Europe Can Not Hide

This article on the Guardians website is one that highlights the impacts of glacial melt a lot closer to home. It refers to the Alps which many will have visited on a skiing trip at some point in their lives. It links nicely to previous discussions that have examined how an earlier start to the ablation period could impact humans living in the area.

Guardian Article

A Worldwide Problem

Without water life cannot exist, rather unfortunate then, that over half of the worlds potable water supply comes from rivers. Rivers are sensitive to change, they are fuelled by precipitation and melt water; both of which are likely to be affected by future climate change (Barnett et al., 2005). A variation of temperature from what we consider normal today would see a change in glacial melt water regimes in snowmelt-dominated areas; but is this actually a problem?

It is when you consider the performance of water management systems, which have been built specifically for current climatic conditions (Barnett et al., 2005). A warmer climate would mean less snow accumulating during the winter period and an earlier melt in the summer period. One region that climate change will have a profound impact is in the Himalayan period, again as mentioned in previous posts in terms of volume of ice, it has the 3^rd largest in the world, but what is crucial is that it supplies water to a significant part of Asia. The China glacial inventory shows that there has been substantial melting in most glaciers, one in particular has retreated 750 metres; alarming when it is noted that it is the main contributor to the Yangtze river (Barnett et al., 2005). The inventory suggests that the rate of glacial retreat is increasing.

To draw from another area of the world with respect to proving glacial retreat is a real threat to societies we venture to the Andes. The summit core of the Quelccaya glacier taken in 1976 was layered; it showed the annual cycle of the glacier and could be traced back 1500 years. A core was taken from the same glacier in 1991 and the layers from the past 20 years were non existent because of the percolation of meltwater (Barnett et al., 2005). Melting at the summit of the glacier is taking place and has been for the last 20 years, something that hasn’t happened in the previous 1500 years ago. Both examples show that glaciers are retreating and not just in one area of the world….

My View

Clearly melting of glaciers is taking place, hopefully those reading this blog now realise this. Clearly it is going to have a high impact on the world and not just on one specific region but the impacts are likely to be felt in most areas of the world. 

Himalayan height problems

I read an excellent article this morning that emphasises the issues that scientists have with Himalayan glaciers. The height of the glaciers and the fact they are not accessible means that compared to the Alps and the Andes there is a lack of data.

However, the locals tell of the huge changes that have taken place in the last decade... Enjoy

Himalayan Glacier Melt - Guardian Article

Peru Struggles

This video looks at the potential impacts of climate change in Peru. Whilst the video looks a bit dated, it clearly outlines some of the disasters that Peru has encountered in the past and looks at what could happen more often if glacial melt continues at the current rate in the country.

Test your knowledge

Quizzes by Quibblo.com | SnapApp Quiz Apps

The Costs of Glacial Retreat in the Andes

Some countries and cities that have become dependent on the water that glacial melt provides, it is used for more thank drinking water and in some places it is used as the main source of power through hydro electricity. Vergara et al. (2007) have looked in to the possible implications glacial retreat could have for the Andean region, with particular attention paid to the economic costs that may be incurred.

An introduction to the problem

In the Andes, glacial melt water ensures a year round water supply for agriculture, ecosystem biodiversity, power supplies and potable water (Vergara et al., 2007). Much of the population is dependent on the water that is provided by glacial melt, unfortunately the amount of water is likely to decrease in the future and people will have to adapt to this. Modeling work implies that many of the glaciers in the region could disappear within the next 10-20 years. From 1970 to 2002 glacier cover decreased from 2940km² to 2493km² (Kaser and Osmaston, 2002). The increased melt has seen an increase in runoff, but this runoff is unsustainable. To put it simply, at the moment there is more then enough water because glaciers are melting. Unfortunately, people are dependent on this water and soon it is going to run out!

Most of the population of Peru is located near to the Andes, with the majority of economic activity also present here; both are reliant on the melt water. Quito is a city located in Ecuador, home to 2 million people; when glaciers melt its local economy is likely to falter because water supplies are at risk (Francou et al., 2000). There are numerous projects that could alleviate the problem, none of which are cheap.

Solving the Problem and costs

-          More water sources must be diverted to the city; a reservoir capacity close to 43 million cubic metres will be required, this will cost US$13 million.

