In the news this week...

ADVANCING GLACIERS IN THE KARAKORAM HIMALAYAS

Following on from an earlier study in 2005 that indicated glaciers in the Karakoram Himalaya have not followed the general trend of glacier retreat observed in other parts of the Himalayas, Hewitt (2011) undertook a review of the literature to investigate the later Little Ice Age in the Karakoram and the recent 'expansion'  of the glaciers in the region. From a review of the literature, Hewitt (2011) observed that on average, Karakoram glaciers only declined by 5% between 1920 and 1960, becoming almost static in the 1970s, with some glaciers advancing during this period. From the studies, generally rates of retreat were resumed in the 1980s and into the early 1990s but were largely insignificant and since the 1990s a stabilisation of the glacial balance and advances in the High Karakoram (coinciding with increases in snow cover) were observed.

Hewitt (2011) attributes the relatively static response to global warming of the Karakoram glaciers to their relatively high-elevation 'buffering' against rising atmospheric carbon dioxide levels. Due to the higher altitude, precipitation in the region mainly falls as snow throughout the year, and Hewitt (2011) states that the warmer ocean temperatures may also contribute to greater moisture systems reaching the region. In addition to this, local studies have observed a recent cooling in summer temperatures coinciding with increased cloudiness and greater snow cover, an observation that Hewitt (2011) suggests could be due to the albedo feedback.

Thus, this article suggests that whilst glaciers are retreating across the Himalayas, this cannot be generalised to all glaciers in the region and highlights the complex interaction of feedback mechanisms that control an individual glacier's response to global warming.

OUTLOOK ON CLIMATE CHANGE: MUCH OF THE SAME OR EVEN WORSE!

In preparation for the fifth IPCC report due for 2013 a meeting was held this week by climate scientists to assess any advancements in our knowledge of our changing climate since the last report almost five years ago. Overall, although there has been substantial improvements in modelling, with larger, more sophisticated and integrated models than five years ago, the simulations being produced have remained relatively similar (Science, 2011). Results from one-third of the thirty models expected to be used in AR5, were only slightly more sensitive to greenhouse gas emissions than the past AR4 model and predict similar regional patterns of temperature and precipitation changes throughout the world.

However, some of the simulated responses to global warming in the most recent models did diverge from past estimations. For example the AR4 (2007) report estimated ice sheet melt would contribute to around a 25cm rise in sea levels by 2100. The increased sensitivity of the latest models has increased this value to 32cm, which is higher than the IPCC last conservative estimate but substantially lower than earlier estimates of one metre (Science, 2011). Incorporation of this new value produces a range of cumulative sea level rise from ocean thermal expansion, ice and glacial melt between 63 to 71cm by 2100, a sufficient level to inundate a substantial area of Bangladesh.

Although the meeting did not review all of the models or studies that will be included in the final report, conclusions from the meeting confirm our current understanding of the rate of global warming and the regional impacts that it could have around the world. Despite minimal changes in the observations of the models, this still supports the claim that global warming is occurring and should be seen as evidence for action to be taken to attempt to minimise or reverse this rising trend. Due to the complexity of the Earth's systems, uncertainty can never be removed from models of climate change. However, the consistency between the models analysed in this meeting and models from the last report suggest that the observed warming trend is not anomalous and the simulated regional responses to global warming are likely, within their observed ranges, to occur.

Reference 
Hewitt, K. 2011. Glacier change, concentration, and elevation effects in the Karakoram Himalaya, upper Indus Basin. Mountain Research and Development , 31: 188-200.

Science, 2011 'Climate outlook looking much the same, or worse', Science, 334, 1616

BBC News: Hocus pocus:the disappearing and reappearing Ngozumpa glacial lake

Figure 1: Time lapse video of the Ngozumpa glacial lake filling and draining over a fifteen day period (Source: Live Science, 7th December 2011).

Reflecting the general trend across the region, melting of the debris-covered Ngozumpa glacier in Nepal is of growing concern for scientists due to the rapid growth of the glacial lake at the glacier's snout. Named the 'Spillway', the glacial lake is equivalent in size to 40 Olympic swimming pools contained behind a terminal moraine dam (BBC News, 26th December, 2011). Although it is claimed the threat of a glacial lake outburst flood (GLOF) is less imminent than other glacial lakes, scientists are still monitoring changes in the dynamics of the lake. Using timelapse cameras, research by the Cooperative Institiute for Environmental Sciences (CIRES) have demonstrated dynamic fluctuations in the lake volume reflecting complex interaction of factors controlling inflow and outflow to the lake (Figure 1). Observations from the time-lapse cameras showed a decrease in volume by over 100,000m³ in two days, followed by a recovery of around half of this volume in the five days following this event (BBC News, 26th December 2011).

Although assessments of the Spillway suggest this glacial lake is less of an imminent threat to outburst compared to other glaciers in the region, the results from the timelapse videos demonstrate the complex interaction of factors controlling the growth of glacial lakes in the Himalayas. Beyond a basic understanding of the relationships between glacial lake growth and glacier melt this research highlights our limited understanding of the mechanisms regulating volume within these glacial features. Coinciding increased rates of glacial melt due to climate change, the frequency of GLOFs are increasing. Thus understanding the dynamics behind the formation and regulation of lake volume, being undertaken in studies such as this is becoming increasing important.

Reference:

Amos, J. (2011) 'Taking the pulse of Ngozumpa', BBC News, 26th December 2011. 

National Geographic Special Issue: Water Is Life

Source: Hogshon, R. National Geographic 21st December 2011).

