Tuesday 8 January 2013

The end of the... water?

Happy New Year! Sadly it's time for me to love you and leave you this year, hope the blog enlightened you about some of the issues faced by various parts of the world in terms of sea level rise, and that you've learned something new! 

I'm going to leave you with this recent article from the BBC about our very own country. This article has warned that the Thames may need a second defense! Things are slowly getting serious it seems,,. The engineer, Dr Bloore, has warned that the current Thames Barrier alone may not be able to withstand flooding events in the future, and that other defenses will be required. He said that at the time it was built, 'global warming' wasn't really an issue. But now, he feels urgent preventative action should be taken. Especially after the recent events in New York, this may not seem like such a bad idea after all....

2012 was also apparently the second wettest year on record in the UK (Click here). Constantly throughout the past year, there have been news stories about flooding in various parts of the country, and, come to think of it, we didn't have much of a summer last year! This has been attributed to the band of wind known as the 'jet stream' being lower than usual, and hence directing rain towards the UK. 

So as you can see, through all my blogging, I have been talking about very current issues we are faced with, and given you a range of examples from around the world. With articles like the one mentioned above in the news, alongside 'freak' events such as Sandy, we know things are already not looking too great for us. I have talked about how sea level has been measured historically, and how it is now, as well as the uncertainties involved with this. We know it is a looming issue, that is eventually going to affect our planet at some point. But is it not too late to take immediate preventative measures? I think this is something that policy makers especially should look into.

I hope you have enjoyed reading my blog. Keep your eyes open and your head above water! 

Thursday 27 December 2012

Risky business


Sorry for the delayed post, but I hope everyone has had a good Christmas! Being the time of year that it is, I was reminded of the destructive tsunami that took place back on Boxing Day in 2004. I thought I’d therefore have a look at the impacts of sea level rise in south east Asia, particularly Indonesia.

The last IPCC report projected sea level rise to affect low-lying lands in the region, “increasing the annual number of people flooded in coastal populations from 13 million to 94 million” by the end of the 21st century – 60% of this would occur in South Asia (from Pakistan to Burma), and 20% in South East Asia (from Thailand through to Vietnam) (IPCC, 2007). The report summarised that all Asian coastal areas (especially low lying ones) will be increasingly under threat by sea level rise in the coming future, with the additional risks of tropical storms and surges. The effects will be especially devastating in this area due to its generally high population density, and abundant economic/agricultural activity. For example, 98.4% of Indonesian population live within 100km of a coastline (Forster, 2010).

The impacts of potential inundation due to rising seas will negatively affect these coastlines, as much of their economy relies on the activities that take place here, such as farming. Another issue is the risk of freshwater resources being contaminated with salt water. This article focuses on the Semarang area of Indonesia. The locals are very aware of the problems of inundation, and have taken appropriate precautionary steps such as dike construction, a pumping system, and reconstructing houses with raised floors (see below):



However, for additional infrastructure, they also require finance. In this article, GIS is used to model scenarios of 120cm, and 180cm inundation and the sectors affected them most:



It seems the fishpond area – i.e. fish production – would be affected the most due to changing ecosystem of the water. However of course all the other sectors will be affected to some considerable degree also.

Another article, looking at the Sayung coastal area, pointed to coastal erosion being one of the main issues faced, displacing settlements as a result. Their approaches to tackle this include mangrove planting, elevation of the ground level, using wells for freshwater access, and perhaps focusing more on the tourism sector rather than for example fishpond farming (as this seems to be heavily affected).  

From these studies, it is clear that sea level rise is a very serious threat not just to Indonesia, but I think all the coastal countries in this region. It will not only cause environmental damage, but also lead to socio-economic losses. Therefore steps need to be taken to try hold the water back for as long as possible, although such infrastructure will require some financial aid. Essentially, land use management needs to improve, and the locals need to work together to tackle this.


References:

Forster, H. et al (2010) 'Sea-level rise in Indonesia: on adaptation priorities
in the agricultural sector', Regional Environmental Change, 11(4): 893-904 http://www.pik-potsdam.de/members/sterzel/foerster-et-al-2011


Marfai, M. et al (2008) 'Potential vulnerability implications of coastal inundation due to sea level rise for the coastal zone of Semarang city, Indonesia', Environmental Geology, 54(6): 1235-1245


Marfai, M. (2012) 'Preliminary assessment of coastal erosion and local community adaptation in Sayung coastal area, central java – Indonesia', Quaestiones Geographicae, 31(3): 47-55



Tuesday 18 December 2012

IPCC leak!


A draft of the next IPCC report has recently been leaked by an American blogger, Alec Rawls! It has however led to much debate and argument by climate skeptics about what to actually believe...

An article from New Scientist tells us more about some of the key details of this report.

I’m sure many including myself would agree with Rawls highlighting that humans will be the main driver of climate change. He then goes on to state that changing feedbacks within the climate system affect the impact of solar power on the climate, and that therefore this is essentially one of the key drivers of climate change. This has been questioned by other scientists however, saying that the sun doesn’t have much immediate effect over human timescales generally.

