Tuesday, October 31, 2006

Actions on the Climate Crisis To Be Held Nov. 4th in 21 States Around the USA

For immediate release

October 31, 2006

For more information:

Raya Ariella, 413-243-5665

Ted Glick, 973-338-5398

Actions on the Climate Crisis To Be Held Nov. 4th in 21 States Around the USA

In Concert With 48 Other Countries for the International Day of Climate Action

Just three days before the November 7th election, thousands of Americans will be participating in local actions in 21 states calling for the federal government to take action now to address the global warming climate crisis.

November 4th is the second International Day of Climate Action. Last year, on December 3rd, 80,000 people internationally in 20 countries participated in the first international day. This year there are 48 countries where actions are being organized.

November 4th was chosen as the day of action this year because it falls just before a major United Nations Climate Conference taking place Nov. 6-17 in Nairobi, Kenya. Activists within this mushrooming, grassroots international movement are calling for delegates in Nairobi and the nations of the world to respond to the accelerated pace of climate change by dramatically strengthening the Kyoto Protocol.

In the USA, activists will be calling upon the U.S. government to join the 166 other countries of the world that have endorsed the Kyoto Protocol. They will be demanding that the federal government enact legislation next year to cap and reduce greenhouse gas emissions by 80% as soon as possible.

They are also calling for an end to all federal subsidies for coal, oil, natural gas and carbon-intensive agriculture and for those monies to be used instead to jump-start a renewable energy economy based on wind, solar, tidal power, biomass, small-scale hydropower and other non-nuclear, sustainable energy technologies.

A wide range of actions will be taking place on November 4th.

In Boston, Massachusetts a coalition of groups is organizing the “Boston Coal Party,” channeling the spirit of the Boston Tea Party by featuring colonial-themed street theater in which participants dump boxes of coal, just as our ancestors dumped British tea over 200 years ago.

In Essex County, N.J. scores of bicyclists will ride for 7 ½ miles through the towns of Montclair and Bloomfield in a Bike Ride for a Healthy Planet.

In Virginia 250 or more young people will converge for a youth environmental summit at the College of William and Mary organized by the Chesapeake Climate Action Network.

In Pennsylvania, Florida, Colorado, Michigan, Vermont and Washington, Greenpeace USA’s Hot Seat campaign is organizing “aerial art” actions involving large numbers of people arranged on the ground to make a statement about the need for action to reduce greenhouse gas emissions.

In St. Louis, Mo. the World Aquarium has set up a Global Warming Display, is providing information about their sustainable actions via lighting, insulation, food choices, etc., and encouraging visitors to take action.

The University of California at Berkeley will experience a Climate Change Fair on campus the evening of November 3rd.

And in Boothbay Harbor and Damariscotta, Maine, activists in both communities will be out with a clothesline filled with “dirty laundry” that exposes the environmental rollbacks and contributions to global warming.

Further information on these and the many other local actions in the USA can be found at http://www.climateusa.org .

Information on what is happening internationally can be found at http://www.globalclimatecampaign.org .

Monday, October 30, 2006

The Stern Review of Climate Change: Media Coverage Survey

Today there has been a veritable hurricane of reporting about the just released Nicholas Stern review of the economics of climate change. Matters where complicated by speculation relating to UK govornment policies that have been rumoured to be announced along with the report.

UK National Press Coverage

Broadsheets (Left/Liberal)
Both the Guardian and the Indy devote substantial space to the stern report, prospects for green taxes and other climate change related stories. Good reviews are given of the main points from the stern report. Green taxes are supported and the general criticism is of to many fine words and not enough action.

Stern Review, Green Taxes

Stern Review, Green Taxes

Broadsheets (Rights/Conservative)
The times and telegraph perform admiarably as Tory papers, they manage to give good accounts of the basic science of the report. They also publish entirely disconnected articles on green taxes. The times manages to write a slightly negative but not openly hostile article on green taxes (which both the libdems and tories broadly support). The Telegraph really impressed me by not speaking out against green taxes at all, after giving a very good review of the stern review and evena short video clip it merely states business concerns about international competativeness if the uk moves without other major economies. The FT was always going to be a special case. A good review of the report (perhaps the best from any paper!) is followed by little talk of uk green taxes and quite a bit of thought about the possible expansion of the EU ETS. I might start treading the FT more after this.

Stern Review, Green Taxes

Stern Review, Green Taxes

Financial Times (perhaps free market but non partisan?)
Stern Review, Green Taxes

More serious tabloids (Entire political spectrum)
The daily express and mail played this in an entirely duplicitous manner. They both reported Sir Nicholas Stern's concluions as reasonable and then went on to trash govornment policy measure being proposed as a result of the report. The common line was, hard working families are going to be laboured with yet another stealth tax. The fact that what is largely being discussed by all three parties is tax restructuring was entirely absent.

Daily Express
Stern Review, Green Taxes

Daily Mail
Stern Review and Green Taxes

Less serious tabloids (Entire political spectrum)
The Sun leads with a front page article, we are going to save the planet and you are paying. The coverage of Sterns Review is present only in a letter penned by Tony Blair. Bearing in mind this interesting dichotomy, it seems quite obvious that blears concenrs about climate change are being presented as an elaborate ploy to raise taxes. The star mentions the stern review in brief but relatively objectively, it dosent mention green taxes. The People dosent make any mention of climate change. The Mirror gives a reasonable account of the importance of the review and a fairly supportive line on green taxes.

