ECOLOGY AND ENERGY PRODUCTION

ECOLOGY AND ENERGY PRODUCTION

Friday, April 13, 2018



World faces climate CHAOS because the circulation of the Atlantic Ocean is the weakest it has been in more than 1,500 years, warn scientists


  • A key cog in the global ocean circulation system has not been running
  • If the system continues to weaken, researchers say it may disrupt weather
  • Experts believe the Atlantic began to warm near the end of the Little Ice Age

There could be weather chaos across Europe, US and Africa as scientists warn circulation of the Atlantic Ocean is at its weakest point in more than 1,600 years.
Researchers have found a key cog in the global ocean circulation system has not been running at peak strength since the mid-1800s.
If the system continues to weaken, scientists say it could disrupt weather patterns across the world and cause more rapid increase in sea levels on the US East Coast.

Researchers have found a key cog in the global ocean circulation system (pictured) has not been running at peak strength since the mid-1800s. If the system continues to weaken, researchers say it could disrupt weather patterns across the world and cause more rapid increase in sea levels on the US East Coast
Researchers have found a key cog in the global ocean circulation system (pictured) has not been running at peak strength since the mid-1800s. If the system continues to weaken, researchers say it could disrupt weather patterns across the world and cause more rapid increase in sea levels on the US East Coast
When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role.
The constantly moving system of deep-water circulation - sometimes referred to as the Global Ocean Conveyor Belt - sends warm, salty Gulf Stream water to the North Atlantic where it releases heat to the atmosphere and warms Western Europe.
The cooler water then sinks to great depths and travels all the way to Antarctica and eventually circulates back up to the Gulf Stream, according to the study published in the journal Nature.
However, new research suggests this system has been weakening for centuries.
'Our study provides the first comprehensive analysis of ocean-based sediment records, demonstrating that this weakening of the Atlantic's overturning began near the end of the Little Ice Age, a centuries-long cold period that lasted until about 1850', said study co-author said Dr Delia Oppo, of Woods Hole Oceanographic Institution. 
Pictured is the science-fiction disaster film 'The Day after Tomorrow' showing Big Ben. Researchers said it was not possible to predict a worst-case scenario 
Pictured is the science-fiction disaster film 'The Day after Tomorrow' showing Big Ben. Researchers said it was not possible to predict a worst-case scenario 
Experts believe that as the North Atlantic began to warm near the end of the Little Ice Age, freshwater disrupted the system.
This was called the Atlantic Meridional Overturning Circulation (AMOC).
Arctic sea ice, and ice sheets and glaciers surrounding the Arctic began to melt. 
This formed a huge natural tap of fresh water that gushed into the North Atlantic.
Researchers say the huge influx of freshwater diluted the surface seawater, making it lighter and less able to sink deep, slowing down the AMOC system.
To investigate the Atlantic circulation in the past, scientists first examined the size of sediment grains deposited by the deep-sea currents; the larger the grains, the stronger the current.
Then, they used a variety of methods to reconstruct near-surface ocean temperatures in regions where temperature is influenced by AMOC strength.
'Combined, these approaches suggest that the AMOC has weakened over the past 150 years by approximately 15 to 20 per cent', said lead author Dr. David Thornalley, a senior lecturer at University College London.
Study co-author Dr Jon Robson, a senior research scientist at Reading University, says the new findings hint at a gap in current global climate models.
'North Atlantic circulation is much more variable than previously thought', he said. 
'And it's important to figure out why the models underestimate the AMOC decreases we've observed.'
A  National Oceanic and Atmospheric Administration photo shows  Hurricane Maria approaching the Leeward Islands on 18 September 2017. Researchers believe extreme weather events could become more frequent 
A National Oceanic and Atmospheric Administration photo shows Hurricane Maria approaching the Leeward Islands on 18 September 2017. Researchers believe extreme weather events could become more frequent 
The Little Ice Age, a centuries-long cold period that lasted until about 1850. Experts believe that as the North Atlantic began to warm near the end of the Little Ice Age, freshwater disrupted the system. Pictured is Thames Frost Fair, 1683¿84, by Thomas Wyke
The Little Ice Age, a centuries-long cold period that lasted until about 1850. Experts believe that as the North Atlantic began to warm near the end of the Little Ice Age, freshwater disrupted the system. Pictured is Thames Frost Fair, 1683–84, by Thomas Wyke

WHAT IS THE GLOBAL OCEAN CONVEYOR BELT?

