Category: Themes

Time for Plan B – Geoengineering

There has been a huge amount of coverage of the need to cut Greenhouse Gas emissions as the primary route to slow down, halt and eventually reverse the current global warming trend and rightly so. However, in the background there have been a number of suggestions for actions that mankind could take to directly counter-act global warming. Such measures are collectively known as geoengineering and include such things as the direct removal of carbon dioxide from the atmosphere (e.g. by planting trees or fertilising the oceans) and reflecting incoming solar radiation away from the Earth (e.g. by using mirrors in space or changing the land surface to make it more reflective). These measures have not recevied much public attention, partly because they are all really, really expensive, partly because no-one knows how effective they would be and partly because by discussing the ideas in public we might distract attention from the goal of reducing Greenhouse Gas emissions.

Now, the tide has turned a little. A recent report produced by the Royal Society has highlighted the need to urgently begin considering geoengineering as a Plan B to reducing emissions. The report works through various geoengineering ideas examining their affordability and effectiveness and suggests that there should be a major shift of funding into geoengineering research. The report was widely publicised in the media at the beginning of September and the geoengineering debate is nicely summarised in New Scientist, Issue 2724 [05 September 2009].

The Damned United

David Peace’s novel “The Damned United” is quite a controversial book. It charts the story of the 44 day stay of Brian Clough as manager of Leeds United at the start of the 1974/75 football season. The book is critically acclaimed but it has also been slammed as not being representative of Clough and of what really happened at the time. Having read it I can see that writing a novel about something so recent and about someone so well known is really dangerous territory.

I picked up The Damned United to read towards the end of July but when I noticed that the book is written with a chapter for each day and that (in real history) the period covered started on July 31st I decided to start reading on that day and to read one chapter each day so that I allowed the story to unfold in real time. In some ways this was a bit frustrating because I often found myself wanting to read ahead but it was also interesting to pace the story out correctly as this helped me to get inside the head of the (fictional) Clough. The 44th, and last, day of the story was September 12th (so I finished reading the book a couple of days ago). One thing I will say is that if you don’t like swearing don’t read this book…

Anyway, there are two key things that the book gave me. First, it gave me a real insight into just how desperate it must be to manage a football team that isn’t winning (something which chimes well with the form of my own team – Plymouth Argyle – at the moment). There’s simply no escape from the failure and it’s hard to see how it would be possible to get any sleep whatsoever in this situation (in the book alcohol helps). Secondly, as I read the book it was impossible not to read it as if it was factually correct and so I am now left with a very clear impression of what Brian Clough was like at this time (I only remember him myself from slightly later in his career) but this is an impression that is actually fictional and so I do not know which parts are reasonable and which are not. I’m not sure this is fair on the reader and most certainly on the real individual involved. Tricky

Clouds and solar heating feedback

Clouds play an important role in determining the Earth’s climate. They can have a number of different effects but perhaps the most basic one of all is that clouds generally reflect solar energy back out into space thus lowering the amount of solar heating that strikes the Earth and is absorbed. This reflection contributes to something called the planetary albedo, which is essentially the overall reflectivity of the planet. The Earth’s albedo is generally taken as having a value of a little more than 0.3 which means that just over 30%, or a third, of all the solar energy that arrives at the Earth is reflected back out to space and clouds contribute a lot of this reflection. If the Earth had a higher albedo, it would absorb less solar energy and would potentially be cooler; if it had a lower albedo it would absorb more solar energy and be warmer.

So far so good, but it is actually really difficult to determine what will happen to clouds when the Earth’s atmosphere warms up (as it is). More heat in the atmosphere could mean less clouds as the air temperature rises and the water droplets in the clouds evaporate (becoming water vapour). On the other hand a warmer world will mean a greater tendency for water to evaporate from the land or ocean surface, increasing the humidity of the overlying air and increasing the potential for clouds to form when air cools (e.g. at high altitude).

Some new research has suggested that, in the north-east Pacific at least, a warming ocean is leading to less cloud which in turn leads to more solar energy reaching the surface (lower local albedo), which in turn leads to a warmer ocean, which in turn leads to less clouds, which in turn… This is an example of “positive feedback”  and is a potentially important finding which may help to determine which of the current climate models is doing the best job of predicting future global climate scenarios. But nothing is simple – it’s nigh on impossible to know whether the clouds studied are typical and/or whether the findings can be applied more widely. The work is described briefly in a news item on the BBC Website [24 July 2009].

Marine life mixes oceans

One of my colleagues carries out research examining the small scale mixing processes that go on in the oceans. He uses a complicated camera system with lasers and holograms and maps out the swirling motion of the water by tracking particles in the water [see here]. In the past he has ended up with some interesting pictures of little (microscopic) creatures in the water and he has begun to think about how these creatures stir up the oceans as they move around.

