Tag Archives: PNAS

Roger Pielke Jr. just can’t help himself

At Keith Kloor’s a little while back, I tried to reach something of an amicable cease-fire with Roger Pielke, Jr. I decided to set aside his constant attacks on the scientists who blog at RealClimate in the interest of moving the discussion on mitigation options forward.

Roger, though, just can’t help himself.

Stefan Rahmstorf and Dim Coumou published an article in PNAS examining the influence of warming on the likelihood of extreme temp events, notably in the context of the blistering 2010 Russian heat wave. Roger accuses Rahmstorf of cherry-picking his period of analysis, and then uses this accusation to cast aspersions on the integrity of climate science more generally.

Here is another good example why I have come to view parts of the climate science research enterprise with a considerable degree of distrust.

Climate science — or at least some parts of it — seems to have devolved into an effort to generate media coverage and talking points for blogs, at the expense of actually adding to our scientific knowledge of the climate system. The new PNAS paper sure looks like a cherry pick to me.

What’s Roger’s actual complaint with the Rahmstorf and Coumou paper? Roger writes:

Look at the annotated figure above, which originally comes from an EGU poster by Dole et al. (programme here in PDF). It shows surface temperature anomalies in Russia dating back to 1880. I added in the green line which shows the date from which Rahmsdorf and Coumou decided to begin their analysis — 1911, immediately after an extended warm period and at the start of an extended cool period.

Obviously, any examination of statistics will depend upon the data that is included and not included. Why did Rahmsdorf and Coumou start with 1911? A century, 100 years, is a nice round number, but it does not have any privileged scientific meaning. Why did they not report the sensitivity of their results to choice of start date? There may indeed be very good scientific reasons why starting the analysis in 1911 makes the most sense and for the paper to not report the sensitivity of results to the start date. But the authors did not share that information with their readers. Hence, the decision looks arbitrary and to have influenced the results.

Roger obviously didn’t bother to actually read the paper he’s attacking.

If there’s one thing Roger can’t stand, it’s scientists pointing out that man-made global warming is making certain kinds of extreme events worse. If there’s another thing he can’t stand, it’s the scientists who blog at RealClimate. Put them together, and Roger goes off the deep end.

UPDATE:

Caught out, Roger is predictably moving the goal posts rather than acknowledging that his attacks were unjustified.

First Roger attacked Rahmstorf and Coumou for ignoring the pre-1911 data. He uses this ostensible sin of omission to smear the larger field. Except of course this is completely false. When this is pointed out, Roger moves the goalposts and claims that Rahmstorf and Coumou didn’t actually look at the 1880-2009 data because they didn’t use a linear trend to look at the 1880-2009 data. [Edited to add: this is an implicit rather than explicit claim by Roger, as we’ll see.] The paper is quite clear about making the case that the data (for 1911 on and for 1880-2009, for synthetic data and actual obs) are better described by a nonlinear trend, and the passage I cited in the original point makes it clear that the 1880-2009 data were analyzed using a nonlinear trend.

Roger then has the chutzpah to claim that Rahmstorf has “confirmed” Roger’s “critique”:

It would be quite shocking indeed if Rahmstorf actually “confirmed” Roger’s critique. But of course he did no such thing. When Roger claims “they did not run the analysis from 1880″, he’s completely wrong (see the above excerpt from the paper). When he claims Rahmstorf has “confirmed” his critique, what Roger really means is that Rahmstorf confirmed that they did not look at the 1880-2009 data using a linear trend- which, again is perfectly clear in the paper itself. So it has gone a bit like this:

Roger: “They didn’t look at the whole record!”

Uh, yes, they did.

Roger: “No, they didn’t perform The Analysis* for the whole record!”

*Valid only for Roger’s definition of “The Analysis”.

Roger has taken a concession that the paper did not do something it never claimed to have done and declared victory. Perhaps at some point he’ll realize that claiming something does not make it so.

FURTHER UPDATE:

Roger has repeatedly made the claim that Stefan Rahmstorf “confirmed” Roger’s critique. Roger’s original critique was that the 1880-1910 were not analyzed by Rahmstorf and Coumou. This original critique is patently false, as the paper shows in the excerpt I posted above.

The basis for Roger claiming that Rahmstorf “confirmed” his critique was Rahmstorf stating that a linear trend was not used in analyzing the 1880-2009, as is clear in the paper.

