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In climate drama, the volcano is no villain

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BY SARAH WILD

New analysis of ash clouds created from large volcanic eruptions shows the temporary cooling effects are changed as the environment becomes hotter.

On 15 June 1991, the Mount Pinatubo volcano in the Philippines erupted with a cataclysmic explosion so violent, the volcano collapsed in on itself. Its gas and ash cloud reached about 40km into the air, and in the weeks that followed, the cloud entered the stratosphere and spread around the globe. During the next year, the average global temperature dropped by about 0.5°C.

A volcano is an opening in the Earth’s crust that allows hot, molten rock to escape to the surface. It also allows gas and ash to escape from the high-temperature interior of the earth.

Volcanic eruptions play an important role in cooling the planet. The sulphur gases from the volcanic plumes combine with other gases in the atmosphere, and these aerosols scatter solar radiation, reflecting it into space. But scientists are concerned that climate change could make eruptions less effective at reducing global temperatures. This feedback loop, in which climate change could hinder or amplify the ability of volcanic eruptions to combat rising temperatures, is currently not included in future climate scenarios.

The VOLCPRO project set out to investigate two different types of eruptions to see if global heating would compromise their cooling effect.

Thomas Aubry, a researcher at the University of Cambridge in the United Kingdom and Marie Skłodowska-Curie Actions (MSCA) fellow on VOLCPRO, wondered whether an eruption like Mount Pinatubo would have had the same cooling effect were it to happen a hundred years later in a world where global temperature rise – through the effects of climate change – continues unchecked.

High intensity eruption

The first type of eruption, similar to Mount Pinatubo, is known as a high intensity eruption. This type emits plumes of ash and particles that reach 25km or higher into the atmosphere, and contains billions of tons of sulphur gases. Relatively rare, an eruption of this very powerful type arises every few decades –– Mount Pinatubo was one of the largest eruptions the world had seen in a century.

The second type is smaller, but more frequent. ‘We were wondering how climate change will affect these two different types of eruptions, the small ones versus the big ones,’ said Aubry.

The VOLCPRO team modelled historical eruptions showing their influence on climate, and then simulated what would happen if those same eruptions took place in the future, when the climate has changed and global temperatures are hotter.

Their simulations relied on the UK Met Office’s advanced climate model. ‘Inside that (UK Met Office) model, we added another model that can simulate the rise of a volcanic plume and how high this volcanic column can rise depending on, for example, the wind condition during eruption day, or the temperature in the atmosphere on the day, and so on,’ Aubry said.

For the large eruptions, they found that the cooling would be amplified by global warming, ‘which is kind of good news,’ said Aubry. ‘More global warming, more volcanic cooling.’

In a warmer atmosphere, the plumes of high intensity eruptions will rise even higher, allowing the tiny volcanic particles to travel further. This haze of aerosols will cover a wider area, reflecting more solar radiation and amplifying these volcanoes’ temporary cooling effect.

The opposite was true of the smaller, more frequent volcanic eruptions. In those cases, the hotter temperatures thwarted the cooling effects from the eruptions.

However, before they push to have their findings included in scientists’ global climate change projections, Aubry wants to investigate other volcanoes and other models to reinforce their results.

VOLCPRO focused on tropical volcanoes, as eruptions around the equator tend to affect climate globally because the volcanic particles spread to both hemispheres easily. By including volcanoes closer to the poles, the researchers will be able to determine how other eruptions respond to higher temperatures. They also want to include more climate models, not just the UK’s, to make sure that their findings are robust.

Volcanic ash

Meanwhile, Elena Maters, a former MSCA fellow now based at the University of Cambridge in the United Kingdom, is working to figure out what happens to volcanic ash in the atmosphere and how it influences cloud formation and, ultimately, climate.

Volcanic ash promotes ice formation in the atmosphere, which ultimately replaces water in clouds. Clouds are one of the biggest question marks in climate research, and the more we understand how they are formed and behave, the more precise our models.

‘The common assumption is that liquid water will turn to ice below zero (degrees),’ Maters explained. That is not always the case and small droplets can remain as liquid down to around minus 35°C. But particles in the atmosphere create ‘catalytic surfaces that make it easier for water molecules to form an ice crystal.’

Mineral dust, from sand originating in desert regions around the world such as the Sahara and Gobi deserts, is the dominant source of solid particles in the atmosphere. However, there are many other sources, including volcanic ash.

The INoVA project sought to determine the extent to which volcanic ash aids ice formation.

