Category Archives: Climate Change

Namibian rocks reveal new clues about the Cambrian explosion

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A reconstruction of the Burgess Shale site during the Cambrian explosion. Painting of the by D. W. Miller

A reconstruction of the Burgess Shale site during the Cambrian explosion. Painting by D. W. Miller

My UNC colleague Justin Ries and his collaborators just published a paper in Geology that offers an important new clue about the cause of the Cambrian explosion, the rapid radiation and appearance of new life forms on earth just over half a billion years ago.  One theory has been that suddenly increased oxygen levels made this rapid diversification of animal life possible.  But many geologists dismissed this argument because they thought that oxygen concentration had already increased in the earth’s atmosphere by then.  Justin and his team traveled to the desert of namibia to sample the Nama group carbonate rocks from which they measured the sulfur isotopic signature.  Sulfur is used as a proxy for oxygen concentration.  The teams findings indicate that oxygen concentration in shallow seas was indeed very low just before the Cambrian explosion.

Justin is a relatively new faculty in my department and UNC.  He is a carbonate geochemist and also is doing some cutting edge work on the effects of ocean acidification on calcifying organisms.

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UNC marine geologist Justin Ries in the Zebra River Valley, southern Namibia. The Nama Group carbonates, which contain sulfur isotopic signatures suggesting that low marine sulfate and low atmospheric oxygen conditions persisted up until the Cambrian Explosion, loom in the background. (Credit: Gordon Love)

Read the full story on Futurity here.  Excerpted below:

“This period was a game-changer in terms of the evolutionary structure of life,” Ries says. “Our findings are consistent with the idea that it occurred because of major changes in the composition of the ocean and atmosphere at that time.”

Scientists have maintained that relatively high oxygen levels existed on the planet long before the Cambrian period, Ries says, but if that was the case and oxygen was key to the evolutionary event, why did it take until then for the few initial stems of animal life to expand into the thousands of lineages that emerged?

The new research appears to answer that puzzle. The team examined the chemical signature of limestone rocks in southern Namibia, Africa, that were deposited in the oceans between 553 million and 543 million years ago, just before the Cambrian Explosion and found that at that time, sulfate levels in the ancient ocean—and by implication, oxygen levels in the atmosphere—were much lower than previously thought.

Scientists are able to use sulfate—a molecule that is dissolved in seawater—as a proxy for the amount of oxygen that existed, because their respective levels vary in proportion with one another (marine sulfate is primarily derived from the oxidation of terrestrial sulfide).

“This implies that the subsequent alleviation of these low sulfate and low oxygen conditions may have led to the intense diversification of animals in early Cambrian time,” Ries concludes.

Climate Change Seen as Threat to U.S. Security

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From yesterday’s NYT:

Climate Change Seen as Threat to U.S. Security

By JOHN M. BRODER

Published: August 8, 2009

The changing global climate will pose profound strategic challenges to the United States in coming decades, raising the prospect of military intervention to deal with the effects of violent storms, drought, mass migration and pandemics, military and intelligence analysts say.

Such climate-induced crises could topple governments, feed terrorist movements or destabilize entire regions, say the analysts, experts at the Pentagon and intelligence agencies who for the first time are taking a serious look at the national security implications of climate change. Recent war games and intelligence studies conclude that over the next 20 to 30 years, vulnerable regions, particularly sub-Saharan Africa, the Middle East and South and Southeast Asia, will face the prospect of food shortages, water crises and catastrophic flooding driven by climate change that could demand an American humanitarian relief or military response.

An exercise last December at the National Defense University, an educational institute that is overseen by the military, explored the potential impact of a destructive flood in Bangladesh that sent hundreds of thousands of refugees streaming into neighboring India, touching off religious conflict, the spread of contagious diseases and vast damage to infrastructure. “It gets real complicated real quickly,” said Amanda J. Dory, the deputy assistant secretary of defense for strategy, who is working with a Pentagon group assigned to incorporate climate change into national security strategy planning.

Much of the public and political debate on global warming has focused on finding substitutes for fossil fuels, reducing emissions that contribute to greenhouse gases and furthering negotiations toward an international climate treaty — not potential security challenges.

