In the next few posts, I respond in detail to a comment from a reader, sTeve, of the NOAA article in my False Alarm blog. I am grateful when people take the time to comment and, yes, criticize, but I also think this writer oversells the certainty we should feel about alarmist climate science and its conclusions. Perhaps this response will allow readers to judge for themselves, and I will publish sTeve’s response, should he choose to do so.

sTeve writes:

I enjoy reading your writing; you post with eloquence and offer cogent and thoughtful argument. You are, however, dead wrong on all counts, and this greatly disappoints me. Your candidness and intellect would greatly serve our species, yet you have chosen a “closed-minded perspective”.

You offer the cherry-picked denier meme of the earth “cooling since 1998″, yet you already know that that argument has no merit, as it has been debunked countless times. You don’t mention the very strong El Nino of 1998, which had a major impact on global temps; perhaps you should read the papers written on that subject. Here’s a link to get you started: www . skepticalscience.com/global-warming-stopped-in-1998.htm

You already are aware that 1998 is no longer the warmest year on record, having been surpassed by both 2005 and, so far, 2010, yes?

You mention the alleged controversy of “Climategate”, yet four investigations have revealed no wrong doing, and in fact those investigations point to the strength of the science of the study of AGW.

You mention “The planet also cooled from 1945-75″. Did you not also find that the Clean Air Act of 1975 had a major impact on global temps by removing particulates from the atmosphere, thus removing a masking effect on global heating? Our industrial processes during the period 1945 – 1975 were overwhelming the warming of the planet due to the air pollution we were producing. The particulate matter in the pollution acted to reflect the suns warming of the planet. Once the Nixon Administration passed the Clean Air Act, the next 5 – 10 years saw a demonstrable decrease of air pollution, and we now know that global temps began to rise significantly. This is what has our scientists so very worried!

You write: “And, speaking of short periods of time on which to be drawing conclusions: the anthropogenic global warming hypothesis, correlating carbon dioxide increases with temperature increases, is based on only about 23 years-1975-1998. This is hardly a long enough period of time to be drawing long-term conclusions that might well wreck industrial civilization with poorly thought-out carbon curbs. Correlation, as you well know, doesn’t equal causation.”

Sounds plausible…until we look at the facts. “The SCIENCE says that temperatures did not rise from the mid-30s to the mid-70s because of sulfate aerosols in fossil fuels. And what happened in the mid-70s? Clean-air legislation, and more importantly the phasing out of sulfur-rich fuels.”

I find it difficult at best to comprehend your position on human-induced climate change, given the fact that every science academy across the globe, including the NAS, AAAS, AMA, AMS, AGU, and countless other scientific bodies, ALL agree that AGW is happening, it is already bad, it is going to get worse, and we should be doing everything in our power to cut down our emissions of greenhouse gases and pollution in general.

What would it take to convince you, Paul?

How ‘certain’ is alarmist climate science?

Starting at the beginning:

I enjoy reading your writing; you post with eloquence and offer cogent and thoughtful argument. You are, however, dead wrong on all counts, and this greatly disappoints me. Your candidness and intellect would greatly serve our species, yet you have chosen a “closed-minded perspective”.

To call “dead wrong on all counts” a reasonably held, scientifically based albeit skeptical position (as I hope to demonstrate below) betrays a black and white mentality that is not conducive to good science and implies a certainty that most scientific disciplines avoid. For example, physicist Richard Feynman has written: “A scientist is never certain.” And yet, many alarmist climatologists and lay followers are certain, completely certain, or say they are.

In this respect, I like to quote the late Dr. Stephen Schneider, a leading, maybe even THE leading figure in climate alarmism next to Al Gore and James Hansen, who said during a debate with Bjorn Lomborg that when it comes to climate,

we end up with a maddening degree of uncertainty. We end up with scenarios which, if we’re lucky, give us mild outcomes and we end up with scenarios that, if we’re unlucky, give us catastrophic outcomes. We fight amongst ourselves bitterly about the relative likelihoods of these, and have virtually no agreement…[italics added]

In the 2002 Scientific American attack on Lomborg’s Skeptical Environmentalist, Schneider admitted:

I readily confess a lingering frustration: uncertainties so infuse the issue of climate change that it is still impossible to rule out either mild or catastrophic outcomes let alone provide confident probabilities for all the claims and counterclaims made about environmental problems. … uncertainties are so endemic in these complex problems that suffer from missing data, incomplete theory and nonlinear interactions. [italics added]

So, when alarmist climate scientists are being honest, they admit there are many uncertainties in their discipline. When they present their discipline to the public, however, the uncertainties disappear—that is, they adopt a “closed-minded” perspective. This is, in my view, a form of deception of the public, and one of the reasons (among many ) why I am skeptical about almost anything the alarmist climate community claims.

