Tag: global warming

How does Sea Ice affect Climate Change?

There is no doubt that sea ice in the polar regions is melting, but what is the exact role that this plays in the global climate system? To understand climate change we need to understand mixing in the ocean, which is exactly what Andrew Wells at the University of Oxford comes is trying to do by studying a model for sea ice growth in the Arctic.

This video is part of a collaboration between FYFD and the Journal of Fluid Mechanics featuring a series of interviews with researchers from the APS DFD 2017 conference.

Sponsored by FYFD, the Journal of Fluid Mechanics, and the UK Fluids Network. Produced by Tom Crawford and Nicole Sharp with assistance from A.J. Fillo.

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Climate Change will increase Turbulence on Flights

We’ve seen many recent extreme weather events – from mudslides in Columbia to flooding in Australia – which scientists say are a consequence of climate change; but it’s not just the weather that is affected. The Earth’s atmosphere is made up of several layers of air which all flow around each other in patterns known as jet streams and an increase in temperature will cause these to speed up. This is bad news for air passengers, including the 1 million people currently airborne at this very instant, because an increase in the speed of the jet streams will cause more turbulence making flying less comfortable and potentially more dangerous. I spoke to atmospheric scientist Paul Williams…

  • Climate change will cause a 59% increase in light turbulence, 94% increase in moderate turbulence, and 140%  increase in severe turbulence.
  • Turbulence is measured on a scale from 1 to 7 where 1 means light turbulence, 3 means moderate, 5 means severe, and 7 means extreme.
  • Light turbulence is a slight strain against the seat belt, moderate turbulence causes unsecured objects to become dislodged and makes walking around difficult, and severe turbulence results in anything that isn’t strapped down being catapulted around the cabin.
  • Turbulence is caused by wind shear – the higher you go up into the atmosphere the windier it gets – and instabilities within these layers of shear generate turbulence.
  • As the atmosphere is heated, the temperature increase causes the jet streams to move faster, creating more wind shear and thus more turbulence.
  • The researchers hope that results such as this will encourage us to think more carefully about our carbon footprint as there are likely many effects of Climate Change that we do not know about.

You can listen to the full interview for the Naked Scientists here.

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Turning useless Methane into useful Methanol

Methane is 20 times worse than C02 as a greenhouse gas, so when it’s created as a by-product at oil rigs it’s burned. This is better than releasing the methane into the atmosphere, but it’s not an ideal solution as it creates more C02. Jeroen Van Bokhoven and his team at ETH Zurich have found a new way to convert the methane into something cleaner, and a bit more useful…

Jeroen – We form it into methanol. Methanol itself is a resource for many chemicals, we can even convert this to fuels in the end. Methanol is a base chemical which has many different applications.

Tom – Is methane generally quite a reactive substance?

Jeroen – Methane is a rather unreactive substance. One of the difficulties to activate methane is the product that you make, the methanol, is more reactive than the methane itself. That’s why this reaction is so difficult to perform selectively, because the methanol will react further and then you will not end up with the useful product. That’s why this reaction is called the ‘dream reaction’ because it’s so difficult to perform and to achieve a high yield.

Tom – How do you do this? How do you convert methane into methanol?

Jeroen – Well we defined a stepwise process where we have a material which we activate and this activated material is then reacting with methane. Then we switch the conditions and then we have the activated methane reacting with water and this generates the methanol and at the same time it reactivates the material so it can react with another molecule of methane. The novelty is that we use the water and oxygen from the water molecule ends up in the methanol. The previous methods that have been used will always use an oxidant. The novelty here is that we use water, it simplifies the process very much.

Tom – Before your discovery, how do we currently convert methane into methanol?

Jeroen – Currently that is a very involved process. There are two largescale processes involved. One is the steam reforming of methane making ‘sin gas’ that is carbon monoxide and hydrogen. This is high temperature, high pressure process and then in the second step this mixture is reacted over a novel catalyst to methanol. This is only commercially viable if it’s done at largescale. And that’s why at smaller scales the methane is not viable to convert into methanol, so that’s why its burnt. Our process, we envision you can do it at much smaller scales and that it would be profitable to do it that way.

Tom – So is that the end goal here? To use your process at oil well sites where currently methane is just being burnt as flares and you’re saying no what we can do is, ideally, at these sits convert this to methanol and then do something useful with it?

Jeroen – Yes, that is correct. It’s to do something useful with what us now considered a waste product.

