[MUSIC] Hi, we're going to talk about global change, and basically about the drivers of the global change. So we live in a world where humans are causing profound impacts on the global environment. And this is the basis of the idea of global change. Global change is studied by many scientists around the world. And the scientists are interested on studying the drivers of the global change into the ecosystems at different levels. These studies implicate multidisciplinary studies, because there are many different areas that take part in these studies. Like for example, oceanography, the study of the atmosphere, geology, etc. So now I would like to present you the global change drivers, you have the list here. This is the human population and consumption, the energy use and climate change, the land use changes, the pollution, and also, we're going to talk a little bit about invasive species. So here in this slide, you can see this diagram with different graphs. And they are from a study from Will Steffen, Wendy Broadgate, and Lisa Deutsch and other colleagues. And they show how there has been a great acceleration on different socioeconomic trends. Like for example, urbanization, urban population, the consume of paper, or water use. And so you see here data, the trends from 1750 until 2010, and you can see how the last years, there has been a huge increase. And so this is what is called the great acceleration of these socioeconomic trends. With all these trends and great acceleration, we can explain one of the main reasons of this global change. Here in this other image, you can see the map of the world with the global footprint. So the the ecological footprint is defined as a metric that takes into consideration the resource use of humans. And also, the capacity of the Earth to renew the resource that we use. So here in different colors, you can see this ecological footprint in the different countries and different parts of the world. And if you want, you can also calculate your own ecological footprint. So you can calculate your impact on the Earth based on this idea. And you will find some resources in the supplementary material, and websites in which you can freely calculate your ecological footprint. So once we have seen this human consumption, this great acceleration that we are living in recent years, we are going to talk now about the energy use and the climate change. So basically, this ecological footprint is due to different aspects, different reasons. But the largest contribution of this ecological footprint is the carbon emissions from the fossil burning, so this is carbon dioxide, basically. And here in this graph, you can observe this trend, and also, you see how it is also in the work of Hannah Ritchie and Max Roser. There's a website called Our World Data, and there you will be able to find more data related to these carbon emissions of humans. So there's a video that we will we will talk on only about climate change, and there's more information about this process. But now I would like to talk about one of the main processes that take place, and that is important to know to understand this climate change, which is the greenhouse effect. Now, the greenhouse effect is natural in the Earth, there's a natural greenhouse effect. And it's basic for living organisms, in fact, it's critical to support life as we know it on the Earth. The process of the greenhouse effect is that some solar radiation arriving to the Earth, and some of the solar radiation is absorbed by the Earth and the atmosphere, but some of this radiation is reflected. So this would be the natural greenhouse effect. But in the last years, what has happened is that there has been an increase of the burning of fossil fuels. And there has been an increase of what we call the greenhouse gases. So here you have some of the most important greenhouse gases, like for example, carbon dioxide or methane. And so this increase has strengthened the greenhouse effect, and has caused the climate warming that we know nowadays. Another important driver of global change are land use changes. Different activities associated with production and consumption will create different types of land uses. And these different types of land uses and land use changes will affect ecosystems and vitamin in different aspects. Like for example, size and quality of the habitats, or the balance between domesticated and wild species, or also properties related to the chemical and physical properties of the non-living part of ecosystems and functioning of the ecosystems. We can describe deforestation, which would be an example of land use change. We can define deforestation as the cutoff or removal of trees in a forested area. So that finally, we can estimate the first land use change depending on the gains or losses of these forested areas. Another important driver is pollution. There also has been a rise on the environmental pollution around the last years. And we can find pollution in different parts of the environment, like for example, in the water, and in the soils, in the air. So that we can find also different compounds of this pollution, different types of pollutants, depending on the site we find it, and the human activities that take place on there. Now I would like to introduce Dr. Angel Hsu, she has done research related to pollution. And I would like to mention that she is now in a project of a database of many of these environmental drivers of the global change. And she's trying to work with different disciplines so that finally, they can give solutions to many of the environmental problems that we have. I would like to introduce now Nancy Robalais, she's a researcher specialized on the study of hypoxia disease, the oxygen depletion in seawaters. In concrete, she has been installing a concrete case study in the story of the Mississippi River, this is in the Gulf of Mexico. And there she has detected that it is an important zone with this hypoxia. Basically, this depletion of oxygen is caused by human activities that take place in the river, and finally arrive into the sea. So basically, activities that release residuals of nitrogen and phosphorus. So this is one of the largest human-caused hypoxic zones that has been described. And she's working on trying to give evidence of the causes and also possible ways of reverse its harmful effects in this natural area. Okay, so now I would like to talk about the last global change driver I'm going to mention, which are the biological invasions. Voluntary or involuntary transport or introduction of biological species outside their natural area is as ancient, as old as humanity. But the recent years, with the globalization, there has been an increase of this process, these introductions of biological species. And many of these exotic species, it is known that they have the capacity to alter the functioning of the new ecosystems. So that finally, they can create damage, this is ecological damage, but also economical damage on the ecosystems. These definitions related to biological invasions can be found in a book from Dr. Montserrat Vila. She's a researcher specialized on biological invasions. She has many research articles and chapters of books and other publications related to invasive species and biological invasions. And she's also a member of international organizations that are working with these invasive species aspects. She is specialized in ecological and economic impacts of invasive species. And also, how reactive factors can control the establishment of non-native species, for example. Another woman I would like to introduce is Dr. Francesca Girardi. She has done many research in invasive species too, and she was specialized on crayfish invasions, which are an important threat for biodiversity in aquatic ecosystems. Okay, so now we have seen all these global change drivers. And I would like to mention that all these drivers has produced impacts on the Earth, and there are what is called responses to these drivers. So the responses can be at a community level, community responses, but also at the individual organism level, or populations. So that there can be processes like declines, extinction, or phonology changes, for example. And also, that all these drivers can cause impacts on human society, like for example, on the health of humans and food security. So to finish this video, I would like to talk about the Anthropocene, and the anthropogenic biomes. Anthropogenic biomes of the world, and basically, it would be another point of view, another way of representing the variance of the world. So the idea is that there are anthropogenic biomes, which are called anthromes, and they are defined by the population density and land use intensity. So in the map, you can see the parts of the Earth, the parts of the world in which there are more human activity. And another concept is Anthropocene, so the Anthropocene is a proposed era, a proposed epoch, that starts when the human impacts increased. So in the moment that there is a significant human impact on the Earth geology and ecology. This concept is still in discussion, as I mentioned, it is a proposal of an epoch. And there's still some discussion between geologists especially, on which is the moment that it starts, and which are the main traits that define this geological new era. But while they are discussing, the reality is that, from a social and cultural point of view, this concept is already being used. So that it is being used with the idea that we are in a new era, in a new moment of the history of the Earth, in which there are important inputs into the environment, and a great acceleration of the socioeconomic activities. [MUSIC]
