During the last visit to Luleå Tekniska Universitet, the eminent meteorologist Sir Brian Hoskins, apart from offering a lecture about his innovative studies on the Hadley Cell, devoted some time to discuss about some other subjects with several members of the Atmospheric Science Group. Climate change was one of them, both from a scientific point of view, with relation to certain investigations which are being carried out within the Group, and from a broader perspective embracing its political and economic aspects.
Sir Brian has contributed important advances in the comprehension of atmosphere dynamics, which pose major implications in several areas of climate science and meteorology. Among his contributions, his novel modelling of the Hadley Cell has unveiled some unknown features of this dynamical process of the Earth atmosphere, which has given place to a better understanding of climate as well as to the improvement of General Circulation Models.
In his seminar at LTU, Prof. Hoskins presented his work on the Hadley Cell, based on an analysis which goes beyond the traditional mechanical approach. In it, they are taken into account thermodynamic and dynamic constraints determining the cross-equatorial flow, which doesn’t appear any more like a steady stream; according to his model, it seems to be difficult for the air to move from a hemisphere to the other at first. However, in the lower layers of the atmosphere, the friction of the moving air masses with topographic features, together with diabatic processes, counteract these constraints, determining a flux between both hemispheres which takes place in certain longitudes and periods as “filaments”, defining a wave pattern of the cross-equatorial air exchange. In the upper troposphere, the lack of friction determines a different behaviour which, together with the latter, compose a totally different depiction of the dynamics of the Hadley Cell.
This new model poses the convenience of reviewing several aspects of the atmospheric studies. It can entail implications, whose reach should be enquired, for weather, climate, and circulation models, which must be reformulated according to it. Furthermore, it provides novel criteria for performing chemical and photochemical atmospheric studies, and it could serve as a useful tool to improve the research on other planet’s atmospheres, two subjects included in the research lines list of the Atmospheric Science Group.
Another field of interest of Sir Brian, on which he works with special dedication, is human induced climate change and its effects; the ways to palliate them and to manage the consequences.
During his visit to Luleå, he kept discussions with member of the Group about different subjects, among which certain scientific aspects of global warming were included. But he is also an expert in the socio-political and economical management of the process. As such, he has been a member of the UK’s Natural Environment Research Council, and has taken a seminal part in the establishment of the Intergovernmental Panel on Climate Change’s scientific assessments, as well as in the Stern review on the economic implications of the climate change. As a member of the UK’s Climate Change Committee, he contributed to the government commitment to reduce the greenhouse gases emission up to an 80% by 2050. He promoted the creation of the Grantham Institute for Climate Change at Imperial College, London, which he currently chairs, and of which he was its first Director (2008-2014).
Although climate change is nowadays widely accepted as a universal problem caused by human activity which has to be urgently and jointly faced, it is worth taking a look in the status of the issue, so we asked Prof. Hoskins a few questions to get better insights into it. First of all, it seems to be clear right now that the intense use of organic fuels is the main factor in the global warming, though some still claim that other natural factors, and in particular Solar activity, plays an important role in the phenomenon.
Prof. Hoskins thinks that:
"The role of solar activity in climate change has been a topic of interest, and some confusion and debate, between those saying that all we see is due to fluctuations in the sun, and those sustaining that changes in the Sun are not important at all.
I think the truth is somewhere in between those two. What we do into the planet in terms of increasing greenhouse gasses is incredibly important, and is dominant, however an important part of the background is what we might call the natural variability, which includes changes in the weather as a part of the Earth System, but also changes in the Sun provide an important part of the background.
I wouldn’t say that changes in the Sun are dominant, but I would say they are an important part of natural variability on which the increasing greenhouse gasses are on top".
Therefore, something should be done about it, it seems… In the opinion of Prof. Hoskins:
"There are two things we have to both manage:
From this answer, it can be inferred that some consequences of the climate change have been already triggered. The question, regarding this matter is: are the foreseen problems so far, at least, those we are going to suffer for sure?
