The new paper that was published in Science this week will, hopefully, be a wake up call that it's not just global warming that is of great concern, it's the changes in the oceans. When people talk about the ocean and CO2, mostly it's in terms of ocean acidification. However the changes we are causing to the oceans go way beyond changes in pH. It's not just shellfish and other pH sensitive species that are affected by the changes we are bringing about. The oceans are crucial to climate (think ENSO), to our food supply, and to biodiversity.
The paper was from a large international team of scientists led by Jean-Pierre Gattuso of the Observatoire Océanologique de Villefranche-sur-Mer. It concludes by summarising four critical messages - the main one being that we must immediately make substantial reductions to CO2 emissions (my emphasis):
- The ocean strongly influences the climate system and provides important services to humans.
- Impacts on key marine and coastal organisms, ecosystems, and services from anthropogenic CO2 emissions are already detectable, and several will face high risk of impacts well before 2100, even with the stringent CO2 emissions scenario (RCP2.6). These impacts are occurring across all latitudes and have become a global concern that spans the traditional north/south divide.
- The analysis shows that immediate and substantial reduction of CO2 emissions is required in order to prevent the massive and effectively irreversible impacts on ocean ecosystems and their services that are projected with emissions scenarios more severe than RCP2.6. Limiting emissions to below this level is necessary to meet UNFCCC's stated objectives. Management options that overlook CO2, such as solar radiation management and control of methane emission, will only minimize impacts of ocean warming and not those of ocean acidification.
- As CO2 increases, the protection, adaptation, and repair options for the ocean become fewer and less effective.
Oceans are critical, not trivial
Oev Hoegh-Guldberg, one of the authors, has written about the paper at The Conversation. He wrote (my emphasis):
Until recently, you might be forgiven for thinking that the oceans were a trivial component of Earth’s climate system, and that the consequences of change were minimal. After all, only 5% of papers published on climate change involve ocean systems. The Intergovernmental Panel on Climate Change (IPCC), which evaluates the peer-reviewed scientific literature, did not devote a regional chapter to the ocean until its most recent major report.
Yet the ocean system could not be more important: it regulates the global temperature and atmosphere, feeds 3 billion people, and largely determines our weather. The ocean also has lots of “inertia” – which means that getting the ocean to change takes a lot of energy, but once it begins to change, slowing it down becomes more or less impossible.
Below is part of figure 1 from the paper, showing the expected changes under two scenarios - RCP8.5 - the high emissions pathway, and RCP2.6, which will require that we draw down CO2 from the atmosphere this century. It paints a stark picture.
|Fig. 1 Environmental changes over the industrial period and the 21st century for a business-as-usual scenario and a stringent emissions scenario consistent with the UNFCCC target of increase in global surface temperature by 2°C. (A to E) Changes in globally averaged (A) SST, (B) sea level, (C) sea surface pH (total pH scale), (D) ocean volume (in % of total ocean volume) with saturation state of calcium carbonate in aragonitic form (Ωa) above 1 and above 3, and (E) dissolved oxygen. RCP8.5, red lines; RCP2.6, blue lines. Source: Gattuso15|
Distinguishable in a decade over 41% of the global ocean
Many of the changes in ocean physics and chemistry are happening very quickly. The authors write that combined changes will be seen in just a decade from now over 41% of the ocean - too soon and too much!
Both the magnitude and rate of the anthropogenic carbon perturbation exceed the extent of natural variation over the last millennium and over glacial-interglacial time scales (14–16). Variability of pH in coastal waters is considerably larger than that in the open ocean, partly driven by upwelling (17), freshwater input (18), eutrophication (19) and biogeochemical processes (20). Anthropogenic trends in biogeochemical variables—notably in pH, PCO2, and the saturation of calcite and aragonite—emerge from the noise of natural variability much faster than sea surface temperature (SST) (21). The combined changes in these parameters will be distinguishable from natural fluctuations in 41% of the global ocean within a decade (22), and the change in aragonite saturation over the industrial period has been more than five times greater than natural variability over the past millennium in many regions (15).