I let Rahmstorf know that Roger was claiming Rahmstorf confirmed Roger’s critique. Rahmstorf responded:

That is truly bizarre, since what I responded to Pielke (in full) was: “We did not try this for a linear trend 1880-2009. The data are not well described by a linear trend over this period.” As shown in the paper and above, our main conclusion regarding Moscow (the 80% probability) rests on our Monte Carlo simulations using a non-linear trend line, and of course is based on the full data period 1880-2009. Nowhere did we “use 1910-2009 trends as the basis for calculating 1880-2009 exceedence probabilities”, and I can’t think why doing this would make sense. Faced with this kind of libelous distortion I will not answer any further questions from Pielke now or in future. As an aside, our paper was reviewed not only by two climate experts but in addition by two statistics experts coming from other fields. If someone thinks that using a linear trend would have been preferable, that is fine with me – they should do it and publish the result in a journal. I doubt, though, whether after subtracting a linear trend the residual would fulfill the condition of being uncorrelated white noise, an important condition in this analysis.

And on a final note, Pielke actually had the nerve to write this:

You may read the paper differently than I do and you may interpret Rahmstorf’s comments differently than I do — happens all the time on these blogs. In such a situation I propose that the best course of action would be to solicit further information to resolve the dispute. Or, perhaps you’d rather we just make comments about motives and call each other names

This, after he wrote a post impugning the field over an “omission” that existed only in his mind. Unreal.

Roger Pielke Jr. crying wolf. Again.

It seems Roger Pielke Jr. is in a little tizzy about a paper that was just published in PNAS by Anderegg et al., which demonstrates that those unconvinced by the mainstream climate science narrative are not only a minority in the community, but a disproportionately under-published, under-cited, and elderly one at that.

Roger claims that this paper is a “black list” and explicitly equates it with the McCarthy witch hunts of the 1940s and 50s which ruined the lives of thousands of people.

Is the paper, in fact, “a new black list”? For a “list” it’s quite a curious one, as it does not name a single person. Rather Roger conflates the paper itself with information taken from a blog post, appearing nowhere in Anderegg et al.

Roger then whines that his dear ol’ dad shouldn’t be categorized as someone “Unconvinced” by the IPCC view of climate change. He asks:

What sort of views does my father hold that would qualify him to lead the “climate skeptics” list?

Roger suggests that the criteria are perversely Kafkaesque- “it is complicated, trust me”; “there is no better evidence of your denier credentials than denying that you are a denier. Trust me”; etc.*

He claims that someone could be placed on the paper’s imaginary list for doing nothing him or herself, merely appealing to über-denialist Senator Inhofe: “it turns out that you don’t even have to sign an open letter or argue against immediate cuts for emissions. You can simply appear unwillingly on Senator James Inhofe’s list.”

What does the paper actually say?

We define UE [Unconvinced] researchers as those who have signed reputable statements strongly dissenting from the views of the IPCC.

Does Roger Pielke Sr. fall into that category? Judge for yourself.

Still, that was back in 1992. Perhaps more recently Pielke Sr. has changed his mind about the IPCC view of climate change? Let’s let Pielke Sr. speak to that in his own words (emphasizing underline in the original):

[I]n the Pielke et al 2009 EOS paper we present evidence to show that this IPCC conclusion [about the relative influences of CO2 and other climate forcings] can be rejected.

The facts that: there is no “list” in the paper; his father unquestionably meets the criteria of the paper to be labeled Unconvinced; and far from suffering any sort of McCarthyite ruining of their lives, people like his father are actually invited on major media outlets for television interviews don’t play as well in Roger’s fevered persecution narrative, with it’s hysterical invocation of McCarthyism. But facts aren’t really something that appear to trouble Roger much.

And of course Roger has turned whining about imagined persecution into something of a second career.

*In my experience, the amount of trust someone deserves is inversely proportional to the frequency with which they demand it while offering no corroborating evidence.

UPDATE: Just to be clear about what this paper does and does not do (prompted by a comment)-

It does not list names of individuals. It used a database of letters that individuals voluntarily, publicly signed to examine relative citations, publications, etc. No names appear in the paper itself. The only names used (none were actually listed) to generate data were taken from preexisting lists.

If Roger is so aghast at the thought of creating a catalog of names that could be used as a “black list”, his complaint would properly lie with the individuals- like his father- who actually decided to create them, not the authors of this paper. Assuming that the outrage was genuine in the first place, of course.

Can we expect Roger to contact the signatories and publishers of these lists and accuse them of fomenting McCarthyism?