This week the National Geographic have released a special series dedicated to the importance of freshwater for humans and global biomes around the world. Specifically related to this blog, one of the articles summaries recent research presented at the American and Geophysical Union last month (National Geographic News, 20th December 2011). Findings from different mountain ranges around the world including the Andes, Himalayas and the Canadian Rockies indicate that rates of retreat are occurring faster than previously anticipated. For example, research by the University of British Columba, Vancouver suggest in the Saint Ellias region of the Canadian Rockies glaciers could decrease to 50% of their size by 2100, of which many may even disappear completely. The article also states that global changes in glacier melt will have severe consequences on local and regional river discharge, as discussed in my last post.

The national geographic provide a variety of interactive applications including: calculating your own water footprint and visual representations that put your water use into perspective compared to other regions of the world. As our population continues to increase, trying to use our freshwater as efficiently as possible has never been more important.

In the news this week...

PAPER COMPARING THE MEDIEVAL WARM PERIOD, LITTLE ICE AGE AND THE 20TH CENTURY WARMING RATES

Using the climate system model 'FGOAL', TianJun et al., (2011) compared the differences between the rates of global warming between the Medieval Warm Period (MWP), Little Ice Age (LIA) and twentieth century. Multiple proxies were used in the model obtained from tree rings, ice cores, pollen and other records from thirty areas around the world, resulting in forcing data on volcanic events, solar insolation, nirous oxide, carbon dioxide and methane (Figure 1). Simulating changes on a global scale, the model indicated a warming during the MWP in all regions except the North Pacific. The model also demonstrated that warming was not uniform, with rates greater in the Northern hemisphere, than in the Southern hemisphere, and greater warming at higher latitudes. However, the overall warming during the MWP was not as strong as observations during the 20th century (Figure 2). During the LIA overall a global cold anomaly was observed in surface temperature, although mean surface temperature remained around +0.5° C in North-east America (although this is comparitively lower than during the MWP and 20th century anomaly).

Figure 1: Time series of forcing data used in the FGOAL model (Source Tian et al., 2011: 3084)



Figure 2: Annual mean surface air temperature anomalies for top to bottom (Medieval Warm Period, Little Ice Age and the 20th century).

Observations from the model support the concept of accelerated warming during the 20th century due to increased inputs of greenhouse gases into the atmosphere. This is evident in Figure 1, where there are significant increases in carbon dioxide, methane and nitrous oxide concentrations in the atmosphere from the Industrial Revolution in the mid-18th century, and is claimed by some (Crutzen, 2002) as the start of the 'anthropocene'.  


PALEOCLIMATIC RECORD SUGGESTS TIBETAN PLATEAU TEMPERATURES WILL DECREASE UNTIL 2068

A paper released by Lui et al., (2011) using palaeorecords from tree rings in the central-eastern Tibetan Plateau suggests that temperatures in the region will decrease until AD 2068 and will then begin to increase. Based on a 2485 year record, the tree ring record observes changes in temperature coincising with the MWP, LIA and 20th century warming, and cycles in temperature related to sunspot activity. Six cold and six warm events (half a standard deviation,±0.4°C, from the mean) were observed during the 2485-year period. Several significant cycles at 1324 year, 800 year, 190 year and 110 year were noted in the temperature series, and the cold events observed in the time-series coincided with periods of sunspot minimum. From the reconstructed temperature record, Lui et al., (2011) projects a decrease in temperature until 2068 reflecting as the earth enters a sunspot minimumn, followed by an increase in temperatures to 2088 (Figure 1).

However Lui et al.,'s (2011) study does not consider other forcings that influence global temperatures. Studies in previous posts have suggested that anthropogenic emissions of GHG's have accounted for a greater amount of the variability in global temperatures during the 20th century relative to insolation and volcanic activity. Therefore further research using multiple proxies covering a larger area is required to validate these findings. 

Figure 1: Reconstructed temperature record from a tree ring proxy in the central-eastern Tibetan Plateau over the last 2485years, and future changes projected due to sunspot variability.

Reference:

Liu, Y., Q. Cai, H. Song, Z. An and H. W. Linderholm (2011) 'Amplitudes, rates, periodicities and causes of temperature variation in the past 2485 years and future trends over the central-eastern Tibetan Plateau', Chinese Science Bulletin, 56: 2986-2994.

TianShun, Z., B. Lou, W. Man, L. Zhang and J. Zhang (2011) ' A comparison of the Medival Warm Period, Little Ice Age and 20th century warming simulated by the FGOALs climate systems model', China Science Bulletin, 56: 3028-3041.

Christmas Number One? Not quite 'I saw mummy kissing santa'!

Now here's a challenge. Making a song about glaciation. Now call me a scrudge but current Christmas songs don't seem to have any relation to Christmas or snow in them at all. So here's my contribution. I can't say I wrote it myself, and it is based on glaciation rather than Christmas so no relation to Santa, but its got snow in it so why could this not be number one? Then we could have education and festivities at the same time. Okay, so maybe I'm taking it too far, but I believe this song produced by Dan Bull on 'glaciation' provides a unique way of explaining scientific topics to a wide variety of people. Coming from someone who cannot think of a word to rhyme with glaciers, I was impressed and thought this song was worth sharing. Let me know what you think…

BBC report: Melting glaciers and changes to the River Ganges (1st November 2009)

I found this clip of a BBC report explaining how the melting Gangotri glacier (the source of the headwaters of the River Ganges) is affecting the the flow of the River Ganges and the communities that rely on the river (Figure 1). Although rather basic, it provides a brief review of the points made in my post last week about the link between melting glaciers and changes in the dynamics of rivers in the Himalayas. However, there are some overlooked generalities made in the report that are worth highlighting:

1) States that all glaciers in the Himalayas are retreating, but at different rates.