But a growing number of policy makers say that the world’s rising temperatures, surging seas and melting glaciers are a direct threat to the national interest. If the United States does not lead the world in reducing fossil-fuel consumption and thus emissions of global warming gases, proponents of this view say, a series of global environmental, social, political and possibly military crises loom that the nation will urgently have to address.

This argument could prove a fulcrum for debate in the Senate next month when it takes up climate and energy legislation passed in June by the House.

Lawmakers leading the debate before Congress are only now beginning to make the national security argument for approving the legislation.

Senator John Kerry, the Massachusetts Democrat who is the chairman of the Foreign Relations Committee and a leading advocate for the climate legislation, said he hoped to sway Senate skeptics by pressing that issue to pass a meaningful bill.

Mr. Kerry said he did not know whether he would succeed but had spoken with 30 undecided senators on the matter.

He did not identify those senators, but the list of undecided includes many from coal and manufacturing states and from the South and Southeast, which will face the sharpest energy price increases from any carbon emissions control program.

“I’ve been making this argument for a number of years,” Mr. Kerry said, “but it has not been a focus because a lot of people had not connected the dots.” He said he had urged President Obama to make the case, too.

Mr. Kerry said the continuing conflict in southern Sudan, which has killed and displaced tens of thousands of people, is a result of drought and expansion of deserts in the north. “That is going to be repeated many times over and on a much larger scale,” he said.

The Department of Defense’s assessment of the security issue came about after prodding by Congress to include climate issues in its strategic plans — specifically, in 2008 budget authorizations by Hillary Rodham Clinton and John W. Warner, then senators. The department’s climate modeling is based on sophisticated Navy and Air Force weather programs and other government climate research programs at NASA and the National Oceanic and Atmospheric Administration.

The Pentagon and the State Department have studied issues arising from dependence on foreign sources of energy for years but are only now considering the effects of global warming in their long-term planning documents. The Pentagon will include a climate section in the Quadrennial Defense Review, due in February; the State Department will address the issue in its new Quadrennial Diplomacy and Development Review.

“The sense that climate change poses security and geopolitical challenges is central to the thinking of the State Department and the climate office,” said Peter Ogden, chief of staff to Todd Stern, the State Department’s top climate negotiator.

Although military and intelligence planners have been aware of the challenge posed by climate changes for some years, the Obama administration has made it a central policy focus.

A changing climate presents a range of challenges for the military. Many of its critical installations are vulnerable to rising seas and storm surges. In Florida, Homestead Air Force Base was essentially destroyed by Hurricane Andrew in 1992, and Hurricane Ivan badly damaged Naval Air Station Pensacola in 2004. Military planners are studying ways to protect the major naval stations in Norfolk, Va., and San Diego from climate-induced rising seas and severe storms.

Another vulnerable installation is Diego Garcia, an atoll in the Indian Ocean that serves as a logistics hub for American and British forces in the Middle East and sits a few feet above sea level.

Read the full article here (you need a free NYT membership to log in)

Why do we fly? Ecologists’ sins of emission

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There is a neat article (or “peer-reviewed letter”) in this months Frontiers in Ecology and the Environment about the carbon contribution of conservation ecologists’ airplane flights.  Their point is that we fly too much and are clearly part of the problem.  They also point out the obvious hypocrisy.

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The unease about frequent flying should be particularly acute for the community of ecologists and conservation scientists – a group of professionals who commonly speak out against emissions, yet by virtue of their own behavior have individual carbon footprints that probably exceed the per capita footprints of most Americans.

We thirteen conservation scientists span a wide range of jobs (academic institutions and non-governmental organizations) and career stages (junior to senior scientists), and – although not a random sample – we are fairly representative of those in the conservation field. The results give pause: the emissions from our flights account for an astonishing two-thirds of our average carbon footprint. Thus, in spite of considerably lower-carbon lifestyle choices (eg diet, purchasing/driving a hybrid car, home energy conservation) that made our non-flying carbon footprint 16% smaller than the average American’s, our total emissions are double that of the American average and more than ten times the global average (Figure 1; WebPanel 1). The mismatch between individual behavior and conservation platitudes has already been noted (eg Bearzi 2009) and is a source of considerable embarrassment for the conservation community (Dowie 2008).

You too can calulate your carbon footprint:  using this carbon footprint calculator (which is the one Fox et al used) or several others which can be found online.  BTW, anybody know about the accuracy of these things, which one is “best”, etc.?