The Sun
Stern Review, Green Taxes

The Star
Stern Review, n/a

The People

The Mirror
Stern Review, Green Taxes


Sir Nicholas Stern Interviewed on The Economics of Climate Change

Sir Nicholas Stern, a former World Banks chief economist has just produced a report for the UK govornment into the economics of climate change.

Speaking about this report to the Today Show stern made a strong argument in favour of a higer magnitude of action, including a restructuring of the tax system to punish polloution not wealth.

The interview is available here.


Sunday, October 29, 2006

Stern Review Conclusions via Climate Ark

Stern Review on Economics of Climate Change

Given overwhelming and robust evidence (Item #1 below), the scientific debate on global warming is now closed and it is time for action (#2) which will require going beyond science to
policy and advocacy formulation.

A major new report by chief British government (#3-6) and former World Bank chief economist
Nicholas Stern finds that the benefits of determined worldwide steps to tackle climate change far outweigh the costs, and that failure to make these investments will lead to
"economic upheaval on the scale of the 1930s Depression",
"more than both world wars"
while rendering
"swathes of the planet uninhabitable"
and turning
"200 million people into refugees".

This is not alarmist doomsdayism - it is the best policy predictions based upon the current science. There are many ways to know climate change, science being important but just one of
them. The report is the best policy document to date regarding likely apocalyptic social and economic outcomes of doing nothing to address the global ecological crises of which climate change is part and paramount.

"The chance to keep greenhouse gases at a level which scientists say should avoid the worst effects of climate change 'is already almost out of reach... the benefits of strong, early action considerably outweigh the costs'."
The report estimates stabilizing greenhouse gases in the atmosphere will cost about one per cent of annual global output by 2050. But if the world does nothing, it could cut global consumption per person by between five and 20 per cent. He suggested rich nations take responsibility for emissions cuts of 60-80 per cent from 1990 levels by 2050. Further, a global carbon price was needed, affixing a clear cost to pollution, and this could be created through tax (#7) [EI's carbon tax plan at http://www.climateark.org/lincoln_plan/ ], trading or regulation. And with only perhaps a decade to act with force, it is imperative that a Kyoto successor agreement is negotiated as early as next year.


Friday, October 27, 2006

Prophets of Hope and Climate Change

This is from the Prophets of Hope Myspace...Check it Out

Myself and a couple of friends formed the Prophets of Hope because we are very worried about the world we live in and because we wished to highlight the fact that the the real danger to our existence and world is Climate Change.

It is not terrorism or the distractions that our politicians and corporations promote.

We hope to inspire people into taking individual action and applying political pressure for the radical changes needed.

Climate change is a reality, our only hope is that we all work to overcome the problems and together build a sustainable future.


Of course, we are simply trying to find new ways to try to get the publicity required to get action on climate change to be taken. The best way to show a real movement in society is to move to the streets. Get to it on november the 4th. Join Stop Climate Chaos and Campaign against Climate Change, make your voice heard!

Create Your Own!

Monday, October 23, 2006

We can achieve green growth

China Dialogue Editor Isabel Hilton with UK Climate Change Minister Ian Pearson

Isabel Hilton: This is the first ministerial meeting in the UK China Sustainable Development Dialogue. What do you hope to get out of it?

Ian Pearson: We hope to get an agreement on joint work in sustainable consumption and production. When you look at the embedded carbon in the products that we buy and the fact that China manufactures most of them these days, it’s clear that we have a common agenda here. Some work has also been done on forestry policy and we hope to take that forward as well – global deforestation is a huge issue that we need to tackle. The Chinese have been particularly keen to talk about urban development and of course the biggest issue today is climate change – the science and some of the daily reports we are now seeing are very worrying.

IH: Your department has given some support to www.chinadialogue.net. Is the UK China Sustainable Development Dialogue between governments and experts or do you envisage a wider dialogue?

IP: I would like it to be all of those. I think government to government dialogue is important. You can get some things done at a ministerial level that there can be some reticence about at official level. But official level cooperation is also extremely important – we’ve been pleased how much of this we’ve seen so far under the dialogue. China’s 11th Five Year Plan has sustainability written into it and I think it’s a remarkably impressive document.

IH: Although China’s last Five Year Plan missed several of its environmental targets. Is it your impression that the 11th Plan will hit them?

IP: I get the sense that they are taking it more seriously this time. There’s nothing like talking to people to really get an assessment of how important it is to them. I know the priority has been growth – and trying to ensure balanced growth, but sustainability has risen up the agenda in China.

IH: After twenty years of growth in China, there has certainly been a change of tone and a shift in official statements from the top. How much of a priority is it now for China to balance the economy and the environment?

IP: I think the environment is being given a higher priority under the 11th Five Year Plan and in the way that it will be implemented. I don’t think there’s any doubting that. The Chinese government has recognised the severe pollution problems that have been created as a result of its rapid industrial development and is taking practical measures to deal with that.

IH: How far do you think it goes?