Prof. Hoskins agrees with the assertion, and replies that "those problems are what the Intergovernmental Panel on Climate Change (IPCC) established in terms of a consensus, and I think that are what we will get if we are lucky. If we are unlucky, then maybe some thresholds in the climate system will be passed; one of them could be the raise in the sea level for instance, one of the biggest problems from my point of view. There is a lot of interest now in how unstable the ice sheets in Antarctica are with relation to this particular worry.
And there are other aspects of the climate system we depend on; many billions of people, for example, depend on the monsoons; are these monsoons to stay the same? The indications from models show that they may become some of stronger, causing problems of flooding, and there are active break monsoons which occur on the timescale of a few weeks and, if those became longer in period, they could cause difficulties. So, there are many sensitivities to think of with relation to the weather which could make living in certain regions difficult. Indeed, there is a lot of fairly intensive discussion on the contribution of weather to the Syrian crisis for instance [http://journals.ametsoc.org/doi/pdf/10.1175/WCAS-D-13-00059.1].
There is no doubt that changes in climate make people more unsettled, and the possibilities of conflict come greater. Here, only a small migration has unsettled Europe…if Bangladesh becomes difficult to live in, where do the people…? You can imagine the unsettling…India doesn’t want people to go there, so the stresses and strains of living on this planet could become greater.
What worries me is that, even without a huge change in climate, they could be social tipping points if not natural ones (I prefer the word thresholds, but the popular word is tipping points).
So, yes, probably we’ll suffer some problems in the near future…
There is no doubt. Climate change is increasingly going to give problems. Sea level rise is a problem in many parts of the world, and the rise is expected to reach 2 meters by the end of the century. Huge populations living on coastal areas are going to be in trouble. The ice is melting in the arctic, as well as the permafrost. With the increase of mean temperature, the larger amount of water vapor in the atmosphere will cause probably quite more intense heavy storm events…It is not going to be an easy ride even if we manage this; there will be changes and they have to be coped with…in certain places of the world now life is difficult, and it is going to be even more difficult in the future. I think if we try and reduce these changes as much as we can, and if we help one another in the changes as they actually occur we can ride it through".
By following the thread of Prof. Hoskins discourse, a question appears to be relevant at this point: do we have the time to avoid some consequences of the changes caused so far? He declares to be “cautiously optimistic”, and asserts that
"We do, but we can’t just wait for it to happen; we need the governments of the world to help it happen".
And he continues considering that:
"The crucial time, I think, is the next twenty years. If we can handle this properly to reduce greenhouse gasses emissions… There are interesting signs that the amount of CO2 is not going up much. During the last three years, the raise seems to have stopped. It is due to the western world and China efforts in stopping the growth.
Then, it depends on India and on the amount of technology transfer and the help that the western world can give to India, and then Africa, along with the development that has to occur… can we help that development to occur in a different path from the one we have chosen?
If we had fifty years, I think this would just happen naturally, the thing is that we’ve got to do this over the next twenty or thirty years, so we have to accelerate the process for this transformation, and we have to go from the time of fossil fuels to the new age of doing things using renewables; the sustainable way of doing it. It is a revolution which has to happen so quickly.
Fortunately, these things can happen quite quickly once they start, because they become very attractive".
As a global problem, there was a tentative intention to establish a universal agreement with legal force as a necessary tool to effectively fight the climate change. Although it can be thought to be the only way to reach a real solution, Prof. Hoskins explains that "the current treaty is the Paris Agreement [signed within United Nations Framework Convention on Climate Change -UNFCCC-], which came to force the countries that have accepted the agreement, but it is actually very much leaving it up to the individual countries to volunteer what they will do. This really goes back to Copenhagen [Copenhagen Climate Change Conference], where I and many others had hoped that there would be an agreement which would force countries to actually reduce their greenhouse gasses emissions but, in retrospect, that was not possible, because it would have needed an international police to say: hey! you are not doing what the agreement says you should do, and you will have this punishment for not doing that. That is not realistic, and Copenhagen was important for telling us really what was possible. Paris then was the agreement which eventually came on what was possible; which put a frame to the work that we want to do, and that was a very clear statement from all the countries of the world that we wanted to keep the change in global temperature well below 2º C, and that was a very strong agreement because the implications of that are huge.
