Here, we present two ways to think about how lessons are sequenced in the Human Energy Systems Unit. The Instructional Model, immediately below, emphasizes how students take on roles of questioner, investigator, and explainer to learn and apply scientific models in each section of the unit. Further below, the Unit Storyline Chart highlights the central question, activity, and answer that students engage with in each lesson of the Human Energy Systems Unit. Instructional Model Like all Carbon TIME units, this unit follows an Instructional Model (IM) designed to support teaching that helps students achieve mastery at answering the driving question through use of disciplinary content, science practices, and crosscutting concepts. To learn more about this design, see the Carbon TIME Instructional Model. The instructional model for the Human Energy Systems Unit includes two phases, described in the Unit Overview, in which students play the role of questioners, investigators, and explainers. The first phase focuses on helping students to understand, analyze, and explain multiple phenomena associated with climate change (What is happening to the planet?). The second phase focuses on global carbon cycling (What causes changes in CO2?). Across the unit, classroom discourse is a necessary part of three-dimensional Carbon TIME learning. The Carbon TIME Discourse Routine document provides guidance for scaffolding this discourse in lessons. The core of the Carbon TIME Instructional Model is the Observation, Patterns, Models (OPM) triangle, which summarizes key aspects to be attended to as the class engages in unit inquiry and explanation. The OPM triangle for the Human Energy Systems Unit, shown below, articulates the key observations students make during the unit investigation, the key patterns they identify through analyzing their investigation data, and the central scientific model that can be used to answer the unit’s driving question. Observations, Patterns, and Models for Phase 1: Climate Change Observations and patterns: trends in global climate data. Students investigate multiple representations of data about four global phenomena, comparing the representations to look for patterns in the data. They end the Lesson 2 with four clear long-term trends: The extent of Arctic sea ice is decreasing Sea levels are rising Global average temperatures are rising Global concentrations of CO2 are rising Models: The Greenhouse Effect and CO2 as the driver. Students learn to use the Greenhouse effect to explain the connections among the long-term trends: Increasing CO2 levels are causing increases in global temperatures; the increasing temperatures are causing sea level to rise and ice to melt. Thus, atmospheric CO2 is the driver—the factor that causes change in the other variables. Observations, Patterns, and Models for Phase 2: Global Carbon Cycling Observations and patterns: Students use visualizations and graphs to investigate changes in atmospheric CO2 concentrations. Key patterns include: The annual cycle: CO2 concentrations in the northern hemisphere decline every summer and rise every winter. The long-term trend: Global CO2 concentrations have increased from about 310 to 400 ppm since the late 1950s. Models (and Explanations): Students explain carbon cycling and energy flow between carbon pools by connecting global, macroscopic, and atomic-molecular scales, and answering the Four Questions: Carbon Pools: carbon atoms are found in CO2, living organisms, soil organic carbon, oceans, and fossil fuels Carbon Fluxes: Changes in photosynthesis drive the annual cycle; combustion of fossil fuels drives the long-term trend. Energy Flow: CO2 and other greenhouse gases cause climate change. Stability and Change: The photosynthesis and cellular respiration fluxes are large, but balanced. So, the smaller but unbalanced flux from combustion of fossil fuels is steadily increasing the size of the atmospheric CO2 Unit Storyline Chart Another way to familiarize yourself with the sequence of lessons in the Human Energy Systems Unit is with the Unit Storyline Chart depicted below. The Unit Storyline Chart summarizes a unit phenomenon-based driving question associated with each lesson, what classes will do in each lesson to address the question, what conclusions they will come to, and how they will transition to a subsequent lesson. Download Unit IM and Storyline Chart