LATER UPDATE: Roy Spencer has outdone Roger, equating the use of publicly signed open letters with the abduction, torture, and murder that took place under the Spanish Inquisition.

The age of polar bears

In a paper recently published in PNAS entitled “Complete mitochondrial genome of a Pleistocene jawbone unveils the origin of polar bear” Charlotte Lindqvist and coauthors performed genomic sequencing and analysis on the oldest polar bear fossil discovered to date, finding that it was surprisingly genetically and temporally proximate to the brown and polar bear’s last common ancestor:

Intriguingly… this ancient polar bear, which exhibits a very short branch length, lies almost directly at the branching point between polar bear and the genetically unique clade of ABC [from the Admiralty, Baranof, and Chichagof islands -TB] brown bears (Fig. 3B). Thus, both cladistically and anagenetically, this ancient specimen existed very close to the most recent common ancestor of polar bears and brown bears.

Phylogenetic network of complete mt genomes (excluding the VNTR repeat) of 11 polar and brown bears based on Neighbor-Net analysis with LogDet distances (see scale bar).

Along with stratigraphic dating of the fossil to ~110-130 kya (thousand years ago), their work enabled them to peg the “birth” of polar bears at ~150 kya, meaning that they survived the Eemian (AKA Riss-Würm, Ipswichian) interglacial:

The discovery of this jawbone confirms that the polar bear was already a distinct species at least 110 kya…

…we estimated the mean age of the split between the ABC bears and the polar bears to be 152 ky, and the mean age for all polar bears as 134 ky, near the end of the Eemian interglacial period and completely in line with the stratigraphically determined age of [this fossil].

This finding, which should have been celebrated as a coup for our knowledge of polar bear evolution, has instead become yet another target of global warming denialism.

It has been touted by those who refute the reality of and/or problems posed by man-made (anthropogenic) warming of the climate as evidence that anthropogenic warming poses no threat to polar bears, as they had survived previous episodes of warming before. And some of these claims actually go back to the jawbone’s initial discovery, years earlier.

A similar claim has been made that anthropogenic warming poses no threat to polar bears because their numbers are actually increasing.

Let’s take these in reverse order. UCN/SSC Polar Bear Specialist Group Chair, Dr. Andrew Derocher:

The various presentations of biased reporting ignore, or are ignorant of, the different reasons for changes in populations. If I thought that there were more bears now than 50 years ago and a reasonable basis to assume this would not change, then no worries. This is not the case.

The bottom line here is that it is an apples and oranges issue. The early estimates of polar bear abundance are a guess. There is no data at all for the 1950-60s. Nothing but guesses. We are sure the populations were being negatively affected by excess harvest (e.g., aircraft hunting, ship hunting,self-killing guns, traps, and no harvest limits). The harvest levels were huge and growing. The resulting low numbers of bears were due only to excess harvest but, again, it was simply a guess as to the number of bears…

Comparing declines caused by harvest followed by recovery from harvest controls to declines from loss of habitat and climate warming are apples and oranges. Ignorant people write ignorant things.

Derocher is saying that such claims are at heart a combination of two forms of fallacious reasoning, the cherry pick (polar bear populations are increasing during a certain interval) and the non sequitur (therefore they are not threatened by anthropogenic warming). The claim that polar bear populations are rising only holds true for a subset of populations, and only does so then because the period is selected to begin at a low point brought about by unregulated hunting. Once hunting restrictions were put in place, populations began returning to their historic norms. This dynamic can be seen in recent assessment reports of the two Alaskan polar bear stocks-

US Fish and Wildlife Service’s January 2010 Southern Beaufort Sea (SBS) Polar Bear Stock Assessment Report:

Prior to the 20th century, when Alaska’s polar bears were hunted primarily by Natives, both the Chukchi/Bering seas and Southern Beaufort Sea stocks probably existed near carrying capacity (K). Once harvest by non-Natives became common in the Southern Beaufort Sea in the early 1960s, the size of these stocks declined substantially (Amstrup et al. 1986, Amstrup 1995). Since passage of the Marine Mammal Protection Act (MMPA) in 1972, both Alaska polar bear stocks seem to have increased…

The January 2010 Chukchi/Bering Seas (CBS) Polar Bear Stock Assessment Report similarly states:

Prior to the 20th century, when Alaska’s polar bears were hunted primarily by Alaskan Natives, both stocks probably existed at near carrying capacity (K). The size of the Beaufort Sea stock declined substantially in the late 1960’s and early 1970’s (Amstrup et al. 1986) due to excessive sport harvest. Similar declines could have occurred in the Chukchi Sea, although there are no population data to support this assumption. Since passage of the MMPA, the southern Beaufort Sea population grew during the late 1970’s and 1980’s and then stabilized during the 1990’s (Amstrup et al. 2001b).