IP: China is such vast country this can’t just be driven from the centre. It requires people in towns and cities to develop policies and to work on environmental issues. In such a vast country, performance is bound to be patchy. But I think a lot has happened in Shanghai. Shanghai wants to set higher standards environmentally and in terms of its economy and skills base. And if you talk to the mayors of Shenzhen or Guangzhou, they want to do something about it too. They still want to grow, but they are committed to doing something about the environment as well.

IH: What do you think Britain can learn from China in this process?

IP: I’d be interested to hear more about the green GDP report that China has produced. I also think we can learn from the Chinese commitment to building the world’s first carbon neutral city in Dongtan. I’m pleased that ARUP, a British-based international company, have provided a lot of expertise in this. In terms of the scale of their ambition to tackle the environment in creating a city like that, there’s something we can learn. We need to be looking at our proposals for developing new homes in the Thames Gateway with the same degree of ambition that the Chinese are adopting in Dongtan.

IH: You are minister for climate change and this dialogue is about sustainable development – can you explain the connection between climate change and sustainable development?

IP: Sustainable development, as I see it, is about one planet living. If everybody consumed resources at the same level as the UK, we would need three planets to live on – and we’ve only got one. It’s about living within our environmental means as well as our economic means. In the past we’ve just put the word “sustainable” in front of everything and devalued what sustainable development means. But one planet living can give us all a moral purpose.

IH: But this is not something the UK has achieved, so why should China listen to the UK on this question?

IP: We certainly haven’t achieved one planet living, but we believe that’s the direction we need to go in – and go in quickly. Our economy has grown by over 40% since 1990. At the same time, greenhouse gas emissions went down by 15%; it’s estimated that if we hadn’t taken action our greenhouse gas emissions would actually be 15% higher today, rather than 15% lower. We have put in place a range of different policy initiatives – we were the first country in the world to introduce a climate change levy and the first country to introduce an emissions trading scheme. We were the architects of the European Trading Scheme. We were the first country in the world to introduce an energy efficiency commitment on energy supplies, which has already produced around £3 billion of benefits in terms of energy efficiency measures, whether it be loft insulation or energy-efficient light bulbs in people’s houses.

The UK needs to do more, both domestically and internationally, but I don’t think people should forget some of the things we actually have done – and in a fairly painless way. I don’t think that our economy has suffered. So my message is that we can achieve green growth – and China can as well. It’s going to be vitally important that China does exactly that, because in the next 10 or 15 years it is set to be the world’s biggest economy. And the US has got to do it as well.

IH: At the launch of chinadialogue about ten days ago, a Chinese journalist came up to me and said: “What China needs is money and technology, not dialogue.” As you embark on this dialogue, what do you feel about that?

IP: I don’t think China needs money, but I do think it needs technology. I think we have a historical responsibility as a result of our past CO2 emissions. The message should be: the UK has discovered that there are better ways of industrialising, we think it’s worth your looking at them. There are opportunities for growth in ways that we weren’t aware of when we were growing strongly back in the 19th century.

IH: But the British government comes under a lot of criticism at home for the rather stately pace of all this. Missing your own emissions targets for a government which is quite keen on targets is rather embarrassing, isn’t it? You could have been more vigorous more early, surely?

IP: I do agree we should do more. We must do more, though I certainly wouldn’t use the phrase “stately pace”. We certainly haven’t given up hope of achieving a 20% reduction in CO2 by 2010. Measures in the energy white paper next year will also help set us on the path to a 60% reduction in CO2 emissions by 2050. We will continue to look at what more we can do as a government. It’s an increasingly urgent task, and although we’re only 2% of the world’s problem, I believe we have a moral responsibility because we were the first nation to industrialise. You can only credibly give international leadership if you’ve got credible domestic policies. You’ve got to walk the walk.

IH: People are now thinking beyond 2012 to the regime that will follow Kyoto. What would you like to see China do for that regime?

IP: Firstly I’d like to see China fully participate in the debate. It’s good that China has been involved in the Gleaneagles dialogue process, which provides a unique space in which we can collectively discuss what needs to be done, rather than getting into negotiating mode where lines are drawn between different parties. China has got some of the best scientists, the most thorough analyses to be found anywhere in the world. China knows that as it grows it’s going to be a world-leading force. It knows that climate change and climate security is going to be an issue for China. I’m very optimistic that China will come to the conclusion it’s in their own interest to do something about tackling their CO2 emissions.

If you look at the figures for world population growth, we will grow to 9 billion by 2015. If you look at the carbon costs of feeding 9 billion people – you can’t avoid carbon when you’re producing food -- that amount of carbon equates to the amount you can safely emit into the atmosphere if you’re going to avoid dangerous climate change.

In other words, everything that’s non-food related will have to be zero carbon: we will need zero-carbon power generation and zero carbon transport by 2015.

It shows the scale of the challenge. Zero-carbon power generation is possible. I’m keen that in the UK and Europe we lead the way. We need to say that all power generation in Europe will be zero carbon by 2020.

(During his visit to China, Ian Pearson will be meeting Du Ying, his counterpart at the National Development and Reform Commission. He will also be taking part in a roundtable event on Sustainable Development Governance and will attend the Asia Carbon Expo.)

The authors:

Ian Pearson is the minister of state for climate change and the environment in the British government.

