Climate Changes Shift Springtime in Europe

gollum123 writes to mention a BBC article on a study of Europe's changing climate. The study collated information from 17 nations and 125,000 studies involving 561 species. The results indicate that, at least in Europe, 'Spring' is coming earlier and earlier every year. From the article: "Spring was beginning on average six to eight days earlier than it did 30 years ago, the researchers said. In regions such as Spain, which saw the greatest increases in temperatures, the season began up to two weeks earlier. The findings were based on what was described as the world's largest study of changes in recurring natural events, such as when plants flowered. The team of researchers also found that the onset of autumn has been delayed by an average of three days over the same period."

Comments

Re:MOD PARENT UP

[RsG]

The mods probably saw "cooling trend" and "1970" and assumed the poster was bringing up the tired old arguement that we used to think the earth was headed into a new ice age.

The arguement usually goes that before 1970 we thought there was a new ice age coming, due to a global cooling trend. This is usually followed by the arguement that climate scientists don't know what they're talking about, and that man-made global warming is a myth. What this "talking point" ignores is that the so-called "new ice age" never had much scientific credibility; it is primarily remembered because it had a great deal of press coverage. Further, IIRC the global warming hypothesis goes back to at least 1968.

In every single /. discussion involving climate change, the above arguement is made as a talking point by people who dislike the notion that humans are affecting global temperature. So, after a while I suspect that moderators get a wee bit trigger happy whenever someone mentions the words "cooling" and "1970" in a post about climate change.

Note that the GP's point is valid, as there was an observed period of lower temperature 30 years ago (which is what sparked all the media speculation regarding a new ice age). However, I'm sure the scientists who did this study took that trend into account, and in any case the cooling trend was both brief and comparatively small.

Re:30 years ago?

[slightlyspacey]

As a matter of fact, there was ... from Newsweek "The Cooling World" April 28, 1975, page 64:

In England, farmers have seen their growing season decline by about two weeks since 1950, with a resultant over-all loss in grain production estimated at up to 100,000 tons annually.

So, as a rough estimate growing seasons are about the same as they were in the 1950s. The researchers only went back 30 years so they wouldn't have to deal with this "anomaly". That is known in some circles as "cooking the data".

Re:someone's going to blame 'greenhouse gasses'

[vruba]

I'm reading the article article you linked to, and it seems to support the greenhouse gas theory. For instance, in section 5 (split over pages 2 and 3):

In terms of the causes of the increase in ocean heat content we believe that the long-term trend as seen in these records is due to the increase of greenhouse gases in the Earth's atmosphere

I can't find any mentions of volcanism. Please point them out or provide a better source.

The Earth did cool 1940 - 1970

[puzzled]

      The Earth was cooler from 1940 to 1970 - this was due to diesel engines producing sulfate aerosols, which are highly reflective. Right now we gain about 4.0 watts/meter^2 due to CO2 and methane, but we lose about half of it due to the sulfate aerosols still in the stratosphere. The cleaner burning fuels we implemented in the 1970s resulted in lower amounts of that stuff in the atmosphere, hence the reversal of the cooling (dimming, actually) trend.

Re:Yes....well......

[Coryoth]

And in related news, scientists say Mars is emerging from an Ice Age.

Mars, just like earth, undergoes natural climate fluctuation. On Earth we have Milankovitch cycles, based on the eccentricity, axial tilt, and precession of the Earth's orbit. Mars also has interesting orbital variations, and significantly greater orbital eccentricity than the earth. This results in similar, though differently timed, significant variations in climate. Mars also suffers from severe dust storms which can have a large impact on climate due t changes in atmospheric opacity. Combine that with the current solar variation, to which the IPCC attributes around 30% of the Earth's observed warming, and it isn't that surprising that Mars might be experiencing some climatic change currently.

The real difference between climate change on Mars and climate change on Earth is that the degree of change currently observed on Mars is entirely explainable in terms of observed natural effects, while the climate change on Earth is not. Anthropogenic effects, to the very bestof our knowledge, are required to explain the currently observed warming on Earth.

Re:Is it us or is it mother nature?

[Coryoth]

Yes. Now we know that the centerpiece of that summary, the "Mann Hockey Stick", turned out to be a scientific fraud.

Which is to say, you didn't read it. Honestly, have a look at chapter 12 (Attribution) of the IPCC Third Assessment Report. You'll find just a single mention, buried in the qualitative section, of Mann's study, listed amongst 5 other different palaeological climate reconstructions by different authors, and only to note that "the 20th century warming is highly unusual." You can see those reconstructions (plus several others) charted together if you're curious. Mann's studies, let alone the "Hockey Stick", far from being "the centerpiece", get scant mention. Instead the attribution factor considers many studies using indices and time series methods, pattern correlation methods, and optimal fingerprint methods. This table provides a summary of the attribution studies considered, along with the method, the uncertainty, the timescale considered etc. You might care to note that Mann is not involved in any of the studies considered.

Of course calling Mann's work a "scientific fraud" is rather unfounded too. You may note, in the chart linked above, that there are many other historical temperature reconstructions, done indepdently by different people, that arrive at a similar result to Mann. There is also the recent National Academy of Sciences report on the subject which concluded, with high confidence, that the earth was the warmest it had been in 400 years, and that while there was less confidence in reconstructions going further back, they still point to the earth undergoing unusual recent warming. On the other hand you have the Chairman of the Committee on Energy and Commerce, and an economist and someone from the mining industry claiming it is all bunk. At least McIntyre and McKitrick wrote some semi-respectable papers, though there is considerable dispute about their methodology (at least as much, if not far more, than there is about Mann's).

Let's cast all of that dispute aside however, and assume that Mann was full of crap - that still makes no difference whatsoever to the content of the attribution chapter of the IPCC report I linked to, and which you so very clearly didn't bother to read. I don't mind people having differing opinions, but when they are based on apparently willful ignorance I am a little appalled.

Re:Yes....well......

[Coryoth]

The climate changes on Earth are entirely explicable as natural variation as the IPCC TAR made clear in 2001. The man-made hypothesis is based upon the attribution studies based on climate models.

It's interesting you say that - could you provide me a reference for where the IPCC TAR concludes that the changes are "entirely explicable" as natural forcings? When I read through the conclusion of the attribution chapter I don't see anything about natural forcings providing adequate explanations. On the contrary we have

• "The observed warming is inconsistent with model estimates of natural internal climate variability."
• "The observed warming in the latter half of the 20th century appears to be inconsistent with natural external (solar and volcanic) forcing of the climate system."
• "The observed change in patterns of atmospheric temperature in the vertical is inconsistent with natural forcing."
• "Anthropogenic factors do provide an explanation of 20th century temperature change."
• "It is unlikely that detection studies have mistaken a natural signal for an anthropogenic signal."
• "The detection methods used should not be sensitive to errors in the amplitude of the global mean forcing or response."

The best I can grant you is: "Natural factors may have contributed to the early century warming." but the warming in the last several decades cannot adequately be attributed to natural factors alone.