So in these stocks, polar bear numbers are up from a low brought about by unregulated, non-Native hunting.  But what are the current population trends? SBS Stock Assessment Report [following emphases mine]:

The Southern Beaufort Sea stock experienced little or no growth during the 1990’s (Amstrup et al. 2001b). Declining survival, recruitment, and body size (Regehr et al. 2006, Regehr et al. 2007), and low growth rates (λ) during years of reduced sea ice during the summer and fall (2004 and 2005), and an overall declining growth rate of 3% per year from 2001-2005 (Hunter et al. 2007) indicates that the Southern Beaufort Sea population is now declining.

CBS Polar Bear Stock Assessment Report:

Based on demographic data 2001 to 2006, the overall population growth rate in the Southern Beaufort Sea population declined approximately 0.3% per year (Hunter et al. 2007). Until 1992 it is likely that the Chukchi/Bering seas stock mimicked the growth pattern and later stability of Southern Beaufort Sea stock, since both stocks experienced similar management and harvest histories. However, since 1992 the CBS population has faced different stressors than the SBS population. These include increased harvest in Russia (150 – 250 bears/yr) (Kochnev 2006, Ovsyanikov 2006, Eduard Zdor personal communication) and greater loss of summer sea ice habitat from global warming (Overland and Wang 2007), which suggest that using the growth rate for the Southern Beaufort Sea may not be applicable. The status of the Chukchi/Bering seas stock was listed as data deficient (Aars et al. 2006) due to the lack of abundance estimates with measurable levels of precision. The population is believed to be declining and the status relative to historical levels is believed to be reduced based on harvest levels that were demonstrated to be unsustainable in the past.

Moreover, the long term concern about polar bear survival is not based solely on whatever the current population trend happens to be (whether one of increase or decrease), nor only on the effects of the anthropogenic warming that they have already experienced. The concern is based upon not only existing stressors but also the additional threat posed by future anthropogenic warming on top of those already in play.

A similar case of fallacious reasoning is at work in claims that polar bears surviving the Eemian interglacial means that they aren’t threatened by anthropogenic warming- i.e., “If polar bears survived the warming of the previous interglacial, they aren’t threatened by anthropogenic warming.”

How does the Eemian compare in terms of climate? At its warmest, modeling and paleoclimatic evidence (e.g. here) suggest that the Eemian was as much as 1-3°C warmer in the Northern Hemisphere vs. the preindustrial Holocene climate, with even higher seasonal values occurring at high latitudes- perhaps 4-5°C warmer in the Arctic summer, with a concomitant substantial reduction in seasonal sea ice (e.g. here).

So, the thinking apparently goes, if polar bears survived that, a little man-made global warming should be a walk in the park, right?

Not so much. As in the Eemian, expected anthropogenic warming will not be globally uniform, and polar amplification will ensure that the Arctic warms up more and more quickly than the global average. The mid-range of the fossil fuel intensive end (A1FI) of the AR4 projections for the global average by the end of this century is ~4°C, which translates to July Arctic temperatures ranging in some areas more than 5°C higher than their modern (2000 CE) average values. Seasonal sea ice reductions equivalent to or greater than Eemian maximums are expected by the end of this century, and perhaps in as little as 30-50 years (e.g. here, here, here).

Whereas Eemian polar bears had thousands-to-tens of thousands of years to adapt to changes in their environment, today’s polar bears are facing equivalent or greater changes on time scales at least an order of magnitude more rapidly, on top of their reduced population levels and other modern stressors like pollutants.

As in many aspects of the physical world, it’s not simply the amount of something, it’s also the rate and other variables that make a difference. I drink about 2 liters of water a day. If I were stupid enough to increase my rate of water intake by an order of magnitude, I’d be risking death. Expecting polar bears to shrug off unchecked global warming because they survived the Eemian is no less foolish- and may have an equally lethal result.

Ipswichian

Reductions in US GHG emissions through household actions

Amongst discussions of US emissions regulation and the viability of individual action as a response to the climate problem, a recent study caught my eye which is both relevant and encouraging.

