I’ve long viewed the anthropogenic global warming (AGW) denial movement with a certain sense of bemusement. The causal links are rock-solid – could it really be a coincidence that atmospheric CO2 levels started rising at the very same moment as industrial civilization got into swing, within decades reaching magnitudes big enough to decisively interrupt the glacial-interglacial cycle that previously held steady for hundreds of thousands of years? Is it really surprising that given the heat-absorbing properties of CO2 (known to science since the 18th century), global temperatures entered into a period of steep ascent since the 1970s, rising by around 0.9C from the 1900-1910 period to the last decade? Occam’s Razor anyone? And considering that only 6C or so separate us from the Ice Ages, when ice sheets descended into central Europe, southern England was a polar wasteland scoured by icy, dust-laden winds and dessication affected even the tropics, should not even the possibility of seeing the world warm by up to 6.4C during this century – corresponding to the high end of the IPCC’s forecasts in 2007 – invoke a certain level of concern?
I plan to write more on climate change, since it is going to be one of the key trends of this century (along with resource depletion and growth in computing power). But for now – and to forestall any future objections – I would like to take a moment to expose the top myths and misconceptions of AGW deniers.
10
It’s all a conspiracy – scientists want research funding and environmentalists want to impose socialism on us.
Frankly the idea that tens of thousands are colluding in a massive conspiracy is risible. If anything it is the denier camp which has economic incentives to promote their views, given the funding they receive from the fossil-fuel industry. The Bush administration scientists pursued a campaign of disinformation and outright censorship regarding AGW. So who are the real conspirators?
9
In past warmings temperatures in Antarctica began rising some 800 years prior to rising CO2.
The warmings took 5000 years to complete, so CO2 can’t account for just 1/6 of it. The initial warming is likely related to the Earth’s orbital cycles around the Sun. After a certain critical level of temperature rise is passed, more CO2 is released into the atmosphere – perhaps from its deep ocean sinks, since it takes around a millennium to diffuse heat to the ocean depths. This further amplifies warming in a positive feedback loop. Read more here and here.
8
There is no scientific consensus on AGW. And even if there is, it doesn’t mean it’s right.
Yes there is. In a January 2009 poll, 97% of climatologists active in research today said they believed that “human activity is a significant contributing factor in changing mean global temperatures”. A 2004 study by Naomi Oreskes of close to a thousand papers related to global climate change found that not one rejected the Scientific Consensus on Climate Change.
Though consensuses are sometimes wrong, they are right in the vast majority of cases. Though Patrick Michaels may claim there is a “paradigm problem” (borrowing from T. Kuhn’s Structure of Scientific Revolutions) with the conservative IPCC which serves to suppress mavericks, it goes the other way too – the IPCC generally neglects to mention new, outlying research which suggests that climate may change at a much more sudden and violent pace because of previously-unknown positive feedbacks and underestimated climate sensitivity.
7
Satellite sensors and equipment on weather balloons show evidence of cooling, thus disproving that eight of the hottest years have been since 1998 and other sensationalist claims.
Satellites don’t just measure the troposphere (the lowest level of the atmosphere) – which is what matters – in isolation, but also the higher stratosphere. The latter is expected to cool during global warming, because more heat is absorbed by the Earth and less is re-radiated into space. Furthermore, satellites are dependent on weekly recalibration by weather balloons so they cannot even be said to be independent.
As for the weather balloons, the problem is that during the 1960’s and 1970’s their on-board thermometers were not shielded from the Sun’s glare – thus inflating temperatures for that time period. Since this (obvious) oversight was fixed in the past couple of decades, the juxtaposed records appear to invalidate global warming…appear being the operative word. For when the analysis is restricted to just night-time measurements, surely enough the data shows a clear warming trend.
6
With “friends” like Al Gore, the global warming lobby needs no enemies!
Al Gore is a popularizer who happens to make good money from his activities. He has an admirable spirit of capitalist enterprise. Good for him. For the record, I haven’t even watched An Inconvenient Truth in full (and don’t plan to any time soon – it is nothing more than a basic and long-winded intro to the subject). The pilot fishes who drone on about AGW-supporters being “Gore’s dupes” are (US-centric) idiots.
