3.4 Climate projections

Learning objectives

After reading this module, students should be able to

• assess global CO ₂ emissions and determine which countries and regions are responsible for the greatest emissions currently and historically
• explain the relationship between fossil fuel usage and CO ₂ emissions
• link variables such as wealth, population, fuel imports, and deforestation to CO ₂ emissions
• use IPCC future climate projections to assess future global temperature scenarios
• distinguish between weather events and climate change, and discuss the differences between weather forecasting and climate projections
• analyze the anthropogenic impact on climate by examining climate change without people
• assess the regional and global impacts of climate change on air temperature and precipitation

Introduction

In the Module Modern Climate Change we discovered that the global warming of approximately 1°C over the past 200 years was human induced through an enhancement of the natural greenhouse effect. We learned that the burning of fossil fuels has upset the natural carbon cycle, which has steadily increased the amount of carbon dioxide (CO ₂ ) in the atmosphere since the 1750s. Finally we looked at ancillary evidence of this warming to see the immediate impact of these changes. In this module we will investigate the findings of the Intergovernmental Panel on Climate Change (IPCC) and look at future climate projections. We will inspect these findings and analyze their impacts on a global scale.

Who is responsible? factors to consider

In 2007, the IPCC was awarded a share of the Nobel Prize for its work in the area of global climate change. The IPCC is organized through the United Nations and is composed of over 3,000 scientists from around the world who are working together to understand current climate change and project future climate scenarios. As of 2011, the IPCC has released four comprehensive reports, and it has concluded, “Most of the observed increase in global average temperature since the mid-twentieth century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” This widely known statement essentially means that the probability of occurrence is greater than 90% that the current global warming is caused by humans burning fossil fuels. In response to these findings, the United Nations Framework Convention on Climate Change has called for numerous international meetings in cities including Kyoto, Bali, Copenhagen, and others where the leaders of world have gathered to discuss strategies to mitigate this looming disaster. At these meetings, scientists, politicians and world leaders review the current state of knowledge about the problem and strategize for the future. This chapter will take a large-scale view of the global challenges of climate change.