EXPeditions - The living library of knowlegde

Anna Vignoles - Why education inequalities matter and how they can be reduced

Education systems are unequal in most societies around the world in that we see big gaps in achievement levels.
About Anna Vignoles 
"Formerly Professor of Education at the University of Cambridge, I am the Director of the Leverhulme Trust and an economist of education.
I’m an economist of education, which means I apply economic principles to the study of education. I do lots of work on trying to understand the effectiveness of different education systems, of understanding the causes of inequality in our education systems, and I try to come up with practical solutions to how we can narrow these inequalities."
Key Points
• There are very few systems in the world that don't have education inequalities. Pupils who experience them are more likely to suffer once they join the labour market.• There are two types of education inequality: the first is the difference in achievement levels that you see in the system. The second is inequality between children within schools.• One solution is targeted spending, where the State deliberately spends more on children who are likely to be otherwise at a disadvantage.
Most education systems are unequal
Education systems are unequal in most societies around the world in that we see big gaps in achievement levels, particularly between children from more advantaged families and children from more impoverished families. The inequalities that we see in educational achievement are ubiquitous. There are very few systems in the world that don't have them – some systems just have more significant inequalities than others.
The reason why education inequality matters so much is that education is an investment. In other words, those who don't get the skills that you get from investing in education, then suffer when they join the labour market. They end up having more inferior quality jobs, and they earn less. You’re more likely to be employed if you have higher levels of education. Conversely, if you haven't invested in education, you’re more likely to be unemployed.
Being unemployed is associated with a whole range of poor outcomes, ranging from poor well-being to poor physical health. It goes beyond just being about education inequalities. Education inequalities map onto many other disparities that last a lifetime, particularly labour market inequality and inequalities related to well-being. As a society, we should be very concerned about education equity. It matters, and although we see inequalities in educational achievement across the board, some systems have done a far better job at abating those inequalities.

Anna Vignoles - Why we should invest in education and how to measure the return

We think of education as an investment because when you invest in more education, you gain skills that are valuable in the labour market.
About Anna Vignoles 
"Formerly Professor of Education at the University of Cambridge, I am the Director of the Leverhulme Trust and an economist of education.
I’m an economist of education, which means I apply economic principles to the study of education. I do lots of work on trying to understand the effectiveness of different education systems, of understanding the causes of inequality in our education systems, and I try to come up with practical solutions to how we can narrow these inequalities."
Key Points
• We think of education as an investment because when you invest in more education, you gain skills that are valuable in the labour market.• The benefits of investing in education from a society perspective are greater than the pure returns that an individual gets, and that's why we must have both compulsory and state-funded education.• Many factors impact the efficiency of an education system, such as family background or the quality of the teaching in a specific school.
We think of education as an investment because when you invest in more education, you gain skills that are valuable in the labour market. It makes you more productive in your work. Consequently, you earn more. We can think of it as investing in yourself, in your own human capital. It's important to note that economists don't think that people get an education just to make themselves more skilled or just because they want to get a better job. People get an education for a variety of reasons, and going through education can be very enjoyable. However, the economic aspect is that it's an investment that will give you a return, just as though you were investing in another form of capital.

Peter Girguis - The methane cycle and the challenge of global warming

Peter Girguis, Professor of Organismic and Evolutionary Biology at Harvard University, describes methane and the uncertainty of its effects on Earth.
About Peter Girguis
"I’m a Professor of Organismic and Evolutionary Biology at Harvard University.
My research focuses on the deep sea and the relationship that animals and microbes have to one another, but also to their environment. We do a lot of work developing new tools to make measurements that we couldn’t make before. I do so with an eye towards democratising science, with a hope that all have an opportunity to study the deep ocean."
The methane cycle
Here on Earth we have a number of different cycles. Most of us are familiar with the water cycle, for example, or the oxygen cycle. Methane is a cycle that is really important not only on Earth today, but also in Earth’s past. Let’s start with methane. What is it? Methane is a molecule that we use as a fuel. So whenever you light your stove or barbecue you are burning, in part, methane. It’s an interesting molecule because it is so robust. It’s a carbon and four hydrogens that are covalently bonded, which makes it incredibly stable. In other words, if you were to bottle up methane in a glass ampule and leave it on the bench, it would be stable for a very long time; it doesn’t react very quickly.
Key Points
• Most of us are familiar with the water cycle, for example, or the oxygen cycle. Methane is is a potent greenhouse gas and its cycle is really important not only on Earth today, but also in Earth’s past.• Methane is a stable molecule that can be broken down for fuel, but it’s also a potent gas that may contribute to rapid climate change. The majority of methane is produced by microbes in the deep sea.• If we get to the point where the heat that we are seeing in our atmosphere and upper ocean warms up enough of the deep sea, we are going to be releasing gigatonnes of methane into the ocean and we don’t know what’s going to happen.• As we study methane cycling in the deep sea, we do put some thought into what could possibly happen at these seeps, especially as it relates to our human activities and the role we’ve played in warming the atmosphere in the upper ocean.• It is critical that we as humans stop thinking of ourselves as being separate from the natural world. The deep sea is 80% of our planet’s living space and remains largely mysterious yet profoundly essential for the well-being of living things on Earth.