-         Water infrastructure will have to be built at a faster pace than was previously thought because of the lack of melt water, this will cost US$100 million over 20 years.

(Vergara et al., 2007)

Ecosystem effects

-          Reduced water regulation will mean a decrease in biodiversity, with many species of fauna not being able to survive the seasonal changes (Mulholland et al., 1997).

Power Generation

-       80% of power in Peru is from hydropower.

-       

      An example – Average annual power supply from the Canon Del Pato hydropower plant would drop from 1540 gigawatt-hours to 1250 gigawatt-hours with a 50% reduction in glacial runoff. If there was no glacial runoff, this would reduce to only 970 gigawatt-hours, a significant reduction(Vergara et al, 2007). A further example of the contribution of meltwater to total stream yield is shown in the table below, it highlights the significant decrease in yield when there is no meltwater adding to the flow.

Economic this lack of power could have major implications for the country. It would be feasible to see rising energy costs as the supply decreases for homeowners. Hydropower plants will also see a reduced income because of the decrease in the amount of energy they will be able to produce. All negative news for the economy (Vergara et al., 2007).

A sentence to think about from Vergara et al., (2007) “Peru will likely have to invest in additional power capacity, most likely thermal-based, at a cost of US$1 billion per gigawatt installed”.

My View

Clearly the Andean region of the world has become over reliant on the water that comes seasonally from meltwater. They will not be able to continue to rely upon this water as the meltwater amount decreases with the continued reduction in glacial size. Their are numerous ways in which the countries could adapt, unfortunately though, the measures they will have to take will probably mean a lot of change at a high cost. How well each country prepares for and adapts to the inevitable decrease in water will determine how the country and the economy in particular cope with the changes.

Bibliography

Kaser, G. and Osmaston, H. (2002) Tropical Glaciers, Cambridge University Press: New York.

General Trends

Over the last week I have read a few articles of interest regarding research related to glaciers. The question I have been pondering is whether glaciers can be used to predict future climate change? They have of course been around for a long time and are affected by the climate so it would make sense that if we can look at how past climate has affected them then perhaps we can infer what will happen in the future.

Indications of their usefulness

-       The Intergovernmental Panel on Climate Change (IPCC) has recognized the significance of glacial melt as a temperature sign. They have used fluctuations in there extent in all of their reports since 1990 (Barry, 2006). The use of the data implies that they are a reliable sign of climate fluctuations.

-       A change in glacier length is an obvious illustration of the impact that climate change is having, but this doesn't foresee future climate change. There are 800 glaciers that are monitored every 5-10 years but of these only 100 have long term records (Haeberli, 1998).

-       The issue with just using glacier length as an indicator of climate change is the time lag between temperature change and the change in the glacier length.

-       Oerlemans (1994) used glacial length data to predict global warming. The graph underneath shows Oerlemans prediction in relation to other predictions made using different proxies. It is very similar to the predictions that are made using other proxies, indicating that glaciers can be used to infer temperature. 

Figure 1: Source Real Climate Blog (WWW)

-       The response times of glaciers have been split in to three different groups, listed below; so progress has been made for inferring climate change.

-       Type 1 – steep slopes, extensive crevassing, high velocities near the terminus – 30-20 years response time

-       Type 2 – intermediate characteristics – 40-60 years response time

-       Type 3 – low slopes, moderate crevassing and low terminal velocities – 60-100 years response time.

Barry, 2006

As discussed in previous posts a survey of glacial trends worldwide is not yet possible due to an uneven distribution of measurements. Despite the lack of available data for individual areas the general trends are well known and are illustrated in the below graph which shows the retreat of numerous glaciers over time.

Figure 2: Top graph shows the glacial retreat and advance, bottom graph shows the location of the glaciers.
Source: Real Climate Blog (WWW)

My View


It is true that glaciers can be used as a proxy to infer past temperature. Anybody doing a study on such a thing must take in to account the time lag between the temperature change and the change in the glacier. However, temperature is not the only thing that impacts glaciers, there are a number of factors to take in to account including the amount of precipitation and perhaps human influences. This presents a problem for inferring past temperatures from glaciers, a solution may be to look at multiple proxies and infer temperatures from them, glaciers just being one of the proxies used.

In terms of future climate change, this post does not answer the question and the question must therefore roll over on to future posts.