For my part, I don’t believe sTeve’s alarmist position is “dead wrong,” although it could be wrong (and is certainly alarmist in the sense that “consensus” climate science wishes us to be alarmed, perhaps without good reason). There isn’t enough empirical evidence at this point to state, with any certainty at all, that either position, skeptical or alarmist, is scientifically certain and beyond debate, although I believe that, on balance, the skeptical position is more plausible.

Was the past decade warmer or cooler?

The writer goes on:

You offer the cherry-picked denier meme of the earth “cooling since 1998″, yet you already know that that argument has no merit, as it has been debunked countless times. You don’t mention the very strong El Nino of 1998, which had a major impact on global temps; perhaps you should read the papers written on that subject. Here’s a link to get you started: www . skepticalscience.com/global-warming-stopped-in-1998.htm

I’ll get to the question of how warm (or cool) the last decade was in the next post. For now, I am always fascinated when anyone who mentions that the planet hasn’t warmed, and might even have cooled, since 1998 is attacked as “cherry-picking.”

First, it is significant that the planet hasn’t warmed on average in more than a decade (again, I’ll get to sTeve’s claim that the planet warmed from 2000-2009 in the next post) because none—not one—of the many alarmist computer models predicted anything but considerable warming, at least .2° Celsius, for the past decade. And yet, we’re told these models are reliable.

Ironically, what the models predicted is that the planet would have cooled if human carbon emissions weren’t creating “unnatural” warming, as shown in this IPCC 2007 figure.

Figure 1: IPCC models show the planet cooling (blue line) without human carbon emissions.
Figure 1: IPCC models show the planet cooling (blue line) without human carbon emissions.

And then, the planet didn’t warm as expected, a fact that produced consternation in alarmist climate circles, as revealed by many of the comments in the Climatic Research Unit’s “Climategate” emails. Indeed, a good number of the CRU emails were devoted to ways to “hide the decline” from the public and even other scientists.

For example, IPCC author Kevin Trenberth notes, in one of his Climategate emails: “The fact is that we cannot account for the lack of warming at the moment and it’s a travesty that we can’t.” I could quote several other emails in the same vein. Trenberth is a firm believer in anthropogenic global warming, and yet it would be news to him and many others in the warmist movement that the decade’s cooling “has been debunked countless times.”

Baron Georges Cuvier, one of the fathers of scientific classification, wrote in 1822: “The essence of science is, without a doubt, the ability to predict phenomena.” That is, a scientific hypothesis stands or falls on the basis of the success of its predictions, and a failed prediction often falsifies an hypothesis. Based on this criteria, which is widely accepted in science (at least outside of climate science), the alarmist warming hypothesis has failed. Despite the alarmist predictions, human-caused carbon emissions did not cause the warming predicted for the past decade, which means natural cooling factors clearly predominated; that is, human carbon emissions are clearly not the “principal” driver of climate, at least for this time period.

Cherry-picking from 1975-1998

Secondly, the anthropogenic warming hypothesis is based entirely on another “cherry-picked” set of dates: 1975-1998 (or so)—a mere 23 years. Before 1975, the planet had cooled for about 35 years. (Alarmist climate science says this cooling was due to human-caused aerosols, not a natural cycle; more on that in a later post). Before 1940, the planet was coming out of a five-century-long cold spell dubbed the Little Ice Age (roughly 1350-1850), which was the coldest the planet has been in 10,000 years (that is, since the Younger Dryas cooling). Not even alarmists suggest that it was human industrial activity that pulled the planet out of this LIA cooling; the 1850 warming was entirely the result of natural factors.