EJ Milner-Gulland - Land conversion and the end of the wild

EJ Milner-Gulland, Tasso Leventis Professor of Biodiversity at the University of Oxford, discusses the damage to our ecosystems and how we can fix it.
About EJ Milner-Gulland
"I’m Tasso Leventis Professor of Biodiversity at the University of Oxford and Director of the Interdisciplinary Centre for Conservation Science.
My research is about the conservation of nature, and my passion is to try and find a way for humanity, nature and wildlife to live together sustainably."
A world under threat
Our main conservation challenges are trying to avoid the threats that we face all around the world. Interestingly, we can see different changes in species loss in different parts of the world, but the threats are pretty consistent across the whole world.
Around 50% of species that are under threat are there because of various kinds of land conversion. For about a quarter, it’s over-exploitation: and a lot of that is trees and fish, not just the things you typically think of as conservation-dependent. Then there are other factors like invasive species and pollution.
Interestingly, climate change is the main driver for only around 5 to 10% of threatened species at the moment, but obviously that is going to continue.
Key Points
• Right now, only 5 to 10% of threatened species are endangered due to climate change, but this will increase.• Land conversion is the main reason that the world has lost more than two-thirds of its wild terrestrial vertebrates since 1970.• New ecosystems and groups of species will emerge over the coming decades.• When we value some species over others, we need to remember that it’s our construction. It’s not how nature actually works.

Yadvinder Malhi - Deforestation and climate change

Yadvinder Malhi, professor of Ecosystem Science at the Oxford University, explains the climate change risks associated with deforestation.
About Yadvinder Malhi
"I am a Professor of Ecosystem Science at the University of Oxford, and I study the living world, how it works and how it changes.
I am an ecosystem scientist who explores the functioning of the biosphere and its interactions with climate change. I am the Director of the Oxford Centre for Tropical Forests which addresses major issues facing tropical forests, and lead the Ecosystems Programme of the Environmental Change Institute at Oxford, which does diverse research on ecosystems."
What is happening to Earth’s ecosystems?
Earth’s ecosystems have been changing throughout human history; They began to change as soon as humans started evolving and interacting with ecosystems. Some of the earliest changes occurred when humans expanded out of Africa; As humans migrated across other continents and onto islands, they started hunting out the large animals, the megafauna and pushed certain species to extinction.
More recently, however, the rate of change in ecosystems has been accelerating. The most significant factor driving this change is the conversion of natural ecosystems into agriculture and cattle land. This loss of natural habitat, in turn, is causing a decline of these ecosystems and their biodiversity. Yet, as we move forward through the 21st century, an additional agent of change is coming. Climate change affects ecosystems that are even more remote and otherwise removed from the immediate loss of habitat due to deforestation and the like. Climate change, unfortunately, implies a much broader range of effects.
Key Points
• A lot of the functioning of the biosphere is determined by what happens in the tropics. Tropics contain much of the carbon stored in living biomass globally, and a lot of water and rainfall circulates through tropical forests.• Ecosystems that reach a tipping point may begin to accelerate climate change. Currently, the land biosphere absorbs around a quarter of the carbon dioxide from fossil fuel emissions, and acts as a moderate brake on the rate of climate change.• Humans have been deforesting and changing forests since the dawn of agriculture. However, throughout the 20th century, these frontiers have moved into wilderness areas that were relatively unaffected or difficult to transform such as the rainforests.• We can't lose the vast treasure houses in the tropics where agricultural frontiers are expanding, and most of the deforestation is currently taking place. It's also worth reminding that Europe and North America are the most deforested landscapes on Earth.