Work by Hewitt (2005) has demonstrated this statement cannot be applied to all glaciers in the Himalayas. Hewitt (2005) shows that glaciers in the Karakoram region are largely remaining static and some are advancing. This highlights the spatial complexity of glaciers within the Himalaya, and emphasises the importance of local research, as general patterns cannot be generalised across the entire region.

2) The retreat of the Gangotri glacier by 15m in 6 months.

The period of retreat described in the clip occurred during the summer months between May to October when the rates of glacier melt are at that greatest in most parts of the Himalayas. Although it visually provides a persuasive argument for the retreat of glaciers, in order to assess the significance of this rate of retreat can only be evaluated by comparison of long-term changes in the extent of the Gangotri snout.

Figure 1: Video of a BBC report on the melting Gangotri glacier and potential impacts on the River Ganges. First aired on the 1st of November in 2009 this report occurred in the weeks before the 2009 Copenhagen Summit and the release of the ClimateGate scandal where the IPCC were forced to retract their statement that all Himalayan glaciers potentially all vanishing by 2035.


Reference:
Hewitt, K. (2005) 'The Karakoram anomaly? Glacier expansion and the 'elevation effect', Karakoram Himalayas', Mountain Research and Development, 24, 4: 332-340.

In the news this week...

USAID STUDY TO ASSESS ASIAN WATER RESOURCES

United States Agency for International Development have teamed up with a University Boulder team to carry out a four year study investigating the contribution of snow and glacier melt to water resources supplied by the Himalayas. This report aims to increase our understanding of the snow and glacial input to river discharge which can then be used to predict future variability in river discharge under climate change.Due to the limited data available in the region, USAID will use a combination of remotely sensed data to produce time-series maps of intra-annual snowfall and glacial ice melt (NSIDC, 7th December, 2011). This will be combined with meterological and hydrological data in the region to estimate current relationships between snow and glacier contribution and river discharge that can then be extrapolated to predict future river discharge under differenet warming scenarios.

The findings of this study will be highly beneficial for scientists and policy makers within the regions, potentially highlighting the regions that will be at most risk under climate change allowing mitigation methods to be put in place to reduce water scarcity threat in these areas. The data could also be informed in further development schemes, such as avoiding the development of new irrigation plants in areas that are assessed at being at high risk of reductions in river discharge. As my last post has stated, changes to Himalayan glaciers is anticipated to have substantial intra-annual and longer term impacts on river discharge in the region, however, with studies like this being undertaken, our ability to understand the factors determining these changes and how they may change in the future may allow mitigation measures to be put in place to attempt to reduce their impacts.

Figure 1: Major rivers within the ten countries surrounding the Himalayas with headwaters in the mountain area (Source: NSIDC, 7th December 2011).

ICIMOD RELEASE NEW REPORTS SUGGESTING HIMALAYAN GLACIERS ARE MELTING

Following the retraction of a statement in the Fourth IPCC report that ‘all of the Himalayan glaciers would have melted by 2035’, the IPCC has announced that the most recent conclusions from three ICIMOD reports provide new evidence Himalayan glaciers are melting Compiling data from across the Hindu-Kush Himalaya (HKH) Region, these reports provide the most recent data regarding climate change for the region. However, although these reports are the most comprehensive studies yet, ICIMOD state that further research needs to be carried out (ICIMOD, 4th December, 2011)

The reports:

1) The Status of Glaciers in the Hindu-Kush Himalayan Region.

The first report used remotely sensed data to estimate the current extent and distribution of glaciers within the HKH region. Identifying approximately 54,000 glaciers within the region, the lack of data in the region is underlined as of these only ten have been continously monitored to assess changes in glacial mass. Conclusions from the remotely sensed data showed an overall reduction in glacial mass in the central and eastern Himalayas, with reductions over the last thirty years being 22% and 21% in Bhutan and Nepal respectively.

Although additional research will need to be carried out this comprehensive report provides a baseline that can be used to inform discussions over climate change within the Himalayas and can be used to direct further research in the area.

2) Snow Cover Mapping and Monitoring in the Hindu-Kush Himalayas

This report uses regional monitoring to observe changes in the HKH region over the last decade. It concludes that there has been regional disparities within the mountain chain with snow cover decreasing within the central part of the Himalayas, but monitoring indicating a slight increase within the eastern and western regions.

3) Climate Change in the Region: The State of Current Knowledge..

Reviewing the current literature available under the three broad headings: climate and hydrology; biodiversity and ecosystems; and atmospheric changes. The reports underlines the bias of the limited spatial data within the region, often restricted to areas of easier access at lower elevations. Despite this, the report identifies several conclusions within the region including:

•  More pronouced warming in the winter months than the summer months (A claim supported by Singh et al., (2006) report cited in my last post).
• The average overall warming in the region (around 0.74°C in the last 100years) is greaer than the global average, although the ICIMOD emphasis that this is not evenly distributed across the region.
• The report found that warming was most pronounced in the higher altitudinal regions such as the central Himalayas and the Tibetan Plateau, and related to the second report may partially account for the reduction in snow cover in these regions 

• Significant changes in mountain habitats are beginning to occur with the mountain treeline shifting to higher elevations, and the report suggests that some species at higher elevations may disappear as the ecosystems change.