When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role.
This is due to a constantly moving system of deep-water circulation often referred to as the Global Ocean Conveyor Belt which sends warm, salty Gulf Stream water to the North Atlantic where it releases heat to the atmosphere and warms Western Europe.
The cooler water then sinks to great depths and travels all the way to Antarctica and eventually circulates back up to the Gulf Stream.
When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role
When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role
This motion is fuelled by thermohaline currents - a combination of temperature and salt.
It takes 1,000 years for water to complete a continuous journey around the world.
Researchers believe that as the North Atlantic began to warm near the end of the Little Ice Age, freshwater disrupted the system, called the Atlantic Meridional Overturning Circulation (AMOC).
Arctic sea ice, and ice sheets and glaciers surrounding the Arctic began to melt, forming a huge natural tap of fresh water that gushed into the North Atlantic.
This huge influx of freshwater diluted the surface seawater, making it lighter and less able to sink deep, slowing down the AMOC system.
Researchers found the AMOC has been weakening more rapidly since 1950 in response to recent global warming.Dr Robson said it could be because the models don't have active ice sheets, or maybe there was more Arctic melting, and thus more freshwater entering the system than currently estimated.
Another study in the same issue of Nature, led by scientists from the Potsdam Institute for Climate Impact Research, looked at climate model data and past sea-surface temperatures. 
They found the AMOC has been weakening more rapidly since 1950 in response to recent global warming.
The AMOC weakening may already have an impact on weather in Europe.
'Model simulations further suggest that an AMOC weakening could become the main cause of future west European summer atmospheric circulation changes, as well as potentially lead to increased storminess in Europe', lead-author Levke Caesar from the Potsdam Institute for Climate Impact Research told MailOnline. 
Pictured are people walking down a flooded section of Interstate 610 in floodwaters from Tropical Storm Harvey in August last year. If the system continues to weaken it could cause a rise in sea levels on the US East Coast, making events like this more common 
Pictured are people walking down a flooded section of Interstate 610 in floodwaters from Tropical Storm Harvey in August last year. If the system continues to weaken it could cause a rise in sea levels on the US East Coast, making events like this more common 
A crew retrieves a sediment core drilled from the seafloor. The new study provides the first comprehensive analysis of ocean-based sediment records to demonstrate that the Atlantic Ocean's overturning circulation began to weaken near the end of the Little Ice Age
A crew retrieves a sediment core drilled from the seafloor. The new study provides the first comprehensive analysis of ocean-based sediment records to demonstrate that the Atlantic Ocean's overturning circulation began to weaken near the end of the Little Ice Age
'Additionally an AMOC weakening has also been connected to above-average sea-level rise at the U.S. east coast and increasing drought in the Sahel, the latter because the AMOC influences the position of the Intertropical Convergence Zone.   
'With respect to prevention, it would be prudent to rapidly reduce the emissions of carbon dioxide in order to avoid further destabilisation of the climate system', Dr Caesar said.   
Together, the two new studies provide complementary evidence that the present-day AMOC is exceptionally weak. 
Dr Thornalley added: 'What is common to the two periods of AMOC weakening - the end of the Little Ice Age and recent decades - is that they were both times of warming and melting.
'Warming and melting are predicted to continue in the future due to continued carbon dioxide emissions.'

WHAT SHOULD THE EU BE DOING TO PROTECT PEOPLE FROM CLIMATE CHANGE?

In 2013, the European Academies' Science Advisory Council (EASAC) published a report which looked at the frequency of extreme weather events. 
Since then, there has been a continued rise in how common these events occur. 
In order to cope when such adverse weather conditions strike, they made recommendations as to how the EU can better protect its citizens from climate change. 
1. Information
The report claimed that in order to best deal with the issues, it is necessary to understand them first. 
To understand how global warming will affect the extremes of weather, it is necessary to study and model them. 
2. Heat waves
Across the European continent, heatwaves can vary massively and have vastly different impacts. 
Understanding the nuances of these phenomena is key to weathering the storm. 
3. Flood defence and early warning
Good practice in flood preparedness and for flood defence across Europe should be shared, including information about different responses to flood preparedness and flood warnings.
4. Agriculture
The report stated that the agriculture sector as a whole needed to improve.
Vulnerability to extreme weather and possible measures to increase resilience should be produced.
5. Strengthen the knowledge of climate change 
The research found that it was crucial that we viewed climate change adaptation as a continuous process. 
In order to do this sustained observations, analysis and climate modelling about the Earth are integral parts of a robust and flexible climate-change adaptation strategy.
It claims knowledge dissemination, innovation and building international relationships is key.
6. Changes in policies 
Before adaptation can be achieved, there are several barriers which include  those that are physical, technical, psychological, financial, institutional and knowledge-based. 