I have my Marine Ecology class do this every year when I give a general lecture about climate change.  Last time I did mine, I was curious how much I’d reduce my footprint if I downsized from a Hummer to a Prius (I don’t drive either-I have a Rav4 and ride my bike to work a lot); remarkably the savings barely equaled my annual carbon contribution from flying for work and I typically only fly ~20,000 per year!  Pretty amazing.  Also interesting is the importance of how MUCH you drive, which again, can wash out the benefits of driving a small car (if you drive a lot).  I have been trying to fly less.  I rarely go to conferences and only give one invited lecture a year.  But those decisions are partially because I prefer to save my travel time for field work.  It is a tough balance-just enough miles to achieve AA gold status but not so much that I melt the earth!

References

Helen E Fox, Peter Kareiva, Brian Silliman, Jessica Hitt, David A Lytle, Benjamin S Halpern, Christine V Hawkes, Joshua Lawler, Maile Neel, Julian D Olden, Martin A Schlaepfer, Katherine Smith, Heather Tallis (2009) Why do we fly? Ecologists’ sins of emission. Frontiers in Ecology and the Environment: Vol. 7, No. 6, pp. 294-296.

Bearzi G. 2009. When swordfish conservation biologists eat swordfish. Conserv Biol 23: 1–2.

Dowie M. 2008. The wrong path to conservation. The Nation. Sep 10. www.thenation.com/doc/20080929/dowie

More climate delusionism and questionable science

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Poor Bob. Looks like no-one is taking him seriously these days, according to a recent post over at Jennifer Marohasy’s blog:

“PROMINENT scientists with long publications records, such as Bob Carter, are routinely described by the media as not being climate scientists and really not reputable scientists at all if they aren’t on the alarmist bandwagon”

On his website, Bob defines himself as a palaeontologist, stratigrapher, marine geologist and environmental scientist”. A quick search of the Web of Science database for publications shows that RM Carter has indeed had a pretty prolific career for a scientist since 1970, publishing 74 papers in scientific journals. The vast number of these are indeed focused on Bob’s background – geology and stratigraphy. But how would this qualify Bob to be a ‘climate scientist’? The vast majority of Bob’s claims of  ‘expertise’ seems to come in the form of opinion pieces, letters to newspaper editors and media relationships (warning of ‘Global Cooling‘, or giving lectures on ‘the myth of dangerous human-caused climate change’). There’s a reason no-one will take Bob Carter seriously – his ‘long publication record’ doesn’t stand up to scrutiny, and there is a complete lack of understanding or science to back up the majority of his anti climate change statements. In other words, take his opinion pieces (such as the usual crap published in ‘quadrant’ magazine) with a pinch of salt.

Speaking of other paid shills, it seems that the Brisbane Institute is trying it’s best to lose all credibility by inviting the infamous Jay Lehr to give a seminar on climate change:

The Brisbane Institute is holding a public seminar featuring Dr Jay Lehr, Science Director of the Heartland Institute, whose visit to Australia is being hosted by the Australian Climate Science Coalition.

If the Heartland Institute sounds familiar, this is the same institute that set about to muddy the waters in the Tobacco debate as funded by tobacco lobbyists (Phillip Morris), and sets up annual “International Conferences on Climate Change” to promote dubious science as funded by Exxon. Spot the paid agenda? Here’s what the Brisbane Institute has to say on Jay Lehr:

Dr Lehr is a powerful, entertaining speaker who focuses on describing the impact of advancing technologies on the local, regional, national, and global economy.  An economist and futurist, Dr Lehr combines five decades of expertise and experience in agricultural economics, agronomy, environmental science and business administration with great enthusiasm for the future.

He has spoken to hundreds of groups, seminars, major news networks, radio programs and has written nineteen books to dispel what he believes are the unfair and inaccurate claims made by environmental advocacy groups.  Dr Lehr is an economist and environmental scientist who believes that the course of action provided under the CPRS Bill is a folly, which Australians should reject.

