The boundaries of reasonable climate change debate


in Geek stuff, Politics, Science, The environment, Writing

In his well-argued book Why We Disagree About Climate Change, Mike Hulme does a good job of establishing the boundaries of the legitimate debate about climate change and what we ought to do about it:

Many of the disagreements that we observe are not really disputes about the evidence upon which our scientific knowledge of climate change is founded. We don’t disagree about the physical theory of absorption of greenhouse gases demonstrated by John Tyndall, about the thermometer readings first collected from around the world by Guy Callendar, or about the possibility of non-linear instabilities in the oceans articulated by Wally Broecker. We disagree about science because we have different understandings of the relationship of scientific evidence to other things: to what we may regard as ultimate ‘truth,’ to the ways in which we relate uncertainty to risk, and to what people believe to be the legitimate role of knowledge in policy making.

That’s as good a concise summary as I’ve seen. If the people you are debating accept that temperatures are rising, that greenhouse gasses cause warming, and the the climate system may react to human emissions in deeply disagreeable ways, you are within the realm where reasonable discussions can occur. By contrast, if your partners in discussion assert that climate is not changing, greenhouse gasses have nothing to do with it, and that any change will surely be benevolent and gradual… well… here be dragons.

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{ 13 comments… read them below or add one }

Milan November 17, 2009 at 7:03 pm

It would be awesome if someone could take the borders metaphor further and make a map of the climate change debate akin to this map of web communities.

Milan November 18, 2009 at 2:54 pm

To borrow a phrase from William Whewell, there is a ‘consilience of evidence’ when it comes to the science of climate change: multiple, independent lines of evidence converging on a single coherent account. These forms of evidence are both observational (temperature records, ice core samples, etc) and theoretical (thermodynamics, atmospheric physics). Together, these lines of evidence provide a conceptual and scientific backing to the theory of climate change caused by human greenhouse gas emissions that is simply absent for alternative theories, such as that there is no change or that the change is caused by something different.

. November 24, 2009 at 11:21 am

Some comments from Facebook:

Joel McLaughlin Milan – would you extend the parameters of “acceptable debate” to Bjorn Lomborg’s argument which, at its most basic, accepts that climate change is real but the massive global costs of fixing it would be better spent curing malaria, AIDS, and otherwise improving living conditions in developing nations? Given that resources are scarce, Lomborn argues should be allocated efficiently.

Antonia M That would be rather less efficient as the problems you list will be so far exacerbated by the effects of climate change that the most efficient spending for long-term mitigation would be on climate change. Of course, the costs of cultural and economic shift to low-carbon ‘green’ economies is to an extent a one-time hit which should reduce after the initial investment, allowing for investment in global health and development.

Antonia M Just for example. Pouring money into helping people to improve land and housing which may have to be abandoned is hardly efficient. Malaria will need to be tackled as part of approaches to dealing with climate change anyway.

Milan Ilnyckyj If we do not prevent catastrophic climate change, our other undertakings may be moot. The fact that other good actions are less costly does not diminish the necessity of stabilizing GHG concentrations at a safe level.

That said, Lomborg’s position is not outside of the debate, as defined here.

Russil W Brad DeLong summarizes Bjorn Lomborg’s position: “Greatly expanding development aid would do much more good for the world than spending the same amount of money fighting global warming, so let’s do neither.”

Mike S It is worth noting how climate change “deniers” employ traditional neo-con/FoxNews debating strategies (shoot the messenger, throw up a straw man, extrapolate exceptions etc). As this underscores the lack of anywhere near sufficient corporate, political and to be fair social will to mitigate ghg production (just as the post Cold War era … Read moredemonstrated the first world’s will to effect global wealth re-distribution lagged far behind it’s rhetoric/ambitions). Regardless of how “catastrophic” climate change WILL be, the only way our capitalist society CAN address it is by co-opting corporate interests to pursue amelioration efforts (carbon sequestration etc).

Otherwise this debate is just another Scopes Monkey Trial.

. November 30, 2009 at 6:54 pm

Mike S.

Not that I agree with Conrad Black’s ultra right bias at the best of times but I’d like to see/know more data on the following claims:

-“the world has not grown a millidegree warmer since the start of this millennium. And its mean temperature rose by only one centigrade degree in the 25 years before that”

-“the Intergovernmental Panel on Climate Change (IPCC), has estimated that the mean world temperature will increase by between 1.8 degrees C and 4 degrees C in this century . . . [which would] substantially increase world food production” …

-The Polar ice caps aren’t melting at all; the ice sheets over the oceans are, but that over land is actually thickening, so water levels are not being affected (I’d like to see more data on this)

Again though, IMHO his conclusions disregard for example ecological “tipping points” such as ocean currents/salinity as well as the likelihood of catastrophic (to some regions/peoples) consequences from unknowable weather pattern changes.