And though Jurassic Park was brilliant and Prey was very good, with “friends” like Michael Crichton the AWG denial lobby needs no enemies!
5
Surface measurements indicating warming are flawed because increasing urbanization over the past few decades skewed the global data upwards, since cities hang on to heat better than the natural landscape.
Intuitively unlikely, because the greatest warming took place over Arctic regions well away from big population centers (global warming is more severe there because retreating ice and reduces snowfall diminishes the albedo of the land, resulting in greater heat absorption). Furthermore, urban heat islands occur mainly at night and are reduced in windy conditions. A study showed that global temperatures have risen as much on windy nights as on calm nights, “indicating that the observed overall warming is not a consequence of urban development”.
4
The global warming alarmists base their theories of man-made climate change on spurious allegations of a “Hockey Stick”, and neglect the dominant role of water vapor as a greenhouse gas.
Late 20th century temperatures are indeed anomalously high relative to the past millennium, thus forming a hockey stick on a temperature over time graph for the period. Evidence for AGW is far more extensive that just this, however.
Although water vapor is indeed acknowledged to be the most important greenhouse gas, it is primarily a feedback because of its extremely short (ie measured in days) residence time in the atmosphere. This means it merely responds to forcings such as CO2 levels or solar radiation. Increased anthropogenic emissions of greenhouse gases will amplify the greenhouse effect, strengthen evaporation and increase the amount of water vapor in the atmosphere.
3
You can’t use computer models to predict something as complex and chaotic as the global climate.
Though the details are indeed hard to capture, it is easy to see that a thicker blanket of greenhouse gases will cause the Earth to absorb more heat and force the climate system into a new, hotter and more energetic equilibrium. It’s also clear that due to changes in albedo, some areas will warm faster than others and global water and air flows will be altered. There is nothing wrong with using computers to model them by solving lots of physical equations – it’s much quicker than doing it by hand (speaking of which, in the 1890’s the Norwegian chemist Svante Arrhenius solved the riddle of the Ice Ages, attributing it to and correctly predicting the lower CO2 levels of that time; using the same method, he forecast a temperature rise of 5-6C for a doubling of CO2 levels, thus almost mirroring the IPCC’s high-end scenarios). Finally, it’s not all computer models, of course – there’s also paleoclimatic studies, which if anything hint at an even more pessimistic state of affairs. Our current atmospheric CO2 level of 384+ ppm was last observed during the Pliocene 3mn years ago, when global temperatures soared by 3C.
2
Climate fluctuations are all down to solar cycles and cosmic rays.
This does not account for the strong warming seen since the 1970’s – as you can see in the graph below, direct measurements of solar output since 1978 show a steady rise and fall over the 11-year sunspot cycle, with no upwards or downward trend.
Though there are arguments about the relative importance of solar forcing in the distant past, it is clear that in the present day its effects have been largely swamped by the sheer amount of CO2 we’ve emitted – though it continues playing an important role as perhaps illustrated by how the 1998-2003 period of mid-latitudinal drought coincided with the peak of the most recent wave.
Similarly, cosmic rays can’t explain the recent warming either.
1
Global warming my ass! There’s a mighty blizzard where I live right now!
Weather is not climate. Using this example as “proof” of the lack of AGW is about as valid as citing a particular heatwave as “proof” for it. That is, not at all.
Furthermore, global warming does not mean absolutely every place on Earth will on warm – due to heat redistribution, some places will warm much more than others, and some might even cool. For instance, the collapse of the ocean conveyor belt in the North Atlantic could theoretically plunge Europe in a new Little Ice Age.
Other objections
Not to worry. Though warming is happening, the IPCC is unduly alarmist since there are many negative feedbacks. Past changes were slow and we will adapt easily over the coming centuries. It will get warmer, nicer and crop yields will soar. And if not, there’s always geo-engineering.
Somewhat more intellectually valid…but still probably wrong.
As mentioned in #8, the IPCC is a slow, conservative institution that has up till now relied on conventional AGW models without accounting for potential catastrophic positive feedbacks (ocean acidification and the dessication of the Amazon rainforest removing vital CO2 sinks; melting permafrost and oceanic clathrates resulting in massive methane releases). Since Greenland and West Antarctica were recently found to be inherently much more unstable than previously thought, large-scale ice sheet collapse and inundations could occur over decades rather than the centuries and millennia projected in IPCC reports. Though there may exist negative feedbacks, such as a drier troposphere or increased cloud formation (yet even here the question of whether it will constitute a positive or negative feedback is poorly understood), they seem easily outnumbered by positively positive feedbacks.