Doing a little digging, it seems that Jay Lehr is a self proclaimed internationally renowned speaker, scientist and author who has published over 900 journal articles. 900! Seem incredible? Too incredible to be true – at best I could find 25 (16 as first author). Most of these are focused upon mainly on ground and waste water, and several of them appear to be in questionable journals (Texas Banking, Proceedings of the National Waste Processing Conference amongst other highlights). Unsurprisingly, none of them are related to climate change. He’s also published a few books of little relevance (my favourite is “Fit, Firm & 50 A Fitness Guide for Men and Women over 40“).

Lehr proclaims to have “…on 36 occasions has testified in congress to explain the realities of environmental issues as it related to pending legislation”. What you won’t find on his webpage is that Lehr is actually a convicted felon in the US, imprisoned by the US government and fired from several positions / associations for defrauding the EPA! So exactly where is the evidence that Lehr is either an economist or environmental scientist, or that his opinion on climate change is worth a damn? Either way, i’m sure The Australian newspaper will have a field day given their complete lack of objectivity and balanced reporting (read here for more). I’ll sign off this post with words from my colleague John Quiggin, who untill a few weeks ago was an active supporter of the Brisbane Institute:

Even judged against the low bar set by climate delusionists in general, the Heartland Institute is a disgrace. Its most notable achievement was the publication of a list purporting to be of scientists whose work contradicted mainstream climate science. Such lists, common in the delusionists attempts to deny that they are pushing fringe science, usually contain large numbers of name with few or no relevant qualifications. The Heartland list was different. It contained the names of lots of genuine scientists, but misrepresented their position. Even when scientists protested against this misrepresentation, Heartland refused to take their names off the list on the basis that they (a bunch of rightwing hacks with no qualifications whatsoever) were better placed to interpret the results of scientific research than were the authors of that research.

The Heartland Institute has no legitimate place in public life and anyone who works for or with it brands themselves as a charlatan. It is to be hoped that the Brisbane Institute’s decision to promote Heartland’s lies is the result of a negligent failure to check on the credibility of their speakers rather than a decision to legitimise this body.

Climate change and coral reefs: Trojan horse or false prophecy?

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Ove is too shy and modest to say so, but he just published a critical response to a provocative  article by Maynard et al. (2009).  He also blogged about this episode here and here.  Ill paste the abstract below and also an excerpt.  The full article is hidden behind Springer’s Corporate Wall of Greed.  But if you want the full paper write Ove, Jez or me.  The debate goes on…

O. Hoegh-Guldberg (2008) Climate change and coral reefs: Trojan horse or false prophecy? A response to Maynard et al. Coral Reefs (2009) 28:569–575

Abstract Maynard et al. (Coral Reefs 27:745–749, 2008a) claim that much of the concern about the impacts of climate change on coral reefs has been “based on essentially untested assumptions regarding reefs and their capacity to cope with future climate change”. If correct, this claim has important implications for whether or not climate change represents the largest long-term threat to the sustainability of coral reefs, especially given their ad hominem argument that many coral reef scientists are guilty of “popularising worst-case scenarios” at the expense of truth. This article looks critically at the claims made by Maynard et al. (Coral Reefs 27:745–749, 2008a) and comes to a very different conclusion, with the thrust and veracity of their argument being called into question. Contrary to the fears of Grigg (Coral Reefs 11:183–186, 1992), who originally made reference to the Cassandra syndrome due to his concern about the sensationalisation of science, the proposition that coral reefs face enormous challenges from climate change and ocean acidification has and is being established through “careful experimentation, long-term monitoring and objective interpretation”. While this is reassuring, coral reef ecosystems continue to face major challenges from ocean warming and acidification. Given this, it is an imperative that scientists continue to maintain the rigour of their research and to communicate their conclusions as widely and clearly as possible. Given the shortage of time and the magnitude of the problem, there is little time to spare.

