Monday, February 15, 2010

Getting a sinking feeling yet?
There has been a recent spate of papers regarding the phytoplankton and carbon sequestration. I take a particular interest in this subject, as my undergraduate thesis looked at the effects of iron limitation on oxidative stress responses in diatoms. In this post, I'll attempt to synthesize the findings of these different papers to find the "take-home message", as they say.

First up is Le Quéré et al (1). They used data from atmospheric monitoring stations in the southern hemisphere tracking CO2 concentrations from 1981-2004 and an ocean general circulation model (OGCM) called PISCES-T to model the flux of carbon dioxide into/out of the ocean from/to the atmosphere. The details are complicated, but basically the message here is that the OGCM shows a flattening in the trend of the carbon dioxide flux from the atmosphere to the ocean (the blue line), which is different from the trend that you would predict based on atmospheric carbon dioxide concentrations alone (the red lines).

One of the little-known (at least by the lay public) facts about the oceans is that vast areas are virtual biological deserts due to the lack of nutrients. Unlike coastal areas, however, the limiting nutrient in most of the open oceans is actually iron. Hence, dust storms that carry sand from the Sahara actually end up fertilizing plankton growth in the Atlantic Ocean through iron deposition. Cassar et al (2) contend that a similar process of fertilization results in enhanced phytoplankton productivity in the Southern Ocean.

However, complicating the issue, Sunda 2010 (3) and Shi et al (4), discuss the effect of increasing ocean acidification on biological availability of iron.

In a nutshell, even though increasing ocean acidity (decreasing pH) due to increasing atmospheric carbon dioxide concentrations increases the solubility of iron, the biological availability of this iron to phytoplankton actually decreases. Keep in mind that this represents a double-whammy for calcifying phytoplankton, because increased CO2  concentrations also impair the ability of these organisms to grow and sequester CO2 (5).

As an aside, I'll note that one of the things I was looking at as an undergrad was whether iron limitation also inhibited phytoplankton's ability to handle oxidative stress (i.e., damage from ultraviolet radiation and/or high irradiance); iron is a crucial component of the ascorbate peroxidase enzyme, which reduces damaging hydrogen peroxide to harmless water. Thus, it is theoretically possible that the effects of increased UV radiation due to the Antarctic ozone hole could be exacerbated by iron limitation in phytoplankton by compromising their ability to manufacture heme-containing enzymes necessary to mitigate oxidative stress effects.

On the other hand, Peck et al (6) argue that melting ice sheets are exposing more open ocean and thus creating new carbon sinks - about 3.3 million tonnes' worth so far. They speculate that a further 50 million tonnes of carbon could be fixed annually if another 15% of the remaining Antarctic ice is lost.

So where does this leave us? First, that ocean acidification is the 500-pound gorilla in the room that few (if any) in the mainstream media are talking about. Second, that the effects of acidification may be even worse than we first thought, if it results in a reduction in biological availability of iron to phytoplankton. This is further complicated by uncertainty associated with the effects of climate change on desertification and wind patterns. And third, that the magnitude and - to a lesser extent - the direction of ocean-atmosphere carbon cycle feedbacks remains uncertain.

1. Le Quere, C., Rodenbeck, C., Buitenhuis, E., Conway, T., Langenfelds, R., Gomez, A., Labuschagne, C., Ramonet, M., Nakazawa, T., Metzl, N., Gillett, N., & Heimann, M. (2007). Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change Science, 316 (5832), 1735-1738 DOI: 10.1126/science.1136188

2. Cassar, N., Bender, M., Barnett, B., Fan, S., Moxim, W., Levy, H., & Tilbrook, B. (2007). The Southern Ocean Biological Response to Aeolian Iron Deposition Science, 317 (5841), 1067-1070 DOI: 10.1126/science.1144602

3. Sunda WG (2010). Iron and the carbon pump. Science (New York, N.Y.), 327 (5966), 654-5 PMID: 20133563

4. Dalin Shi, Yan Xu, Brian M. Hopkinson, François M. M. Morel (2010). Effect of Ocean Acidification on Iron Availability to Marine Phytoplankton Science, 327 (5966), 676-679 : 10.1126/science.1183517

5. Riebesell U, Zondervan I, Rost B, Tortell PD, Zeebe RE, & Morel FM (2000). Reduced calcification of marine plankton in response to increased atmospheric CO2. Nature, 407 (6802), 364-7 PMID: 11014189

6. Peck, L., Barnes, D., Cook, A., Fleming, A., & Clarke, A. (2009). Negative feedback in the cold: ice retreat produces new carbon sinks in Antarctica Global Change Biology DOI: 10.1111/j.1365-2486.2009.02071.x

Sunday, February 14, 2010

Where have we heard this before?