So what does the report have to say about sea level in particular? The IPCC believe that the Arctic may actually experience ice-free summers by the end of the century. This claim has of course been challenged by other scientists who claim this will happen even earlier (perhaps by 2050). The possibility is prevalent, however it looks like only time will tell. Ice sheet movement has also apparently been included in the models of sea level change.

I guess the question of the moment amongst climate scientists following this leak is the extent of solar effects on our climate vs fossil fuels? And that humans really are the main forcing factor of climate change now. For instance, this blog ridicules the IPCC by saying that their report doesn’t even make logical sense.
Uh oh! Who are we to believe now? The climate world is full of such contradictions, it’s hard to predict what the actual truth is. This was however just a draft report, that has seemed to have caused a stir in the climate world. Over the next few months we will have to wait and see what is actually to come...

A few sites to check:

Tuesday 4 December 2012

Polar Express


A recent article from the BBC has outlined the findings of a number of polar research teams, in terms of the effect of ice from Greenland and Antarctica on sea level rise. The mechanisms of these ice sheets are pretty difficult to track and measure accurately. What this combined study has found is that the contribution of melting Polar ice has been one fifth of the overall rise in sea level since 1992.

Additionally, the East Antarctic ice sheet has actually gained mass due to more snowfall, whereas the West Antarctic, Antarctic Peninsula, and Greenland ice sheets, have all lost mass. As Professor Shepherd summed up perfectly, "We would expect Greenland to melt more rapidly because the temperatures have risen…West Antarctica to flow more quickly because the ocean is warmer. And we would also expect East Antarctica to grow because there's more snowfall as a consequence of climate warming."

They concluded by saying how the ice sheets have contributed 11.1mm on average to sea level rise as a whole. The study has proved to us just how much these ice sheets have actually contributed to sea level rise thus far, and has given us one final, overall estimate for this.
The graph below (taken from the BBC article) shows the combined effects:




It’s good that they finally have collaborated all the uncertainties in terms of estimates, to give us a clearer picture of what’s really been going on. The future is still uncertain, however these new figures definitely seem to have helped, and hopefully scientists will be able to work onwards from this and find out more in the coming years about what lies ahead...

Check out the article for a short video clip, and more information: http://www.bbc.co.uk/news/science-environment-20543483  

Thursday 29 November 2012

Sea level rising, but islands growing...?!


A couple of weeks ago I talked about how many island nations were at serious risk of inundation if sea levels rose. However there has in fact been some evidence that seems to have contradicted this! It has been argued that these islands are in fact growing! But how could this be possible, after having seen all the other existing evidence, pictures, and videos that clearly show how much of a threat the waters are to these islands?

A recent study by Kench and Webb (2010), where they used historical aerial photos and satellite images, has shown that 23 out of the 27 central Pacific islands studied either retained the same land area, or actually increased in size over the last 19-61 years, whilst the sea level rose by 2mm during this same period. (Edwards, 2010). 

Eroded coral debris had in fact been pushed back up towards the coasts by a mixture of wind and strong waves due to changing weather patterns  - Kench claimed that this showed how the islands were coping with the changes (Daily Mail, 2010).

So this study has given us a completely different perspective on sea level rise, and really makes one think about what other changes are taking place alongside it. Hunter made a good point by mentioning other issues which may affect this further, such as ocean warming, and acidification (Daily Mail, 2010).

There are clearly a number of different forces acting upon global ocean patterns and these small islands. Sea levels may be rising, but I think that in order to determine the fate of these islands, it depends on which forces have the greatest impact. The strength of the sea itself may be stronger and more destructive in some areas compared to others. Kench believed that the islands are simply moving with the changes. (Daily Mail, 2010). 

The diagram below is just an example that depicts changes in reef island characteristics of a selected part of Tuvalu (Funafuti Atoll) from 1984-2003.



It shows how these islands have altered their shape over this period of time.

However, one point to note with this study as a whole was that it explored Pacific reef islands; it does not account for other parts of the world, different coastlines, or even the other oceans and associated islands – sea level rise does still pose a threat to many other areas of the world and so the findings here cannot be generalised. Just thought it was interesting though, as the evidence does seem to legitimately show the islands that were studied have grown! This is still quite a fresh discovery, and I think more studies are required to explore these findings, and to show us further evidence that this really is the case.

References

Anonymous (2010) ‘Low-lying Pacific islands 'growing NOT sinking' as sea levels rise’, Daily Mail: http://www.dailymail.co.uk/sciencetech/article-1283669/Low-lying-Pacific-islands-growing-sinking-sea-levels-rise.html#ixzz2DeAXQ4Qr

Edwards, T. (2010) ‘Pacific islands ‘growing not sinking’, as sea levels rise’, The Week: http://www.theweek.co.uk/politics/14185/pacific-islands-%E2%80%98growing-not-sinking%E2%80%99-sea-levels-rise#

Kench, P. & A. Webb (2010) The dynamic response of reef islands to sea-level rise: Evidence from multi-decadal analysis of island change in the Central Paciļ¬c, Global and Planetary Change, 72 (3): 234-246 http://www.pacificdisaster.net/pdnadmin/data/original/SOPAC_2010_The_dynamic_response.pdf