Climate scientists struggle to explain warming slowdown | Hacker News Reader

Climate scientists struggle to explain warming slowdown

reuters.com

31 pointsstfu18 comments

This article is ridiculous, leading with quotes from Bjorn Lomborg and Richard Tol, neither of whom are scientists or conduct climate research.

It even undercuts its own headline, but waits until nearly the end to do so:

"The IPCC has consistently said that fluctuations in the weather, perhaps caused by variations in sunspots or a La Nina cooling of the Pacific, can mask any warming trend and the panel has never predicted a year-by-year rise in temperatures."

Carbon dioxide, by itself, is a rather weak greenhouse gas. Most if not all of the models discussed here (note that there is no scientific consensus on a single model) involve a runaway process in which the rise of CO₂ triggers a precipitous rise in other warming agents. It is this part that has failed to pass (so far).

So the debate returns to its basis, which is precaution. Alas, regarding this science can tell us nothing about its optimal level. Are we willing to bet that the rise in CO₂ will continue to not trigger a runaway process? For developed nations, limiting CO₂ emissions bears only moderate economic harm, and many are not willing to take the bet. For upstart giants like China and India, tough emission limits involve a halt in development, delaying by decades (if not centuries) the time at which they may catch up with Western standards of living.

Are we willing to bet that the rise in CO₂ will continue to not trigger a runaway process?

The problem with that argument is you can make it for anything that's not well understood.

According to this chart:

http://www.planetseed.com/files/uploadedimages/Science/Earth...

We are due for another 100K years of dropping temperatures.

"The climate system is not quite so simple as people thought," said Bjorn Lomborg

This is the understatement of the year. The Earth is an extremely complicated system.

It's a silly strawman comment from an author who has made a career out of making himself controversial.

And yesterday:

> The summer ice melt in parts of Antarctica is at its highest level in 1,000 years, Australian and British researchers reported on Monday, adding new evidence of the impact of global warming on sensitive Antarctic glaciers and ice shelves.

http://www.reuters.com/article/2013/04/15/us-antarctica-ice-...

It's a complicated topic, I guess.

While I agree this article panders to the climate change skeptics, the following paragraph captures the actual issue:

"Some experts say their trust in climate science has declined because of the many uncertainties. The UN's Intergovernmental Panel on Climate Change (IPCC) had to correct a 2007 report that exaggerated the pace of melt of the Himalayan glaciers and wrongly said they could all vanish by 2035."

The rash of black and white statements about what will happen based on "unequivocal" data and dire predictions of gloom and doom. All because some folks decided to use their view of science to push a political agenda in a direction they wanted to go (or their supporters did).

We risk having the public, especially the US public who is woefully under-trained in what science is, retreat further into mysticism and various other belief systems. That would be bad for everyone.

I'm no expert on Earth's climate but I do find it interesting that we are technically in an "ice age" right now. This sort of implies to me that we should expect a rise in temperature as a natural part of climate change.

http://en.wikipedia.org/wiki/Ice_age

The current Ice age is 2.6 million years old. We have been in an inter-glacial period aka the warm part of an ice age for the last 11,400 years. Which if anything suggests we should be heading to the colder part of an Ice age as they don't last all that long. http://en.wikipedia.org/wiki/Interglacial

PS: These things also nest, Brief periods of milder climate that occurred during the last glacial are called interstadials. Which are inside an Iterglaical which is inside an ice age.

How can you publish an article like that and not include a graph? Anybody know what data they are taking about?

Here are some graphs which make this seem less interesting.

http://www.planetseed.com/relatedarticle/temperature-change-...

PS: This is the kind of article that ignores error bars in predictions. The point is to create interest and sell articles.

>Here are some graphs which make this seem less interesting.

Your source shows a graph that stops in 2005 and one that stops in 2000. But the subject of OP is how much it seems to be warming (or not) in this century. Those extra 7 to 13 years of data that your graphs left out is the interesting part.

If you want more recent data here it is: http://data.giss.nasa.gov/gistemp/graphs_v3/

However, my point was looking further in the past you see a more complex trend than the near strait line temperature increase from 1960-2000 or 1920-2000 that are used to scare people. Basically, the five year average is more random than some carefully crafted graphs show.

Right, and it was a plausible response back when the rate of increase had only been slow-to-none for ~5 years. But as the length of the slowdown increases to more than a decade and starts to approach two decades that becomes less tenable. There's a REASON those two charts haven't been updated, which is that even a plot of the five year average points WOULD show a slowdown if you did it today.

Yes, it's true that there have been extended slowdowns/downturns before, (eg, 1920-1940) but those were seen as needing an explanation. (Or at least some handwaving.) AFAIK we don't really have an explanation for the current slowdown. One possible explanation is that sensitivity to CO2 is lower than we thought.

It's talking about the general flattening of the temperature trend in the last decade or two. Try this:

http://www.woodfortrees.org/plot/wti

The default woodfortrees index averages a bunch of different global temperature series so you don't have to pick just one. (It starts in 1979 because that's when we first had satellite coverage.)

If you try to plot a linear rate from that, the trend depends on what year you start from. From some starting years the trend is increasing (though less than predicted) but from other starting years the trend is flat or even decreasing. For an example of the latter, here's a trendline for the last ten years:

http://www.woodfortrees.org/plot/wti/from:2003/plot/wti/from...

There is a sort of "missing heat" problem, but that has (probably) already been solved: http://news.mongabay.com/2013/0328-hance-climate-missing-hea...

This is being heavily flagged because it is an inconvenient truth. Oh the irony.

Reply on news.ycombinator.com