Isabel Hilton is the editor of chinadialogue


BEYOND THE IVORY TOWER: The Scientific Consensus on Climate Change

Published first in Science on Dec 3rd 2004.

BEYOND THE IVORY TOWER: The Scientific Consensus on Climate Change

Naomi Oreskes*

Policy-makers and the media, particularly in the United States, frequently assert that climate science is highly uncertain. Some have used this as an argument against adopting strong measures to reduce greenhouse gas emissions. For example, while discussing a major U.S. Environmental Protection Agency report on the risks of climate change, then-EPA administrator Christine Whitman argued, "As [the report] went through review, there was less consensus on the science and conclusions on climate change" (1). Some corporations whose revenues might be adversely affected by controls on carbon dioxide emissions have also alleged major uncertainties in the science (2). Such statements suggest that there might be substantive disagreement in the scientific community about the reality of anthropogenic climate change. This is not the case.

The scientific consensus is clearly expressed in the reports of the Intergovernmental Panel on Climate Change (IPCC). Created in 1988 by the World Meteorological Organization and the United Nations Environmental Programme, IPCC's purpose is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature (3). In its most recent assessment, IPCC states unequivocally that the consensus of scientific opinion is that Earth's climate is being affected by human activities:
"Human activities ... are modifying the concentration of atmospheric
constituents ... that absorb or scatter radiant energy. ... [M]ost of the
observed warming over the last 50 years is likely to have been due to the
increase in greenhouse gas concentrations"
[p. 21 in (4)].

IPCC is not alone in its conclusions. In recent years, all major scientific bodies in the United States whose members' expertise bears directly on the matter have issued similar statements. For example, the National Academy of Sciences report, Climate Change Science: An Analysis of Some Key Questions, begins: "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise" [p. 1 in (5)]. The report explicitly asks whether the IPCC assessment is a fair summary of professional scientific thinking, and answers yes: "The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue" [p. 3 in (5)].

Others agree. The American Meteorological Society (6), the American Geophysical Union (7), and the American Association for the Advancement of Science (AAAS) all have issued statements in recent years concluding that the evidence for human modification of climate is compelling (8).

The drafting of such reports and statements involves many opportunities for comment, criticism, and revision, and it is not likely that they would diverge greatly from the opinions of the societies' members. Nevertheless, they might downplay legitimate dissenting opinions. That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords "climate change" (9).

The 928 papers were divided into six categories: explicit endorsement of the consensus position, evaluation of impacts, mitigation proposals, methods, paleoclimate analysis, and rejection of the consensus position. Of all the papers, 75% fell into the first three categories, either explicitly or implicitly accepting the consensus view; 25% dealt with methods or paleoclimate, taking no position on current anthropogenic climate change. Remarkably, none of the papers disagreed with the consensus position.

Admittedly, authors evaluating impacts, developing methods, or studying paleoclimatic change might believe that current climate change is natural. However, none of these papers argued that point.

This analysis shows that scientists publishing in the peer-reviewed literature agree with IPCC, the National Academy of Sciences, and the public statements of their professional societies. Politicians, economists, journalists, and others may have the impression of confusion, disagreement, or discord among climate scientists, but that impression is incorrect.

The scientific consensus might, of course, be wrong. If the history of science teaches anything, it is humility, and no one can be faulted for failing to act on what is not known. But our grandchildren will surely blame us if they find that we understood the reality of anthropogenic climate change and failed to do anything about it.

Many details about climate interactions are not well understood, and there are ample grounds for continued research to provide a better basis for understanding climate dynamics. The question of what to do about climate change is also still open. But there is a scientific consensus on the reality of anthropogenic climate change. Climate scientists have repeatedly tried to make this clear. It is time for the rest of us to listen.

References and Notes

A. C. Revkin, K. Q. Seelye, New York Times, 19 June 2003, A1.
S. van den Hove, M. Le Menestrel, H.-C. de Bettignies, Climate Policy 2 (1), 3 (2003).
See www.ipcc.ch/about/about.htm.
J. J. McCarthy et al., Eds., Climate Change 2001: Impacts, Adaptation, and Vulnerability (Cambridge Univ. Press, Cambridge, 2001).
National Academy of Sciences Committee on the Science of Climate Change, Climate Change Science: An Analysis of Some Key Questions (National Academy Press, Washington, DC, 2001).
American Meteorological Society, Bull. Am. Meteorol. Soc. 84, 508 (2003).
American Geophysical Union, Eos 84 (51), 574 (2003).
See www.ourplanet.com/aaas/pages/atmos02.html.
The first year for which the database consistently published abstracts was 1993. Some abstracts were deleted from our analysis because, although the authors had put "climate change" in their key words, the paper was not about climate change.
This essay is excerpted from the 2004 George Sarton Memorial Lecture, "Consensus in science: How do we know we're not wrong," presented at the AAAS meeting on 13 February 2004. I am grateful to AAAS and the History of Science Society for their support of this lectureship; to my research assistants S. Luis and G. Law; and to D. C. Agnew, K. Belitz, J. R. Fleming, M. T. Greene, H. Leifert, and R. C. J. Somerville for helpful discussions.