Bibliography

Haeberli, W. (1998) Historical evolutionand operational aspects of worldwide glacier monitoring, in Haeberli, W., Hoelze, M. and Suter, S. (Eds.), Into the second century of worldwide glacier monitoring – prospects and strategy. Paris: UNESCO, Paris, 35-51.

A year in the life of

My View

This short video is the first video on the blog where we get to see a year of the glacier. This means that we can be sure that pictures are not taken at different times of year. The video does clearly show that the glacier is retreating.

I have talked a lot about glaciers retreating but many people remain skeptical of the fact that this is taking place on a worldwide scale. My next post should end the doubts that remain in the minds of many.

Past Scepticism, the future and sea level rise

Arendt et al. (2002) concentrates on Alaskan glaciers but the points made are relevant to glaciers around the world and the findings they report are thought provoking with regard to sea level change and the contribution that melting mountain glaciers could have. Arendt et al. (2002) starts by highlighting some of the problems that have plagued glacial scientists in the past, showing how difficult measurement of retreat is due to the number of glaciers and the size of some of the larger glaciers. 

Arendt et al (2002) criticise previous findings; in particular the fact that mountain glaciers have contributed to sea level rise, adding 0.2-0.4mm/year for the last century (Persson, 1996). Why? Simply the fact that there has been insufficient measurements of glacier mass balance to be able to draw up firm conclusions on the worlds glaciers. Obviously sampling every one of the worlds 160,000+ glaciers would be a costly and time consuming job; so there are only 40 glaciers worldwide that have been monitored for over 20 years. Of these 40 glaciers few are high latitude glaciers and most of them have been selected because of the ease of access and their small size, not because they are representative of the majority of glaciers (Arendt et al. 2002). In Alaska there are three glaciers that are monitored, all three are small glaciers, past studies have used the data from these glaciers as representative of all Alaska’s Glaciers with regards to the contribution they make to sea level rise. 

Technology continues to develop and Arendt et al (2002) use this technology to more effectively find the extent to which Alaskan mountain glaciers have contributed to sea level rise. Using airborne laser altimetry to measure the volume of 20% of the glaciers in the Alaska region. They measure a total of67 glaciers to predict more accurately the contribution of Alaskan glaciers to global sea rise. This technique likely represents the future of how glacier retreat is measured and certainly the results from this are more reliable than the data collected using only 4 glaciers.

The results

The laser altimetry shows that glacial thinning in the area has become more prevalent in recent years (twice as fast in the last 5 years, compared to the thinning from the mid 1950’s to the mid 1990’s). The results are substantially different to previous estimations of contribution to sea level change. Arendt et al. (2002) found that Alaskan glaciers contributed 9% of the observed sea-level rise (1.5mm/year +/-0.5mm) over the last 50 years and in the last decade this figure could be as large as 3.2mm/year. Clearly previous estimates of the contribution must be questioned, not just for Alaskan glaciers but for estimations made around the world. 


 “Mountain glaciers may be contributing a substantial fraction of the increased rate of sea level rise suggested by satellite observations from 1993 to 1998” (Arendt et al., 2002; 385). A statement that clearly implies the major percentage of sea level rise that is likely attributable to glacial melt.




My View


This post can be split in to two separate parts in my opinion. The first being the past problems with observing glaciers. Clearly scientists in the past have not had sufficient data to be accurate in their predictions. Whilst Arendt et al (2002) show how progression can be made by using technology to assess glaciers they still only sample 20% of the glaciers in the region and so we still cannot be 100% sure of what is taking place with regard to the glacial mass balance. Unfortunately the sampling of 100% of the worlds glaciers is not likely to take place in the near future and so we must do what we can with the data available to prepare for the changes that may come about in the world.

The second part of the article shows the significant contribution made by Alaskan glaciers to sea level change. Just under 10% is highly significant proportion and it would be fascinating to know the percentage of contribution from glaciers worldwide. Needless to say it would likely be a large proportion and means that we should be looking at how best to control the rate of melting that is taking place.

A powerful line

"Retreat of Tibetan Plateau glaciers affects at least half a billion people"    

                                                                                                    Kehrwald et al., 2008 pg1.


My View


Again the scale of the problem is outlined, clearly it is not one to be brushed under the carpet.