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The Oceans Are Still Part of the Globe
There are a lot of news stories out today about a new study that explains the recent 'pause' in global warming. The background is that the rate of surface temperature warming over the last 10-15 years is lower than in decades previous, which has led some to claim that global warming has stopped or slowed down. The new study says that this can be explained by a natural cycle in the Pacific Ocean that has been burying some of the heat, thus masking the true warming.
Adopting the term 'pause' or 'hiatus,' as almost all of the stories do, is a little problematic and may lead to confusion, I think. So a couple of clarifications are in order.
1. While it is true that the short-term rate of warming has been lower than before, there is still a good case to be made that this is statistical noise, due to natural variability, in a long-term trend. If you look at the temperature record, you can find other similar 'pauses' in the middle of clearly upward trends. See the figure below.
2. Typical graphs (like the one above) show surface temperatures. But oceans are part of the globe, too! So slowing of surface temperature warming does not mean that global warming has slowed. If you move a big pot of hot soup from your kitchen counter to your refrigerator, the ambient temperature of your kitchen may fall for a little while. However, putting the soup in the refrigerator does not magically make the heat go away. It will eventually be dissipated back into the kitchen.
When you put this all together, you get something like the following: The new study suggests that global warming continues, but that natural cycles in the Pacific Ocean have pulled some of the heat from the surface, which may be the main reason that surface warming appears to have slowed. This cycle is temporary and the heat may be returned to the surface.
More here and here.
4 comments:
While I agree with you, the fact we're in a relatively stable period of temperature rise - nearly 10 years - makes it harder to make the case to the ignorant and skeptical.
Jared,
I notice your chart starts with 1970, when by the way, Time Magazine (I think, but it might have been some other magazine) was warning of global cooling. Picking starting points is critical to any kind of analysis, as the shorter time periods on your chart so clearly illustrated. To some extent by cherry picking starting points you can get almost any data set to tell multiple different stories. If your chart had started with the 1940s it would have shown global cooling until the 1970s. If you go all the way back to 1850s, which was the end of the roughly two century Little Ice Age (i.e. and abnormally low starting point), global temperatures have been increasing at the rate of slightly less than 1 degree centigrade per century. That is just data that cannot be denied. The question is, what does the data tell us?
I assume your answer is that anthropogenic CO2 has caused most of the observed increase. But anthropogenic CO2 has only been an issue since roughly the end of World War II. So what accounts for the observed increase the century before that? I think you have to admit that there have been times in the past when global temperatures have been both higher and lower than now when anthropogenic CO2 could not have been the cause. So, how can you be so sure the cause since 1970 is mostly anthropogenic CO2 and not whatever caused fluctuations prior to that?
Now as I understand it, there has not been enough increase in surface water temperatures to account for the “missing” warming, so some have speculated that it is “hiding” in the deep waters. I suppose that with world-wide Ocean currents that may be possible, but clearly the warmth has to pass through surface water to get to the deep water so I find that answer unsatisfactory.
Essentially all the forecasting models missed the current pause in global warming, so at a minimum this illustrates that those models may be missing variables or making incorrect assumptions or both or something else is going on. I really don’t have a dog in that fight. I’m perfectly willing to leave that to you scientists to work out. As long as you scientists limit yourselves to building models and working the bugs out of them, I say more power to you. But if you transition from dispassionate scientist to political advocate, then I do care. Don’t use your buggy models to justify political solutions that will damage our fragile economy.
Just wondering what data we have that shows the oceans have absorbed the heat.
Greg, did you read either of the links?
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