Out Of Everything We Do To The Oceans, Is Climate Change The Worst?

… It is, according to this story in Carbon Brief.

Never mind what BP did to the Gulf, never mind the Exxon Valdez. Never mind over-fishing, pollution, de-oxygenated blooms at the mouths of rivers worldwide.


The Carbon Brief story references  a paper just published in Nature Communications titled “Spatial and temporal changes in cumulative human impacts on the world’s ocean.”

The paper says “Globally, increases in climate change stressors (sea surface temperature anomalies, ocean acidification and ultraviolet radiation) drove most of the increase in cumulative impact, confirming the need to address climate change to maintain and sustain marine ecosystems globally.”

However, they also write “Nearly 66% of the ocean experienced increases in cumulative impact over the 5-year study span  Increases tended to be located in tropical, subtropical and coastal regions, with average increases in 77% of all exclusive economic zones.” That would suggest that other human contributions might be more significant.

And in fact, according to the paper, “Overall, countries with greater increases in coastal population had larger 5-year changes in cumulative impacts.”

Well, okay–they suckered me in. Let’s look at sea surface temperatures, which, according to the European Environmental Agency are 1 degree Celsius higher than they were 140 years ago.

Here is how they describe the impacts:

“Some organisms are now appearing earlier in their seasonal cycles than in the past.”

“The consequences include increased vulnerability of North Sea cod and stocks to over-fishing”

“Fish and plankton have expanded their geographical distribution further north in response to increasing temperatures. Depending on the species this expansion occurs at an average rate of 30 -100 km per year.”

The horror.

My problem with the paper is that they lump together various potential impacts–sea surface temperatures, acidification and UV radiation–and assign it a score that is hard to disambiguate. The only impacts I have seen discussed with regards to acidification are to coral reefs, and it appears that impacts are being re-evaluated as the reefs show surprising resilience–as soon as other human impacts, such as dynamite fishing, are removed from the picture.

I have seen no discussion of the impacts of UV radiation. Perhaps a better-informed reader will guide me.

The upshot appears to be that 1C of warming sea surface temperatures have changed seasonal movement and growth patterns in some species, very similar to what has happened on land.

Until there is greater visibility on how their metrics are defined I will remain of the opinion that climate change has had far less impact on our oceans than pollution, over-fishing and introduction of alien species. Just as it has been on land.


4 responses to “Out Of Everything We Do To The Oceans, Is Climate Change The Worst?

  1. Impact of NASA’s adoption of Karl’s ‘we have to hide the hiatus’ dataset on your bet: Joe Romm’s back in the game.

    Feb by HaroldW at Blackboard:
    GISS average anomaly 2000-2009 is currently 0.556 K
    Given the bet (0.15 K increase over the decade), the break-point is an average for 2010-2019 of 0.706 K.
    GISS average anomaly 2010-2014 is currently 0.612 K.

    Average anomaly for 2015-2019 would have to exceed 0.8 K for Romm to win. Compare to last year’s record high of 0.68 K.

    Current numbers are .599 for 2000-2009, and .680 for 2010-2014
    Now last year’s record is .75, and the new target is .818.

    Under my comparison to a decade prior,
    2010-2000 = 31 ,2011 +6, 2012 +1, 2013 +5, 2014 +20
    for a total of 63 vs bet line of 75. Before the update this was just 40.
    Remaining years he would need 15+ 12/5 = 17.4 to catch up
    70, 64, 67, 55, 66
    87, 81, 84, 70, 83 would be targets.

    Before the update, Romm was 35 behind, and needed 22 to catch up.
    66 60 63 49 60
    88 82 85 71 82
    Same targets, but with about .04C being added by SST adjustment, .06C for 2014.

    • The new target hasn’t gotten higher. By July 1, NASA’s numbers were .566K for 2000-2009, making the target .816K, under the old numbers.

  2. At the time, I said I liked Romm’s side of the bet, since 1.5 is pretty cool for a lukewarmer. Felt really foolish about it lately. I still think you are in OK shape.
    .82K over five years is likely, with this year probably coming in above that.
    The benefit you have is that it would mean an unprecedented 5th straight increase, so future years could average lower.
    There of course is also five years for another adjustment.

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