Week 5 Reflections

I found this week to be so interesting. Two very different topics both relating to the ocean. The rate of ocean acidification is really scary. It throws up a lot of questions about the future stabilities of ocean life and what consequences will come of these interruptions in the early life stages of some of the smaller organisms. Dr Ceri Lewis is an inspiration. Obviously very dedicated to her work and has great enthusiasm.

The influences on the ice sheets and how the flow of glaciers happens was eye-opening. I loved the video link to the team in the Himalayas. I thought the series of photographs and the guys passion for his project very inspiring.

Both themes this week show just how devastating some of the potential results of climate change can be. I have put up a few links in one of my posts a couple back. I’m intrigued about how the sea levels will rise unevenly around the globe and want to look into that a bit more.

Thanks again all involved.

5.7 The Impact of Ocean Acidification

Ocean acidification has enormous implications for the functioning of natural systems. However, its human impact cannot be overlooked either. Engage with your peers in the discussion below to answer these two questions:

I got involved in the discussion but I also wanted to post here. WARNING - I don't seem to have anything very positive to say about these subjects this week...

1. Will marine organisms be able to adapt to ocean acidification given the time scale for the predicted changes?

The acidification is happening at an unprecedented rate. pH levels have, historically, been as low as those predicted in the future. But the change was gradual. Species had time to adapt to the altered habitat around them. They had time to evolve. What we are seeing now does not allow for that. As the bottom of the food chain falters the consequences will make their way through to the larger species, rendering our oceans, eventually, unrecognisable.

2. Increased carbon dioxide in the atmosphere is likely to lead to sea level rise. Are rising sea levels more of a threat to humanity than ocean acidification?

A rising sea level affects coastal communities around the world; approximately 150 million people live within 1 meter of current sea level. And that’s not taking into account any increase in future population. Think of the displacement of people this would create. A greater density of people, an instable climate in which farming is uncertain. We would need to harvest food from the sea. It’s quite possible that, given our current fishing crisis there would be a shortage. Then, if you take out of the equation the animals that would be unable to reproduce in an acidified ocean, we can say that we’re left with a whole lot of problem. I think the two are going to happen simultaneously. How can we separate the two?

5.4 Calving events

How might processes like ocean and atmospheric warming cause mass loss from calving to increase? What do you think are the key controlling processes? 

There is some really interesting reading about this subject. The dominant discussion seems to be in the effects of a warming ocean. Greenland and the Western Antarctic Ice Sheet come up frequently as the two main ice sheets that Glaciologists are concerned about. Greenland is warmer, in general, than the Southern polar region, so may be more sensitive to change. Below are some examples of how the ice sheets are being affected, and ways in which calving rates could increase.

Thermal Expansion. In the past one of the major factors affecting sea level rise has been through thermal expansion of the oceans. This is still true, but as global temperatures rise this will be reflected in ever rising sea levels.

Ice-shelves. These are the ice sheets that extend over the ocean. It's the first line of defence and the area where calving happens most frequently. As the sea temperatures rise, the ice shelves are warmed from underneath. This would cause them to break up more readily. Large icebergs would form and drift out to sea. However, the water trapped in the ice shelves is already accounted for in sea level measurements, so these events would not really cause any rise. The danger comes because some of these ice shelves act as buttresses to greater quantities of inland ice. If this inland ice was left unsupported it could flow to the edge of the oceans, calve away and contribute to sea level rises. There are particular fears of this in the Western Antarctic Ice Sheet.

Precipitation: A warmer climate encourages the uptake of water vapour into the atmosphere, which then falls as precipitation. Snow, in the polar regions. The three reasons behind this are 1. Warmer air can carry more moisture; 2. Warmer waters means more evaporation; 3. Reduced sea ice means more of the ocean is uncovered, so, again, more evaporation. This would, seemingly, lead to an increase in ice cover... However observations seem to be showing that the balance is in favour of the loss of ice cover.

Basal lubrication. There seem to be conflicting and changing discussions around this issue. A study, using computer models based on observations during fieldwork in Greenland from The University of Bristol revealed that by the year 2200 lubrication would only add a maximum of 8mm for that year to sea-level rise – less than 5% of the total projected contribution from the Greenland ice sheet.

Lead author, Dr Sarah Shannon, from the University of Bristol, says,

 “This is an important step forward in our understanding of the factors that control sea-level rise from the Greenland Ice Sheet. Our results show that melt-water enhanced lubrication will have a minor contribution to future sea-level rise. Future mass loss will be governed by changes in surface melt-water runoff or iceberg calving.”

“We found that the melt-water would lead to a redistribution of the ice, but not necessarily to an increase in flow.”

There is also a hint of a discussion on why sea level rise is not uniform across the globe, which is fascinating. It suggests that the regions affected first will be around the poles and then “slosh” from Antarctica. The Northern hemisphere will experience the greatest sea level rise and it may actually fall, eventually, around Antarctica.