Martin Siegert - The planet's time machine

Martin Siegert, Deputy Vice-Chancellor at the University of Exeter and an antarctic glaciologist, explains how the poles are changing.
About Martin Siegert
"I am Deputy Vice-Chancellor at the University of Exeter and was Co-Director of the Grantham Institute, Imperial College London.
I am an Antarctic glaciologist who studies how the ice sheets have changed in the past, how they are changing now, and how they will change in the future."
The Antarctic time capsule
The reason that we’re keen on learning about the distant past is because our climate is changing, and it’s interesting for us to understand the times in the past when it’s been most similar to the climate we’re heading towards. For the last 170 years or so, the level of greenhouse gases in our atmosphere has been rising as a consequence of burning fossil fuels – what is known as anthropogenic warming: in 1850, the level of carbon dioxide in the atmosphere was about 280 parts per million, whereas now it’s over 415 parts per million. To know if this change makes much of a difference, we must put it into the context of our geological past. The Antarctic ice sheet is the planet’s own time machine as it holds air samples from previous times. By examining it, we can understand what the composition of the atmosphere was like back then and compare it to the present. How do the air samples come to be? The ice that’s buried deep beneath the surface of Antarctica was once snow that has been covered by subsequent snowfall. After about 70 years of burial from surface snow, the air within the snow gets cut off from the atmosphere above. It’s a little air bubble – a time capsule – that keeps going down with further snowfall. At the bottom of the ice sheet – it’s very thick: over 4,000 metres thick in some places – the age of that ice is somewhere around 800,000 to a million years old. What’s remarkable about it is that, essentially, we have a time machine that can take us back, allowing us to get a sample of the earth’s atmosphere between now and 800,000 years ago, as well as every year in between.
Key Points
• The Antarctic ice sheet is the planet’s time machine as it holds air samples from previous times. At the bottom of the ice sheet – it’s very thick: over 4,000 metres thick in some places – the age of that ice is somewhere around 800,000 to a million years.• Currently, we are at 415 parts of CO2 per million, something we have never seen in the ice core record. We are concerned that we are heading to levels that we haven't seen since the Pliocene, between 5 and 2.5 million years ago.• In the Pliocene, temperatures on this planet were somewhere around three or four degrees warmer than they are right now and the level of the sea was 20 metres higher than it is.• Through satellite observations, we can be 100% sure that the polar ice sheets are starting to experience the most melting as a consequence of human-induced global warming. If it all melted, sea level globally would go up by about 60 metres.• The level of CO2 is still rising, and if we don’t reduce our emissions to zero in about 30 years’ time, it’s completely possible for the level of CO2 in the atmosphere to get somewhere near 1,000 parts per million.

Martin Siegert - Beneath the polar ice sheets

Martin Siegert, Deputy Vice-Chancellor at the University of Exeter and an antarctic glaciologist, examines the changes in the Antarctic.
About Martin Siegert
"I am Deputy Vice-Chancellor at the University of Exeter and was Co-Director of the Grantham Institute, Imperial College London.
I am an Antarctic glaciologist who studies how the ice sheets have changed in the past, how they are changing now, and how they will change in the future."
Measuring polar ice sheets
The polar ice sheets are changing, which is a very concerning issue. As a glaciologist, I study how the Antarctic ice sheet flows and what’s underneath the ice. I predominantly use geophysics – my preferred geophysical technique is radar. The reason I use radar is because radio waves travel straight through cold ice, but they bounce off the bottom of the ice sheet so we can measure the two-way travel time of the radio wave; that is, we know the velocity of the radio wave in ice, so we can measure the ice thickness. If we know the ice thickness, we can measure the topography underneath the ice. Greenland and Antarctica have a 3,000- and 4,000-metre thick ice sheet, respectively, and underneath each one hides a very complex landscape.
Antarctica’s ice sheet is divided into the West Antarctic ice sheet and the East Antarctic ice sheet. The East Antarctic ice sheet is by far the biggest of the two, and most of it is resting on land above the level of the sea. Underneath, there are amazing mountains, valleys and landscapes. The last mountain range to ever be discovered was the Gamburtsev subglacial mountains in the middle of the East Antarctic continent. West Antarctica is a different situation. It’s still a continent, but it lies below the sea level. Unusually, the ice sheet that covers it is also grounded below sea level, reaching over two kilometres below sea level in some parts.
Key Points
• Greenland and Antarctica have a 3,000- and 4,000-metre thick ice sheet, respectively, and underneath each one hides a very complex landscape. Both the ice sheets are now experiencing significant amounts of mass loss.• Most of the 20 centimetres of sea level rise that we’ve seen since 1850 is due to the thermal expansion of the ocean and the subsequent melting of valley glaciers all around the world.• Future sea level change is likely to be dominated by melting of the polar ice sheets. On its own, East Antarctica has enough ice to raise sea level by approximately 57 metres. A tenth of the planet’s population live close to the edge of the ocean.• The increase in carbon dioxide and other greenhouse gases into the atmosphere has a warming effect. If we don’t reduce emissions to zero in 30 years’ time, the ice sheets will start to melt even more rapidly than they are now.• We have to use ice sheet models to understand how Antarctica is likely to change in the future but we have no measurements as Antarctica has the last few parts of land surface of our planet that have not been measured. It's an imperative job to do.

