The decline of coral reefs has entered the literary world: a recent New Yorker featured Kimiko Hahn’s poem The Fever about coral bleaching. Take a look before it disappears from the online site.
The poem includes the passage "I wonder if it’s, yet again, the ozone layer". Hopefully the author is playing off the history human impacts on the environment not suggesting ozone depletion is the cause of coral bleaching. UV light does play a role; thankfully no corals are growing on the shores of Antarctica.
The poem's appearance is well-timed. First, in the past month, there have been warm-water anomalies in Florida, in Okinawa (Ishigaki) and the Northern Mariana Islands. In each case, people on the ground reported coral bleaching was underway. The predictive ability never ceases to amaze me. You can see the temperatures maps at NOAA's Coral Reef Watch (the data is best visualized using Google Earth).
Second, the IPCC's full Working Group II report - that's the climate change impacts section - is now available. The impact of climate change on corals reefs is one of several "cross-cutting" themes including the impact of climate change on coral reefs. Rather than look flip through the 20 chapters of the full report for information about corals, you can just read the case studies at the end (scroll down, it is before the appendix). The summary is a pretty solid survey of the science; unfortunately, since the IPCC report was finished a while back and could not include some more recent results.
Third, a terrific meta-analysis by John Bruno and Elizabeth Selig of UNC published a few weeks ago in the free (yes, free to anyone) online journal Public Library of Science documents the decline of coral cover across the Indo-Pacific. Bruno and Selig went through the arduous task of analysing every survey of coral cover conducted in the past 40 years. They found coral cover across Indo-Pacific reefs may have declined from over 40% in the 1980s to closer to 20% today. The method of averaging the data over such a large area may be questioned; there may be bias in where we choose to study corals. But the study makes it very clear that coral cover is decreasing. The paper has caused quite a stir (see Coral Bones and Climate Shifts for some accessible discussion).
The decline is believed to be caused by the usual suspects: overfishing, destructive fishing practices, disease, pollution / sedimentation, and coral bleaching due to rising ocean temperatures. The gradual decline in coral cover may seem to point to the direct human threats rather than coral bleaching, the rationale being that coral bleaching events like the 1997/1998 event are widespread and should result in step changes in coral cover (punctuated equilibrium over gradualism?). A tempting argument, but the data does not support it.
In truth, individual events are never that widespread. Coral bleaching has yet to occur in concert across globe or even across the massive and diverse region in the Bruno and Selig study. For example, the famed 1997/1998 was not really global: events occurred in the Indian Ocean, the Caribbean, and parts of the Pacific, due in part to El Nino. The "Indo-Pacific" covers SE Asia and Australia east to Tahiti, an area largely not affected by the 1997/1998 El Nino (the W Pacific is, if anything, cooler during El Nino events; bleaching on the Great Barrier Reef happened when the Pacific flipped to La Nina conditions in 1998).
So, if bleaching was a major cause of a decrease in coral cover, a gradual decline, not a step change, in total average coral cover for a large region, or for the entire globe, is exactly what we should expect to see. That's not to say bleaching is "the" cause, rather one of the causes.
This year, the N Marianas and Okinawa. Next year?
Wednesday, August 29, 2007
Coral decline in the Indo-Pacific
Wednesday, August 22, 2007
The Cleantech Collective
I wanted to spread the word about the launch of the Cleantech Collective,
an exciting new online forum for people interested in or working on sustainability and clean energy:
"Cleantech Collective is a moderated online business community for clean tech investors, entrepreneurs, policymakers and concerned citizens. If that's you, sign up and start building a personal network with your peers and leading environmental experts...create a profile and promote your business...submit your own content, rate posts and leave comments... get advice you can use from the web's leading experts on clean technology."
Leak of Asia-Pacific climate policy
Apparently I’m not the only one talking about energy intensity.
The declaration – you can read it here – is a remarkably evasive document (if it is genuine...). It takes real craftsmanship to construct something like this.
