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Climate Change 

May 17, 2013

The Other 99%: Celebrating Endangered Species Day

Tanystropheus
We celebrate Endangered Species Day on May 18th. We have reasons to celebrate because though human activities have many species on the brink of annihilation, there is serious commitment ranging from individuals to nations states to both protect those species, and to bring them back from the brink. Nevertheless, the threats to species are growing in number and severity. The following essay will not be cheery, and I hope to convince you that avoiding extinction is a very difficult problem and its consequences are severe. I will therefore begin with the optimistic message: The fact that we humans are the cause of the current species crisis is reason to be hopeful. We cannot save species from devastating physical events such as asteroids and volcanoes, but we can save them from ourselves.

It is well known, based on the fossil record, that the majority of species that have ever existed are now extinct. That’s why you will often hear the phrases, “99% of all species that have ever existed are extinct”, and “extinction is the fate of all species”. Let’s examine these statements for a moment. The first is a somewhat factual measure. No one knows if 99% is the correct figure, but we do know that most species that have ever evolved are now extinct. The reason that the Earth is still teeming with millions of species is, of course, because new ones evolve all the time. The second statement is a bit more problematic though; it’s an assumption, not an observation. To scientifically predict the fate of a thing is to presume that we know and understand all the forces controlling it, and that we know what those forces will do in the future. That of course is certainly not the case here. Even more problematic is the fact that even though changing conditions might cause the extinction of a species, changing conditions also drive evolution! In a sense then, extinction is an evolutionary failure. Okay, it’s not quite that simple, but here’s what I mean. Under what circumstances does evolution fail and lead to extinction?

Such cool headgear (Wikipedia)

Such cool headgear (Wikipedia)

Imagine that you are lucky enough to be a spectacular dinosaur living somewhere on the planet 65 million years ago (some of you know what’s coming…). You are the culmination of archosaurian evolution which got started some 175 million years before, in the wake of the devastating end Permian mass extinction. Unfortunately for you, today is the day that a giant asteroid from outer space collides with the Earth somewhere in the vicinity of today’s Yucatan Peninsula. The energy released by the collision is some 19,000 times greater than the explosive force of the world’s current nuclear weapons arsenal. The survival of your species depends on enough of its members surviving the ensuing environmental catastrophe, and that could happen in two ways. First, you could have the individual capacity to acclimatize to the changes happening around you. For example, it’s possible that many animals survived by taking advantage of underground dwellings, or their abilities to enter into some sort of resting phase. Second, your species could adapt to the changes. In either case, evolution is at work. The capacity to acclimatize is generally a function of the physiology, behaviors and so on that evolved in your ancestry, while adaptation is the result of current genetic variation and natural selection. Extinction will occur if the magnitude or severity of the environmental changes overwhelm your capacity to acclimatize, or your species’s capacity to adapt (e.g. limited genetic variation) or the rate at which it can adapt. Sadly, non-avian dinosaurs neither acclimatized nor adapted, and today exist only as fossils or in the movies. This has happened repeatedly during the history of life. The end Permian mass extinction of 251 million years ago resulted from overwhelming changes of climate, ocean conditions and atmospheric composition. Ultimately, it was driven by massive volcanism in the Siberian region. The mass extinction 65 million years ago was also the result of significant changes in climate, driven by massive volcanism in India’s Deccan region, coupled with that rock from outer space. That collision would have heated large regions of the North American continent, darkened the skies for months, and subsequently cooled the planet for years.

Today the Earth is on the brink of another mass extinction, but this time we humans are the volcanoes and asteroids. Driven by an exploding population and rapidly increasing rates of resource consumption, we are sequestering landscapes and habitats or destroying them outright, over-exploiting wild species, and changing the climate at rates that overwhelm the ability of species to acclimatize or adapt. Climate change is by far the most dangerous of the bunch because while we can confer protection from exploitation on landscapes and species, we cannot protect them from changing temperatures, seasons, patterns of rainfall and ocean acidification. Even as we work to curb our climate-changing habits by developing alternatives to fossil fuels, engineering more efficient transportation systems and planning our own socio-economic adaptations, species must also acclimatize and adapt. This will be accomplished either by species movement to track favourable climates, or staying put and acclimatizing and adapting. Unfortunately, there are severe limitations to each.

