Welcome, in this course on climate change and indigenous peoples and local community. We first want to introduce you to the context and evidences related to the climate as both natural and anthropogenic phenomena. First, the climate is what is considered as the meteorological variables such as temperature, wind, humidity, precipitation is largely determined by how much of the energy coming from the sun will be absorbed and stay in the planet. For this, the atmosphere's play an important role. A certain gases absorb the infrared radiation coming from earth surface and reradiated in all directions, including back downwards. This is called the greenhouse effect. And without this, the planet would be 33 Celcius degree cooler, so it keeps the planet habitable. There is astrophysical and geophysical phenomena involved in shaping the climate of the planet. Three main astrophysical phenomena known as the Milinkevich Cycle play an important role in how much energy we will receive from the sun. For instance, there is the eccentricity related to the orbit shape of the planet that changed over 100,000 year cycle. Then the obliquity, the actual tilt, which relate to the actual tilt of the planet with respect to the orbital plane. And that changed in cycle lasting 41,000 years. And then the actual procession, which is the gradual shift of the orientation of the planet's rotational axis taking place in a cycle of 26,000 years. In addition to the astrophysical phenomena, there is also natural geophysical factor like volcanic eruption, continental drift, atmospheric and surface reflectivity. And altogether those natural factor shape the climate. Now when the mean and the variability of the climatic properties such as wind, temperature, etc., show changes over an extended period of time. That's what we called the climate change. Over the history of the planet, the climate has been constantly changing. There have been seven glacial advances and retreats in the last 650,000 years, with the last ice age taking place around 11,000 years ago, marking also the beginning of the modern climatic era. In contrast with the climatic change that have occurred all over the planet history, the modern climatic change taking place since the beginning of the industrial era two last centuries. As shown, for instance, in the increase of the temperature known also as the global warming has been taking place in such a drastic way that even ancient geophysical event don't reach this space. As for instance, calculated by the mean, the global average of surface of the land and the ocean. It has been shown that since the 1880, the temperature has increased of about 1 Celsius degree, more or less after the beginning of the industrial era. When analyzing carefully the different natural factor that might drive this climatic change, expert from the IPCC, the Intergovernmental Panel of Climate Change showed another combine nor independently the natural factors such as volcanic eruptions, solar radiation or orbital changes might explain the observed change we have seen in the temperature. However, taking into account the anthropogenic factor, they have seen a clear pattern between the greenhouse emission and the temperature increase. So in short, there is evidence that since the 1880 as shown in those graph, that anthropogenic factor are driving mostly the observed changes. It's mostly then due to greenhouse gases emission that have been increasing since the two last century's enriching unprecedented level never seen in the last 800,000 years. Specifically, the carbon dioxide is about 400 per million, while about two centuries ago it was only 280 per million. The emission of carbon dioxide is coming mostly from the burning of fossil fuel, which comprise about 60% of the total emission of carbon dioxide in 2010. But also deforestation and land uses changes affect the emission or important in the emission of carbon dioxide. When going beyond only considering carbon dioxide, but taking all the greenhouse gases together and considering both the direct and indirect emission. It has been shown that among the different economic sector, that's the industrial and the power sector that are the most important in the emission of carbon of greenhouse gases. So in conclusion, while the planet has known climatic change since the planet is born, the last modern climatic change taking place this 200 last year's is an a president drastic pace. And this is most lead you to entrepreneur nick factor to human factor, mostly to the greenhouse gases emission in particular carbon dioxide, which has increased since the beginning of the industrial era. [SOUND]
