Other Science – Page 3

The heat is on

We hear a lot about global warming these days – increasing temperatures that result from higher concentrations of greenhouse gases in the atmosphere which trap heat emitted from the Earth’s surface. But the planet is heating up for another reason, namely that all of the energy that we use that is generated from non-renewable sources eventually ends up being dissipated as heat. The problem is neatly presented in a recent essay in New Sciensist, Issue 2702 [4 April 2009] by astrophysicist Eric Chaisson from Tufts University, Massachusetts, USA. The second law of thermodynamics tells us that energy eventually tends to dissipate into heat and so everything we do that utilises energy ends up generating heat that can nothing but warm the planet. Currently, this kind of heat input to the Earth system has only increased the temperature of the biosphere by 0.1 degrees Celsius but as energy use soars in the future a 3 degrees Celsius rise within 300 years is not unlikely – on top of “ordinary” global warming this is a significant amount. However, there is a way out of this problem, namely to generate energy from renewable sources. This works because energy from renewable sources is already accounted for in the global thermal budget, for example solar energy already warms the Earth so if we use some of it to generate electricity which then ends up dissipating as heat we’re not adding more heat to the system. This is another good argument for increasing our use of renewable energy sources (along with the fact that this would reduce greenhouse gas emissions) and it turns out that there’s is loads of power available in this way (there is ~7000 more power in the sunlight arriving on Earth as the current power consumption of all humans). It almost seems like a no-brainer to me.

In Defense of Food

I’ve just finished reading “In Defense of Food” by Michael Pollan (lent to me by an American work colleague). I have to say that this is one of the most thought-provoking books that I have ever read, making me question almost every aspect of my relationship with food. The book contains a really short and simple summary of its message which is “Eat Food. Not Too Much. Mostly Plants” – short, snappy and nice and easy to remember. There is lots of interesting material about how the growth of nutritionism (focusing on the nutrients within food rather than the food itself) and food science (which has replaced much of the food we used to eat with highly processed food substitutes). By pushing for ever highly yields we are now supplied with “food” that is high in calories but low in micro-nutrients and evidently this combination fails to suppress hunger (because the body still craves the micronutrients that it is not getting) and causes to eat more and take in more calories. There’s so many interesting insights and suggestions in the book that all I can really say is that you should get hold of a copy and read it for yourself. I think it is time well spent.

Humans as ultra-mobile worms

Any alert readers of this site (ha, as if there are any readers…) might have noticed that I am gradually working my way thorugh some recent back issues of New Scientist highlighting a few interesting articles along the way. Something that intrigued me from New Scientist Issue 2697 (28 February 2009) was the response to a letter from a parent asking a question on behalf of their daughter (age not given). The daughter wanted to know why humans have evolved to have two systems to excrete waste products (“poo” and “wee”). I’ve never thought about this before, but the responses indicated that in fact we only have one real excretion system, “wee”, as this takes waste products from inside our bodies and ejects them to the outside. It turns out (and this is the good part) that really our bodies can be thought of as having an elongated annular shape, by which I mean that we are a chunk of connected organic matter that surrounds a long tube. We feed by drawing material in through our mouth, squashing it about a bit, squirting acid on it, sucking the good bits into our interior and leaving what is left to drop out of the end of the tube. This is certainly a very different view of things, but clearly it is not wrong. Now I keep thinking of humans as being quite like some ultra-mobile and (presumably) ultra-intelligent worms, roaming through space enveloping food, and leaving a trail of waste behind us… What a great question.

Sunshine on a rainy day

It is a rainy day today here in Plymouth so it’s a good time for me to draw attention to a fascinating and very beautiful image of what visible light from the Sun looks like when it is split into its constituent colours in New Scientist Issue 2697 (28 February 2009). It would be a breach of copyright for me to include the image in this post but here is a direct link though to the image on its own.

It won’t be pretty as the climate changes

Earlier this week I helped to assess some presentations given by final year Ocean Science degree students. The presentations were the endpoint of a year-long integrating case study module in which small groups of students work together to tackle a realistic consultancy-type project relating to their degree area. Several of this year’s topics related to future changes that are likely to occur in coastal regions as a result of climate change and, in particular, sea level rise (for example, there was one project on the threat to the main south-west railway line at Dawlish and another on the need to protect or re-route the coastal road at Slapton [both locations in Devon, UK]). Anyway, I don’t want to go into details about these projects but there was one thought that struck me very firmly as I reviewed the material in front of me, namely that because significant sea-level rise is going to occur and because there will be significant impacts on infrastructure such as railway lines, roads and housing, developed coastal areas ARE going to change and it’s not going to be pretty.

There was one picture of Dawlish showing the railway line, which runs along a seawall, with nice “safe” houses perched up on the hills behind the low-lying coastal strip. It is inevitable that at some point in the not too distant future the seawall will crumble, the railway line will be lost and the low-lying area will be inundated, but the houses further back an up will be okay. The thought that struck me though was that no-one will come along and landscape the eroding and flooding coastal strip; no-one will tidy up the damage, remove the old buildings, the concrete blocks and the twisted metal etc. So once we start to lose coastal infrastructure of this type (and lose it we will) there will be a region that, for want of a better description, will look like some kind of war-zone and this, in turn, will lead to abandonment of the surrounding safer/higher areas because who will want to live next to a wasteland?

