Lecture

[Brian Ellis]

Last night, I went to a high-profile lecture entitled Atmospheric Chemistry and Climate Change in the Anthropocene. The target audience was the academics of the region. It was supposed to have been given by Nobel laureate Paul Crutzen (the guy who linked supersonic aircraft and ozone depletion c. 1970). Unfortunately, he had to call off at the last moment and his place was taken by Prof. Jos Lelieveld, whom I had never met. He is the Director of the Max Planck Institute of Chemistry at Mainz and is probably the world's #1 on aerosols and cloud formation.

He took us through the usual carbon cycle, CO2, CH4 and N2O thingies, before getting down to the nitty-gritties of the effects of aerosols in different parts of the world, especially those caused by industrial activities, and how they affected the weather, with respect to altitude. In particular, he pointed out the lack of scientific data and its potential variability in climate modelling. Of course, this is mentioned in the 2007 IPCC reports, but he took us into greater depth.

We then had a look at the particularities of the Mediterranean basin and how it would fare over the next century, citing the work of Schãr of the Swiss Federal Institute of Technology, Zurich, and Giorgi of the Abdus Salam International Centre for Theoretical Physics, Trieste, both of whom have specialised in this aspect of climate over many years. If the modelling is correct, it looks as if I've not chosen the best place to live! However, all is not lost as I'm sure to be dead before it kicks in at its worst!!!

All in all, it was an evening well spent. I picked up a page of notes I took of little titbits of information.

[cjolley]

I lived in Mainz in 1966 at the age of 14.
The only subject I recall thinking about was " How do I go about finding a girl to kiss me."

[Dr Mordrid]

1. go to most any city on Earth
2. stand on a street corner
3. wave money

[DukeP]

Do post Your notes, Brian.

~~DukeP~~

[cjolley]

You too Doc.

[Brian Ellis]

Do post Your notes, Brian.

~~DukeP~~

As they stand, you would not understand them as they are simply keywords used to jog the memory plus the refs I already mentioned.

Perhaps the definition of 'anthropocene' may interest you: the geologic era where the climate is influenced by human activities. The term was coined by Crutzen and started c. 1900. Even if we do as much as we can to stop influencing the climate now, the damage we have already done will still be felt tens of thousands of years from now because many of the positive feedback mechanisms will still play a role.

Two keywords I wrote down are shiptrails and pyrocumulus. You can see shiptrails in an animation here. They were used as an illustration of how even a tiny source, such as a ship, of nucleating aerosols can result in cloud formation. They are a low-level version of aircraft contrails which usually are generated at near-tropopausal altitudes.

This can be extrapolated to the clouds being formed as the aerosols (the brownish haze) from Chinese pollution is being blown towards Japan and then onto North America:

These actually cause a cooling effect. Similar effects can be seen by the sub-micrometre aerosol pollution from N. America adding to Europe's own pollution in this paper.

The pyrocumulus effect is one which I was not very familiar with. All I knew was that cumulus clouds formed downwind from the front of a wide forest fire and I assumed that it was pricipally because of the quantities of water vapour generated. What I learnt was that deliberate burning of the Amazon forest was actually changing the climate by providing nucleating aerosol particles which changed the rainfall weather patterns, reducing rainfall in some critical areas. See this Master's thesis.

A rather stupid but important sea level problem that climate change could produce is that increased wind velocities could exacerbate the, say, 50 cm - 1 m rise by 2100, in that "piling" of the water is predicted to increase from a current 3 m to > 5 m, so that exposed coasts could have an effective 3 m rise over current flood levels, even if the sea level itself does not reach even +1 m. The NW coast of continental Europe (Jutland to Pas de Calais) could be particularly vulnerable to this effect.

The following image is of interest to us, of course, and shows khamsin dust blowing as an aerosol from N. Africa over the E. Med. The white over Cyprus is where the low-level dust (mostly < 1000 m) is diverted upward by the orographical disturbance of the Troodos massif, causing nucleation of the residual humidity at the lower temperatures. This is something we see 2-3 times/year from mid Feb to late March.


The outlook for the Med basin is not good: temps may increase, along with tropospheric ozone, more than the average global predictions and precipitation will decrease, except in the western half of the Iberian peninsula.

There is also a correlation between air quality and temperature. As temperatures rise, so the air quality deteriorates.

Incidentally, one interesting "asides" remark that he made is that carbon isotope measurements of atmospheric CO2 and CH4 correlate exactly with modelling showing the sources of the increased C, and thus radiative forcing, being of fossil origin.

Will that do?