There are plenty of examples of dramatic climatic shifts in Earth history. The Younger Dryas-Holocene transition 11,000 years ago consisted of a series of sudden jumps over a few years. Sea levels can also rise at rates far exceeding those needed for smooth human adaptation. Considering that greenhouse gas levels are rising at rates probably unprecedented in Earth history and that global dimming may have suppressed as much as half of the real warming (thus indicating that the climate sensitivity to CO2 levels used in conventional climate models is dangerously under-estimated), changes in coming decades are likely to be rapid and not for the better. Ocean acidification will finish off the world’s already depleted fish stocks and droughts in today’s temperate regions will break the world’s major breadbaskets; though agriculture can in principle be moved to Siberia and the Far North, the soils there are thin and acidic, and are unlikely to compensate in net terms.
Geo-engineering is, not surprisingly, rather risky – the climate system is not well understood, and fiddling with it could further worsen the problem. And not every country is expected to have absolutely altruistic aims when it comes to tweaking the world’s climate. Yet ultimately, for once we agree – I think it very likely that humanity will be forced into gambling with geo-engineering as the century unfolds. Perhaps climate stability is doomed and geo-engineering – in essense, humanity taking control of planetary ecological services previously provided for free – is already the only realistic choice left.
The hypocrisy of “Earth Day”, and other limp-wristed measures: the one issue where I find common ground with the deniers
Considering that there are 8760 hours in a year, turning off your lights for one of them is going to do absolutely zilch and is nothing more than an empty gesture of false atonement for one’s ecological sins; it is a kind of social placebo to delude people into thinking they’re doing something good for the environment, whereas in reality it is just an escape clause for guilt-ridden liberals that allows them to avoid making the real and initially painful changes society needs to attain long-term sustainability. As such, I join AGW-denying conservatives in boycotting this farce – albeit for obviously diametrically opposite reasons.
Yo Watermelon (green on the outside and red on the inside):
http://mat-rodina.blogspot.com/2009/06/green-new-name-of-totalitarianism.html
Agree or not, there’s an entertainment factor with him (Concerning myself, I’ve yet to march 100% with anyone. That said: IMO, MR serves as a nice counterweight to the bias shown by those propping some other views out there.)
In my limited knowledge of the subject, I think there’s something at play relating to some of the human made air pollution and the increased temperature.
Awhile back, I recall a piece saying that a reverse trend can develop. As explained, the melted ice areas lead to more water, which serves to cool the air temp.
Post 2
Of possible interst, I just received a note claiming that there has been a global cooling trend since 1998.
These links were sent in that note:
http://www.climatedepot.com/a/429/Report-Democrats-Refuse-to-Allow-Skeptic-to-Testify-Alongside-Gore-At-Congressional-Hearing
http://neoavatara.com/blog/?p=4169
A news weatherperson recently said that the cool North American east coast spring weather is likely to even out with a warm September and October.
I recall a prior instance, where a weather expert said that global warming doesn’t necessarily mean hotter summers. Rather, an overall average warmer over the course of a given year scenario. According to this source, the greater disparity is to be found in the night time temperatures. I don’t recall the reasons given for this claimed predicament.
I love watermelons. 😉
Re-“melted ice areas lead to more water, which serves to cool the air temp”. That is nonsense. First, for obvious reasons water is warmer than ice. Second, when there’s ice a lot of the solar energy goes into melting the ice – rather than heating the surroundings. Third, and most importantly, the albedo of ice is around 90% – whereas that of dark blue water is just 20%. This means that open water is going to be absorbing a great deal more heat, rather than reflecting it back into space.
Re-cooling since 1998. That is a good example of selective curve fitting on the part of deniers, because 1998 was an anomalously hot year due to a strong El Niño.
NASA global temperature measurements – note the sudden jump in 1998 by 0.3C and retreat, followed by a resumption of the secular warming trend.