Overall these three reports represent a significant step in bridging some of the major knowledge gaps present in this region, and highlights the benefits of using remotely sensed data when access is to the study area is limited. These reports also support the growing evidence that changes due to global warming may be exaccerbated in the Himalayan region, and therefore the continuation of studies such as this are highly important.

Up the creek without a paddle: Intra-annual and longer term changes to river discharge in the Himalayas

Continuing from last weeks post on GLOFs, this post shall review the impacts that glacier distribution and mass may have on discharge of rivers whose headwaters are situated in the Himalayas. Supporting one-third of the world’s global population (Singh  et al., 2006) changes in glacial melt will alter the discharge of these rivers on both intra-annual and also longer-term timescales.

CONTRIBUTION FROM GLACIAL MELT

It is estimated that the River Ganges is replenished by meltwater from approximately 4,000 glaciers and over 3,300 are calculated to contribute to the annual discharge of the River Indus (Thayyen and Gergan, 2010). Rees and Collins (2006) demonstrated that Himalayan glaciers contribute to both intra-annual variations in river flow and also in addition to precipitation, longer-term changes in annual river discharge. The contribution of a glacier to river flow is basin-specific with the glacial melt component comparatively higher in glacierised basins than less glacierised basin, with the latter receiving a greater contribution from surface runoff (Rees and Collins, 2006).

However, although the extent glacial coverage in the basin will undoubtedly contribute to the initial contribution, and thus subsequent change, of the glacial melt component to the river discharge, the significance of the affect of changing glacier discharge will also depend on surface runoff input by precipitation. This applies to both intra-annual and longer-term river discharge variability.

INTRA-ANNUAL VARIABILITY

Thayygen and Gergan's (2010) study of the Dokriani glacier in Garwhal, Himalaya monitored the summer variability of runoff at three hydrometric and meterological stations at different altitudes in the basin between 1998-2004 (from 3,400masl just below the glacier snout to 2,360masl in an unglacierised region further down in the valley).  Over this six-year period, summer streamflow gradually decreased from 290 x10⁶m³ in 1998 to the lowest measured discharge of 123 x 10⁶m³ in 2004 (Thayyen and Gergan, 2010). Discharge from the uppermost station, 600 metres below the glacier snout also recorded a 50% decline in discharge over the same period. However, observations at the lowest station (Tela) indicate that the glacier component to the total river discharge downstream nearly doubled, from 18% in 1998 to 34% in 2004. Thus contribution of the glacial component to river flow increased despite the actual discharge from the glacier decreasing. Comparison against precipitation values between 1998-2004 showed a fall in summer precipitation. Therefore, glacier melt was acting as a buffer against reduced surface runoff, augmenting the years of low summer flow (Thayyen and Gergan, 2010). This is an key point as it highlights the importance of glacial discharge to maintaining river discharge during low flow periods, thus supplying communities with a freshwater source when the demand is the greatest during the summer months. This is underlined by the lowest specific runoff values recorded in the study with the lowest specific yield from the glacierised catchment 15mm day^-1, 4mmday^-1 higher than the non-glacierised (precipitation-dependent) catchment (Thayyen and Gergan, 2010).

Singh et al. (2006) also demonstrated the intra-annual importance of glacier melt to river flow. Applying the SNOWMOD snowmelt model to same glacier, Dokriani, between 1997 and 1998, the model showed a linear increase in stream discharge with a rise in temperature for both of years, with glacial melt and rainfall contributing 87% and 13% respectively. The model also highlighted variation in runoff within the summer months with the largest percentage changes in runoff occurring in September and the smallest in July in 1997, whilst the reverse was recorded in 1998. Related to 1998, the highest percentage change in June (23%) attributed to a later onset of the monsoon (Singh et al., 2006). However, in the subsequent months, the impact of precipitation changes decrease and the glacial component becomes more important and thus air temperature, which influences glacial melt becomes the main factor. Using the limited duration of data available, the model projected that a 2°C rise in temperature would cause summer discharge to increase by approximately 28% (Singh et al., 2006).

LONGER TERM VARIABILITY

In addition to augmenting low flow during the summer months, changes in glacier melt will affect long-term annual discharge of rivers with headwaters in the Himalayas.

Bhutiyani et al., (2008) studied the flow of four rivers in the northwestern Himalaya from 1961-2004, with an extended study for one of the rivers, Satluj River, from 1922-2004. In the absence of specific catchment data, regional temperature and precipitation were used to analysed the changes in discharge in each of the rivers obtained from hydrographs. Initial observations from the basins showed insignificant changes in the relatively less glacierised Beas and Ravi river discharge, whilst Chenab, the most glacierised catchment showed a significant increase in discharge between 1961-2004. However, precipitation from the summer monsoon in the Beas catchment decreased, demonstrating that glacial melt is again buffering against reductions in river flow. Temperature in the northwest region of the Himalayas has being warmed by approximately 4.4°C in the winter months in the last two decade (Bhutiyani et al., 2008). This has caused an increase in glacial melt as the transient snowline increases in altitude causing greater ablation rates at the glacier snout. The short-term implications of increased glacial discharge, as observed in Beas, Ravi and Chenab is either a maintenance of river discharge as precipitation decreases or, as in the case of Chenab where precipitation was relatively constant, an increase in river flow.

