change.
So it’s no surprise that the CR’s own readers have asked for some more clarity on a few basic questions. Here they are:
Question: What about recent centuries when the climate has changed without the burning of fossil fuels (like the Medieval Warm Period and the Little Ice Age that followed it)?
Short answer: Every millennium has warmer and cooler periods caused by volcanic dimming, changes in ocean currents and fluctuations in solar output. Today’s warming is not related to such events.
Question: Aren’t lots of scientists climate skeptics?
Short answer: Not really, except you can always find people who will say remarkable things when money’s at stake.
Question: Since there’s so much carbon below the surface, wasn’t it once all in the atmosphere?
Short answer: No, never. Less than 1% of the world’s carbon is in the atmosphere today. If you could somehow get it all up there, no living thing would remain on earth.
Question: Since plants use CO2, isn’t more of it likely to make a greener world?
Short answer: Your teacher was right – Plant photosynthesis does use CO2. But higher CO2 concentrations destroy plant growth as well, through desertification, drought and salinity. Only the Arctic tundra is likely to be greener in the coming carbon age.
Question: Didn’t I read somewhere that climate scientists had “cooked the books?”
Short answer: Yes, you did, and it made great press for a week or two. But every serious inquiry into “Climategate” has confirmed the scientific findings. Even the leading skeptic scientist testified to Congress that the climate data and related research was “excellent.”
The Little Ice Age…
Sometime during the 13th century, glaciers began expanding in Europe and Greenland, following a couple of centuries in which Scandinavia and Greenland enjoyed warmer and milder temperatures. Most researchers note that these were not synchronous global events, but they happened over the earth in irregular patterns. But to be sure, the Vikings grew abundant crops and settled the southern tip of Greenland at one point; and Hans Brinker could use his silver skates all over Holland’s canals a few centuries later.
What caused these fluctuations? Any honest treatment would say that the science has a lot of room for development here. But most researchers see changes in solar radiation, changes in volcanic activity (ash dims the sunlight and cools the earth for years at times) and changes in ocean circulation. But throughout all these periods, CO2 concentrations were level at 280 parts per million. Today, our warming is accompanied by CO2 concentrations approaching 400 ppm. And viewed in the context of the longer climate records, these climatic events are hardly noticeable.
|The Medieval Warming and Little Ice Age hardly show up in overall climate records|
Aren’t Lots of Scientists Skeptics?
Former-skeptic Gov. Christie put the scientific climate consensus at 90%. Sounds generous, but it’s really not. Whenever a great industry’s profits are put at risk by new awareness, there’s inevitably a battle of supposed experts. It happened with electric utilities and acid rain. It happened with the aerospace industry and nuclear “star wars” under Pres. Reagan. It happened with the tobacco industry and lung cancer. And it happened long before with the British maritime industry and the African slave trade. In each instance, long after the experts knew the facts with little doubt, opposing forces could produce supposed experts to offer contradictory testimony. (See the April 6, 2011 CR for how this can backfire on the industry that purchases such testimony.)
The debate over climate change is no exception, except that the skeptic-experts generally aren’t actual researchers. For example, in 2004, the University of California San Diego conducted a detailed review of the prior decade’s scientific journals: They examined all 928 articles published in refereed scientific journals between 1993 and 2003 having key words “climate change” that were listed in the ISI database. Not a single paper in this group disagreed with the consensus position that humans are responsible for at least part of the currently observed climate change. [Click here to read the report.]
More recently, in May 2010, 255 members of the National Academy of Sciences (NAS), the prestigious academy of America’s most accomplished and authoritative scientists, wrote to Congress saying: “There is compelling, comprehensive, and consistent objective evidence that humans are changing the climate in ways that threaten our societies and the ecosystems on which we depend.” [Read it here.]