There is no doubt that many species are now on the move in response to climate change. Most pronounced are expanding ranges of many tropical or warm temperate species as tropical air and water temperatures expand outward from the equator. Examples include the Humboldt squid, normally restricted to waters of the tropical and south eastern Pacific, but is now a frequent and abundant species in waters as far north as Alaska. The increasing incidence of normally tropical diseases such as West Nile virus are also testimony to increasingly favourable conditions in regions that were previously too cool. Habitat expansion for those species occurs at the expense of other habitats of course. Regions of cooler temperatures are shrinking, leaving no room for migration of the species there. In alpine regions many species are moving upward, but of course can go no higher than the highest mountains. Polar species are not only faced with changing habitats, such as the drastic reductions of summer ice coverage in the Arctic Ocean, but must deal with the newcomers from warmer regions. And therein lies the another limitation. Given the rate at which conditions are changing, on a timescale of decades, there is absolutely no guarantee that a species will have the genetic capacity to evolve and adapt rapidly enough to survive. For scientists, the answer will in many cases be a wait and see experiment. The results will no doubt be intriguing and valuable, but that will be small comfort for any species that come up short.

There is a final limitation, and that’s based on relationships. No species exists in isolation, humans included. Every species interacts with other species and is dependent on other species for survival. That’s how we evolved! Species adapt to changing conditions, and in turn their new adaptations alter the world around them. We are united in a gigantic global network of biological relationships which includes production, predation, competition, parasitism, reproductive services, habitat engineering, and recycling. When species move, when they change, some of those relationships are disrupted. Even now we see the synchrony of spring flowerings, fruitings, nesting etc. becoming de-synchronized. And these relationships are not formed on the fly! They are the evolutionary result of species interactions occurring over time, and indeed the systems or networks that they produce are likewise products of evolution. In studies by myself and colleagues (see Further Resources below) of ecosystems in the wake of the end Permian mass extinction, we found that while the number of species recovered very quickly within a million years of the extinction, the networks of relationships so formed were unstable and weak. It took several million more years before system robustness recovered to pre-extinction levels. And during that time, the dominant vertebrates of the land, the ancient relatives of humans and other mammals, were eclipsed by the rise of the dinosaurs. They would have to wait another 175 million years before another opportunity for dominance would present itself. Those timescales would try the most patient of humans.

So what do we do? I believe that we must become better stewards of the planet. I know that some will argue that we should not be stewards at all, but consider this. Humans already occupy to varying extents some 48% of the planet’s dry surface and we directly utilize or otherwise co-opt 24-41% of global photosynthetic production. We are already stewards of the planet! The real problem is that we are rather poor stewards. We either absolve ourselves collectively of this responsibility or we embrace it. The choice is ours, and the fates of an uncounted number of species now depend on us. Therefore, let us indeed celebrate Endangered Species Day, for while it is a reminder of the dire state of our environment, it also recognizes our acceptance of an awesome responsibility.

Further Resources
Some of these are fairly technical (sorry!), but please feel free to submit any and all questions.

 


Filed under: Climate Change — Peter @ 11:13 am

March 12, 2013

Global temperatures are close to 11,000-year peak

News from Nature.
“Global average temperatures are now higher than they have been for about 75% of the past 11,300 years, a study suggests. And if climate models are any indication, by the end of this century they will be the highest ever since the end of the most recent ice age.”