Scientists agree there's a problem. Human emissions are causing a dangerous change in the earth's systems. Despite clear scientific evidence built on well-understood physical principles, politicians and industry are dragging their feet. So-called "contrarian scientists" allege that there's a peer-review conspiracy keeping them out of the literature. Americans balk at an international protocol to limit emissions because it would put the U.S. at an economic disadvantage. The Cato Institute proposes that fears are being played up by scientists as a ploy to garner more research funding. Uncertainty about the extent and progression of the problem, and fear-mongering over the economic cost of doing something about it are used as excuses to delay action.

Am I talking about carbon dioxide and anthropogenic global warming? No, I'm talking about CFCs and the ozone hole from 30 years ago.

Read this summary for a full accounting of the parallels.

Saturday, February 6, 2010

Welcome to Gilead

A recent poll conducted by DailyKOS/Research 2000 of 2003 self-identified Republicans found some interesting results:
Should Barack Obama be impeached, or not?
Yes 39
No 32
Not Sure 29
Do you think Barack Obama is a socialist?
Yes 63
No 21
Not Sure 16
Do you believe Barack Obama was born in the United States, or not?
Yes 42
No 36
Not Sure 22
Do you believe Barack Obama wants the terrorists to win?
Yes 24
No 43
Not Sure 33
I'm sure many of these questions would have had mirror-image responses among Democrats if you had asked them about Bush in 2004 (except for wanting the terrorists to win - that's just nuts). The really worrying responses were these:
Should same sex couples be allowed to marry?
Yes 7
No 77
Not Sure 16

Should gay couples receive any state or federal benefits?
Yes 11
No 68
Not Sure 21

Should openly gay men and women be allowed to teach in public schools?
Yes 8
No 73
Not Sure 19
Should sex education be taught in the public schools?
Yes 42
No 51
Not Sure 7
Should public school students be taught that the book of Genesis in the Bible explains how God created the world?
Yes 77
No 15
Not Sure 8
Should contraceptive use be outlawed?
Yes 31
No 56
Not Sure 13
Do you believe that the only way for an individual to go to heaven is though Jesus Christ, or can one make it to heaven through another faith?
Christ 67
Other 15
Not Sure 18
Anyone care to ask Ron Paul these same questions? I think the answers would tell you what the real "Ron Paul Revolution" would entail.

Note that Sarah Palin isn't doing much to distance herself from these views, either. This is from the Q&A session at a recent Tea Bagger - er, I mean Tea Party convention:
"I think, kind of tougher to, um, put our arms around, but allowing America's spirit to rise again by not being afraid to kind of go back to some of our roots as a God fearing nation where we're not afraid to say, especially in times of potential trouble in the future here, where we're not afraid to say, you know, we don't have all the answers as fallible men and women so it would be wise of us to start seeking some divine intervention again in this country, so that we can be safe and secure and prosperous again. To have people involved in government who aren't afraid to go that route, not so afraid of the political correctness that you know -- they have to be afraid of what the media said about them if they were to proclaim their alliance on our creator."

Here's my analysis of the Tea Party movement: the GOP has realized that courting the Religious Right is no longer sufficient to guarantee them the White House or even a majority in Congress. As such, they need to re-brand themselves to attract the independents (and perhaps even Democrats) and make them actually believe that the GOP is the party of small government and fiscal responsibility. Nevermind that government actually grew (by 61,000 positions) under Ronald Reagan, the poster child of the small government movement. It shrank by 373,000 under Clinton. Reagan also greatly expanded Social Security. Taxes went up. But none of this fits the established Republican-Democrat narrative.

Link to the full poll results is here.

Wednesday, February 3, 2010

Mann cleared of allegations of research misconduct

Finding #1:
After careful consideration of all the evidence and relevant materials, the inquiry committee finding is that there exists no credible evidence that Dr. Mann had orhas ever engaged in, or participated in, directly or indirectly, any actions with an  intent to suppress or to falsify data. While a perception has been created in the weeks after the CRU emails were made public that Dr. Mann has engaged in the suppression or falsification of data, there is no credible evidence that he ever did so, and certainly not while at Penn State.
Finding #2:
After careful consideration of all the evidence and relevant materials, the inquiry committee finding is that there exists no credible evidence that Dr. Mann had ever engaged in, or participated in, directly or indirectly, any actions with intent to delete, conceal or otherwise destroy emails, information and/or data related to AR4, as suggested by Dr. Phil Jones.
Finding #3:
After careful consideration of all the evidence and relevant materials, the inquiry committee finding is that there exists no credible evidence that Dr. Mann had ever engaged in, or participated in, directly or indirectly, any misuse of privileged or confidential information available to him in his capacity as an academic scholar.
Finding #4:
After careful consideration of all the evidence and relevant materials, the inquiry committee could not make a definitive finding whether there exists any evidence to substantiate that Dr. Mann did engage in, or participate in, directly or indirectly, any actions that deviated from accepted practices within the academic community for proposing, conducting, or reporting research or other scholarly activities.
Full report at:

I predict this will be met by the denialosphere with further claims of a conspiracy.

How did Fox News spin it?

Penn St. Investigating Scientist Over Research Misconduct