Thursday, April 12, 2018




Deadly volcanic eruptions that could wipe out MILLIONS of people may be triggered by melting glaciers, warns scientist


  • The relationship between glaciers and volcanic systems is changing 
  • Global warming is causing glaciers to melt and exposing mountains
  • This is decompressing underground magma systems and increasing the chance of a volcanic eruption 
Massive volcanic eruptions that could wipe out millions of people may be another consequence of global warming.
At least, that's according to a French scientist who claims that the retreat of glaciers will trigger more frequent eruptions all over the world.
Gioachino Roberti, a PhD Student at the Universit√© Clermont Auvergne in France has looked at how the weight of large ice sheets compresses the crust and mantle below.
Removing that pressure can open up channels within the rock through which magma travels towards the surface, causing deadly volcanic eruptions.  
The retreat of glaciers can also cause landslides, further destabilising volcanoes and helping trigger eruptions.  

Glaciers and volcanoes exist in a delicate state of balance that is being rapidly changed by a warming planet. Researchers have found a correlation between melting glaciers and pressure on the magma chambers of volcanoes
Speaking to the press at the European Geosciences Union General Assembly held in Vienna today, Mr Roberti explained how volcanoes deform under their own weight.
At the conference titled 'Hazards in the wake of climate change', he said: 'Ice melting from the mountain removes the ice from the slope and this can cause collapse.' 
'The ice acts like some sort of protective layer and when the ice melts away the mountain is free to collapse. 
'If the mountain is also a volcano, you have another problem. 
'Volcanoes are a pressurised system and if you remove pressure via melting ice and landslides then you can have an eruption.'
Using mathematical modelling to understand the geological processes, his research team discovered that decompression would go deep enough to affect the magmatic system.
Research has found that at Mt Meager (pictured) the landslide that occurred in 2010 was as a result of retreating glaciers caused by global warming. These landslides then put pressure on the volcanic system beneath the mountain, making eruptions more likely 
Research has found that at Mt Meager (pictured) the landslide that occurred in 2010 was as a result of retreating glaciers caused by global warming. These landslides then put pressure on the volcanic system beneath the mountain, making eruptions more likely 
'Landslides can actually trigger volcanic eruptions,' Mr Roberti said.
'We can say that glacial retreat and landslides have an effect on the deep magmatic system.
'This allows magma to reach the surface due to the significant decompression.  
Mr Robert looked at the Mt Meager volcano in Canada in an attempt to understand how melting glaciers impacts volcanic activity.
The volcano last erupted 2,430 years ago and is constantly measured by experts.
'Mt Meager, north of Vancouver, is a glaciated volcano and in 2010 the largest landslide in Canadian history occurred here,' he said.
'We documented slope deformation and glacial retreat prior to the failure. 
'The glacial part of the bottom of the mountain retreated and during the hottest part of the summer the slope catastrophically failed.
'We found a correlation between high temperature, ice melting and landslides.'
This graphic depicts the simplified theory of the interaction between glacial retreat, landslides and the tendency for volcanic eruptions. Retreating glacial ice exposes the mountainside and increases the likelihood of landslides and also the likelihood of a volcanic eruption 
This graphic depicts the simplified theory of the interaction between glacial retreat, landslides and the tendency for volcanic eruptions. Retreating glacial ice exposes the mountainside and increases the likelihood of landslides and also the likelihood of a volcanic eruption 
Mr Roberti also revealed that there are further signs of deformation around Mt Meager and that glaciers are melting inseveral locations. 
'The equilibrium over the mountain is changing,' Mr Roberti said. 
It is this changing dynamic that makes landslides and volcanic eruptions ever more likely. 
David Rothery, Professor of Planetary Geosciences at The Open University, said: 'This new research nicely demonstrates that if you change the load on a volcanic mountain - for example by removing some ice - the likelihood of a mechanical collapse and possible ensuing eruption will be slightly increased.
'Eruptions are triggered by a complex array of factors. I suspect that many eruptions caused by glacial melting might happen eventually anyway, given enough time - but this research shows that warming could increase the chances of those eruptions happening sooner rather than later.' 
The weight of large ice sheets compresses the crust and mantle below. Removing that pressure can open up channels within the rock through which magma travels towards the surface, causing deadly volcanic eruptions
The weight of large ice sheets compresses the crust and mantle below. Removing that pressure can open up channels within the rock through which magma travels towards the surface, causing deadly volcanic eruptions

WHAT IS EARTH'S 'RING OF FIRE'?