‘On a yearly average, there’s about 10 times less volcanic ash (than mineral dust) in the atmosphere,’ Maters said. ‘But you can have big eruptions that can quickly, in a matter of hours to days, release huge amounts of particles, and this has been neglected in a lot of climate modelling and even in cases that look at the impacts of volcanoes.’

Ice formation

As part of INoVA, Maters and colleagues investigated the efficacy of volcanic ash in promoting ice formation. They compared this to the ubiquitous mineral dust, testing to see which types were the most successful.

Volcanic ash is mostly glass, with a sprinkling of minerals like feldspars and iron oxides. The composition of the ash depends on the make-up of the magma roiling underneath, and the speed at which it is explosively ejected from the volcano, among other things.

Previous studies compared only a handful of ash types, said Maters, whose research focuses on volcanic ash reactivity and chemistry. ‘You can’t measure two or three samples and then make a conclusion for all volcanic ash and volcanic eruptions worldwide. They vary hugely in the glass composition, the proportion of glass to minerals, the types of minerals, and so the experiments I did were trying to get to the bottom of the range of efficacy of volcanic ash from different types of eruptions,’ she said.

Maters took nine ash samples with a range of compositions and used them to create nine synthetic samples through melting and rapid cooling. She compared these 18 samples to identify which properties make volcanic ash more active in creating ice. In another study with a group at Karlsruhe Institute of Technology in Germany, Maters and colleagues analysed another 15 volcanic samples to identify their ice-making properties.

She suggested that the most ice-active component in volcanic ash is alkali feldspar, a mineral composed of aluminium, silicon and oxygen commonly found in the Earth’s crust. ‘Now, having this understanding of which minerals in ash are good at nucleating (forming) ice,’ said Maters, ‘you might be able to predict when a volcano erupts whether that volcano, based on its magma composition, could produce ice-active ash.’

While her work was previously very laboratory-based, the Covid pandemic has forced her into modelling, she joked. She is now investigating the 2010 Eyjafjallajökull volcanic eruptions in Iceland to see how that introduced ice-forming particles into the atmosphere, and how those particles compared to the abundance of mineral dust.

The study will examine how volcanic ash has a role in ice formation when we actually plug it into the atmosphere. It will compare it to other types of particle, such as mineral dust and asks the question, “Does it matter?”

As better climate models are developed, ‘It’s a proof of concept to demonstrate that explosive eruptions could be important to include’, said Maters.

The research in this article was funded by the EU. This article was originally published in Horizon, the EU Research and Innovation Magazine.  

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Environment

Using nature and data to weather coastal storms

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Photo: NASA

BYANDREW DUNNE

Extreme weather events are becoming more frequent and intense, sometimes with tragic consequences. Europe’s coastal cities are preparing to meet the challenges with help from nature and data from outer space.

As the people of La Faute-Sur-Mer – a small French coastal town in the Vendée north of La Rochelle – tucked into bed on the night of 27 February 2010, a violent storm was raging out at sea.

Swirling, cyclonic winds, high waves and heavy rain blown up across the Bay of Biscay combined with a high spring tide to wreak havoc as it battered the coastline of western France. Residents awoke to a scene of utter devastation.  

Perched perilously between the Atlantic Ocean on one side and the river Lay on the other, the town was completely inundated by flooding from the storm surge. Homes, property and businesses were ruined.

Of the 53 people in France who died as a result of Storm Xynthia, 29 were from La Faute.

In a town with a population of just 1000 people, it was a devastating tragedy.

Extreme weather

Such extreme weather events are becoming more common and seaside regions are particularly vulnerable, says Dr Clara Armaroli, a coastal geomorphologist who specializes in coastal dynamics (how coastlines evolve). 

In response, the University School for Advanced Studies (IUSS) in Pavia, Italy, is leading a pan-European project to develop an early-warning system to increase coastal resilience. Armaroli coordinates the project, called the European Copernicus Coastal Flood Awareness System (ECFAS).

‘Given climate change and sea-level rise, we know there will be an increase in the tendency and the magnitude of coastal storms,’ Dr Armaroli said.

‘What’s needed is an awareness system at a European level to inform decisions.’

ECFAS has been set up to develop a proof-of-concept for an early-warning system for coastal flooding. It will develop a functional and operational design.

It draws on data and uses tools from the EU’s Copernicus Earth observation satellites and from the Copernicus Services.

Central to this is how data about storm surges, magnitude of flooding and potential impact could be incorporated into the EU’s Copernicus Emergency Management Service (Copernicus EMS).

Copernicus EMS is a space-based monitoring service for Europe and the globe that uses satellite data to spot signs of impending disaster, whether from forest fires, droughts or river flooding.

Coastal flooding is not yet part of the Copernicus emergency management mix so ECFAS wants to ‘plug the gap’ says Armaroli. 