Friday, October 20, 2006

Blair: We have 10-15 years to stop climate change.

Blair calls for tough action on climate change but is exposed by an ever increasing credibility gap. The govornment is commited to 60% cuts by 2050 but even with broad cross-party support for setting yearly targets to ensure we are on a path the govornment seems resistant. All lib-dems, many tories and many labout mps have suported this (400 of the 630mps) so where is the resistance, and the urgency?

From the BBC News Website:

Tony Blair will later press for urgent action on global warming at a summit of EU leaders in southern Finland.

The meeting will focus on securing stable energy supplies - something Mr Blair will argue is closely linked to climate change.

In a letter published ahead of the summit, the prime minister said Europe must lead the world in changing to a low-carbon economy.

He said the world faced a "catastrophic tipping point" over climate change.

The letter, which was also signed by Dutch PM Jan Peter Balkenende, warned that failure to act would affect economic growth and long-term energy supply and would cause conflict and insecurity.

"We have a window of only 10 to 15 years to take the steps we need to avoid crossing catastrophic tipping points"

Joint letter

Energy is top of the agenda for the summit, where the EU leaders will be joined for dinner by Russian President Vladimir Putin.

They hope to negotiate better deals for oil and gas companies operating in Russia and better access to the Russian pipeline network.

Mr Blair says it is right to focus on external energy policy but the pace of climate change means the two are linked.

"We have a window of only 10 to 15 years to take the steps we
need to avoid crossing catastrophic tipping points,"
the letter warns.

"These would have serious consequences for our economic growth prospects, the safety of our people and the supply of resources, most notably energy."


Commission President Jose Manuel Barroso said on Wednesday that climate change was the most pressing problem for political leaders.

And a plan to cut Europe's energy consumption by 20% before 2020 has been outlined by the European Commission.

No new decisions will come out of the Lahti meeting, but Mr Blair wants an "in-depth debate" at another summit next year.

He also wants progressively tighter limits to be put on total CO2 emissions from industry, and an agreement to invest more in renewable energy technology.

Greenpeace's John Sauven said Mr Blair's record on the climate issue was hypocritical.

"He finally grasps that we don't have long to stop catastrophic climate change but in his decade in power CO2 emissions have gone up in Britain,"

the campaigner said.

"He says he wants to strengthen the European emissions trading scheme, but last year he was suing Brussels to weaken it. He's done nothing to combat aviation or the trend for gas-guzzling cars."


Tuesday, October 10, 2006

Impact from the Deep

This is a Copyrighted Scientific American article

Impact from the Deep

Strangling heat and gases emanating from the earth and sea, not asteroids, most likely caused several ancient mass extinctions. Could the same killer-greenhouse conditions build once again?

By Peter D. Ward

Philosopher and historian Thomas S. Kuhn has suggested that scientific disciplines act a lot like living organisms: instead of evolving slowly but continuously, they enjoy long stretches of stability punctuated by infrequent revolutions with the appearance of a new species--or in the case of science, a new theory. This description is particularly apt for my own area of study, the causes and consequences of mass extinctions--those periodic biological upheavals when a large proportion of the planet's living creatures died off and afterward nothing was ever the same again.

Since first recognizing these historical mass extinctions more than two centuries ago, paleontologists believed them to have been gradual events, caused by some combination of climate change and biological forces such as predation, competition and disease. But in 1980 the understanding of mass extinctions underwent a Kuhnian revolution when a team at the University of California, Berkeley, led by geologist Walter Alvarez proposed that the famous dinosaur-killing extinction 65 million years ago occurred swiftly, in the ecosystem catastrophe that followed an asteroid collision. Over the ensuing two decades, the idea that a bolide from space could smite a significant segment of life on the earth was widely embraced--and many researchers eventually came to believe that cosmic detritus probably caused at least three more of the five largest mass extinctions. Public acceptance of the notion crystallized with Hollywood blockbusters such as Deep Impact and Armageddon.

Now still another transformation in our thinking about life's punctuated past is brewing. New geochemical evidence is coming from the bands of stratified rock that delineate mass extinction events in the geologic record, including the exciting discovery of chemical residues, called organic biomarkers, produced by tiny life-forms that typically do not leave fossils. Together these data make it clear that cataclysmic impact as a cause of mass extinction was the exception, not the rule. In most cases, the earth itself appears to have become life's worst enemy in a previously unimagined way. And current human activities may be putting the biosphere at risk once again.

After Alvarez

To understand the general enthusiasm for the impact paradigm, it helps to review the evidence that fueled it. The scenario advanced by Alvarez, along with his father, physicist Luis W. Alvarez, and nuclear chemists Helen V. Michel and Frank Asaro, contained two separate hypotheses: first, that a fairly large asteroid--estimated to have been 10 kilometers in diameter--struck the earth 65 million years ago; second, that the environmental consequences of the impact snuffed out more than half of all species. They had found traces left by the blow in a thick layer of iridium--rare on the earth but common in extraterrestrial materials--that had dusted the globe.