Filed under: Climate Change — Peter @ 6:52 pm

March 8, 2013

Ocean Acidification

It’s no longer news that warming temperatures are not the only negative consequence of the increasing concentrations of atmospheric greenhouse gases. Add increased weather variance, changing rainfall patterns and sea level rise to the list. One of the most dire impacts, however, and one that seems to be rather inescapable, is ocean acidification. Ocean waters become more acidic as the amount of carbon dioxide dissolved in the water increases. This has been happening as the amount of carbon dioxide in the atmosphere has been increasing. The oceans have a tremendous capacity to absorb carbon dioxide, but we are rapidly exhausting that capacity. When the gas dissolves in seawater, it triggers a complicated set of reversible chemical reactions, sort of chain from carbon dioxide, to carbonic acid, to bicarbonate and hydrogen ions, to carbonate and more hydrogen ions. Normally, the system is driven toward the carbonate end of things, resulting in very moderate acidity (high pH, which is a measure of the concentration of reactive hydrogen ions in the water), and conditions suitable for the precipitation of carbonate minerals, most notably calcium carbonate. Calcium carbonate is the material used most commonly by marine organisms for building skeletons, for example animals such as corals, snails, clams, and numerous microscopic plankton. One of the great dangers that we face as the oceans become more acidic is that all these organisms, and the ecosystems that they are parts of, will decline.

The Science Today team at the California Academy of Sciences recently produced a very nice short video discussing these topics. View the full video, and leave comments here, or for the Sci Today team!


Filed under: Climate Change — Peter @ 2:40 pm

February 28, 2013

Columbia Journalism Review affirms coverage of “secretive climate-denial funding network”

(copyright The Simpsons?)

A new report from the CJR seconds an earlier report from The Guardian in the United Kingdom, that substantial millions of dollars are being donated anonymously, and often secretly, to support dissemination of the denialist point of view regarding climate change and global warming. One could also argue that large sums are donated to groups dedicated to getting the word out that the scientific evidence is overwhelming and that action must be taken. As noted in the reports, however, those groups tend to be more transparent. Regardless, advocacy for or against a problem is meaningless if there is firm evidence against your stance. Given the lack of any scientific support for a denialist position, one must therefore wonder about the motives.

A very nice report on the reports can be found in this article from Physics Today.


Filed under: Climate Change — Peter @ 10:26 pm

February 13, 2013

Cryosat spots Arctic sea-ice loss in autumn

Arctic iceThe dramatic recent decline in Arctic sea-ice cover is illustrated in new data from Europe’s Cryosat mission. The data currently consists of only a few years right now, so it’s not possible to say if this is a trend or not. Importantly, however, it does reveal that winter ice growth is not compensating for the increasingly dramatic loss of summer ice that is now, unfortunately, a well established trend. Also, the big differences already detected by this mission points to a high variability of seasonal ice growth and loss, a variability that could be indicative of a system in transition. Read more here.


Filed under: Climate Change — Peter @ 9:58 pm

November 1, 2012

SFGate: N.Y.’s Cuomo links storm, climate change

Prominent climate scientists were unwilling Wednesday to do what New York Gov. Andrew Cuomo did: blame climate change for the devastating storm known as Sandy that wreaked havoc along the Eastern Seaboard. Read the full article here.


Filed under: Climate Change — Peter @ 9:09 pm

October 31, 2012

It’s time

President Obama, it’s time to talk about climate change.

Partially submerged yellow cabs in a parking lot in Hoboken, N.J., on Tuesday. (Charles Sykes/Associated Press)

Partially submerged yellow cabs in a parking lot in Hoboken, N.J., on Tuesday. (Charles Sykes/Associated Press)