Freudian slip I guess, link to his article here:

Milan November 30, 2009 at 7:02 pm

”the world has not grown a millidegree warmer since the start of this millennium. And its mean temperature rose by only one centigrade degree in the 25 years before that”

Firstly, the warming trend is clear. Global surface temperature increased 0.74 ± 0.18 °C between the start and the end of the 20th century. The warming is primarily caused by the accumulation of human-generated greenhouse gasses in the atmosphere. This doesn’t mean that every single year will be hotter than the year before, since there are random variations to contend with. It does mean that global temperatures will keep rising as the concentration of greenhouse gasses rise.

-The Polar ice caps aren’t melting at all; the ice sheets over the oceans are, but that over land is actually thickening, so water levels are not being affected (I’d like to see more data on this)

This is patently false. There is extensive melting throughout the cryosphere: the Arctic, Greenland, glaciers, etc. The 2007 Arctic sea ice minimum was the lowest ever. The global glacier index shows that the melting is a widespread phenomenon.

While the melting of floating sea ice doesn’t alter sea level, the melting of ice in Greenland and Antarctica does. Also, as ice melts and reveals darker water or rock, more of the sun’s energy is absorbed. This causes further warming.

Many different sources of information are listed in my climate primer. I really suggest taking a look at some of the IPCC summaries, as well as the websites of places like the Met Office.

Tristan November 30, 2009 at 7:22 pm

“The Polar ice caps aren’t melting at all; the ice sheets over the oceans are, but that over land is actually thickening, so water levels are not being affected (I’d like to see more data on this)”

This is hilarious. The person would like to see more data on the thing they already know. How do they know it? Data? Pure speculation? So, in the first case, they would like to see more data that corroborates the results they’ve got from their existing data (we can ignore the second case). In reality, if they look at more data, their view will be disproven. So, in an ideal world (where they’re right) they’d like to see more data on this, but in this one, they rightly conclude they are better off not seeing any more.

. November 30, 2009 at 7:26 pm
Mike S November 30, 2009 at 7:29 pm

Milan: thanks;
Tristan: Huh?

Milan November 30, 2009 at 7:35 pm

Also, if sea ice was melting while ice on land was accumulating, sea levels would actually be falling.

The IPCC’s Fourth Assessment Report makes clear that:

“Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level”

“Increases in sea level are consistent with warming. Global average sea level rose at an average rate of 1.8 [1.3 to 2.3]mm per year over 1961 to 2003 and at an average rate of about 3.1 [2.4 to 3.8]mm per year from 1993 to 2003.”

Milan November 30, 2009 at 7:38 pm

The Copenhagen Diagnosis, based on peer-reviewed research, says this about ice and sea levels:

“A wide array of satellite and ice measurements now demonstrate beyond doubt that both the Greenland and Antarctic ice sheets are losing mass at an increasing rate. Melting of glaciers and ice caps in other parts of the world has also accelerated since 1990. ”

“Summer time melting of Arctic sea ice has accelerated far beyond the expectations of climate models. This area of sea ice melt during 2007c2009 was about 40% greater than the average prediction from IPCC AR4 climate models.”

“Satellites show great global average sea level rise (3.4 mm/yr over the past 15 years) to be 80% above past IPCC predictions. This acceleration in sea level rise is consistent with a doubling in contribution from melting of glaciers, ice caps and the Greenland and West Antarctic ice sheets.”

“By 2100, global sea level is likely to rise at least twice as much as projected by Working Group 1 of the IPCC AR4, for unmitigated emissions it may well exceed 1 meter. The upper limit has been estimated as – 2 meters sea level rise by 2100. Sea level will continue to rise for centuries after global temperature have been stabilized and several meters of sea level rise must be expected over the next few centuries.”

Milan November 30, 2009 at 7:41 pm

the mean world temperature will increase by between 1.8 degrees C and 4 degrees C in this century . . . [which would] substantially increase world food production”

What is the source on this claim? Most people seem to think 2˚C is the point at which climate change becomes ‘dangerous.’

Mike S December 1, 2009 at 2:09 am

Again, I don’t agree with “Lord” Black on much else and certainly wasn’t vouchsafing his assertions/quotes, only wondering (albeit while being too busy/lazy to look myself) if there was any validity to his claims. Your evidence is much more in line with what I understood/believed and as such serves to support my initial statement regarding debating strategies. (The three types of deceit: Lies, damn lies and statistics).

. December 1, 2009 at 11:52 am

“IN 1974 Henry Kissinger, then America’s secretary of state, told the first world food conference in Rome that no child would go to bed hungry within ten years. Just over 35 years later, in the week of another United Nations food summit in Rome, 1 billion people will go to bed hungry.

This failure, already dreadful, may soon get worse. None of the underlying agricultural problems which produced a spike in food prices in 2007-08 and increased the number of hungry people has gone away. Between now and 2050 the world’s population will rise by a third, but demand for agricultural goods will rise by 70% and demand for meat will double. These increases are in a sense good news in that they are a result of rising wealth in poor and middle-income countries. But they will have to happen without farmers clearing large amounts of new land (there is some scope for expansion, but not much) or using up lots more water (in parts of the world, water supplies are stretched to their limit or beyond). Moreover, they will take place while farmers also wrestle with the consequences of climate change, which, on balance, will do more harm than good to farmland round the world.

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