This will ensure that coastal flooding is monitored in future and that such vulnerabilities become part of its watching brief.

In addition to charting the progression of storms that break on Europe’s coastlines, the ECFAS team is integrating data about the changes to shorelines caused by coastal erosion. It’s a growing concern as sea-levels rise across the globe.

Boundary erosion

‘The vulnerability and exposure of our coastal areas are also increasing due to erosion, which is narrowing the boundary between the land and the sea,’ said Dr Armaroli.

The early-warning system will gather data from an array of sources, all of which impact flood risk. This includes geographic factors such as land use and cover, soil type, tidal changes, wave components and sea levels. 

It is being designed to provide forecasts for coastal storm hazards up to five days out. Potentially, it could work in tandem with pre-existing regional and national systems to improve local defenses.   

Looking beyond the proof-of-concept stage, Armaroli hopes ECFAS-Warning for coastal awareness can play a critical role in helping areas better prepare for when disaster strikes.

‘Our work has started a process, but in the future, we hope this can really help increase the resilience of our coastal areas to the coming extreme weather events,’ she said.

On the west coast of Ireland, in the Atlantic seaport town of Sligo, an environmental engineer named Dr Salem Gharbia is taking the challenges faced by coastal cities to the next level.

With the project – SCORE – Smart Control of the Climate Resilience in European Cities – Dr Gharbia’s team is building a network of ‘living labs’ to rapidly and sustainably enhance local resilience to coastal damage.

‘Coastal cities face major challenges currently because they are so densely populated and because their location makes them vulnerable to sea-level rise and climate change,’ he said.

With SCORE’s network of 10 coastal cities – from Sligo to Benidorm, Dublin to Gdańsk – Dr Gharbia intends to create an integrated solution that should help coastal centres to mitigate the risks.

‘The main idea behind the concept is that we have coastal cities learning from each other,’ he said.

Co-created solutions

‘Each living lab faces different local challenges,’ he said, ‘But each has been established to include citizens, local stakeholders, engineers, and scientists to co-create solutions that can increase local resilience.’

Through the network, SCORE wants to pioneer nature-based solutions such as the restoration of floodplains or wetlands that reduce the risk of flooding in coastal regions. It’s a model that is already proving effective.

One example, a project to bio-engineer sand dunes in Sligo for stronger natural defenses, is also being tested in Portugal.

The team is developing smart technologies to monitor and evaluate emerging coastal risks. In addition to using existing Earth observation data, this means the community can become involved through new citizen science projects aimed at expanding local data collection.

In Sligo, locals are already getting involved in the monitoring of coastal erosion using what Dr Gharbia terms ‘DIY sensors’ – drone kites – equipped with cameras, to survey local topography.

Elsewhere, citizens are helping to monitor and record water levels and quality, as well as wind speed and direction with a variety of other sensors.  

Sustaining local citizen involvement in this way is crucial to SCORE’s success, said Gharbia.

‘It’s essential that this is two-way for citizens,’ he said.

Without engaging them fully in the process of co-design and co-creation of ideas to mitigate risks, you will never get them committed to the types of solution proposed.’

Data sources

All of this, of course, is creating a wealth of new data from a multitude of sources. But Dr Gharbia is adamant that an integrated approach is critical.

‘The main reason we’re developing this system is,’ he said, ‘We’ve realised that to increase climate resilience we have to utilise all the information coming in from different sources.’

Ultimately, the goal behind the work is for a real-time, early warning system that could be used by local and regional policy makers to test a range of ‘what if’ scenarios.

Currently, the team are categorising the data and optimising the systems and models. In time, they hope other regions can learn from the approach and develop similar living labs.

Dr Gharbia said the impact of his research project should be ‘to create an integrated solution that can be used in multiple different locations and can make a big impact in increasing local coastal resilience.’

Resilience like it should spread far and wide. ‘The main purpose is a solution that can be replicated and scaled up,’ said Dr Gharbia. The tragic consequences of more frequent and more intense coastal storms must be averted.

The research in this article was funded by the EU. If you liked this article, please consider sharing it on social media.

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Heat, drought and wildfires during one of the warmest Julys on record

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Amidst extreme heat, drought and wildfires, many parts of the world had just experienced one of three warmest Julys on record, the UN weather agency said on Tuesday.

According to the World Meteorological Organization (WMO), temperatures were close to 0.4℃ above the 1991-2020 average across much of Europe, with southwestern and western Europe being the most above-average regions, because of an intense heatwave around mid-July.

“This is despite the La Niña event that’s meant to have a cooling influence,” explained WMO spokesperson Clare Nullis.