Deitz et al. have an open access paper in PNAS entitled Household actions can provide a behavioral wedge to rapidly reduce U.S. carbon emissions. They employ a conceptual model developed by Pacala and Socolow called stabilization wedges, and examine what reductions can be achieved through relatively simple and low-cost changes in US household behavior.

They break these changes into five broad categories:

W (home weatherization and upgrades of heating and cooling equipment); E (more efficient vehicles and nonheating and cooling home equipment); M (equipment maintenance); A (equipment adjustments), and D (daily use behaviors).

Click to embiggen

These actions represent gains in efficiency and/or reduced energy consumption (vs. the adoption of supplemental solar or wind energy, for example).  These are arguably the lowest hanging fruit of all in terms of emissions cuts as they not only reduce GHGs, but end up saving the consumer money in the long term as well. Or as Amory Lovins has put it, energy efficiency is “better than a free lunch, it’s a lunch you get paid to eat”.

All said, these reductions would result in a yearly carbon savings of 123,000,000 metric tons and could account for up to 3 wedges (or as much as 44%) of apportioned US emissions reductions over ten years, a stunning result. In contrast to stunt low-GHG lifestyles, a campaign to provide government incentives and alter social attitudes towards such behavioral changes could be tremendously effective- achieving (as Deitz et al. point out) more of a GHG savings than eliminating all emissions from “the petroleum refining, iron and steel, and aluminum industries, each of which is among the largest emitters in the industrial sector.”

[Note: See Deitz’s response below.] Although it could conceivably have been included in such an evaluation, I was unsurprised to see discussions of relatively small changes in diet and their respective emissions impact (among other benefits) left out- I would wager this remains too politically unpopular a topic to seriously discuss at a US-wide policy level, even as the topic is being discussed abroad [UPDATE: who could have possibly foreseen such a reaction?].

[UPDATE: I see Dot Earth covered this one as well. Anyone confused by their numbers vs. mine (i.e. 8% vs. 44%), note that they’re describing overall change to emissions while I was talking about percentage of emissions reductions goal.]

[LATE UPDATE: Lead author Tom Deitz has responded in the comments, noting that their paper is also available here and explains that the diet issue was avoided not for political reasons but because the necessary lifecycle accounting was beyond the scope of their study.]

Darlings of the denialosphere reaffirm that, underlying natural variability, the man-made global warming signal is real – and say it’s accelerating

OR: DENIALIN’ AIN’T EASY

Monday, like any other day, was a pretty miserable one to be a climate denialist.

As with Intelligent Design proponents (née Creation Science proponents, née Creationists), 9/11 Truthers, the anti-vax loons, et al., in order to give themselves the appearance of credibility, climate denialists have to simultaneously wrap themselves in the vestments of science while rejecting what the science actually says. It is, as you can imagine, an entirely unconvincing act.

The evidence that man-made processes, notably our emissions of greenhouse gases, are warming the planet and altering the climate has grown astoundingly in the 30 years since the National Academies of Science-commissioned Carbon Dioxide and Climate: A Scientific Assessment. Each week, evidence pours in in the form of primary scientific literature documenting the changes to our climate, their already-significant impacts on plants and animals, and so on. Calls to cut GHG emissions are heard from the science academies of nations around the world. There is, to put it mildly, a stunning lack of scientific evidence suggesting we should keep on as we are and expect no fallout.

Hence you get Serious Thinkers like Jonah Goldberg asserting that, despite a study’s lead author’s clear statement that his paper on sunspots has nothing to do with anthropogenic warming, we should in fact believe it has something to do with- and indeed undermines- our understanding of anthropogenic warming. There are only a few avenues open to denialists who seek to keep up the charade that they care about science: attempt to discredit the actual science and substitute their own bloggy version, champion studies that are tremendously flawed, clumsily misrepresent papers that don’t actually challenge the undeniable reality of anthropogenic warming, or some combination thereof.

Enter Kyle Swanson and Anastasios Tsonis.

Swanson and Tsonis have been exploring an apparent series of climatic regime changes (marked by the synchronization, coupling, and decay on multidecadal scales of naturally variable climate features) superimposed on the long term warming trend of the 20th century (e.g. here and here). They think that the existence of these regimes might better explain some features of the temperature record than the mechanisms usually invoked (e.g. mid-century cooling via sulfate production). Naturally, their hypothesis has been seized upon by a denialosphere desperate for anything that seemingly challenges the mainstream on global warming (e.g. here, here, here, etc.) and touted as evidence that “the science isn’t settled”, “nature not humans controls the climate”, and similar rubbish. Thus Swanson and Tsonis became a sort of fig leaf behind which the denialists sought to conceal their anti-science beliefs.