Now the countries of the world haven’t quite recognized how strong the implications of that are, but they have volunteered to do quite a lot, and they have also accepted we will meet every few years and reassess how we are doing, and try and bridge the gap. The gap is huge; if the countries of the world actually do what they said they would do, it would probably reduce the raise in temperature to maybe something close to 3º C (probably a bit more). So, the questions now are:
The prospects do not look positive, although Prof. Hoskins keeps a hopeful attitude:
"The reason I am optimistic…(maybe we are not quite reaching two degrees , but close to two degrees), is that the technologies to achieve it are getting that much more attractive ,and in some ways there is a race to become the leaders on those technologies. A country like China is wanting to lead the world process, partly because it wants to be seen as a world leader, to achieve its right for a position as a world leader, and secondly because it wants to lead in the technologies. And the reason I think the United States will not be let far behind is that their companies will also want to be leaders. So there is going to be a race, a very good race to be the leaders.
In Marrakesh [Marrakech Climate Change Conference], Donald Trump said US was going to withdraw from all this, but China kept on going ahead with its ideas. It has approved a five years plan to reduce the use of carbon, which is a strong plan on this, and means they are going down that direction. And the rest of the countries said they will go forward as well. So, there are many things to make us optimistic despite what is going on in the US. And of course California and many other states, as well as many companies, they all want to go this way, so I remain pretty optimistic; we will keep on going in this direction.
What we don’t know is how forgiving the climate system will be. We can run models, and we have got some pretty good ideas from them about the changes in climate might be, but there are maybe some surprises. The changes the models give should be slowed, and perhaps the climate system might be helpful to us. Or it could have some ‘jokers in the pack’; some surprises waiting for us which probably wouldn’t be very nice, so we don’t know what the climate system is going to do for us".
One of the factors that could determine the actions to be taken regarding the reduction of the climate change inertia is the attitude of citizenship towards the measures to be applied in order to achieve it. Probably it will be necessary to change some consumptions behaviour, which can be perceived as losses in the life standard. It could be a problem delaying the application of those measures…
Prof. Hoskins recognizes that:
"Governments seem to find it very difficult to lead; they’re responsive to what they think their electorate is saying and what is going to make them popular. That’s why the change in technology is so important inasmuch it makes things cheaper and the health and equality better, so those benefits are those we should really try to build on. Together, they can drive people’s actions along with the alternatives being of similar cost.
On the other hand, if you measure standards of living by the number of times you fly to the Mediterranean, probably the standard is going to go down. But if you can measure quality of life in other ways, then it’s probably going to go up. So we may have to decide what do we think is a good quality of life. People now, in the western countries, are dashing around the world; it is almost frantic. Maybe we should get through this frantic period… I think there are ways through this transformation that we can actually get people with a quality of life which is better.
[Unfortunately] we are seeing a raise of the populism (BREXIT, Trump…). It is a setback in terms of the way people appreciate the world and their place in it. Those things lead to people looking more inwards and in a selfish way…newspapers and media can try and create the opposite impression, and I still hope that we can have that outward looking nature, because if we don`t have it we’re in trouble".
In summary, we are in a hurry to palliate the unpleasant consequences of our activities by deeply modifying our lifestyle, and the sticking points are many.
But Prof. Hoskins assures "we are doing the right sort of things. In the UK, it was approved the Climate Change Bill [Sir Brian was a member of the Committee which helped deciding what the reduction target should be]. We said the UK should be aiming to reduce its greenhouse gasses emissions by 80% by 2050, and now that is in law.
I do believe that in many ways we can make the world moving into a pleasanter place than the present one, provided we take the leadership on it rather than just saying, Oh my God! What’s happening? Can we manage this?
We should take control and make the world pleasant for our children".
It is up to us…