Within a decade of this prodigious announcement the killer's thumbprint turned up, in the form of the Chicxulub crater hiding in plain sight on the Yucatán Peninsula of Mexico. Its discovery swept aside most lingering doubts about whether the reign of the dinosaurs had ended with a bang. At the same time, it raised new questions about other mass extinction events: If one was caused by impact, what about the rest? Five times in the past 500 million years most of the world's life-forms have simply ceased to exist. The first such event happened at the end of the Ordovician period, some 443 million years ago. The second, 374 million years ago, was near the close of the Devonian. The biggest of them all, the Great Dying, at the end of the Permian 251 million years ago, wiped out 90 percent of ocean dwellers and 70 percent of plants, animals, even insects, on land [see "The Mother of Mass Extinctions," by Douglas H. Erwin; Scientific American, July 1996]. Worldwide death happened again 201 million years ago, ending the Triassic period, and the last major extinction, 65 million years ago, concluded the Cretaceous with the aforementioned big bang.

In the early 1990s paleontologist David Raup's book Extinctions: Bad Genes or Bad Luck? predicted that impacts ultimately would be found to be the blame for all these major mass extinctions and other, less severe events as well. Evidence for impact from the geologic boundary between the Cretaceous and Tertiary (-K/T) periods certainly was and remains convincing: in addition to the Chicxulub crater and the clear iridium layer, impact debris, including pressure-shocked stone scattered across the globe, attests to the blow. Further chemical clues in ancient sediments document rapid changes in the world's atmospheric composition and climate that soon followed.

For several other extinction periods, the signs also seemed to point "up." Geologists had already associated a thin iridium layer with the end Devonian extinctions in the early 1970s. And by 2002 separate discoveries suggested impacts at the end Triassic and end Permian boundaries. Faint traces of iridium registered in the Triassic layer. And for the Permian, distinctive carbon "buckyball" molecules believed to contain trapped extraterrestrial gases added another intriguing clue [see "Repeated Blows," by Luann Becker; Scientific American, March 2002]. Thus, many scientists came to suspect that asteroids or comets were the source of four of the "big five" mass extinctions; the exception, the end Ordovician event, was judged the result of radiation from a star exploding in our cosmic neighborhood.

As researchers continued to probe the data in recent years, however, they found that some things did not add up. New fossil analyses indicated that the Permian and Triassic extinctions were drawn-out processes spanning hundreds of thousands of years. And newly obtained evidence of the rise and fall of atmospheric carbon, known as carbon cycling, also seemed to suggest that the biosphere suffered a long-running series of environmental insults rather than a single, catastrophic strike.

Not So Sudden Impact

The lesson of the K/T event was that a large-body impact is like a major earthquake leveling a city: the disaster is sudden, devastating, but short-lived--and after it is over, the city quickly begins rebuilding. This tempo of destruction and subsequent recovery is reflected in carbon-isotope data for the K/T extinctions as well as in the fossil record, although verifying the latter took the scientific community some time. The expected sudden die-off at the K/T boundary itself was indeed visible among the smallest and most numerous fossils, those of the calcareous and siliceous plankton, and in the spores of plants. But the larger the fossils in a group, the more gradual their extinction looked.

Slowly, paleontologists came to understand that this apparent pattern was influenced by the sparsity of large-fossil samples for most of the soil and rock strata being studied. To address this sampling problem and gain a clearer picture of the pace of extinction, Harvard University paleontologist Charles Marshall developed a new statistical protocol for analyzing ranges of fossils. By determining the probability that a particular species has gone extinct within a given time period, this analytical method teases out the maximum amount of information yielded by even rare fossils.

In 1996 Marshall and I joined forces to test his system on K/T stratigraphic sections and ultimately showed that what had appeared to be a gradual extinction of the most abundant of the larger marine animals, the ammonites (molluscan fossils related to the chambered nautilus) in Europe, was instead consistent with their sudden disappearance at the K/T boundary itself. But when several researchers, including myself, applied the new methodology to earlier extinctions, the results differed from the K/T sections. Studies by my group of strata representing both marine and nonmarine environments during the latest parts of the Permian and Triassic periods showed a more gradual succession of extinctions clustered around the boundaries.

That pattern was also mirrored in the carbon-isotope record, which is another powerful tool for understanding rates of extinction. Carbon atoms come in three sizes, or isotopes, with slightly varying numbers of neutrally charged particles in the nucleus. Many people are familiar with one of these isotopes, carbon 14 (14C), because its decay is often used to date specific fossil skeletons or samples of ancient sediments. But for -interpreting mass extinctions, a more useful type of information to extract from the geologic record is the ratio of 12C to 13C isotopes, which provides a broader snapshot of the vitality of plant life at the time.

That is because photosynthesis largely drives changes in the 12C-13C ratio. Plants use energy from the sun to split carbon dioxide (CO2) into organic carbon, which they exploit to build cells and provide energy; happily for us animals, free oxygen is their waste product. But plants are finicky, and they preferentially choose CO2 containing 12C. Thus, when plant life--whether in the form of photosynthesizing microbes, floating algae or tall trees--is abundant, a higher proportion of CO2 remaining in the atmosphere contains 13C, and atmospheric 12C is measurably lower.