But this is only looking at a local scale… Also this week I read an interesting article in New Scientist Issue 2697 (28 February 2009) on how human civilisation will have to adapt and change to live in a warmer world. While large parts of the globe may become unable to sustain existing populations, other parts (e.g. northern latitudes) may become more suitable for human habitation either as a result of changes in temperature, rainfall, soil condition etc. I’ve been comfortable with the idea that the world will change as climate changes, but it had never struck me before that along with the serious environmental consequences, it won’t be pretty.

The Hot Topic

There seems to be a pattern emerging for my recent entries to this site, namely that they are all related in some way to climate change and what we need to be doing to cope with it. I don’t want this pattern to take hold too strongly, but I guess that given that my work is focussed on oceanography and meteorology and given that our planet is warming and climates are changing, there is some inevitability about this. Anyway, this entry is just to record that I recently finished reading a really excellent book on climate change due to human-induced global warming and to strongly recommend it to anyone interested in this topic (and to be honest, if you’re not interested in this topic then you should be and you soon will be…). The book is called “The Hot Topic” and is written by Gabrielle Walker (coincidentally mentioned in another entry on this site a few days ago) and Sir David King (who until 2007 was Chief Scientific Advisor to the UK Government). The book sets out in simple terms the basic science behind climate change, how we will need to adapt to the changes that will occur, what kinds of technological solutions we might be able to develop to help to reduce our emissions of the so-called Greenhouse Gases and explores the relevant political dimensions and personal and local solutions (what we can all do to help). It’s quite short, is highly readable and is packed with lots of references to key scientific works that have informed our understanding of climate change. You can find more information about the book from the Bloomsbury Publishing website entry.

Since reading the book I have been much more careful about switching off lights and appliances around the house when they are not needed and have taken a decision not to use the lift at work (my office is on the 5th floor) or to press the button to open the automatic doors. Both the lift and the door use energy every time they are used and that energy most likely comes from the burning of fossil fuels. As long as I don’t end up eating more to provide myself with the extra energy I need to climb the stairs or open the door, I’ll be making a very small contribution to helping to keep the planet cooler in the future. It may not be much, but every little helps.

Ice circles

In the first year tutorial sessions that I run on our Ocean Exploration and Ocean Science courses we give all of our students an opportunity to give a short informal presentation to their group on a topical piece of marine science news (though sometimes the topics, being selected by the students, have relatively little to do with marine science). The idea is that these presentations are a prelude to an assessed presentation that the students give later in the term and a chance to get a bit of practice and confidence-building. Most of these presentations cover topics that I am familiar with but occasionally they throw up something completely new to me… A couple of weeks ago we ran this year’s sessions and one of the students spoke about “ice circles”. These are, what appear to be, perfect circles of ice that form in rivers and rotate slowly as the river flows around and underneath them. One such ice circle, 10 feet wide and potentially the first to be observed in a British river, had recently formed in the River Otter in Devon and the news story had been picked up by this student’s home local newspaper (and reported subsequently in various places including here in The Times newspaper). Apparently ice circles are much more common in Scandinavia and there is some debate about how they form with one suggestion being that they are the result of alien activities… whatever the truth (and personally I don’t go for the alien stories) it’s well worth having a bit of a google for “ice circles” to look at some of the spectacular images that are out there on the web.

Carbon negative? That’s in-tree-ging

A few weeks ago I attended an excellent seminar at work given by a Professor from Cranfield University about the future for marine renewable energy in the UK. A key point that he made was that because there is a time lag between us humans putting “Greenhouse gases” such as carbon dioxide (CO2) into the atmosphere and the effects of these gases showing up in the global climate change signal we need to be thinking not about carbon neutral technologies (which don’t add CO2 to the atmosphere) but rather what we actually need are carbon negative technologies that actively reduce the concentration of CO2 in the atmosphere.

A recent article in New Scientist (“Clearing the Air” – Issue 2690: 10 January 2009) picks up on this point and describes attempts to develop systems for scrubbing CO2 out of the atmosphere. Currently, a number of prototype CO2 scrubbing devices have been developed and although the challenge is great, the prospects for producing larger and more efficient versions seem to be encouraging. I found it interesting to read that CO2 is a commodity that some parts of industry pay good money for (e.g oil companies use CO2 to flush out old oil-fields and fruit and vegetable growers use CO2 to enrich the air in greenhouses) – apparently CO2 can cost as much as $300 per tonne.

However, it occurs to me that nature does already possess an excellent piece of technology for removing CO2 from the atmosphere – namely the tree. So, perhaps what we need to do is to plant a lot more trees (and, of course, stop chopping down those that already exist). A diagram that accompanies an article in this week’s New Scientist (“Hacking the planet: The only climate solution left” – Issue 2697: 28 February 2009) seems to back this idea up. It shows various different methods of geoengineering that might help to cool the Earth, ranging from placing mirrors in space, growing reflective crops, seeding clouds and fertilising the oceans with iron. Each method is given a pair of ratings to show when the technology might be ready to make a difference and what the technology will cost and guess what, “Foresting” is, arguably, the best bet, having low cost and a relatively fast timescale (“within decades”) with the only drawback being the amount of land area needed. Still, there’s lots of unused land around the place, so why don’t we all get planting. It might not have an instant and dramatic effect but as long as we don’t use lots of energy maintaining the resulting trees it would be a step in the right direction.