The oceans can only take up so much CO2
Another important point made in the paper is about how much CO2 the ocean can absorb. Under the lowest emissions pathway (RCP2.6), the oceans can take up to 56% of emissions, which means that global warming proceeds more slowly. However under the high emissions pathway (RCP8.5), it drops to 22%. That will make the surface warm up much more quickly as more CO2 accumulates in the atmosphere.
Broad impacts of CO2 on the oceans
- Changes in ocean physics and chemistry - impacting pH, sea temperatures, sea ice and sea level, among other things.
- Effects on biological processes and ecosystems - in terms of warming, ocean acidification, deoxygenation, and the additive, synergistic, or antagonistic impact of multiple drivers working together.
- Effects on ecosystem services and ocean-related human activities - in terms of ocean carbon uptake, coastal protection (and the increasing cost), risks to capture fisheries, negative impacts on aquaculture, impact on tourism (especially to coral reefs), and human health - with the migration of parasites and disease hosts.
Rather than repeat everything in the paper, below is Figure 3, which only shows example of the impacts of the change in pH and sea surface temperature in different regions:
|Fig. 3 Regional changes in the physical system and associated risks for natural and human-managed systems. Projected changes in SST (ΔSST) and pH (ΔpH) in 2090–2099 relative to preindustrial under the RCP2.6 and RCP8.5 scenarios are displayed in different colors on the map. The major ocean regions are indicated as well as examples of risks for natural systems and fisheries [modified from (1)]. Text in parentheses specifies the level of confidence (157). Source: Gattuso15|
The risks are far-reaching. They will be felt all over the world.
The authors also discuss options for future management treatments as four main types: mitigation, protection, repair and adaptation, as illustrated in their Figure 4 below:
Fig. 4 Four clusters of actions against climate change, including ocean acidification. For each cluster, a nonexhaustive list of actions is shown. [CO2]atm is concentration of atmospheric CO2; GH, greenhouse; GHG, greenhouse gases; MPAs, marine protected areas. The mitigation pathway leading to CO2 reductions is represented in bold, consistent with the consensus view that significant reductions in CO2 emissions is presently the only actual “solution” to the ocean impacts of climate change and ocean acidification (see main text).
Setting out management treatments goes beyond what is usual for scientific papers, and is very welcome. It shows that all these will be necessary if we are to limit the damage we are causing. And to implement these treatments will cost money. We will need to start investing sooner rather than later. Reducing CO2 will mean that the costs of some other treatments will be less. Otherwise we'll be spending all our time and effort trying to keep up (and failing). (Like deniers who want to address worsening heat waves by deliberately not reducing CO2 and just installing air conditioning, thereby making heat waves much worse.)
WUWT says no worries, think PETM
Anthony Watts at WUWT pays scant attention to this important paper. The only protest article he's got (so far) is a bit of silliness (archived here) from another denier blog. Something about a research focus article discussing an abiotic zone off Tanzania appearing several tens of thousands of years after the onset of the extreme temperatures, around the time of the Paleocene-Eocene Thermal Maximum. Therefore we don't need to worry. The ocean will die in good time.
Never mind that changes are happening many, many times faster than they happened 56 million years ago. Nor that we can directly measure the changes that are happening now - while it is much more difficult to work out just what happened over a period spanning 170,000 years or so, when going back 56 million years in the past.
One of the papers that his article referred to indicated the difficulties:
Records of tropical sea-surface temperatures (SSTs) from calcareous organisms are rare, as deep-sea sediments commonly have poor microfossil preservation (Zachos et al., 2007). Here we report new geochemical and faunal data from an expanded section from the continental margin of East Africa that provides information about the PETM in the tropics.