“We saw this in some places, but not globally,” she added, noting that it was “one of the three warmest [Julys] on record, slightly cooler than July 2019, warmer 2016- but the difference is too close to call”.

Record temperatures

Portugal, western France and Ireland broke record highs, while England hit 40℃ readings for the very first time.

National all-time records for daily maximum temperatures were also broken in Wales and Scotland. 

Spain also had its hottest month on record in July, with an average national temperature of 25.6°C – with a heatwave from 8 to 26 July that was the most intense and longest lasting on record.

Using data from the European Commission’s Copernicus Climate Change Service, the UN weather agency confirmed that Europe had its sixth warmest July

The heat travelled further north and east ushering very high temperatures across other countries, including Germany and parts of Scandinavia, with local July and all-time records broken at several locations in Sweden. 

Temperature anomalies

At the same time, from the Horn of Africa to southern India, and much of central Asia to most of Australia experienced below-average temperatures.

It also dominated a band of territory stretching from Iceland, across Scandinavia via the Baltic countries continuing as far as the Caspian Sea.

Moreover, temperatures were generally below average in Georgia and throughout much of Türkiye.

Polar ice shrinking

July also saw the lowest Antarctic Sea ice on record, a full seven per cent below average.

Arctic Sea ice was four per cent below average, ranking 12th lowest for July according to satellite records.

WMO cited the Copernicus Climate Change Service in saying that Arctic Sea ice concentration was the lowest for July on satellite record, which started in 1979, and sea ice there was the 12th lowest ever.

Glaciers have seen a “brutal, brutal summer,” Ms. Nullis continued.

“We started with low snowpack on glaciers in the alps, reported by meteorological services, and now successive heatwaves- this is bad news for glaciers in Europe. The picture for Greenland’s glaciers is more mixed, however, as there has not been relentless heat”.

In the throes of the heat, WMO Secretary-General Petteri Taalas said in a press conference on 18 July, “this kind of heatwave is the new normal”. 

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Giraffes, parrots, and oak trees, among many species facing extinction

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Around one million species are facing extinction, according to a report from IPBES, an independent intergovernmental science and policy body supported by the UN.

It may be surprising to learn that even giraffes, parrots, and oak trees are included in the list of threatened species, as well as cacti and seaweed.

It may be surprising to learn that giraffes, parrots, and even oak trees are included in the list of threatened species, as well as cacti and seaweed.
Seaweed is one of the planet’s great survivors, and relatives of some modern-day seaweed can be traced back some 1.6 billion years. Seaweed plays a vital role in marine ecosystems, providing habitats and food for marine lifeforms, while large varieties – such as kelp – act as underwater nurseries for fish. However, mechanical dredging, rising sea temperatures and the building of coastal infrastructure are contributing to the decline of the species.
The world’s trees are threatened by various sources, including logging, deforestation for industry and agriculture, firewood for heating and cooking, and climate-related threats such as wildfires.
It has been estimated that 31 per cent of the world’s 430 types of oak are threatened with extinction, according to the International Union for Conservation of Nature (IUCN) Red List of threatened species. And 41 per cent are of “conservation concern”, mainly due to deforestation for agriculture and fuel for cooking.
Giraffes are targeted for their meat, and suffer from the degradation of their habitat due to unsustainable wood harvesting, and increased demand for agricultural land; it’s estimated there are only around 600 West African giraffes left in the wild.

Catastrophic results for humanity

The current biodiversity crisis will be exacerbated, with catastrophic results for humanity, unless humans interact with nature in a more sustainable way, according to UN experts. 
“The IPBES report makes it abundantly clear that wild species are an indispensable source of food, shelter and income for hundreds of millions around the world,” says Susan Gardner, Director of the Ecosystems Division at the United Nations Environment Programme (UNEP).
“Sustainable use is when biodiversity and ecosystem functioning are maintained while contributing to human well-being. By continuing to use these resources unsustainably, we are not just risking the loss and damage of these species’ populations; we are affecting our own health and well-being and that of the next generation.

Indigenous knowledge

The report illustrates the importance of indigenous people being able to secure tenure rights over their land, as they have long understood the value of wild species and have learned how to use them sustainably. 
Examples of the kinds of transformative changes that are needed to reduce biodiversity loss, include an equitable distribution of costs and benefits, changes in social values, and effective governance systems.
Currently, governments around the world spend more than $500 billion every year in ways that harm biodiversity to support industries like fossil fuels, agriculture, and fisheries. Experts say these funds should be repurposed to incentivize regenerative agriculture, sustainable food systems, and nature-positive innovations.

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