So, it was interesting when news of some research conducted in California broke recently. The work has measured the effect that jellyfish swimming in weater have on the mixing of the water water itself. Jellyfish were used because they are relatively simple and can be simulated in models quite well but the principle of ocean mixing by organisms is being considered more widely. In fact, the idea was suggested by Charles Darwin’s grandson some time ago. It turns out that the new research suggests that the mixing could be significant although the extrpolation to all ocean-going organisms, in particular the really small ones (of which there are huge numbers) is a rather uncertain process. It has been suggested that this organismal mixing could be as big as that produced by the other key mixing processes – wind and ocean tides. The result won’t change the results of ocean models because these work by adding in as much mixing as is necessary to get the “right” results but it may point a way to understanding global ocean mixing more thoroughly and it suggests that my colleague’s potential to view the water motion around smaller organisms might be a really fruitful direction to go in.

The research is reported in New Scientist, Issue 2719 [01 August 2009] and also on the BBC Website [29 July 2009].

Raindrops are falling…

As I write this it is pouring with rain and has been for several hours. It is what seems to have become a typical summer’s day… But what do raindrops actually look like as they fall? A recent news item on the BBC Website (20 July 2009) reports on new research that has used high-speed cameras to film falling drops of water and the result is some fascinating footage of complex deformation and break-up (there is a viewable clip that accompanies the news item). It is thought that the research might improve rainfall models although apparently the drops used are on the large size for typical UK rain.

Spare a thought for sea grass

It is common knowledge that coral reefs and coral reef ecosystems are under threat but it is less well known that sea grass meadows are also struggling. Sea grass  is found in shallow coastal waters across the whole planet and are important as a refuge for crustaceans, young fish and larger creatures such as dugongs and turtles. A recent meta-analysis (pooling data from 215 regional studies from 1879 to 2006) has revealed that the total area of seagrass meadows has declined by 29% since 1879. It is thought that much of the damage is done by sediment dumping, pollution and nutrient run-off which decrease water quality, starving the sea grass of the sunlight it needs to grow. The research is highlighted in New Scientist, Issue 2716 [11 July 2009].

Sea level rise – it just goes on and on…

New Scientist, Issue 2715 [04 July 2009] contains a substantial article on sea level rise which sets out the latest findings on rates of sea level rise and puts these into the context of past changes in sea level. It seems that a rise of 80cm by 2100 is a pretty standard projection, a rise of ~2m by 2100 is within the realms of possibility and even bigger rises cannot be discounted. An important point to bear in mind is that when projections are given for 2100 it is important not to forget that this isn’t the end of the story and that sea levels will continue to rise after this point and also that although much greater changes have occurred earlier in the Earth’s history we need to remember that humans weren’t around then…

A tale of two gases (and the Southern Ocean)

It’s reasonably well known (!) that carbon dioxide levels in the atmosphere are increasing… it’s also reasonably well known that increased carbon dioxide levels in the atmosphere are leading to increased carbon dioxide levels in the oceans (leading to ocean acidification). However, new research reported in New Scientist, Issue 2715 [04 July 2009] suggests that in the Southern Ocean, the picture isn’t quite that simple. Measurements from the Southern Ocean show that carbon dioxide levels have flattened off in recent decades (having previously increased) and a new modelling study points the finger of “blame” for this at the hole in the ozone layer in this region. Lower levels of atmospheric ozone (at high levels) and increased levels of carbon dioxide (at lower levels) have changed the energy balance in the atmosphere, generating stronger westerly winds, enhancing ocean circulation and encouraging carbon-rich water to rise up from the deep (a process known as upwelling). The result is surface water that is less able to absorb carbon dioxide from the atmosphere. This is a great example of an unexpected feedback effect of one part of the Earth-atmosphere system with another and just goes to show how complex and inter-connected all of these processes really are.

Noctilucent clouds

Noctilucent clouds are a rare type of cloud that comprise ice crystals so high up in the atmosphere that they reflect sunlight to the surface of the Earth long after sunset. It seems that noctilucent-like clouds are sometimes observed a few days after space shuttle launches – the shuttle launch creates eddies that carry water into the thermosphere (90-500km altitude). Similar clouds were also recorded as being observed in the days following the Tunguska blast (in Siberia) in 1908. The similarity between the two sets of observations has led to a suggestion that the Tunguska blast was caused by a wet, icy comet crashing to Earth rather than a dry, stone asteroid as had previously been thought. The story is described in New Scientist, Issue 2715 [04 July 2009]

Cricket, Lovely Cricket?

Having found myself needing to start reading a new book a few days before the start of the first Ashes Test Match, it seemed appropriate to pick up Lawrence Booth’s “Cricket, Lovely Cricket?”. Booth is a cricket write for The Guardian newspaper and Wisden Cricket Monthly and so well placed to write a series of chapters exploring various aspects of the game of cricket, including the personalities of the different cricket nations, the role of fans in the game, the England v Australia rivalry. I enjoyed the book – it satisfied the requirement of getting me into a cricket mood for the summer without being too obsessive and it left me intrigued about some of the stories told. It’s just a pity that as I write this, on the last day of the First Test, Australia are pummelling England towards defeat as usual…