A 25% reduction in energy intensity, essentially producing more income with less energy is important, yes. Especially in China and India. But is it an accomplishment? No. Like the US and Canadian targets based on emissions intensity, this target is a farce. It is destined to happen with or without a "climate" policy. The real advance, as the graph shows, would be a decrease in the greenhouse gas emissions per unit of energy production.
Thursday, August 16, 2007
Reporting and promoting science
Science sells these days. In the push for advertising dollars and readership, the conventional and electronic media strive to link new scientific results to the pressing issues of the day.
And, to be fair, in the push for tenure and grant dollars, we academics can be guilty of the same. The holy grail used to be getting a paper in Nature or Science. Now it is getting a paper in Nature or Science so that the paper will be reported on CNN or the BBC.
The intent, in either case, can be benign. A lot of the published science today, on subjects like climate change, is important news. But in the effort to "frame" - to use the terminology in the Matt Nisbet and Chris Mooney article that created buzz earlier this year - science for public and political consumption, a lot of mistakes are being made. It ranges from the inaccurate reporting and questionable publicity of the mythical lake that would resolve the very real crisis in Darfur to outright abuse of statistics to throw stones at solid science.
Take these three recent headlines... please.
1
I call this is a "false positive". There's been a huge and unnecessary uproar over the discovery of a minor mathematical error in the NASA GISS historical temperature dataset. The error means that 1998 was no in fact the warmest year in US history, but is tied with 1934. As the NASA scientists themselves report (pdf), the error has a negligible impact on the global temperature, no impact on global rankings of the warmest years, and absolutely no impact on the evidence for human influence on the climate (see Tamino or Realclimate for details).
2) Warming will pause then full steam ahead, scientists contend
This is the "we didn't read the whole paper". These reports of a "global warming" forecast for the next decade come from a innovative short-term climate modeling study published in Science. The goal of the study was to test the ability to predict climate on decadal or shorter time-scales, a specially developed climate model that explicitly considers the frequency of large-scale atmosphere-ocean oscillations like El Nino (see Tamino). At the end of the study, after a lengthy model validation against observed data from the recent past, the authors discuss the model's predictions for the next ten years, stressing they are contingent on stochastic variables like the occurrence of El Ninos. The headlines made it seem as though the scientific community had confidently concluded that 'warming will pause' for a couple years.
3) Trees won't fix global warming
And finally, "we just didn't understand the paper". The headlines are based on research, presented at last week's ESA meeting, from Duke University's Free Air Carbon Enrichment (FACE) site, where scientists have been testing the effect of higher CO2 levels on tree growth for the past ten years. In the past, scientists had thought that higher atmospheric CO2 would effectively 'fertilize' plants. The Duke experiments showed that this fertilization effect was limited by the availability of water and nutrients (press release). In an effort to link the result to a public issue - carbon offsets - the media stories reported that new research shows planting trees won't work to combat global warming. In other words, planting trees won't take up ANY carbon. Of course it would; all that wood is made of carbon, where else could it come from? The Duke research only showed that there won’t be an extra growth bump because there’s more CO2 levels in the air, not that there won't be any growth at all.
This is the danger of popularizing science. As we saw with the coverage of the Darfur Lake, more attention was given to the initial headline than to the later reports that the 'lake' did not in fact hold any water. Unfortunately, with such quick turnaround in reporting, it is vital that all of us, the one's doing the research, the one's writing the press releases and the one's writing the news story, get it right the first time. It's not a trivial task. But otherwise, these misrepresentations (about global temperature) or misintepretations (about short-term climate prediction) or mistakes (about trees and carbon) make it into the public consciousness.
Monday, August 13, 2007
Arctic sea ice about to set record / Photo of the week
In case you missed it, William Chapman of the University of Illinois reported last week (on his site Cryosphere Today) that Arctic sea ice has, or will very soon, reach an all-time low, breaking the previous record low in 2005. 
Skeptics are awaiting the results of the sea ice's blood test.
The news reminded me of this photo of the east coast Greenland I took a few weeks ago. This is well south of the sea ice limit, but as you can see, there are plenty of icebergs (leftovers from winter ice? Products of calving ice shelves / land ice on the coast?)