Although in the short-term (four decade) period of these three rivers, glacial retreat causes a rise in stream discharge which would be beneficial to local communities, the longer term (1922-2004) study at Satluj shows a reversal of this increase in a longer time frame. Between 1922-2004 the river discharge fluctuated from above normal to below normal discharge (Bhutiyani et al., (2006). From 1945-1990 above normal discharge was observed within the Satluj river. Whilst the initial rise (1945-67) coincided with relatively static temperature changes and a rise in precipitation, the later phase (1968-90) occurred during a period of increasing temperature and a decline in monsoon precipitation suggesting glacial melt was buffering river discharge against falling surface run-off input (Bhutiyani et al., (2008). Since 1990, discharge has begun to decrease. Bhutiyani et al., (2008) argues that this decline is due to a reduction in the glacier-melt component of discharge which reached its maximum during the 1968-1990 period and has now thinned considerably. The key observations from the longer-term study suggest that in the short term, assuming precipitation remains constant, river discharge will increase. However, in the long-term once glaciers have reached a maximum, their contribution to river flow will begin to decline and subsequently river discharge will also decrease. The current observed weakening of the monsoon will only exacerbate river discharge changes further, with a reduction in flow likely to occur sooner as glacial melt is augmenting against reductions in surface runoff input. This will have significant impacts on communities within the Himalayan region, and will be expanded upon further in my next post.

REGIONAL DISPARITIES.

The complex regional climate with the Himalayas, mean the impacts of future warming on river flow will vary across the mountain chain, The glacio-hydrological regimes in the Himalaya differ related to the decrease in the influence of the monsoon from the east (monsoonal) to the drier west (Rees and Collins, 2006). Using a temperature-index based model, Rees and Collins (2006) modelled the changes in river discharge of two hypothetical catchments, one in the west and one in the east. By using hypothetical catchments, the study could maintain other parameters such as glacial coverage and basin size that could otherwise influence the response of the river to changing glacial melt rate. A baseline scenario using climate data from 1961-90 and a warming scenario of 0.0.6°C were run for a 150 year period starting from 1990. As shown in Figure 1, in the short-term river discharge increases due to rising temperatures increasing glacial melt discharge cause the hypothetical glacier to retreat. Once the rate of new ice exposed by the increasing snowline is no longer offset by the melt of the glacial ice below this line, then the glacial discharge begins to decrease indicated by a fall in river discharge (Rees and Collins, 2006). The diagram also shows that the impacts of the retreating glacier are more distinct in the drier western catchment (Figure 1a), and the initiation in the decrease is sooner and rate comparitively greater in the western catchment compared to in the east where the monsoon suppresses the changes in glacial melt.



Figure 1: Variation in annual mean flow under the 0.06°C yr^-1 warming scenario for a)the western catchment and b) the eastern catchment (Source: Rees and Collins, 2006:2166)



CONCLUSIONS

Review of some of the current literature on hydro-glaciological regimes in the Himalayas demonstrates the important contribution of glacial-melt to both intra-annual and longer-term changes in Himalayan river flow. In addition to augmenting periods of low summer flow, glacial melt also buffers against yearly variations in precipitation across the mountain chain. In the short-term, rising temperatures are anticipated to cause an increase in the glacial melt component to river discharge, with the subsequent change in short-term river discharge (remaining static or increasing) depending on the precipitation regime in that area (declining or stable/increasing). Intra-annual changes to river discharge will also depend on summer precipitation, and under the current pattern of a weakening monsoon, glacial melt is becoming increasing important in augmenting against low summer flow. If current global warming continues, in the long term it is predicted that after a peak in river discharge, discharge will subsequently begin to fall, a pattern simulated in both the east and west Himalaya. This will have significant implications for countries bordering the Himalayas, with over one-third of the world’s population currently dependent on Himalayan rivers for freshwater, and this value is growing. Therefore, changes to river discharge are of growing political and social concern and significant investment will be needed to prepare for declining river discharge in the future.   

Reference:

Bhutiyana, M. R., V. S. Kale and N. J. Pawar (2008) ‘Changing streamflow patterns in the rivers of northwestern Himalaya: Implications of global warming in the 20^th century’ Current Science, 85, 5: 618-626.

Rees, H.G. and D. N. Collins (2006) ‘Regional differences in response of flow in glacier-fed Himalayan rivers to climatics warming’, Hydrological Processes, 20, 10: 2157-2169.

Singh, P., M. Arora and N. K. Goel (2006) ‘Effect of climate change on runoff of a glacierised Himalayan basin’, Hydrological Processes, 20: 1979-1992.

Thayyen, R. J., and J. T. Gergan (2010) ‘Role of glaciers in watershed hydrology: a preliminary study of a “Himalayan catchment”, The Cryosphere, 4: 115-128.

The cream turned sour: Canada has withdrawn from the Kyoto Protocol.

Figure: The Canadian Environmental minister Peter Kent announces that Canada is to withdraw from the Kyoto Protocol

Following on from my post yesterday that the UN should be cautious before hailing the Durban conference a success, today Canada has withdrawn from the legal treaty to cut global greenhouse emissions. Therefore, just because a legally binding deal has been made, it does not prevent countries from abandoning these commitments (The Guardian, 2011).

Under article 27 of the Kyoto Protocol, a country is allowed to withdraw from the protocol after it has been in force for three years. The current protocol came into force on the 1st of January 2008 meaning that Canada is entitled to withdraw if it wanted to, which it has. Although heavily criticised as by environmental organisations and most interestingly China (who were one of the main countries opposing all countries to be legally-bound to reduce emissions under the new protocol) who have stated Canada's decision to leave the protocol as 'irresponsible' (The Guardian, 2011).