Tom – How far away are you from that? What would a setup to do your process look like at, for example, a well site?

Jeroen – At the moment, we are far from a commercial and an actual application. We have shown that the concept works on the very small scale and the next steps in the lab are to scale-up this process as well as to make sure that the rates of reactions – the speed that the reactions run – are sufficient for a largescale operation.

Tom – When you say, you’ve done this in the lab, how much of this methanol are you making? Is it really quite small amounts currently then?

Jeroen – At the moment it is really small amounts yes, but we also have not optimised this at all, so there are huge opportunities for optimisation. We have shown the proof of concept – that’s what the paper is about – and of course the next steps are to understand what the chemical mechanism is better than we do now, and as well as directly trying to scale this up. There are huge opportunities to do the scale up, but the research is not in the stage that we have looked at it. That is really the next thing to do.

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Plankton change genes to combat climate change

2016 was another record-breaker in terms of global temperatures, and it’s part of a longer-term trend which has seen 15 of the hottest years on record since 2001. One victim of this warming is the Artic. The sea ice is steadily retreating, which means that the habitats for species that live there are also radically altering. So are these organisms equipped to cope with the change? Thomas Mock, from the University of East Anglia, has been studying one marine species which use a genetic trick to adapt, as he explains…

Thomas – With our study we have provided first isights into the evolution adaptation of phytoplankton which are little plants floating in the ocean and we selected to sequence one of their genomes. It was a diatome, they prefer to live in nutrient rich and cold water and therefore their natural home are the polar oceans like the Southern Ocean and the Arctic Ocean. In polar oceans they are the base of the entire food web, including fish, birds and mammals like the polar bears and whales. So if their diversity changes according to global warming, which is a significant concern, then the entire food web might change with consequences for human societies.

Tom – You said that you’d looked at the genome of these phytoplankton – is that DNA sequencing?

Thomas – Yes, what we did is we selected one keystone species and we sequenced its DNA. And what we found is that they are very very different to anything that was sequenced before, at least form the marine system.

Tom – And those differences, are they because of the cold and variable environment?

Thomas – Yes that’s what we think. The variability of the polar oceans has basically caused or shaped the genomes of these organisms. What we’ve found is that the adaptation basically boils down to how they use their alleles. Alleles are basically different versions of the same gene. So in our genome we have two versions of each gene. One is derived from the mother and the other is derived from the father. They can be different from each other which impacts how we look. So I can give you an example, for instance the gene for eye colour has an allele for brown and for blue eyes. People can have two for brown, two for blue or a mix of both alleles. And this mix of alleles is basically what we found in our polar diatome genome, but not only for a small number of genes, but for 25% of all genes in the genome. These different versions are used under different environmental conditions.

Tom – So the phytoplankton are in some sense switching on the genes that help them to survive given the current environment?

Thomas – Yes that’s right – they switch on different versions of the same genes in different ways and this makes them able to cope with changing environmental conditions.

Tom – Could you give an example of one of these particular alleles that you found specifically in the phytoplankton?

Thomas – One group of genes we found is the group of antifreeze proteins. And they are expressed, they are used whenever temperatures drop below the freezing point of seawater. These creatures live between the ice crystals – this very very extreme habitat with high salinities and very low temperatures and they can cope in these extreme conditions very well because they have very different types of these antifreeze proteins.

Tom – I’m putting myself in the shoes of one of these phytoplankton. If I’m happily floating about in the sea and then suddenly the sea freezes and I become trapped in sea ice, would I then suddenly switch on this particular version of this protein to allow me to survive.

Thomas – Yeah that’s correct and this is what we actually tested in the laboratory. We simulated sea ice formation and then we looked at how all of the different genes in the genome are expressed.

Tom – Now that we now this, ultimately how is this going to help us, what does this actually mean going forwards?

Thomas – We hope that we can make predictions better about polar organisms cope with global warming. We have global warming and the most threatened ecosystems are polar ecosystems because they are the most sensitive – we see a retreat of sea ice and so on. What we didn’t know so far is how these organisms cope. What are the mechanisms that underpin how they can cope? And with our study we can say that they have a very broad tool set. To me it doesn’t seem to be all doom and gloom, they are very resilient to be honest. With our study we can say that they are very well equipped to cope with global warming and potentially also loss of sea ice.

You can listen to the full interview for the Naked Scientists here.

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