Earth's so-called 'Ring of Fire' is a horseshoe-shaped geological disaster zone that is a hot bed for tectonic and volcanic activity.
Roughly 90 per cent of the world's earthquakes occur in the belt, which is also home to more than 450 volcanoes. 
The seismic region stretches along the Pacific Ocean coastlines, where the Pacific Plate grinds against other plates that form the Earth's crust.
It loops from New Zealand to Chile, passing through the coasts of Asia and the Americas on the way. 
In total, the loop makes up a 25,000-mile (40,000-kilometre) -long zone prone to frequent earthquakes and eruptions.
The region is susceptible to disasters because it is home to a vast number of 'subduction zones', areas where tectonic plates overlap.
Earthquakes are triggered when these plates scrape or slide underneath one another, and when that happens at sea it can spawn tsunamis. In response to questions, Mr Roberti said that although the research is concentrated on Mt Meager, the theory could apply to mountains around the world.
'Similar systems all around the Pacific ring of fire could be affected, including: British Colombia, Alaska and Kamchatka in Russia.
'There are glaciers in Peru and Chile in the Andes and you also have Iceland, but there is a different relationship between glacier and volcano there.'
With regards to the pressing concern of environmentalists about the melting ice in Antarctica, Mr Roberti mused over the different systems but did 
'The Antarctic is a different scale issue as it is different types of glacier. In that case the deeper compression of ice means you wouldn't have partial melting.
'If you melt kilometres of ice you might have deeper decompression and partial melting at a deeper level.'  
While it is still just speculation, if there is magmatic activity beneath the Antarctic ice shelf, decompression could put excess strain on the system. 
But not everyone is convinced by the research. 
Alison Graettinger, Assistant Professor of Geosciences at the University of Missouri, said: 'The abstract proposes that a landslide at Mt Meager has the potential to trigger a volcanic eruption, not just melting glacial ice. 
'The abstract doesn't have the room to provide more information on how the melting of glacial ice has weakened part of the volcano, leading to an increased potential for a landslide. 
'In order for a volcanic eruption to be triggered by a decrease in load (weight of ice or mass of rock) the magma chamber also needs to be ready to erupt. 
'This means that decreasing ice volumes due to climate change will not cause volcanoes to erupt that were not close to eruption anyway. Ice on your classic stratovolcano is thinner than ice in ice caps, such as in Iceland, and the melting alone will have less impact on the volcanic system than in areas where ice is thicker. 
'Because of the conditions that need to be met for this scenario to work it means that even if a few volcanoes were to be pushed towards eruption from ice melting, or landslides related to melting of ice, it would not be all ice clad volcanoes, nor even all volcanoes under thick ice. 
'The study proposes that Mt. Meager may be one such volcano, but the study merely points out the potential, and not that all the conditions mentioned above have been met.'
Oregon students investigate post-eruption process of volcanoes
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HOW IS GLOBAL WARMING AFFECTING GLACIAL RETREAT?

Global warming is causing the temperatures all around the world to increase. 
This is particularly prominent at latitudes nearer the poles. 
Rising temperatures, permafrost, glaciers and ice sheets are all struggling to stay in tact in the face of the warmer climate.  
As temperatures have risen to more than a degree above pre-industrial levels, ice continues melt.
For example, melting ice on the Greenland ice sheet is producing 'meltwater lakes', which then contribute further to the melting. 
This positive feedback loop is also found on glaciers atop mountains. 
Many of these have been frozen since the last ice age and researchers are seeing considerable retreat. 
Some animal and plant species rely heavily on the cold conditions that the glaciers provide and are migrating to higher altitudes to find suitable habitat. 
This is putting severe strain on the ecosystems as more animals and more species are living in an ever-shrinking region. 
On top of the environmental pressure, the lack of ice on mountains is vastly increasing the risks of landslides and volcanic eruptions.    
The phenomena is found in several mountain ranges around the world.
It has also been seen in regions of Antarctica.