So why did they leave? The answer, put simply is money. With a target of reducing emissions to 6% below 1990s levels, Canada's current emissions have increased by a third of their estimated 1990 value. Thus, in order to meet their target, Canada would have needed to spend approximately £8.7 billion (equivalent to $1,600 in taxes for every Canadian family), on buying carbon permission permits (AAUs) from other countries that are emitting less greenhouse gases (GHG) then their quota allows (The Guardian, 2011). Although this would allow Canada to meet their target, a criticism of AAUs is that the country itself has not actually reduced its emissions but has 'bought' the allowance off of another country. However, this is irrelevant as by leaving the protocol Canada do not have to invest in these permits.

Canada claim that their withdrawal from the treaty will have limited impacts on global GHG emissions as they only contribute 2% of the world's emissions (The Guardian, 2011). Environmental minister of Canada Peter Kent, claimed that the target set for Canada was unrealistic and in order to meet their target they would 'need to remove every vehicle of every kind from Canadian roads or close down the entire farming and agricultural sector' (The Guardian, 2011). Peter Kent goes further to argue that because the two largest emitters USA and China are not part of the current protocol and therefore iit cannot work. Behind this claim, is that Canada is the world's third largest producer of oil (which is highly energy and water intensive) and does not want to threaten the prospect of this industry growing in the future. 

 Therefore, as I have previously suggested it all comes down to money and whether the protocol makes economic sense. Although a deal has been done to draw up a second legally binding protocol, if loop-holes such as the right to walk away from the treaty remain then the effectiveness that the new treaty will have to force countries to reduce their emissions will be limited. If countries can simply leave the protocol before they have to pay for their industrial activities then reversing the current increase in GHG emissions seem highly unlikely.

The question now is how other countries will respond to this? Will others follow suit or will Canada mirror the current UK situation in the EU and will be cut out off a protocol that will drive movements towards sustainable development in the future?

                                        
For listen to the press release given by Canada's Environmental Minister Peter Kent click here.

Reference:

The Guardian (2011) 'Canada pulls out of Kyoto Protocol', The Guardian, 13th December 2011.

Vaughan, A. (2011) 'What does Canada's withdrawal from the Kyoto Protocol mean for the treaty?', The Guardian, 13th December 2011.

In the news: Durban a Done Deal: But is it a success?



Figure: British Oxfam activist protesting about the COP-17 Conference in Durban.  


Following from my post on the Durban climate summit last week, after the conference was extended over the weekend an agreement has been made to start working towards a a new Protocol which would legally bind both developed and developing countries to reduce their carbon emissions by 2020. This would differ from the current Kyoto Protocol which only legally binds developed nations (that have signed the agreement) to decrease their carbon emissions. This is a significant step forward and shows a political commitment to try and restrict global warming within the 2°C target set by scientists.

 Entitled 'The Durban Platform For Enhanced Action' a two-page document has been published providing guidelines for countries to voluntarily begin to reduce their carbon emissions by 2015 although legal commitments will not come into place until 2020 (UNFCCC, 2011) . In this interim, developed nations have also agreed to continue to be legally bond to reduce their emissions with the first Kyoto Protocol expiring in 2013. However, although this is being hailed a success by the UN and some other countries, critics have argued that the paper has simply glossed over the disputes between developed and developing (particularly China and India) and significant negotiations are still needed before a protocol will be produced (The Guardian, 2011). Further criticism arises from small island states and environmental NGOs which argue that global carbon emissions may have peaked by 2020, and that a legal agreement needs to be brought into force sooner than the proposed 2020 date (The Telegraph, 2011).

However, how realistic is it to expect countries to produce a treaty by 2015 let alone, bring the date forward as the smaller island nations suggest? The UN economic summit in Brussels is an obvious example. Countries self-interests are still at the forefront of international debates about our global future, in the economy and also in the environment. Although, the nations have all signed onto reducing their emissions, the next talk in Qatar will highlight the true commitment that developing nations have to enter into a legally binding agreement when targets are drawn up for each nation (The Telegraph, 2011).

Therefore, although the UN may feel like the 'cat that's got the cream' I suggest that they should delay their celebrating as that cream may just well turn out to be sour.
                                                

To read the two-page agreement for yourself, click here. The Guardian has also released a three-minute video which includes the opinions of this new agreement by some of the delegates at the conference.

Reference:
Gray, L (2011) 'Durban climate change: the agreement explained', The Telegraph, 11th December 2011.

Harvey, F. and D. Carrington (2011) 'Durban climate conference agrees to do a deal- now goes the hard part', The Guardian, 12th December 2011.
 

BBC's Frozen Planet: On Thin Ice

From the offset I want to state that the BBC has not (unfortunately) given me any incentive to endorse their series of Frozen Planet narrated by David Attenborough. Focused on the Arctic and Antarctica, this series has mainly being orientated to the biology in these frozen landscapes with the sixth episode dedicated to the Inuit tribes that live on the ice shelves. However, the last episode entitled 'On Thin Ice', was dedicated to the impacts that climate change is having in these polar regions, of which certain aspects were highly relevant to this blog.

It is important to acknowledge that the documentary does not state where it gets its statistics for ice melt rate and increasing air temperatures, or the uncertainties associated with these models. Despite this the use of time-lapse imagery and different case studies mean it expresses historic and future changes in a way that is easy to understand for those who may have a limited knowledge on climate change.