Note that 1998-like temperatures have become the norm since 2002, while 2005 and 2007 were actually slightly higher. In fact, even cherry-picking the starting year to be 1998 will reveal a positive though slow warming trend.
Instead of selectively picking years that are good for your case, it is more appropriate to use the method of moving decennial averages, which shows absolutely no deceleration in global warming.
(Also note that solar intensity has been declining since the early 2000’s, and that aerosol emissions – which partially block out the Sun’s rays – have been rising across east and south Asia. All other things like CO2 being equal, this means temperatures should have, if anything, fallen, in the past few years. But instead they remained on a slightly positively inclined plateau. Given that solar intensity cycle should entering its rising phase right about now, I expect a noticeable intensification of warming in the next five years).
Mark Lynas also has an excellent article on this matter, Has global warming really stopped? This graph shows what kind of pattern linear curve fitting exercises over 8 years can yield for the last 30 years.
Note how the very last “8 year cooling trend” could only be discerned for the 1987-1995 period.
Re-uneven warming. Yes, that’s true. Winters will warm more than summers, and nights will warm more than days. I imagine it’s simply a function of heat diffusion – a thicker greenhouse blanket will serve to increase the Earth’s insulation, meaning less heat is lost to space during periods of darkness.
PS. One last note, this time re-Arctic ice cover. It is certainly in rapid decline, with a tipping point in multi-year ice coverage reached in 2005.
Why is Greenland called Greenland? Why are there places in Europe with wine in the name, in areas where wine normally doesn’t grow? Why have I registered news of ice caps melting on Mars? Didn’t the modern man burst out of the African Savannah and thrived after ice caps melted 10 000 years ago?
I must say I am sceptical of the AGW, but even if it was an uncontested truth, what are we to do? Are we to feel sorry for the industrial revolution that eventually allowed us to use computers instead of pen and paper, commute to work on a car or a train (yes production of trains as well as their powering generates CO2) and go from Europe to America in 8 hours instead of spending days on a ship?
It is sad that the debate is largely political. The environmentalists seem to be just as hypocritical as the conservative deniers. I would certainly not mind if Central London only had electrical cars and buses only. It is sometimes a choke zone with the famed double-deckers being the smelliest of them all but giving people carbon allowances nationwide makes me worried. On the other hand if the conservative deniers had their way London’s choke zone would probably get worse. A compromise between these two discourses would be a blessing.
“Why is Greenland called Greenland? Why are there places in Europe with wine in the name, in areas where wine normally doesn’t grow?”
Well, I’m Norwegian. We gave the names Iceland and Greenland. If you look at pictures from Greenland in summertime, it’s actually green there. But there’s also ice. (The climate on Iceland has always been milder than on Greenland because of the Gulf stream, so if it’s icy there then it’s also icy on Greenland).
As for the Old Norwegian (Norse) word “vin”, it means grass plain. Thus, “Vinland”, the name the Vikings gave to America, means (grass) plain land. You can find the same word in lots of places in Norway, for instance Granvin (pine tree plain) and Björgvin (the older name for Bergen, birch plain).
Besides, everyone in the Norse settlement on Greenland actually died 600 years ago because the climate was so bad. And where are the frozen remnants of shrubs and trees from 1000 years ago if the climate was warmer then?
Face it, you’re in denial, and denial isn’t good for your mental health.
The problem is not with CO2 per se, but the fact that its levels are rising so quickly at rates unprecedented in geological history. This threatens to unleash change so rapid it would be impossible to curb it or adapt to it.
It’s quite possible that within a few tens of thousands of years of the current warming spike, the deserts will green up and the world will become a very lush, hot and sticky place. But it won’t be of much use if in the next century industrial civilization collapses due to the twin shocks of environmental degradation and drawdown of concentrated energy resources.
Congestion charging is entirely separate from the AGW debate. The issue there is excessive smog, which blights the lives of those in its locale but has no major global consequences.
One update: the startling revelation that 2009 may have been the 2nd warmest year on record, even despite that solar radiation is close to its cyclical minimum.
If It’s That Warm, How Come It’s So Damned Cold?
It is a matter of fact that there was a medieval warm period just 800 years ago where temperatures were higher than today. That’s when Greenland got its name and and the vegetation was different here in Scandinavia.