Course Home Page

Welcome to Earth in the Future!

Our planet is warming. Data shows that the average temperature of Earth has increased by 0.6oC since 1950. The Northern Hemisphere just recorded its 333rd month with temperatures above the 20th century average. In fact, Earth is warming at a rate not experienced for many millions of years, if ever before. This warming and a myriad of associated environmental changes will challenge modern society throughout the 21st century. Scientists are striving to improve predictions of how the environment will change as well as understand the impacts on humans. This course, Earth in the Future: Predicting Climate Change and Its Impacts Over the Next Century is designed to provide the state of the art of climate science, the impacts on humans and natural ecosystems, as well as ways humans can mitigate and adapt to climate change.

The overwhelming majority of climate scientists attribute this warming directly to human activities, specifically the burning of fossil fuels. The concentration of CO2, the most important greenhouse gas, now stands close to 400 parts per million, the highest level in the last 800 thousand years. Scientists have not succeeded in making their case to the general population—only about 50% of people in the US believe that warming is a result of human activities. The goal of this course is not to focus on this ongoing debate or to take sides. The goal of this class is to understand the science of climate and consider the implications of climate change on Earth no matter what its causes. How do we forecast climate? What will Earth be like in the year 2100? How habitable will the planet be at that time? A key factor, completely separate from climate change, is that projections show global population increasing from about 7 billion people today possibly up to 14 billion at the end of this century. Like climate, population is very difficult to forecast, hence the range of estimates is very broad. In fact, habitability is a central part of population projections, with lower estimates factoring in significant increases in mortality as a result of overpopulation as well as decreases in fertility.

World map showing projected increases in mean surface temperature in 2009
Figure 1.1: Projected increase in mean surface temperature in 2099. Note the sharp warming in high northern latitudes
Credit: United States Forest Service

Let's take a quick look at how the physical nature of the planet has changed over the last fifty or so years. Mountain glaciers have lost over 4000 cubic kilometers of water and the Arctic sea ice has lost 10% of its area. Sea level has risen by 9 cm. That might not sound like a lot but it sure made a difference to flooding during Hurricane Sandy! The ocean surface temperature has increased by 0.5oC and its pH has decreased (it has become more acidic), making it more hostile for many invertebrate animals that make shells out of calcium carbonate. For example, coral reefs are having a harder and harder time growing under increasingly acidic conditions. Today, the world’s forests are being cleared at a rate of 20 football fields per minute! And the Sahara desert is expanding southward at a rate of 48km per year. Today, by many estimates, more than 50% of the species on the planet are considered threatened. The following time lapse videos show dramatic changes in our planet from 1984 to today includung urbanization, deforestation and rapidly receding glaciers.

Dubai shows significant urban development along the coast Las Vegas shows a large increase in size and density

Brazilian Amazon shows large amounts of deforestationColumbia Glacier recedes considerably, showing green land and open waterways

Here are some of the warning signs of climate change shown in graphic images:


Drought

Dead trees in drought stricken Australian Outback Mudcracks in a field in the drought stricken Murray Darling basin of Australia

Click on the images above to see full size version and complete source information.


Flooding

The aftermath of Hurricane Katrina - aerial view of homes surrounded by water Flooding in Bangladesh

Click on the images above to see full size version and complete source information.


Ocean Acidification

Impact of increased CO2 on reef health.  Healthy reef at left, reef that stopped growing at center and algal infested reef at right
Impact of increased CO2 on reef health. Healthy reef at left, reef that stopped growing at center and algal infested reef at right.

Warming and Sea Level Rise

Iceberg - Ilulissat-Greenland Glacier Falling Crack recently exposed in the Pine Island Glacier, Antarctica, evidence that the glacier may soon break up

Click on the images above to see full size version and complete source information.


Deforestation and Desertification

Deforestation in Haiti Deforestation in Morocco World map of desertification vulnerability

Click on the images above to see full size version and complete source information.