Yadvinder Malhi - The Anthropocene

Yadvinder Malhi, professor of Ecosystem Science at Oxford University, walks us through the concept of the Anthropocene – a new geological epoch.
About Yadvinder Malhi
"I am a Professor of Ecosystem Science at the University of Oxford, and I study the living world, how it works and how it changes.
I am an ecosystem scientist who explores the functioning of the biosphere and its interactions with climate change. I am the Director of the Oxford Centre for Tropical Forests which addresses major issues facing tropical forests, and lead the Ecosystems Programme of the Environmental Change Institute at Oxford, which does diverse research on ecosystems."
The Holocene is over
One of the most profound insights emerging over the last few decades is the insight that humans live on a planet where humanity is no longer a minor player in a vast planet with vast oceans, a vast atmosphere, and vast forests. Instead, we’ve begun to understand that humanity is a significant agent in transforming that planet's basic nature and changing its atmosphere, ocean, and biosphere. This transformation in thought is occurring in many different ways. It isn't just about climate change. It isn't just about biodiversity loss. It isn't just about plastics and waste in the oceans. All of these things are considered together.
The word "Anthropocene" has emerged over the last few decades to name this way of thinking. This word comes from the geological time scale, where there are aeons and periods and epochs. Moreover, by using this geological time scale, what “Anthropocene” implies is that we've moved into a new geological epoch. We've left the epoch in which all of human history has occurred, the Holocene, which began around 10,000 years ago. Before the Holocene, there was the last major ice age, and the Holocene signalled a period of climate stability for approximately 10,000 years. During that period of climate stability, all of human civilisation occurred.
What the Anthropocene proposes is that the Holocene is over. We've now moved into a new world where the climate is entering a period of instability. Many aspects of the earth are changing so profoundly that it's likely to leave a geological record in the sediments of history. For example, if a future geologist came from another planet to Earth in a hundred million years, they would see clear signals in the geological record marking the Anthropocene's start.
So, in some ways, “Anthropocene” is a geological term, but it's much more profound than that. The term is trying to offer us a mindset that recognises the world is finite, and that we live as a large entity on this finite planet.
Key Points
• We started noticing in the 1950s that carbon dioxide concentration in the atmosphere was climbing year after year, which was linked to fossil fuel combustion and emissions. This was one of the first signals that we had moved into the Anthropocene.• Humanity is a significant agent in transforming that planet's basic nature and changing its atmosphere, ocean, and biosphere.  The word that emerged for a human-dominated planet is the Anthropocene.• The Anthropocene mindset attempts to underline that limitless growth is impossible. We need to start redesigning society at a fundamental level so that it may sustain itself on a finite planet.• Climate denialism is a real turning back on 200 years of scientific progress and enlightenment and is a rejection of the scientific process using balanced evidence.