By examining the isotope ratios in samples from before, during and after a mass extinction, investigators can obtain a reliable indicator of the amount of plant life both on land and in the sea. When researchers plot such measurements for the K/T event on a graph, a simple pattern emerges. Virtually simultaneously with the emplacement of the so-called impact layer containing mineralogical evidence of debris, the carbon isotopes shift--13C drops dramatically--for a short time, indicating a sudden die-off of plant life and a quick recovery. This finding is entirely consistent with the fossil record of both larger land plants and the sea's microscopic plankton, which underwent staggering losses in the K/T event but bounced back rapidly.

In contrast, the carbon records revealed by my group in early 2005 for the Permian, and more recently for the Triassic, document a very different fate for plants and plankton during those two mass extinctions. In both cases, multiple isotope shifts over intervals exceeding 50,000 to 100,000 years indicate that plant communities were struck down, then re-formed, only to be perturbed again by a series of extinction events. To produce such a pattern would take a succession of asteroid strikes, thousands of years apart. But no mineralogical evidence exists for a string of impacts during either time span.

Indeed, further investigation of the evidence has called into question the likelihood of any impacts at those two times. No other research groups have replicated the original finding of buckyballs containing extraterrestrial gas at the end Permian boundary. A discovery of shocked quartz from that period has also been recanted, and geologists cannot agree whether purported impact craters from the event in the deep ocean near Australia and under ice in Antarctica are actually craters or just natural rock formations. For the end Triassic, the iridium found is in such low concentrations that it might reflect a small asteroid impact, but nothing of the planet-killing scale seen at the K/T boundary. If impacts are not supported as the cause of these mass extinctions, however, then what did trigger the great die-offs? A new type of evidence reveals that the earth itself can, and probably did, exterminate its own inhabitants.

Ghastly Greenhouse

About half a decade ago small groups of geologists began to team up with organic chemists to study environmental conditions at critical times in the earth's history. Their work involved extracting organic residues from ancient strata in search of chemical "fossils" known as biomarkers. Some organisms leave behind tough organic molecules that survive the decay of their bodies and become entombed in sedimentary rocks. These biomarkers can serve as evidence of long-dead life-forms that usually do not leave any skeletal fossils. Various kinds of microbes, for example, leave behind traces of the distinctive lipids present in their cell membranes--traces that show up in new forms of mass spectrometry, a technique that sorts molecules by mass.

Their studies indicate that enough H2S was produced by such ocean upwellings at the end of the Permian to cause extinctions both on land and in the sea. And this strangling gas would not have been the only killer. Models by Alexander Pavlov of the University of Arizona show that the H2S would also have attacked the planet's ozone shield, an atmospheric layer that protects life from the sun's ultraviolet (UV) radiation. Evidence that such a disruption of the ozone layer did happen at the end of the Permian exists in fossil spores from Greenland, which display deformities known to result from extended exposure to high UV levels. Today we can also see that underneath "holes" in the ozone shield, especially in the Antarctic, the biomass of phytoplankton rapidly decreases. And if the base of the food chain is destroyed, it is not long until the organisms higher up are in desperate straits as well.

Kump and Arthur estimate that the amount of H2S gas entering the late Permian atmosphere from the oceans was more than 2,000 times the small amount given off by volcanoes today. Enough of the toxic gas would have permeated the atmosphere to have killed both plants and animals--particu-larly because the lethality of H2S increases with temperature. And several large and small mass extinctions seem to have occurred during short intervals of global warming. That is where the ancient volcanic activity may have come in.

This biomarker research was first conducted on rocks predating the history of animals and plants, in part to determine when and under what conditions life first emerged on the earth. But within the past few years scientists began sampling the mass extinction boundaries. And to the great surprise of those doing this work, data from the periods of mass extinction, other than the K/T event, suggested that the world's oceans have more than once reverted to the extremely low oxygen conditions, known as anoxia, that were common before plants and animals became abundant.

Among the biomarkers uncovered were the remains of large numbers of tiny photosynthetic green sulfur bacteria. Today these microbes are found, along with their cousins, photosynthetic purple sulfur bacteria, living in anoxic marine environments such as the depths of stagnant lakes and the Black Sea, and they are pretty noxious characters. For energy, they oxidize hydrogen sulfide (H2S) gas, a poison to most other forms of life, and convert it into sulfur. Thus, their abundance at the extinction boundaries opened the way for a new interpretation of the cause of mass extinctions.

Scientists have long known that oxygen levels were lower than today around periods of mass extinction, although the reason was never adequately identified. Large-scale volcanic activity, also associated with most of the mass extinctions, could have raised CO2 levels in the atmosphere, reducing oxygen and leading to intense global warming--long an alternative theory to the impacts; however, the changes wrought by volcanism could not necessarily explain the massive marine extinctions of the end Permian. Nor could volcanoes account for plant deaths on land, because vegetation would thrive on increased CO2 and could probably survive the warming.

But the biomarkers in the oceanic sediments from the latest part of the Permian, and from the latest Triassic rocks as well, yielded chemical evidence of an ocean-wide bloom of the H2S-consuming bacteria. Because these microbes can live only in an oxygen-free environment but need sunlight for their photosynthesis, their presence in strata representing shallow marine settings is itself a marker indicating that even the surface of the oceans at the end of the Permian was without oxygen but was enriched in H2S.