So where are we headed? Will the large ice sheets completely melt in the next 90 years? Will the oceans become so acidic than no animals and plants can live? Will grasslands and other semi-arid regions completely dry up leading to famine for entire nations? The answer to these questions is almost certainly no. However, it is likely by the year 2100, if not considerably before, that ships will be able to sail from New York to Tokyo through the Northwest Passage (the route between the Atlantic and Pacific Oceans that runs through the Arctic) without ice breakers, that many species of coral will be extinct as a result of acid oceans and other causes, and that we will have witnessed the migration of massive numbers of people as a result of drought, famine and sea level rise.

Governments around the world are planning for these major changes. For example, the Pentagon is evaluating the impact of an open Northwest Passage on national security, energy policy and fisheries. Biologists are evaluating the ability of species of coral to adapt to an ocean with lower pH and warmer temperatures. And nations from the developed and developing world are pursuing technologies that will expand the limits of habitable land.

The goal of this class is to survey the health of the planet today, with a strong emphasis on climate, and to provide an understanding of how scientists forecast this health will change in the future. We will learn that there are significant uncertainties in these forecasts that mean that we must develop a playbook of strategies to deal with the possible changes that are to come. At the same time, we will monitor the impact of climate and other environmental change on ecosystems, all the way from microscopic algae to humans.

Fortunately, Earth has witnessed rapid changes in climate and environment in the past and geologists have considerable expertise in extracting information on the exact nature of this change as well as how it affected life on the planet.

Quick Facts about Earth 103

Authors

Drs. David M. Bice and Timothy J. Bralower, Professors of Geosciences, College of Earth and Mineral Sciences, The Pennsylvania State University

Instructor

Dr. Timothy J. Bralower

Overview

Earth in the Future is an introduction to Earth's climate system and the challenges we will face in the near future because of these changes. Earth in the Future is an entry level course for Earth Science and Policy BS degree at PSU.

Learning Environment

This website provides the primary instructional materials for the course. The main menu at the top of the page links you to important supporting materials. The Modules tab, in the main menu, will take you to the course lessons. ANGEL, Penn State's course management system is used to support the delivery of this course as well, as it provides the primary communications and submission tools for the course.

Topics of Study

The content of this course is divided into 12 lessons (modules). Each module will be completed in approximately 1 week.

Topics of Study
Module Title
 Module 1 Past Episodes of Climate Change
Module  2 Recent Climate Change
Module  3 Earth's Climate System
Module  4 Introduction to General Circulation Models
Module  5 Global Carbon Cycle
Module  6 Ocean Circulation and its Impact on Climate
Module  7 Ocean Acidification, Red Tides, and Monster Jellyfish
Module  8 Water Resources and Climate Change
Module  9 Climate Change and Food Supply
Module 10 Future Sea Level Change
Module 11 Terrestrial Ecosystems in Peril
Module 12 Adaption to and Mitigation of Climate Change

Acknowledgments

Earth Futures is the brainchild of Eric Barron, founding Director of Earth System Science Center, former Dean of the College of Earth and Mineral Sciences at Penn State, now President of Penn State. We are also deeply grateful to learning designer April Millet in the Dutton e-Education Institute, Earth and Mineral Sciences at Penn State who took the materials and brought them to life. April not only kept us on task but she also continues to provide sage advice about the way we present science. This on-line course could not have been possible without her and Khusro Kidwai who gave us initial guidance. Thanks also to Dutton directors Annie Taylor and David DiBiase for encouragement, inspiration and leadership.

Numerous people have helped point us in the right direction for parts of the course, although they are by no means to be held responsible for the content. They include Donna Green, Katrin Meissner and Shane MacGregor at the Climate Change Research Centre, University of New South Wales, Kamini Singha and Erica Smithwick at Penn State, Walter Barnhardt at the USGS, Scott Wing at the Smithsonian, Ellen Currano at Miami University, and Dennis McGillicuddy at Woods Hole. We thank the staff of the Climate Change Research Centre, University of New South Wales for their hospitality while this course was being developed.

Finally, the course would not have been possible without funding from NASA and the Australian-American Fulbright Commission.