And this year, the NAS itself reported to Congress that “climate change is occurring, is very likely caused primarily by human activities, and poses significant risks to humans and the environment. These risks indicate a pressing need for substantial action to limit the magnitude of climate change and to prepare for adapting to its impacts.” [Read it here.]
|Cigarettes “recommended” by doctors for years|
So had the skeptic-experts folded? Not at all. On February 8, 2011, a group of 41 scientists replied, rebutting everything that the NAS had said. 41 scientists! Now there’s a real controversy, right? Well, look a little closer. Only two of the 41 skeptics were members of the NAS. And 18 of them were retired. You can dress them in white lab coats for the cameras, but few of them are doing the research. In fact, the institute that produced their report has been funded by ExxonMobil in the past (although it no longer discloses its funding sources). [Read the report here.]
And in case anyone’s offended by my historical denial-for-hire analogies, one of the two men in this skeptic group who is an NAS member continues to deny links between tobacco and lung cancer. In this one case, the smart money is with Gov. Christie.
Wasn’t all the Carbon once in the Atmosphere?
We won’t spend long on this. 99.9% of carbon on earth (not including the earth’s mantle and core) is trapped in sedimentary rocks and sea beds. The oceans contain 52 times more carbon than the atmosphere (although they’re getting dangerously acidic from all the carbon they’re absorbing from the air). Fossil fuels contain 5.2 times more carbon than the atmosphere. So let’s not talk seriously about returning all that stuff into the precious air we live in.
More CO2, a Greener World?
The plants of the earth can only use just so much carbon. Every year, humans generate 9-10 billion metric tons of CO2 from burning fossil fuels and by changing land use. Of that amount, 2.3 billion is absorbed by the oceans (although this can’t go on forever, given rising acidity). The land – including all plants – uses 3.0 billion of it. It can’t do any more. That leaves an extra 4 billion tons added to the atmosphere every year. If you’re hoping for a new carbon-rich Eden, you’ve already got it. The earth’s plants are sucking up all they can, and only offset about a third of what we’re emitting.
Cooking the Books?
You remember, the science world recently had its own WikiLeaks scandal. In the summer of 2009, thousands of private emails among scientists from the Climate Research Unit (CRU) at the University of East Anglia (in Britain) were leaked to the public. The CRU is one of the key groups that collect real-time temperature data from stations around the world. You’d think that this stuff would be boring, but it was explosive.
|The skeptic blogosphere had a great time with leaked memos|
The reason? The CRU data was part of the foundation of the “hockey stick”: a graph of global temperatures over the last century that showed basically flat trends until the last few decades, when temperatures shot up with rising CO2. Lots of people, especially skeptic bloggers, wanted to get their hands on the CRU data to prove it false. The freedom of information policies that govern British universities required disclosure, and the CRU was flooded with them from a number of prominent bloggers. Some thought that the bloggers were attempting to prevent them from conducting their daily work.
When the internal emails were finally leaked, you had all-too-human interchanges reflecting a tribal attitude in the climate wars. Us-vs.-them was evident in many letters. It didn’t look like the peer-review process we’re all expecting from science, in which neutral scientists replicate another’s work before publication. The skeptic blogosphere went into overdrive.
An excellent book on this episode was written by Guardian columnist Fred Pearce. [Find it here for $13.]
Several inquiries have been conducted, exonerating the CRU scientists. You might be skeptical about some sort of ole’ boy network at work, right? But the ultimate test occurred in early April 2011, when climate skeptic Prof. Richard Muller of Berkeley took the CRU data, and ran his own numbers, to eliminate what he thought was their biased approach. The result? Same conclusion. He reported his confirmation to Congress, to the horror of coal-supported lawmakers who invited him to testify.
But at a more basic level, allegations of vast scientific scams are generally made by people who don’t understand the scientific community. No one earns his or her PhD by simply affirming what has gone before. Every doctoral candidate has one motive: challenge, refine, debunk, or improve upon what was “known” beforehand. The idea that a few manipulative geniuses can control the science – and that no one will make a name for himself by disproving them – is science fiction, not science.
Well, if you’ve made it this far, Congratulations! You’ve reached the end. I will trouble you no more with explanations of arcane details few of us ever think about. But who knows: Maybe you’ve heard something you’ve always wondered about. I hope so!
Thanks for reading, and may God bless you.