For its part, the reaction from the larger climate science community has been along the lines of, “interesting, but absent any physical explanation, not entirely convincing at the present” and it was repeatedly pointed out that Swanson and Tsonis’s work wasn’t saying anything like what the denialists imagined it to. In the interests of clarifying some misconceptions, RealClimate recently hosted a guest post by Swanson. There, Swanson points out that those attempting to use any findings of increased influence of natural variability over the 20th century as a rebuttal to concerns over enhanced greenhouse warming couldn’t be more wrong; a climate system more sensitive to natural variability is one also that will respond more strongly to anthropogenic forcing:

A climate that is highly sensitive to radiative forcing (i.e., responds very strongly to increasing greenhouse gas forcing) by definition will be unable to quickly dissipate global mean temperature anomalies arising from either purely natural dynamical processes or stochastic radiative forcing, and hence will have significant internal variability. The opposite also holds.

In a new paper published this week in the early edition of the journal PNAS entitled Long-term natural variability and 20th century climate change (or here), Swanson and Tsonis, along with coauthor George Sugihara (from here on “SGT”), have attempted to address more explicitly the mechanism by which this enhanced natural variability hypothesis might work and its impact on the 20th century temperature record.

In the paper, SGT make a point to highlight the same argument made by themselves and others in response to specious (denialist) claims that their findings mean anthropogenic warming is as a result less of a concern:

Viewed in this light, the lack of modeled compared to observed interdecadal variability may indicate that current models underestimate climate sensitivity.

Reiterating that a climate system highly sensitive to natural variability is one also that will respond more strongly to anthropogenic forcing. A higher climate sensitivity would mean, for example, that the IPCC estimates of ~3°C warming in response to doubled CO2 are too optimistic. Continue reading

A case of the Mondays

The August 11th early edition of PNAS is, to put it mildly, a bit of a downer. New papers point to a gloomy future for ocean life (Jackson 2008), amphibians (Wake and Vredenburg 2008), and the trees of the Amazon (Hubbell et al. 2008). Surprisingly, Paul “Malthus was an optimist” Ehrlich’s piece is perhaps the least depressing- suggesting that a Pacala/Socolow type wedge strategy of massively mobilizing existing science and technologies could successfully mitigate much of the longterm danger facing biodiversity due to actions this century (Ehrlich and Pringle 2008).

It’s worth noting that in all of these papers, climate change is presented as but a single component of overall anthropogenic influence on the environment. That’s something that gets lost sometimes in the meta-narrative of a media subject to the tyranny of the story peg, but something that strengthens the case for mitigation rather than weakens it. Although some environmentalists and activists would like to make the issue as simple as tailpipe GHG emissions directly causing extinctions (and indeed sloppy reporting can paint global warming as the cause of nearly everything), the situation is far from that simple, and more precarious because of it.

Large swaths of our biosphere are already being stressed to the point of extinction by more familiar threats- destruction of habitat, introduction of invasive species, overuse of resources, local pollution, etc. Combine these factors with natural predation, competition for resources, disease, etc. and it easy to see why even a moderate amount of climate disruption due to anthropogenic emissions can have an effect far larger than it would on its own. Chytridiomycosis, for example, is sometimes cited as an alternative to global warming in precipitating the extinction of the Golden Toad (Bufo periglenes), but this ignores the strong implication that climate change is creating a more favorable environment for the chytrid fungus in some tropical areas where amphibian populations are at greatest risk, in addition to directly threatening the toad by increasing cloud height and reducing moisture deposition (Pounds et al. 2006). In this case, the addition of a modest amount of warming into the equation seems to have been enough to drive the Golden Toad over the edge into extinction, even if it was not the sole, direct cause.

Anthropogenic, emissions-driven climate change does not have to lead to an increase of 4°C+ or spawn evermore Cat 5 hurricanes in order to massively, negatively impact an environment already being pushed to the brink. The upshot is that we while we may already be committed to additional warming, we have the knowledge and technology to reduce other anthropogenic (and if necessary natural) stressors while we also begin the process of emissions reductions. Provided of course that we are not drawn into the false dilemma fallacy so favored by the delayers.