Antarctica’s ice sheet has been called the ‘sleeping giant’ of sea level, but it’s beginning to stir. Everything we've seen about this change points to human influences on climate – and now we’re at the point where human actions will be needed to stop it. - Dr Ted Scambos


Refs

http://www.aip.org/history/climate/floods.htm
http://earthobservatory.nasa.gov/Features/PolarIce/polar_ice2.php
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2014/may/30/global-warming-vulnerability-greenlands-ice-sheet
http://www.nature.com/articles/ngeo2167.epdf?referrer_access_token=L-oQy7WT-LAYYF8pZ4wR9tRgN0jAjWel9jnR3ZoTv0Pf_LUEqgO1ubFbW_Fvq0s81-HZKnVEK146NaEKgjYtU12w1TH8UO27_Yo_2CBKt-I%3D
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/jan/14/antarctic-ice-sheet-a-sleeping-giant-beginning-to-stir

http://www.ice2sea.eu/2013/08/12/pr2013_09/

Week 4 Reflections

This week has been a very interesting look at climate models and geoengineering. Depending on the scenario entered into the climate models, the future predictions of temperature, extreme events and even an acute change in the patterns of the ocean currents, can have some wildly different results. The predictions tested on past observed and modeled changes show that human actions have caused the changes in the latter half of the century. (IPCC 4th report “There is at least a 90% chance that the observed increase in temperature globally is due to man-made greenhouse gases”.)

Photo I took of some bluebells last year, near where I live, just for fun and prettiness.

I found the huge debate around geoengineering very interesting. It is a broad-reaching topic and arguments are based on both scientific reasoning and ethical beliefs. I understand its controversy. Leaping in with this technology without really understanding the baseline problem, or without first doing what we can to mitigate to rise in greenhouse gases in a more long lasting and sustainable way is simply not going to work. There have been some great analogies I have read!

It's been an interesting introduction to things like the SPICE project.

These technical solutions should be consigned very much to the “Plan B” heading, in my opinion. A very thought-provoking week. Thank you.

4.7 Should We Geoengineer Our Climate?

What is your view on geoengineering? Should it be used to prevent our planet warming? Post your views into the discussion.

There are a number of arguments, both for and against geoengineering, which are backed up by valid evidence and opinions. Firstly, there is the general acceptance that, yes, the Earth is warming, and to a greater extent than can be explained by natural background climate fluctuations. I think we can generally agree on this. There is also strong evidence that the cause of this warming is an increase of “greenhouse” gases, and that this increase is cause by anthropogenic factors, ie us. We are burning fossil fuels at a huge rate, deforesting vast areas of the planet and generally pumping gases like CO2 into our atmosphere. The predictions of what effects these changes are likely to have are all different, depending on the scenario they are based upon, but none of them are good. They point to more severe droughts, more intense flooding and a huge loss in biodiversity as a result.

So what are the answers? How should we respond to this? We obviously have to do something. it would be lovely to believe that the world could quickly cease to use fossil fuels, that all power could be harnessed from renewable sources. Geoengineering is another option. I agree with the majority of the scientific community who have commented on this field (as far as I can tell, that is) that we should be exploring these options, but with the hope that they will never have to be deployed. it shouldn't take us off track to find better, more fundable, longer lasting solutions. The implementation of geoengineering, even of research projects, does of course come with its own huge bundle of problems regarding ownership, funding and profits, let alone what adverse effects it might have. But surely we can’t answer the question without at first trying to gather as many facts about it as possible? Below is a quote from the forward of “Geoengineering The Climate”, written by Martin Rees, the president of the Royal Society in 2010, which I think sums up the argument quite well.

“The continuing rise in the atmospheric concentration of greenhouse gases, mainly caused by the burning of fossil fuels, is driving changes in the Earth's climate. The long-term consequences will be exceedingly threatening, especially if nations continue 'business as usual' in the coming decades. Most nations now recognise the need to shift to a low-carbon economy, and nothing should divert us from the main priority of reducing global greenhouse gas emissions. But if such reductions achieve too little, too late, there will surely be pressure to consider a 'plan B' to seek ways to counteract the climatic effects of greenhouse gas emissions by 'geoengineering'.

Many proposals for geoengineering have already been made but the subject is bedevilled by much doubt and confusion. Some schemes are manifestly far-fetched; others are more credible, and are being investigated by reputable scientists; some are being promoted over-optimistically. In this report, the Royal Society aims to provide an authoritative and balanced assessment of the main geoengineering options. Far more detailed study would be needed before any method could even be seriously considered for deployment on the requisite international scale. Moreover, it is already clear than none offers a 'silver bullet', and that some options are far more problematic than others.”

4.6 Are Ideas to Cool the Planet Realistic?

Geoengineering seems to be one of those topics that no one can really agree on. Should we be considering it at all? Or by doing so are we accepting that we can’t reduce our greenhouse gas emissions and we are simply giving up? There are two sides to this debate, each bringing with it their own arguments and problems.

The main ways in which this technology would be used to mitigate the effects of global warming are:

1. Carbon Dioxide Reduction. These methods aim to reduce the quantity of CO2 in our atmosphere (afforestation, ocean fertilisation).
2. Solar Radiation Management. These are ways in which to reflect more of the sun’s radiation back into space, counterbalancing the increase in greenhouse gases (release of sulphate particles into the atmosphere, cloud whitening).

There are a number of major caveats in the use of these, brought up by a number of questions. Who owns them? Who has the financial benefits? What if they fail?

The technology is possible, the effects might mitigate the warming due to CO2 emissions. But do we want to consider them yet? Perhaps we should research them, because surely it’s always good to have all the information, but with strong governance from a globally representative body.

Using these methods will have side effects detrimental to many regions on the globe, but letting things continue as they are will also have possibly devastating consequences. The real answer is we all need to take responsibility to reduce emissions as individuals, businesses and countries. But how likely is that?
(sorry about the unhappy final note)

REFS:
Various Guardian articles
BBC

The Keeling Curve

Came across this and thought it was interesting. It's from this website.