Chapter 1 - Foundations of Climate Change: What Is Climate Change? Exam Questions And Answers

Chapter 1 - Foundations of Climate Change: What Is Climate Change? Exam Questions And Answers How can Climate Change be measured? 1. Tree rings 2. Corals 3. Ice cores 4. Ocean Sediment cores Causes of climate Change 1. Energy Balance 2. Green House Effect Energy Balance Most important rule of the Earth's climate - energy balance 30% of incoming sunlight is reflected back to space -(means) infrared radiation = heat. The amount of heat radiated is determined on planet temperature GHG GHG are a part of the atmosphere and absorb infrared radiation = earth heats up with more in the atmosphere GHG = Water Vapor (traps the most heat) th eCO2 Carbon dioxide Increase CO2 in atmosphere increase in planetary temperatures increase due to combustion of fossil fuels - industrial revolution. Human are main cause of increase Half of CO2 released is absorbed in the oceans. Methane Powerful greenhouse gas on a Human's Impact on the Climate 1. Significant anthropogenic changes to the planet. 2. Difference between incoming energy (sunlight) absorbed by the Earth and the outgoing energy (infrared radiation) emitted by the Earth back to space. Attributions to modern warming Tectonic Processes - the movement of a continent toward the poles can lead to the growth of an ice sheet on the continent. Because ice sheets are reflective, the growth of a continental ice sheet will lead to more incident sunlight being reflected back to space, which will tend to cool the climate. Output of the Sun - eliminate as modern reason, not enough data Orbital Variations - the closer the earth is to the sun the more heat Unforced Variability - El Nino NOT LIKELY REASON GHG - adding carbon dioxide, or any other gas that absorbs infrared radiation, to the atmosphere should warm the planet by affecting the planet's energy balance. Second, it is a fact that humans are adding carbon dioxide to the atmosphere. The timing of warming, beginning in the nineteenth century after the industrial revolution, and the magnitude of the warming also match scientific theory. Finally, the geologic record shows that changes in climate are frequently associated with changes in greenhouse that adding carbon dioxide, or any other gas that absorbs infrared radiation, to the atmosphere should warm the planet by affecting the planet's energy balance. Second, it is a fact that humans are adding carbon dioxide to the atmosphere. The timing of warming, beginning in the nineteenth century after the industrial revolution, and the magnitude of the warming also match scientific theory. Finally, the geologic record shows that changes in climate are frequently associated with changes in greenhouse gases. Shared Socioeconomic Pathways (SSPs) SSP1 - is a sustainable world where the world's econo-mies gradually shift toward a more environmentally friendly path. B SSP2 - is a world that follows the trends of our world today, leading to generally declining emissions over the twenty-first century due to widespread adoption of renewable energy (although slower than in SSP1). SSP3 - a world that follows the trends of our world today, leading to generally declining emissions over the twenty-first century due to widespread adoption of renewable energy (although slower than in SSP1). SSP5 - a world similar in many ways to SSP1, but it is one that emphasizes economic growth rather than sustainability. As a result, economic growth in this world is very high and fossil fuels power a significant fraction of this growth. Impacts of Modern Climate Change (6) 1. Temperature - Warmer temperatures but it will NOT be uniform. Most people live on land of the northern hemisphere, the average temperature increase experienced by humans will be larger than the global average warming. 2. Precipitation - increased temperature = faster rate of evaporation. Global projections increase 3% but unequal. Increased floods. 3. Sea level & Ocean Acidification - Melting ground ice = runoff to ocean increasing total water. Estimates show sea level rises a few meters for every degree of warming. The oceans absorb 1/4 of carbon. 4.Extreme Events 5. The Alebedo Effect, Polar Amplification and Positive Feedbacks - Ice is more reflective than darker land/oceans 6. Human Society and Natural Ecosystems - as the climate shifts and ecosystems are effected, the benefits of these ecosystems disappear. Climate Tipping Point? Policy Reponses 1. Adaption 2 Mitigation 3. Geoengineering Adaption Responding to the negative impacts of climate change. Sea level rise = sea walls - Response the physical climate risk. - Beyond physical enhancements, human communication, processes, and regulations can be adaptive (e.g., better extreme event warning systems or more climate-informed zoning regulations). - Countries who are financially stable will have a better response effort. Strain on climate debate that those who cause climate change are also the richest countries Mitigation Policies to avoid or minimize climate change. Reduction of emission = reduced ocean acidification. - A need to place fossil fuels on the back burner and focus om renewables (wind/solar/hydro/nuclear/ geothermal/biomass) - CCUS refers to a process by which fossil fuels are burned in such a way that the carbon dioxide generated is not vented to the atmosphere. Rather, the carbon dioxide is captured and used in a range of applications, such as being incorporated in cement or plastic. Geoengineering Manipulation of earths climate system to counteract the effects of climate change caused by greenhouse gas emissions. 1 Injecting Sulphur into the atmosphere where the gas will react with ambient water vapour to form droplets that reflect sunlight back to space. - Will this cause precipitation patterns to change causing droughts or floods depending on the region. 2. CO2 removal - Planting trees as a storage device - however when the tree is cut or dies the CO2 is released back into the atmosphere. - CCUS - removing with exhausts - The scale to remove is enormous based on the amount of CO2 humans are adding to the atmosphere Mitigating Targets 1. Paris Agreement - 2-3C of warming in 2100. No warming should occur above 1.5C = tipping point after. - "well below 2°C above pre-industrial levels while pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels." - emission have to be cut by 50% to stay within the threshold. 2.