Therefore, it’s not unreasonable (and certainly not “dead wrong”) to suppose the late 20th century warming, too, might have a large natural component. And, indeed, I wonder why anyone in his or her right mind would wish the planet to cool since it is the 20th century warming—about .6°C, or one degree Fahrenheit—that allowed us to feed more than six billion people by, in part, extending growing seasons, in part by increasing the amount of CO2 in the atmosphere, since CO2 acts as a fertilizer.

Thus, a peer-reviewed 2003 study of satellite data in Science showed that Net Primary Production, a measure of the planet’s plant growth, had increased 6 per cent between 1982 and 1999. The biggest increase, 42 per cent of the total, occurred in the Amazon rainforest. A primary reason for this increase in biomass, according to the article’s authors? Global warming—hence, a longer growing season—along with higher levels of fertilizing carbon dioxide. The authors conclude: “Most of the observed climatic changes [i.e., warming] have been in the direction of reducing climatic constraints to plant growth.” [italics added][1]

During interglacials, the planet warms, sea levels rise

As for the alarmist charge that the planet is on average warming and that this trend is somehow dangerous: The planet has, everyone agrees, been warming since the end of the last glaciation, roughly 15,000 years ago. That is, we are in an interglacial.The planet also warmed during previous interglacials over the past million years (approximately one interglacial every 100,000 years), reaching temperatures (according to the IPCC itself) that were 1-3°C higher than our interglacial so far, with sea levels 4-6 metres (14-20 feet) higher than sea levels so far.[2]

In other words, if the planet continues to warm and sea levels continue to rise, these increases will be mainly due to the natural factors particular to interglacials. At worst, we may be adding a percentage point or two to what would have occurred whether humans existed or not. That is, the seas may rise 20 feet in, say, 2,000 years rather than 2,100 years. The humanity of 2,000 years from now can probably handle that increase, assuming that anti-carbon policies today haven’t destroyed the economic progress and prosperity that, at the moment, is on the upswing (for supporting data on this improvement, see Chapter 9 of my book, Indur Goklany’s The Improving State of the World, or Matt Riley’s The Rational Optimist).

At the same time, I should add that human activities—mainly agriculture and cities, as Roger Pielke, Sr., argues, but also, to a limited and lesser degree, carbon emissions—are causing some warming. The question is: how much warming? A group called the Scientific Alliance puts the case well, I think:

The enhanced greenhouse effect remains a plausible but unproven hypothesis, with a significant number of question marks hanging over it. The most important question is not whether carbon dioxide warms the earth, but by how much.”[3] [italics added]

So far, the IPCC’s estimates of warming have always—always—been not only too high, but several times too high. A recent paper by Ross McKitrick, Steve McIntyre and Chad Herman compared model predictions with temperature observations. Their conclusion:

Over the interval 1979 to 2009, model-projected temperature trends are two to four times larger than observed trends in both the lower and mid-troposphere and the differences are statistically significant at the 99% level. [italics added]

Modelled and estimated trends (1979-2009) in Centigrade per decade in the tropics, lower trophosphere.

Figure 2: Modeled and estimated trends (1979-2009), in Centigrade per decade, in the tropics, lower troposphere. Source: Ross McKitrick, Steve McIntyre, Chad Herman, “Panel and Multivariate Methods for Tests of Trend Equivalence in Climate Data Series.” Aug. 3, 2010.

Therefore, “cherry-picking” the past decade simply highlights, for those with open minds, that the climate models are far from perfect, and that the conclusions drawn from them are therefore far from “certain,” much less “dead right” (the opposite of “dead wrong”).

I’ll continue my response to sTeve in my next post, including a look at whether the earth has, as he claims, warmed considerably in the past decade or, instead, not only failed to warm but cooled at times.

Notes

1. Ramakrishna R. Nemani, et al., “Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999.” Science, Vol. 330, Issue 5625 (June 6, 2003), pp. 1560-1563. See also Lawrence Solomon, “In praise of carbon dioxide.” National Post, June 7, 2008.

2. IPCC 2007, Summary for Policymakers, “A Paleoclimatic Perspective,” p. 9. “The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 metres of sea level rise.”

3. “The true impact of climategate and glaciergate,” The Scientific Alliance, Jan. 22, 2010.