In today's oceans, oxygen is present in essentially equal concentrations from top to bottom because it dissolves from the atmosphere into the water and is carried downward by ocean circulation. Only under unusual circumstances, such as those that exist in the Black Sea, do anoxic conditions below the surface permit a wide variety of oxygen-hating organisms to thrive in the water column. Those deep-dwelling anaerobic microbes churn out copious amounts of hydrogen sulfide, which also dissolves into the seawater. As its concentration builds, the H2S diffuses upward, where it encounters oxygen diffusing downward. So long as their balance remains undisturbed, the oxygenated and hydrogen sulfide-saturated waters stay separated, and their interface, known as the chemocline, is stable. Typically the green and purple sulfur bacteria live in that chemocline, enjoying the supply of H2S from below and sunlight from above.

Yet calculations by geoscientists Lee R. Kump and Michael A. Arthur of Pennsylvania State University have shown that if oxygen levels drop in the oceans, conditions begin to favor the deep-sea anaerobic bacteria, which proliferate and produce greater amounts of hydrogen sulfide. In their models, if the deepwater H2S concentrations were to increase beyond a critical threshold during such an interval of oceanic anoxia, then the chemocline separating the H2S-rich deepwater from oxygenated surface water could have floated up to the top abruptly. The horrific result would be great bubbles of toxic H2S gas erupting into the atmosphere.

Around the time of multiple mass extinctions, major volcanic events are known to have extruded thousands of square kilometers of lava onto the land or the seafloor. A by-product of this tremendous volcanic outpouring would have been enormous volumes of carbon dioxide and methane entering the atmosphere, which would have caused rapid global warming. During the latest Permian and Triassic as well as in the early Jurassic, middle Cretaceous and late Paleocene, among other periods, the carbon-isotope record confirms that CO2 concentrations skyrocketed immediately before the start of the extinctions and then stayed high for hundreds of thousands to a few million years.

But the most critical factor seems to have been the oceans. Heating makes it harder for water to absorb oxygen from the atmosphere; thus, if ancient volcanism raised CO2 and lowered the amount of oxygen in the atmosphere, and global warming made it more difficult for the remaining oxygen to penetrate the oceans, conditions would have become amenable for the deep-sea anaerobic bacteria to generate massive upwellings of H2S. Oxygen-breathing ocean life would have been hit first and hardest, whereas the photosynthetic green and purple H2S-consuming bacteria would have been able to thrive at the surface of the anoxic ocean. As the H2S gas choked creatures on land and eroded the planet's protective shield, virtually no form of life on the earth was safe.

Kump's hypothesis of planetary killing provides a link between marine and terrestrial extinctions at the end of the Permian and explains how volcanism and increased CO2 could have triggered both. It also resolves strange findings of sulfur at all end Permian sites. A poisoned ocean and atmosphere would account for the very slow recovery of life after that mass extinction as well.

Finally, this proposed sequence of events pertains not only to the end of the Permian. A minor extinction at the end of the Paleocene epoch 54 million years ago was already--presciently--attributed to an interval of oceanic anoxia somehow triggered by short-term global warming. Biomarkers and geologic evidence of anoxic oceans suggest that is also what may have occurred at the end Triassic, middle Cretaceous and late Devonian, making such extreme greenhouse-effect extinctions possibly a recurring phenomenon in the earth's history.

Most troubling, however, is the question of whether our species has anything to fear from this mechanism in the future: If it happened before, could it happen again? Although estimates of the rates at which carbon dioxide entered the atmosphere during each of the ancient extinctions are still uncertain, the ultimate levels at which the mass deaths took place are known. The so-called thermal extinction at the end of the Paleocene began when atmospheric CO2 was just under 1,000 parts per million (ppm). At the end of the Triassic, CO2 was just above 1,000 ppm. Today with CO2 around 385 ppm, it seems we are still safe. But with atmospheric carbon climbing at an annual rate of 2 ppm and expected to accelerate to 3 ppm, levels could approach 900 ppm by the end of the next century, and conditions that bring about the beginnings of ocean anoxia may be in place. How soon after that could there be a new greenhouse extinction? That is something our society should never find out.

PETER D. WARD is a professor in the University of Washington's biology department and its earth and space sciences division, where he investigates both realms. His terrestrial research centers on ancient mass extinction events as well as the evolution and ultimate extinction of the nautiluslike marine animals known as ammonites, which he described in his first article for Scientific American in October 1983. Ward also applies principles gleaned from studying the earth's earliest life-forms to research for the NASA Astrobiology Institute into potential habitats for life elsewhere. He discussed those environments in an October 2001 Scientific American article, "Refuges for Life in a Hostile Universe," written with Guillermo Gonzalez and Donald Brownlee, as well as in a popular book co-authored with Brownlee, Rare Earth: Why Complex Life Is So Uncommon in the Universe (Springer, 2000).

Sunday, October 08, 2006

New Climate Change Forum

Hello all,
I have just started a new forum for my three blogs and for anyone people who i know who wish to discuss climate change...the forum will be moderated as it is intended to be more than a place to rant it is hopefully going to lead to new ideas, collaborations and action. If you are interested then check sign up and have a look at the newly born site. The only material up at the moment is my collection of essays...these are freely editable by members so please add your knoledge to what i already have...rewrite if nessicary just keep the alterations in red so i know what has changed.
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