In the episode, David Attenborough states that the thickness of the Arctic icesheet has decreased by around half since 1980 and is now only a couple of metres in places. Attenbourgh then goes on to add that if the current trends continue, in the summer these areas may become open ocean in the next few decades with similar observations occurring in the Antarctic. Containing 75% of the world's freshwater, it is predicted that  Antarctic surface temperatures have increased by 3°C which is ten times the average rate for the rest of the Earth. Although David Attenborough states that the rise in temperature itself is unlikely to cause significant melting of the Antarctic Ice sheet (unlike the Arctic), rising temperatures could cause ice shelves that are containing the icesheet to melt at the iceshelf-ocean interface. If these iceshelves melt then the icesheet will advance to meet the ocean where it could potentially be melted by the warmer ocean surface water below. Surveys have indicated that iceshelves are melting six times faster that historic rates, with seven major ice shelves such as Larsen B in 2002 and more recently the Wilkins iceshelf already breaking up (The Guardian, 7th December, 2011). This 'wave of melting' that David Attenborough refers to is moving south towards the poles as is anticipated to start to affect the ice shelves holding back the Antarctic continental ice sheet in the next few decades.

The most fundamental point that the episode highlights is the impact that the melting will have on the global climate. As I have previously discussed, ice melt will significantly affect the albedo of the surface, and the replacement of ice by the darker open ocean will cause a positive feedback accelerating temperature rise in these polar regions. Attenborough also states that ice on land (including alpine glaciers) are more important than sea-ice as it can significantly alter sea levels. This emphasises the point that I have been trying to convey about the impacts that glaciers can have on not only a local but also a global scale.

Also, unlike animals such as the Adelie penguin (Pygoscelis adeliae) which can currently migrate further towards the poles, animals such as the snow leopard (Unica unica) in the Himalayas may be under a greater threat to climate change as they are more restricted in the extent that they can migrate to higher altitude locations. This draws attention the biological impacts that climate change may have on the ecosystems in alpine environments and goes beyond the scope of this blog. However, changes to biodiversity and ecosystem functions will likely have impact on local alpine communities as seen in the changing practices of native Inuit tribes in the Arctic.

If you can spare an hour amongst all of the Christmas shopping and present wrapping then I would strongly suggest watching this episode of Frozen Planet. Not shown in the US because of its strong support for climate change, this episode provides an easy introduction into the affect that climate change has had on our polar regions, and as David Attenborough states, 'it is apparent that animals are already adapting to climate change, the question now is can we?'.

To watch the episode go to the BBC website.
For more information, there is also an interactive website produced by the Open University which provides further details about the making of the series and photos from the series.

Reference:
Rees, D (2011) 'Frozen planet: capturing the Wilkins ice shelf in full collapse', The Guardian, 7th December 2011.

In the news this week (Special Edition:Ongoing UN Climate Talks)...



(Source: The Economist, 3rd December 2011)



As this topic has been well covered in the media this week, I thought I would dedicate an entire post to the on-going debates at the UN’s annual climate change conference in Durban. As I type, delegates continue to deliberate our global stance on tackling climate change. The current focus is setting out the details of the Green Climate Fund and the more contested issue of whether a second Kyoto Protocol should be adopted. The latter, as the Guardian illustrated is a highly divided issue, with most developed countries wanting to scrape the initiative whilst developing countries are still mainly behind a new protocol being created (Figure 1) (Coulter, 2011)

Figure 1: Diverging views of public opinion on the threat of climate change between developed and developing nations(Source: The Guardian, 1st December 2011)

The growing gap between the opinion of the public in developed and developing regions was also supported by a survey by the National Geographic of seventeen countries including Britain, Sweden, China and India. This gap has increased since 2007 and may be partly related to the increased awareness of how climate change can impact the environment in developing nations which are currently more significantly affected by extreme weather events.

The current Kyoto Protocol to be blunt has failed to reduce current carbon dioxide emissions which have increased by over a quarter since it came into force in 1997, mainly due to emissions by developing nations (see Figure 2). And this is the issue. The current protocol does not restrict the emissions of developing nations which equate to 58% of the global emissions each year (The Economist, 2011). Thus, the EU suggest that under the new agreement, all countries should commit to reducing their carbon emissions, although the burden on developing countries would be lower than for developed nations.  Some developing nations such as China and India have already agreed improve the carbon efficiency of their industries. However, currently these nations will not turn this into a legally binding agreement as their priority is still economic development rather than reducing global warming.

Figure 2: The contribution of countries to the total carbon dioxide emissions for 2007 (Source: The Economist, 3rd December 2011)

The current outlook from the conference is largely unclear. A new protocol is still possible but it will depend largely on how countries weight the global aim of reducing carbon emissions against their own prioritises of continuing economic growth. With emissions in China per person, now greater than some European countries, their decision in particular will determine whether our target to restrict global warming to 2°C can be achieved (Jacobs, 2011), .

Reference:

The Economist (2011) ‘Climate change talks: wilted greenery’, 3^rd October 2011

Coulter, C. (2011) ‘ Climate change concern highest in the developing world’, The Guardian, 1^st December 2011.

Jacobs, M. (2011) ‘UN talks see delayer countries throw away the 2°C goal’, The Guardian, 1^st December, 2011.

Self titled: Idiots Jump into Dangerous Imja Lake

Following what I have just posted about the risks an outburst can have on communities in the valleys below these lakes, I was disgusted to find this video on Youtube of people trying to cause the next outburst at Imja Lake by jumping into the lake. I could accept it if the people were unaware of what they were doing, but I cannot excuse this as they state in their video that they want to cause a GLOF! Imja lake is one of the four lakes classified in Nepal as being highly likely to have an outburst in next few years. I can understand that it might sound like a good story to tell to you friends down the pub in the evening, but just imagine what would have happened if they had caused an outburst. I was even more horrified to find that this was not a one-off event, but it is a global phenomena. Well call me a spoil sport but in my opinion this activity should be stopped, or at least if they have to continue doing it, jump into lakes that are not at risk of breaching and causing long-term devastation to the communities below.