And it describes some of the changes that occurred during that time, including even acidification in the deep ocean, plus migration and extinction:
The global surface ocean warmed on average by 4–5 °C, and the subsurface ocean by 5–6 °C (Dunkley Jones et al., 2013). The observation of global shoaling of the carbonate compensation depth (Zachos et al., 2005), combined with recent modeling (Ridgwell and Schmidt, 2010) and boron isotope analysis (Penman et al., 2014) support that ocean acidification occurred in both the surface and the deep ocean. Ecosystem changes have been widely documented (Foster et al., 2013; Gibbs et al., 2006; Scheibner et al., 2005; Kelly et al., 1996; Thomas, 2007; Webb et al., 2009) showing, amongst others, migration toward higher latitudes, changes in ecosystem composition, extinction amongst deep sea species, and calcification responses.
Here is the take-away from an article about the PETM at Weather Underground:
There are a lot of uncertainties surrounding the PETM—this extremely warm geologic period has been notoriously difficult to recreate, but recent advancements in understanding the warming have been made. Uncertainties should not be interpreted as misunderstanding. Instead, they should be treated a testament to how sensitive the climate system could be, and how influential humans are on the delicate global energy balance. It is clear that the earth dumped almost all of its stored carbon into the atmosphere, and now we are doing the same by pulling fossil fuels out of the ground and burning them. Just like the previous great global warming did, we are likely catapulting ourselves into a new geologic era: the Anthropocene.
Even if the PETM extinction event doesn't worry Anthony Watts and his bubble of deniers, then this sixth major extinction certainly should. It's happening so much faster.
From the WUWT comments
Alan Poirier's thought is nerveless groupthink:
July 3, 2015 at 10:46 am
It’s truly unnerving when scientists cannot even follow the logic of their own research. That is the very definition of cult and groupthink.
etudiant can't tell arthur from martha, so his or her thought is to be taken as seriously as anything you'll read at WUWT (ie, not)
July 3, 2015 at 10:49 am
We should be grateful that it is as yet not necessary for Prof Schmidt to add similar politically correct verbiage to his publication in ‘Geology’. Of course I suspect that this loophole will get closed soon.
The Ghost Of Big Jim Cooley is one of the hard core conspiracy nutters at WUWT, who thinks all the climate science of the past two centuries is a leftist plot of the BBC:
July 3, 2015 at 10:51 am
Roger Harrabin is a complete waste of space, but Kirsty Wark usually does her research. I didn’t see her interview. The BBC will never give up on climate change; it’s an institution that moved to the Left many years ago, and sees climate change as an excuse to change the world towards Socialism. People around the world should also be informed that Socialism is taking a really big hit in Britain. The Socialist party (Labour) are seriously on the ropes here, and actually could die out.
Mike Bromley the Kurd thinks the Schmidt article, which was mainly about two papers in the same journal issue (here and here), should have had more than the 31 references it cited:
July 3, 2015 at 10:56 am
Schmidt’s reference list is awfully thin.
menicholas refuses to step outside of the denialist "reality". He or she doesn't know anything about paleoclimates or that extinction events happen when things change quickly enough, not when the climate is stable:
July 3, 2015 at 11:02 am
What is most odd to me is that these people continue to speak as though there was even a shred of confirmation that CAGW is based on reality.
The models have failed, there has been 18 plus years of no warming despite rising CO2 levels, storms and extreme weather are no more frequent than they were in the past, and in fact seem to be becoming less frequent, ocean acidification is not based on reality, and even the terminology used is based on fake science.
Looking through hundreds of millions of years of the geologic record and picking out some unusual circumstance, while ignoring reams and reams of data which proved that CAGW cannot happen, is just plain idiotic.
If we’re going to look at the geologic record for clues as to the effects of high levels of co2 on ocean life, how can anyone possibly ignore levels 10 times higher which existed for millions and millions of years and had no ill effects on ocean life?