Filed under: Climate Change — Peter @ 2:26 pm

September 7, 2012

Arctic ice melting at ‘amazing’ speed, scientists find

The declining areal cover and thickness of summer ice in the Arctic Sea continues, with 2012 shaping up to be another record-breaking year. Read the BBC summary here. These declines are of course predicted as a consequence of warming air temperatures due to anthropogenic global warming, but what really alarms me is the speed at which it is progressing. Basically, ice loss is accelerating every year, and has been since we noted a drastic speed-up in 2007. The consequences of an ice free Arctic will be far-reaching. First there are physical consequences. Losing the ice reduces the regional albedo, and creates a feedback that will continue the acceleration. Furthermore, thinner ice means that more light penetrates into the depths, warming the water beneath. The region’s biology is also changing, and this too will accelerate. Warmer, brighter waters will most likely increase biological productivity in the Arctic Sea, which will be good news for some human industries, but isn’t good news for all. The opening of the seaway, and increasing productivity, will change the ecology of the region, displacing many species, while allowing invasion from neighbouring waters in the northern Pacific and Atlantic. Geerat Vermeij and I wrote a predictive paper about this, oh, 4 years ago now. It is difficult to predict exactly what the consequences of those changes will be because of the problem’s complexity, but they will be large. And finally, of course, opening the sea exposes many many resources of interest to humans, including fossil fuel deposits and shipping lanes. Let the wrangling begin. Noe note though is that the Arctic Sea ice melting will not contribute significantly to sea level rise; that ice is already in the ocean.

Our planet continues to change in response to global warming, and it seems that some of those changes are accelerating. I cannot be certain, and we will only know this in hindsight, but in my opinion we are beginning to cross thresholds. The time for discussion is long past. Now is the time for increased mitigation and implementation of adaptive strategies. I don’t think that we are yet at the point where we need to consider drastic measures, such as extreme geoengineering. But, in the same way that a failure to agree upon and implement effective mitigating measures has brought us to this point, we may well be on our way to addressing this problem with technologically challenging, ecosystem-altering, economically difficult and socially painful actions.


Filed under: Climate Change — Peter @ 6:10 am

August 15, 2012

Populations and consumption

fig2This is a draft figure from an essay that I’ve been working on recently (use your browser to “view image” for a larger size). It is a very simple illustration of (1) the irregular relationship between population size and energy consumption, and (2) the variation of per capita rates of electricity consumption among American states. Here is a relevant excerpt from the text of the essay:

For example, globally the United States ranks first in per capita energy consumption (Figure 2a). Yet, among US states California, the most populous state in the union, has the lowest per capita rate of electricity consumption while Wyoming, with a population 66 times lower than California’s, has the highest rate (Figure 2b). Climatic differences account for some of this disparity, with Wyoming having amongst the coolest summer and coldest winter temperatures in the US. Climate alone cannot account for all the variance, however, because California also has two of the top 10 hottest major cities in the country, along with other populous states such as Texas and Florida. Neither of the latter states is in the top five consumption group. On the other hand, other states in the top five group, such as Kentucky, do not have particularly extreme climates, nor large populations, and therefore have considerable room for reducing per capita energy consumption rates while maintaining high standards of living.

Figure caption: Energy consumption rates. A – Total primary energy consumption of the world’s 10 most populous countries (China, India, United States, Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia, Japan), 2009 (BTU = British thermal unit). B – Per capita electricity consumption, United States, 2010. Red – five most highly ranked states (Wyoming, Kentucky, North Dakota, Louisiana, South Carolina), green – five lowest ranked states (California, Hawaii, Rhode Island, New York, Alaska). Florida and Texas are in neither group, but have both high populations and climate extremes.


Filed under: Climate Change,Steinhart Aquarium — Peter @ 10:47 pm

August 3, 2012

Blog policy note

nicubunu_denied_signpng

A reader recently submitted a comment which, while expressing a perfectly legitimate personal opinion, quoted material from one of the “Climategate” e-mails. I will not print any material from those stolen e-mails on this blog. The e-mails were obtained illegally, and I consider it a gross violation of both personal and university property. I intend no disrespect to the person who submitted the comment.


Filed under: Climate Change — Peter @ 8:08 pm
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