Tim Lenton - Climate tipping points

Tim Lenton, Professor of Earth System Science at the University of Exeter, explains climate tipping points, when we may hit them and warning methods.
About Tim Lenton
"I’m Director of the Global Systems Institute and Professor of Earth System Science at the University of Exeter. My work focusses on the transformation of our planet.
Reading Jim Lovelock’s books on Gaia ignited my passion for studying the Earth as a whole system. I study how our remarkable planet came to be the way it is now. I study how humans are transforming the Earth’s system and how we might create a flourishing future within that system."
Tipping points are something that can happen in a whole range of complex systems, including the human body and the entire Earth climate system, or “Earth system”. A tipping point is where a small nudge to a system has a huge outcome. It changes the state or the fate of that system. You could say that a heart attack or death were the bleakest tipping points for the human body; but, in all cases, the crucial thing is that within complex systems, there are cycles. There are closed loops of causality; there are things that scientists call feedbacks. Some of these feedbacks amount to amplifiers.
And that’s what’s driving change.
Identifying the different kinds of climate tipping pointsThere are many potential tipping points in the climate system that human activities are currently causing and could potentially tip for the rest of this century.
A first class of tipping points includes the melting of the great ice sheet on Greenland, on West Antarctica and parts of the East Antarctic ice sheet. A second category of tipping points involves the biosphere: the possibility that we could tip a dieback of the Amazon rainforest or the great forests that cloak the northern high latitudes – the boreal forests – or a major loss of coral reefs in the tropical oceans. Finally, there’s a third class of tipping points, which would involve reorganising aspects of the circulation of the ocean and the atmosphere, and how they’re coupled together.
Key Points
• Like any complex system, the parts of the Earth system are interconnected. A tipping point is where a small nudge to a system has a huge outcome. It changes the state or the fate of that system.• There are three main kinds of climate tipping points: a first includes the melting of the great ice sheets; a second involves a major loss of the biosphere; a third involves the circulation of the ocean and the atmosphere, and how they’re coupled together.• When various tipping points interact in a domino effect, it’s called a “tipping cascade” – and this is what we must avoid at all costs.• We expect some tipping points to be triggered at different levels of warming and that’s the strongest reason, to try and limit global warming, which means stopping fossil fuel burning as soon as possible.
Like any complex system, the parts of the Earth system are interconnected. That’s also true of the climate tipping points that I and others have identified. We know, for example, that as the Greenland ice sheet is melting and fresh water is pouring into the North Atlantic Ocean on either side of Greenland, that this makes the surface waters of the ocean less dense, less salty and less prone to sinking to the bottom of the ocean. We call this extraordinary process: "deep convection of ocean waters".

Tamsin Edwards - Greenland, Antarctica and climate predictions

Tamsin Edwards, Reader in Climate Change at King's College London, discusses changes occurring in Greenland and Antarctica ice and climate models.
About Tamsin Edwards
"I’m a climate scientist and Reader in Climate Change at King’s College London.
My work involves quantifying the uncertainties in climate model predictions, and particularly the changes that we’ll see for the Greenland and Antarctic ice sheets’ contributions to sea level rise."
How does climate change affect ice sheets?
Greenland and Antarctica are fascinating because they encapsulate important parts of climate change. We don’t think about the ice caps much. We think of them as something remote or something ancient, which they are, but they are such key parts of our climate system that the way that climate change is affecting them will last for many generations of humanity. Even if the impacts of sea-level rise take decades or hundreds of years to come about, the partial or total loss of the ice sheets will take millennia to replace. That’s a profound consequence of climate change. Even if we can adapt to extra coastal flooding, even if we move away from the coasts, even if we think we can live with that sea-level rise, the loss of the Greenland ice sheet or the West Antarctic ice sheet is something that would be hard to forgive ourselves for.
The two ice sheets of Greenland and Antarctica are quite different. They are affected by the climate in different ways. Greenland is a more straightforward case of what we think of when we think of melting ice. Greenland is a big block of ice sitting up in the northern hemisphere. It is mainly affected by climate change through the warming of the air over the ice sheet, which has a direct melting effect on the surface. Impacts from the ocean also have an effect. But primarily it’s about the balance between the melting at the surface and any snowfall that’s occurring, particularly in the centre of the ice sheet, where it’s colder and higher. So that’s a more standard way of thinking about melting ice.
Key Points
• Greenland and Antarctica are fascinating because they encapsulate important parts of climate change. The way that climate change is affecting them will last for many generations. The partial or total loss of the ice sheets will take millenia to replace.• The two ice sheets of Greenland and Antarctica are quite different. Greenland is mainly affected by climate change through the warming of the air over the ice sheet. In Antarctica, warm ocean water also causes erosion underneath the ice sheet.• At the core of climate models, such as models of Antarctica and Greenland, we have some key certainties. But at the same time, it’s crucial to bear in mind the balance between the known and the unknown, the certain and the uncertain.• We have to factor climate change into every detail of our planning, of our expectations, of every facet of our society, including equality and how to help the vulnerable, the people who are already struggling to live with today’s extreme weather events.• We have to be able to reach out. We have to understand what people are trying to say to us and listen to them. We have to understand how to change the things that we say so that they can be understood by other people, too.