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Aerosol effects and climate, Part II: the role of nucleation and cosmic rays

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Translations: (Italian)

Guest post by Bart Verheggen, Department of Air Quality and Climate Change , Energy research Institute of the Netherlands (ECN)

In Part I, I discussed how aerosols nucleate and grow. In this post I’ll discuss how changes in nucleation and ionization might impact the net effects.

Cosmic rays

Galactic cosmic rays (GCR) are energetic particles originating from space entering Earth’s atmosphere. They are an important source of ionization in the atmosphere, besides terrestrial radioactivity from e.g. radon (naturally emitted by the Earth’s surface). Over the oceans and above 5 km altitude, GCR are the dominant source. Their intensity varies over the 11 year solar cycle, with a maximum near solar minimum. Carslaw et al. give a nice overview of potential relations between cosmic rays, clouds and climate. Over the first half of the 20th century solar irradiance has slightly increased, and cosmic rays have subsequently decreased. RC has had many previous posts on the purported links between GCR and climate, e.g. here, here and here.

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Aerosol formation and climate, Part I

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Translations: (Italian)

Guest post by Bart Verheggen, Department of Air Quality and Climate Change , Energy research Institute of the Netherlands (ECN)

The impacts of aerosols on climate are significant, but also very uncertain. There are several reasons for this, one of which is the uncertainty in how and how fast they are formed in the atmosphere by nucleation. Here, in part I, I’ll review some of the basic processes that are important in determining the climate effects of aerosols, focusing in particular on their formation. This is also relevant in order to better understand –and hopefully quantify- the hypothetical climate effects of galactic cosmic rays which I’ll discuss in a follow-up post.

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Farewell to our Readers

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We would like to apologize to our loyal readers who have provided us so much support since we first went online in December 2004. However, after listening to the compelling arguments of the distinguished speakers who participated in the Heartland Institute’s recent global warming contrarian conference, we have decided that the science is settled — in favor of the contrarians. Indeed, even IPCC chair Rajendra Pachauri has now admitted that anthropogenic climate change was a massive hoax after all. Accordingly, RealClimate no longer has a reason for existence. The contrarians have made a convincing case that (a) global warming isn’t happening, (b) even if it is, its entirely natural and within the bounds of natural variability, (c) well, even if its not natural, it is modest in nature and not a threat, (d) even if anthropogenic warming should turn out to be pronounced as projected, it will sure be good for us, leading to abundant crops and a healthy environment, and (e) well, it might actually be really bad, but hey, its unstoppable anyway. (Can we get our check now?)

With all due respect…

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Translations: (Italian)

There was a great comedy piece a few years back (whose origin escapes us) that gave examples of how the English would use their language when speaking to a non-native speaker to imply the precise opposite of what was actually being understood. This allowed the English to feel superior without actually damaging international relations. One example was the phrase “with all due respect” which is generally understood to imply that the speaker has a great deal of respect for their counterpart, while the speaker is actually implying that they have no respect in the slightest for their interlocutor. The respect due being precisely zero.

This thought occurred to us when a few of us opened our email this week to see a draft ad being sent around by the Cato Institute (i.e. Pat Michaels) looking for signatories prior to being published in “major US newspapers” sometime soon:

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Advice for a young climate blogger

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Translations: (Italian) (Español)

Congratulations! You have taken the first step towards attempting to communicate your expertise and thoughts to the wider world, which remains poorly served by its traditional sources of information when it comes to complex societally relevant issues like climate change. Your aim to clarify the science (or policy options or ethical considerations or simply to explain your views) is a noble endeavor and we wish you luck and wide readership. But do be aware that you are dipping your blog into sometimes treacherous waters. Bad things can happen to good bloggers. So in a spirit of blog-camaraderie, and in light of our own experiences and observations, we offer some advice that may be of some help in navigating the political climate relatively unscathed.

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Bushfires and extreme heat in south-east Australia

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Translations: (Deutsch) (Español) (Italian)

Guest commentary by David Karoly, Professor of Meteorology at the University of Melbourne in Australia

On Saturday 7 February 2009, Australia experienced its worst natural disaster in more than 100 years, when catastrophic bushfires killed more than 200 people and destroyed more than 1800 homes in Victoria, Australia. These fires occurred on a day of unprecedented high temperatures in south-east Australia, part of a heat wave that started 10 days earlier, and a record dry spell.

This has been written from Melbourne, Australia, exactly one week after the fires, just enough time to pause and reflect on this tragedy and the extraordinary weather that led to it. First, I want to express my sincere sympathy to all who have lost family members or friends and all who have suffered through this disaster.

There has been very high global media coverage of this natural disaster and, of course, speculation on the possible role of climate change in these fires. So, did climate change cause these fires? The simple answer is “No!” Climate change did not start the fires. Unfortunately, it appears that one or more of the fires may have been lit by arsonists, others may have started by accident and some may have been started by fallen power lines, lightning or other natural causes.

Maybe there is a different way to phrase that question: In what way, if any, is climate change likely to have affected these bush fires?