…many scientists are warning of the consequences for key ecosystems such as coral reefs if we continue down the pathway of unrestrained growth in atmospheric CO2 (Glynn 1996; Brown 1997; Hoegh-Guldberg 1999; Hoegh-Guldberg et al. 2007; IPCC 2007). Grigg (1992) warned of the need to explore the issues associated with coral bleaching and global warming using ‘‘careful experimentation, long-term monitoring and objective interpretation’’. Contrary to the opinion of Maynard et al. (2008a), this has been the modus operandi and our understanding of the drivers and the impacts associated with global climate change has made impressive and rigorous progress over the past 15 years. While more research is certainly needed to fill the gaps and uncertainties with respect to how the next few decades and century will unfold, there is little support for the conclusion that coral reefs will survive atmospheric carbon dioxide levels of 600–1000 ppm and increases in ocean temperatures of 2–6_C. For this reason, and the fact that we are currently on a pathway headed towards 1,000 ppm and beyond, we must also strive to communicate the extreme urgency of the situation to the broader scientific and non-science community, and to urge the international community to rein in the emission of carbon dioxide and other greenhouse gases. This will take measures that go far beyond those that have been proposed so far by the international community and will only come about if governments understand the dire circumstances that the world faces if we lose coral reefs and other critically important parts of the biosphere. Hopefully, a clear, objective and coherent voice from the coral reef community will be listened to. We can only hope.

Climate Literacy

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There is a great article on the Earth Forum about Climate Literacy.  The permanant link is here and an expanded version of the article (titled the Climate Literacy Handook) is here (in the Encyclopedia of Earth).  Ill exerpt some of the short version below.  Also check our the Coral Reefs collection at the EoE here.

This handbook presents the basic scientific concepts of climate science for non-technical audiences. It is an elaboration of Climate Literacy: The Essential Principles of Climate Sciences, a set of seven principles and their underlying fundamental concepts that developed by scientists and educators. This set of principles has been reviewed and endorsed by the  U.S. Climate Change Science Program. Commentary and online resources follow each principle, allowing further exploration of key climate literacy concepts. The handbook aims to promote greater climate science literacy by providing an educational framework around the Essential Principles of Climate Science.

A climate-literate person:

  • understands the essential principles of Earth’s climate system,
  • knows how to assess scientifically credible information about climate,
  • communicates about climate and climate change in a meaningful way, and
  • is able to make informed and responsible decisions with regard to actions that may affect climate

Why does climate science literacy Matter?

  • During the 20th century, Earth’s globally averaged surfacetemperature rose by approximately 1.08°F (0.6°C). Additional warming of more than 0.25°F (0.14°C) has been measured since 2000. Though the total increase may seem small, it likely represents an extraordinarily rapid rate of change compared to changes in the previous 10,000 years.
  • Over the 21st century, climate scientists expect Earth’s temperature to continue increasing, very likely more than it did during the 20th century. Two anticipated results are rising global sea level and increasing frequency and intensity of heat waves, droughts, and floods. These changes will affect almost every aspect of human society, including economic prosperity, human and environmental health, and national security.
  • Scientific observations and climate model results indicate that human activities are now the primary cause of most of the ongoing increase in Earth’s globally averaged surface temperature.

The Essential Principles of Climate Science Literacy

  1. Principle 1. The Sun is the primary source of energy for Earth’s climate system.
  2. Principle 2. Climate is regulated by complex interactions among components of the Earth system.
  3. Principle 3. Life on Earth depends on, is shaped by, and affects climate.
  4. Principle 4. Climate varies over space and time through both natural and man-made processes.
  5. Principle 5. Our understanding of the climate system is improved through observations, theoretical studies, and modeling
  6. Principle 6. Human activities are impacting the climate system.
  7. Principle 7. Climate change will have consequences for the Earth system and human lives

PS-sorry for the absence.  I was working on San Cristobal Island in the Galapagos-a truly stunning place.  There were already signs of the pending El Nino.  If you are interested, I blogged about the trip here.


Climate change poised to feed on itself

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Fifteen of Australia’s top climate experts explain how we know humans are altering the atmosphere and why we must act now.

  1. The global average temperature has increased by about 0.8 degrees since 1850, with most of the increase occurring since 1950. The warming varies among decades because of natural fluctuations but the overall trend has been inexorably upward.
  2. The dominant cause of the warming since about 1950 is the increase in the atmospheric concentrations of greenhouse gases released by human activities, of which carbon dioxide (CO2) is the most important.
  3. Warming will increase in future, if emissions of CO2 and other greenhouse gases maintain their present paths. “Business as usual” scenarios for future emissions lead to likely global temperature increases of up to six degrees above present temperatures by 2100.
  4. Climate change cannot be reversed for many centuries, because of the massive heat stores in the world’s oceans. Even if CO2 and other greenhouse gas concentrations were stabilised today at their present levels, a further warming of at least 0.6 degrees would inevitably follow (on top of the 0.8 degrees observed since 1850) and sea-level rise would continue for centuries to millenniums.