The National Snow and Ice Data Center disagrees Chapman's exact data - it uses a different averaging method - but concurs that the sea ice will reach a record minimum before the melt season is over. The Center even started a news site devoted entirely to covering the finer points of the ice melt season. It's a climate junkies dream: not only can you track the bleaching of corals and tropical storms online every day of the week, you can now watch the ice melt too. I'm waiting for the all global warming cable channel, with the 24-7 climate news ticker.
Friday, August 10, 2007
Energy intensity and the challenge that lies ahead
A passage about "energy intensity" in the, er, cheery Thomas Homer-Dixon book The Upside of Down got me thinking more about the historical trend in GHG emissions intensity.
For new readers, a couple months back I showed that the globally-averaged emissions intensity has been decreasing for decades even though the total emissions were increasing. In other words, the economy has been expanding faster than GHG emissions. Therefore, a future emissions target based on the rate of emissions per economic production, as was proposed in Canada, would allow total emissions to increase.
History Database of the Global Environment (similar analysis has been done for the recent past by the IPCC's WG III and by Informetrica for Canada alone).
The graph shows that the emissions per unit energy - the blue line - has been relative stable since the Industrial Revolution. The energy intensity- the green line - mirrors the original emissions intensity curve. It peaked in the 1920s and has been decreasing since.
In other words, the emissions intensity has been falling for the past eighty years because we’ve been producing more stuff with less energy not because we’ve become more efficient, emissions-wise, at producing energy. Over the past three decades, world energy production has actually became less GHG efficient due largely to increased energy use in Asia. Emissions intensity decreased during this time only because, as a planet, we were able to produce more income with less energy.
The graph is useful for articulating the challenge that lies ahead. Since it will take time to rebuild the existing energy production infrastructure ("slow turnover of capital stock"), becoming more energy efficient, producing more stuff with less energy is critical to reducing greenhouse gas emissions in the short-term. That's the green line. But to achieve the long-term emissions reductions (ie. like these proposals) required to avoid dangerous interference with the climate, we'll need to move the blue line. In other words, we'll need to radically change the way be produce, not just use, energy. And, again, with the slow "turnover of capital stock", we need to start planning as soon as possible.
Monday, August 06, 2007
US Energy Bill passes, for now
The US Congress passed the broad and controversial Energy Bill on Saturday. President Bush has threatened to veto the bill over the cuts in oil subsidies and the 15% renewable portfolio standard (RPS) for utilities.
The utilities' anti-RPS argument is that renewable energy potential is low in some parts around the country. It has caught on with the media. As CNN puts it:
Utilities in Southeast and Midwest states that lack wind currents needed to justify new wind turbines would have to pay billions of dollars in penalties to comply with the rules.
Yes, wind energy potential varies geographically. The South would be at a disadvantage if wind were the only form of renewable energy available. The midwest, however, should have some of the highest wind energy potential in the country. And as long as the planet is receiving energy from the sun, there will be at least some wind currents everywhere.
Friday, August 03, 2007
US Congress to debate Energy Bill
The US Congress is debating an Energy Bill today (HR 3221 – read it here). It is different from the recently passed Senate Energy Bill in a number of ways.
Otherwise, the bill is a grab-bag of different projects, many good (testing photovoltaic roofs), many oddly specific (no incandescent lights on coast guard vessels), many that will be labeled pork barrel (money for some rather specific biofuel programs) and many that will cause a double-take (a line item study on ice sheets!).
And then there is this:
Sec. 6102. MANAGEMENT OF FEDERAL GOVERNMENT GREENHOUSE GAS EMISSIONS… so as to achieve zero net annual greenhouse gas emissions from the agencies by fiscal year 2050.”
Yep, the bills says all US government operations are to be carbon neutral by 2050. As the NY Times reports, that would include the Pentagon. Let’s just hope this isn’t used as an argument to shift to nuclear, rather than conventional, warfare.
That is one area where Iraq is leading the US; as Eli points out, if the present trend continues, electricity generation in Baghdad will become carbon neutral by the end of 2008.
UPDATE: President Bush has threatened to veto the bill.