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A global glacier index update

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Translations: (Italian) (Español)

Guest commentary by Mauri Pelto

For global temperature time series we have GISTEMP, NCDC and HadCRUT. Each has worked hard to assimilate global temperature data into reliable and accurate indices of global temperature. The equivalent for alpine glaciers is the World Glacier Monitoring Service’s (WGMS) record of mass balance and terminus behavior. Beginning in 1986, WGMS began to maintain and publish the collection of information on ongoing glacier changes that had begun in 1960 with the Permanent Service on Fluctuations of glaciers. This program in the last 10 years has striven to acquire, publish and verify glacier terminus and mass balance measurement data from alpine glaciers the world over on a timely basis. Spearheaded by Wlfried Haeberli with assistance from Isabelle Roer, Michael Zemp, Martin Hoelzle, at the University of Zurich, their efforts have resulted in the recent publication, “Global Glacier Changes: facts and figures” published jointly with UNEP. This publication summarizes the information collected and submitted by the national correspondents of WGMS portraying the global response of glaciers to climate change, as well as the regional response.

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Weblog awards

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The 2008 Weblog AwardsRealClimate is a finalist for “Best Science Blog” in this year’s Weblog awards. As in years past, we are happy to have this chance to widen our readership over the voting period and we welcome anyone who is visiting for the first time. To get an idea of what we are about, start with the ‘start here‘ button, or look at the index for climate-related topics that you might find interesting. Our goal is to add more context to climate stories that you might see – something that is often missing in mainstream coverage – and give some insight into what the climate science community is thinking and talking about.

As for this poll, historically winners appear to be mostly determined by whose devotees are most adept at voting from multiple machines or writing scripts, so we aren’t too concerned about our eventual placement (and we are especially eager not to emulate last years contest). [Update: We should note that security updates in this year’s poll should prevent that scripting hack from working, and that we aren’t encouraging people to find new ways around the system.]. The voting widget is below the fold (you are allowed to once every 24 hours from a single IP address), and don’t forget to check out other blogs nominated in other categories that you might find interesting.

Finally, a comment on the nature of science blogging: Science is the process of winnowing through plausible ideas, testing them against observations and continually refining our understanding. It is not generally marked by hasty jumping to conclusions; accusations of bad faith, fraud and conspiracy; continual and deliberate confusions of basic concepts (climate vs weather for instance); and the persistent cherry-picking of datasets to bolster pre-existing opinions. Science blogging can play a role in improving science – whether through education, communication or through harnessing the collective endeavors of ‘citizen scientists’ – but the kind of vituperative tone that dominates some blogs greatly diminishes any positive contribution they might make. Science (even climate science) should be about light, not heat. Online voters might want to bear that in mind.

2008 Year in review

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Way back at the end of 2006, we did a review of the year’s climate science discussion. It’s that time of year again and so we’ve decided to give it another go. Feel free to suggest your own categories and winners…

Most clueless US politician talking about climate change (with the exception of Senator Inhofe who’d always win):
Sarah Palin:

Well, we’re the only Arctic state, of course, Alaska. So we feel the impacts more than any other state, up there with the changes in climates. And certainly, it is apparent. We have erosion issues. And we have melting sea ice, of course. [….] You know there are – there are man’s activities that can be contributed to the issues that we’re dealing with now, these impacts. I’m not going to solely blame all of man’s activities on changes in climate.

Most puzzling finding from 2006 that has yet to be convincingly replicated:
Methane from plants

Most reckless extrapolation of short term trends:
Michael “All global warming has been erased” Asher (Daily Tech)

This year’s most (unsurprisingly) abused study:
Keenlyside et al. initialised climate forecasts (and no, they didn’t take our bet).

Climate scientist with biggest disconnect between his peer-reviewed papers and his online discussions:
Roy Spencer

Most worn out contrarian cliche:
The “Gore Effect”. This combines the irrelevant confusion of climate with weather and the slightly manic obsession with Al Gore over the actual science. Do please grow up.

Most bizarre new contrarian claim:
Global warming is caused by undersea volcanoes (and pirates!).

The S. Fred Singer award for the most dizzying turn-around of a climate pseudo-skeptic:
Dennis Avery: “Global warming is likely to continue” (2006) , to global warming is “unstoppable” (2006), to “Say Good-Bye To Global Warming And Hello To Global Cooling!” (2008).

Pottiest peer on the contrarian comedy circuit:
Viscount Monckton of Brenchley

Least unexpected observations:
(Joint winners) 2008 near-record minima in Arctic sea ice extent, last decade of record warmth, long term increases in ocean heat content, record increases in CO2 emissions.

Most consistently wrong media outlet:
The Australian (runner-up the UK Daily Telegraph). Both comfortably beating out the perennial favorite, the Wall Street Journal – maybe things have really changed there?

Best actual good news:
The grown-ups being back in charge starting January 20 (compare with this).

Most inaccurate attempted insinuation about RealClimate:
‘The Soros-funded Realclimate.org’ Chris Horner

Most revealing insight into some US coal companies and year’s best self parody:
Frosty the Coalman (video available here)

Most disturbing trend for science journalism:
The axing of dedicated science units at CNN, the Weather Channel and elsewhere. Can Climate Central and blogging journalists take up the slack?

Happy New Year to all of our readers!