These four conclusions have been known and agreed among thousands of independent climate scientists for more than a decade. However, new findings suggest that the situation is, if anything, more serious than the assessment of just a few years ago.

Click here to read the full article titled “Climate change poised to feed on itself” published in the Sydney Morning Herald by Michael Raupach and John Church, CSIRO; David Griggs, Amanda Lynch and Neville Nicholls, Monash University; Nathan Bindoff, Antarctic Climate and Ecosystems Co-operative Research Centre; Matthew England and Andy Pitman, University of NSW; Ann Henderson-Sellers and Lesley Hughes, Macquarie University; Ove Hoegh-Guldberg, University of Queensland; Roger Jones, Victoria University; David Karoly, University of Melbourne; and Tony McMichael and Will Steffen, Australian National University.

“…cataclysmic global warming is universally understood to be quite a lot like that comet on its earthbound track”

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My friend, David Stout (Professor Emeritus) sent me this interesting piece of commentary regarding why many people are not appreciating the urgency of action on climate change.

The problem is a generational and psychological one.  Mr Micawber rules, because, politically, we elders (who presently have the potential to take difficult and pressing collective decisions) have not evolved to respond to,  and to anticipate and preempt events that are set well beyond our own life spans.  We may be able to crawl out of short-termism into the medium-term, but not into the necessary long term.  Most of us are congenitally unable to process the fact that – as a famous Chinese philosopher pointed out –  if a tree is to reach maturity in one hundred years, then it has to be planted today.

The SALT treaties were possible because the nuclear holocaust was well within the timeline of the leaders. What a difference it would make if the creeping  threat to the Florida coast was within the next five years, not next thirty to fifty.

It is difficult, perhaps too difficult, for the powerful elders to make sacrifices to save their children’s children, when they are neither absolutely convinced of it, nor feel imminent danger to themselves.  Even the relatively young Barak Obama is a time-server, not a time-lord.  The Chinese leaders fall back on the convenient cop-out: “we didn’t cause it.  You, who did, must solve it.”

If, with the same predictive certainty as a future eclipse, the world’s astronomers announced that an annihilating comet was on a collision path with the earth on August 20, 2050, we just might not sit around and smell the roses.  Even if it took all the world’s scientific and technological resources, they would somehow be mobilised with little delay, to seek to find a way to divert it from its path or to destroy it.  That case is  different:  the event would be certain beyond peradventure; the timetable would be exactly known; and it could not be said to have been anybody’s fault or unique responsibility.

The challenge is to keep working so fast and hard on the science, on the geo-politics and on global outreach that cataclysmic global warming is universally understood to be quite a lot like that comet on its earthbound track.

Revealed: the secret evidence of global warming Bush tried to hide

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Sensational headline by The Guardian newspaper? The Obama administration has unclassified over a thousand images of Arctic sea ice to aid scientists in the study of global warming and the impacts of climate change. The images are striking – see this comparison in Alaska between 2006 – 2007. The release of such images is great news – i’m not entirely sure whether these images were ‘kept secret’ by the Bush administration as claimed, but in the growing field of remote sensing, support from the US military satellite data is crucial to understanding local scale changes in the Arctic ice. Click here to see the images in full.

Graphic images that reveal the devastating impact of global warming in the Arctic have been released by the US military. The photographs, taken by spy satellites over the past decade, confirm that in recent years vast areas in high latitudes have lost their ice cover in summer months.

The pictures, kept secret by Washington during the presidency of George W Bush, were declassified by the White House last week. President Barack Obama is currently trying to galvanise Congress and the American public to take action to halt catastrophic climate change caused by rising levels of carbon dioxide in the atmosphere.

One particularly striking set of images – selected from the 1,000 photographs released – includes views of the Alaskan port of Barrow. One, taken in July 2006, shows sea ice still nestling close to the shore. A second image shows that by the following July the coastal waters were entirely ice-free.

The photographs demonstrate starkly how global warming is changing the Arctic. More than a million square kilometres of sea ice – a record loss – were missing in the summer of 2007 compared with the previous year.

Nor has this loss shown any sign of recovery. Ice cover for 2008 was almost as bad as for 2007, and this year levels look equally sparse. (Read More)