While menicholas looked to his warped view of the past to say that there's no problem, Bruce Cobb reckons nothing can be learnt from what happened in the past. That just because hotter seas and ocean acidification in the past caused huge changes, he thinks it doesn't mean it will happen this time around:
July 3, 2015 at 11:09 am
Their fixation on the PETM borders on obsession. It’s total whackiness. That time period, some 56mya can not be compared to today’s climate.
ztabc might think we are heading for an ice age any day now, and mutters something wrong about falsifiability:
July 3, 2015 at 4:35 pm
Science is by definition falsifiable. The main ideas of climatology are not falsifiable. Hence climatology is not science. Do not expect to find science in climatology.
co2isnotevil is another one who, because of his political ideology, thinks climate science is a leftist hoax:
July 3, 2015 at 11:29 am
This is what happens when we allow subjective politics to dictate objective science. Once partisan politics chooses sides, the first casualty is always objectivity. The scientific method as it applies to climate science was replaced by political correctness conforming to the green narrative at about the same time the IPCC was formed. It should be an embarrassment to all scientists that this was allowed to occur.
Ted G is a fan of Elvis and the Beatles and isn't interested in current affairs and world news, which proves (to him) that climate science is a hoax:
July 3, 2015 at 12:30 pm
I grew up in England, as a kid from a working class family, the BBC was was despised by 99% of my family, friends and most of the UK population. Forcing their elite toffy nosed point of view, rationing popular music ie: Elvis. R&B, Beatles, Stones etc.. to a handful of hours a week. Limiting the competition through influencing stupid toffy nosed politicians. Then came the pirate ships – Radio Caroline – Radio London Etc..= Great times in England. The BBC and the ruling class went Bananas. Eventually they sent troops and Police to arrest and shut down those beloved Pirate ship radio stations. And insult to injury Jacked up the mandery radio and TV Licensing fees. I have traveled and lived in many countries since and had a great life. but I still despised the mentality that breed in the BBC and all public broadcasters throughout the western world. to a man they all promote the Global warming agenda and socialism . It’s sickening.
PS. I am a free enterprise, free thinking soul, England you taught me well!
Dr T G Watkins reckons that it's that threat to his little (white anglo) world, multiculturalism, that proves something or the other:
July 3, 2015 at 12:50 pm
Ted G – well said – and interestingly the Aussie ABC follows in its parent’s footsteps whether it be CAGW, socialist leanings and championing multiculturism. Neither reflects the views of the majority that pays for them but only the views of the chattering middle class socialists who refuse to understand that government(s) have no money.
References and further reading
J.-P. Gattuso, A. Magnan, R. Billé, W. W. L. Cheung, E. L. Howes, F. Joos, D. Allemand, L. Bopp, S. R. Cooley, C. M. Eakin, O. Hoegh-Guldberg, R. P. Kelly, H.-O. Pörtner, A. D. Rogers, J. M. Baxter, D. Laffoley, D. Osborn, A. Rankovic, J. Rochette, U. R. Sumaila, S. Treyer, C. Turley. "Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios." Science, 2015 DOI: 10.1126/science.aac4722 (Subs req'd)
The oceans can’t take any more: Fundamental change in oceans predicted - press release from ScienceDaily.com
New report: the chance to rescue the world’s oceans from climate change is drifting away - article about the paper by Ove Hoegh-Guldberg at The Conversation
Video report from the BBC
PETM: Global Warming, Naturally - an article on the Paleocene-Eocene Thermal Maximum from wunderground.com
Schmidt, Daniela. "Some don’t like it hot." Geology 42, no. 9 (2014): 831-832. doi: 10.1130/focus092014.1 (open access)
Frieling, Joost, Alina I. Iakovleva, Gert-Jan Reichart, Galina N. Aleksandrova, Zinaida N. Gnibidenko, Stefan Schouten, and Appy Sluijs. "Paleocene–Eocene warming and biotic response in the epicontinental West Siberian Sea." Geology 42, no. 9 (2014): 767-770. doi: 10.1130/G35724.1 (open access)
Aze, Tracy, Paul Nicholas Pearson, A. J. Dickson, M. P. S. Badger, P. R. Bown, R. D. Pancost, S. J. Gibbs et al. "Extreme warming of tropical waters during the Paleocene–Eocene Thermal Maximum." Geology 42, no. 9 (2014): 739-742. doi: 10.1130/G35637.1 (open access)