Silent Tsunamis

Any environmental feature or process that adversely affects humans and their activities can be regarded as a hazard (Richardson and Reynolds, 2000). Glacial lake outburst floods (GLOFs) are one of these features, releasing up to 30,000m³s^-1 of water into the valley below having substantial social and economic impacts on the communities in the affected area. Although GLOF events rarely affect as many communities as many other hazards such as earthquakes, Richardson and Reynolds (2000) state that the damage in down valley areas for the local communities is of equal significance. The formation and growth of glacial lakes is directly related to glacial mass and therefore climate change and will be the focus of this post.

TYPES OF GLOF EVENTS

GLOFs are mainly triggered by two mechanisms: an outburst from a lake dammed by a terminal moraine (moraine-dammed lakes), or ice-dammed lakes, formed when an advancing tributary glacier blocks the river or discharge of a melting glacier in the main valley causing an outburst when it retreats in the summer months. Identifying how the glacial lake has been formed is highly significant, as each lake will respond differently to changes in glacial mass. Glacial retreat may cause a reduction in ice-dammed lakes in a particular region, however, the increased discharge may result in the formation of more moraine-dammed glacial lakes. Therefore acknowledging the contribution of each process to the glacial lakes present in a region is essential in order to assess how the risk from these lakes may alter with climate change in the future.

Figure 1: Lake Imja Tsho, a moriane-dammed lake in Nepal classified as 'hazardous' on risk assessment inventories (Source: Bajrachraraya et al., 2007: 35).

 

DISTRIBUTION AND RISK OF GLOFs

At some point, every country in the Himalayan region has suffered a GLOF event with 25 in Nepal since the 1930s (Hewitt and Liu, 2010). Qingha (1991) study of 17 GLOF events in the Karakoram Mountains noted that all of the events occurred between June to November coinciding with the monsoon and greatest snowmelt rates. A study by Kattelman (2003) also supports this, with all of the recorded GLOF events in Nepal occurring in July and August. As noted in a previous post, the strength and extent of the Asian monsoon has decreased in some regions of the Himalaya since the 1920s. Following the notion that precipitation contributes to the volume of water in glacial lakes, it could be hypothesised that the risk from GLOFs could decrease, supported by a decline in the number of erosion glacial lakes identified by the ICIMOD between 1960 and 2001 (Bajrachrarya et al., (2007). However, contrary to this, the majority of studies indicate a rise in the overall number of hazardous glacial lakes since the 1950s (Qingha, 1991).

Bajrachrarya et al., (2007) summarise a baseline study conducted by the ICIMOD of over 9,000 glacial lakes in the Himalayas between 1960 and 2001. Studying topographic maps of the region, the ICIMOD monitored the formation and development of glacial lakes that were larger than 0.003km² (the smallest resolution lakes could be identified using the maps available). Major glacial lakes were stated as any lake larger than 0.02 km² which contain at least 6 x 10⁵m³ of water. Focusing on the Dudh Koshi sub-basin in Nepal and the Pho Chu sub-basin in Bhutan, the study noted that 37% and 32% of the glacial lakes identified in 1960 had disappeared respectively (Bajrachrarya et al., 2007). Most of these were either minor supraglacial ponds that had merged to form a single lake, or lakes that were not glacier-fed. However, although the number of lakes had decreased, the overall area of the remaining lake, the majority of which were moraine-dammed, had grown by 21% in Nepal and 8% in Bhutan (Bajrachrarya et al., 2007). In moraine-dammed lakes, as the volume of water grows the hydrostatic pressure acting on the moraine increases and overtopping becomes more frequent. Therefore, as the area increases, the potential of an outburst event also grows (Richardson and Reynolds, 2000).

Table 1: Summary of the types of glacial lakes studies by the ICIMOD in the Dudh Koshi sub-basin between 1960-2001) (Bajrachrarya et al., 2007: 24)

Compared to Nepal where most of the glacial lakes are moraine-dammed, ice-dammed lakes contribute to a substantial proportion of the GLOF events in the Karakoram region (Quingha, 1991; Hewitt and Liu, 2011). Contrasting to other regions of the Himalayas, some of the glaciers in the Karakoram mountain range have been advancing since the 1950s. However, although hazards from moraine-dammed glacial lakes may be lower than in other regions, over 90 outbursts have occurred due to the formation of lakes impounded behind advancing and surging glaciers (Hewitt and Liu, 2011). Of these, 10 have occurred in the Yarkland basin which supports 1.8 million people, 38 million hectares of irrigated land and six hydropower stations (Hewitt and Liu, 2011). Direct costs from an outburst in 1999 were estimated at US$ 25 million, affecting over 18,700 hectares of agricultural land and the risks and potential damage will continue to increase as the Kashgar District, imitating many other populated valleys in the Himalayas, continues to be developed (Hewitt and Liu, 2011).

Hewitt and Liu (2011) state that the future risk of ice-dammed outbursts in the Karakoram region is unclear. Whilst some glaciers have been slowly retreating or have remained static, an increasing number, mainly in the highest part of the range have been advancing, including at least nine glaciers that have been recorded with ice-dammed lakes in the past. Therefore, the study predicted that the overall risk from GLOF events for communities in the Karakoram region, like most of the other regions in the Himalaya is likely to increase with climate change