The climate is changing, people are playing a major role in the changes, and individuals and communities in all parts of the world are experiencing the effects.
Those are some of the key conclusions in the latest reports from the Intergovernmental Panel on Climate Change. The Penn State faculty who were contributors to these comprehensive scientific assessments said they expect that the findings — based on more finely tuned climate models and an expanded look at the effects of climate change — will resonate with the public.
“Our report unmistakably shows that risk for both people and natural systems will increase with additional warming, especially under a 4 degrees Celsius warmer world by the end of this century, if no drastic mitigation measures are put in place within the very near future. Adaptation and mitigation have to go hand in hand,” said Petra Tschakert, associate professor of geography.
Tschakert was a coordinating lead author of “Livelihoods and Poverty,” a chapter in the report “Climate Change 2014: Impacts, Adaptation and Vulnerability,” released April 1. She also was an author of the summary for policymakers and the technical summary, two key parts of the report issued by IPCC Working Group II, and remains a member of the core writing team for the final synthesis report, to be released in October.
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Chris Forest, associate professor of climate dynamics, was a lead author of a chapter in the Working Group I report, released in September 2013, and Klaus Keller, associate professor of geosciences, was a contributing author to the Working Group II report and upcoming Working Group III report.
“I consider myself a scientific diplomat. I’m representing the United States, I’m representing the sciences and I’m representing my discipline,” Forest said.
Their work — all unpaid — lasted more than three years, including cross-continental conference calls and marathon meetings. The College of Earth and Mineral Sciences faculty were part of the effort to assess what recent science has to say about climate change; how much human behavior is contributing to warming air temperatures and oceans, melting ice and various forms of extreme weather; and what these changes mean for people exposed to them.
Tschakert said that even countries that have been hesitant to make commitments through the United Nations negotiations to address climate change may realize that nobody is immune to its effects.
“I strongly believe that the main findings will be a wake-up call for many countries to reduce vulnerabilities in their own societies and invest in effective and fair adaptation now,” she said.
Forest, who was a lead author of Chapter 9: “Evaluation of Climate Models” in the report from Working Group I, “Climate Change 2013: The Physical Science Basis,” said the question of whether climate change is happening already has been answered. The focus is now on evaluating the best way to use the information.
“The scientific community is concerned about what the future risks are,” Forest said. “The future changes in climate are going to be driving what sorts of responses we need.”
“From what we’ve learned with all the advances in the ability to simulate the Earth and climate systems, we have a solid understanding of how the climate will change in the future. We still expect 3 to 5 degrees Celsius warming by the end of the century,” Forest said.
That would mean complete loss of summer sea ice, rising sea levels and more extreme conditions that become more common.
“We need to expect the unexpected,” he said.
This round of reports follows the one completed in 2007, whose contributors included five College of Earth and Mineral Sciences faculty. The IPCC, along with former Vice President Al Gore, received the 2007 Nobel Peace Prize.
The Working Group III report, which will look at options for mitigating climate change through reduction of greenhouse gas emissions, is expected to come out later this month. Karen Fisher-Vanden, associate professor of environmental and resource economics, is a lead author on Chapter 6: “Assessing Transformation Pathways.”
Forest noted that the reports are summarizing research that has been conducted over the past six years and gone through the peer-review process. For his group, that meant testing the accuracy of climate models that are used to understand past climate behavior and forecast what is expected in the future. Scientists can do that by comparing what a model says will happen with real numbers from past weather and climate patterns, such as those responding to volcanic eruptions.
Tschakert explained that as part of the review process, three drafts of each chapter were produced along with one final version for governmental distribution, addressing comments and suggestions from experts and governments who had signed up with the IPCC as reviewers. In the case of her chapter on livelihoods and poverty — a new chapter in the IPCC — a total of 1,370 comments were received, all of which her team needed to address. For Chapter 9 in the Working Group I report, more than 4,000 comments were received and addressed.
Tschakert pointed to lessons learned from the heat waves that hit Chicago and major cities in France in 1995 and 2003, respectively, as examples of the impact extreme weather events can have even in rich countries, especially on the poor and elderly.
“Knowing that heat waves have doubled over the last decades and that the number of very hot days is projected to further increase, we can imagine the consequences such as dehydration, lower work productivity, heat strokes and loss of life, especially for outdoor workers such as farmers and construction workers, women who walk long hours to fetch water, and again elderly people and those without a permanent home,” she said. “We need to prepare for this future and support people in developing good methods for protecting themselves and others.”
The United Nations Environmental Programme and the World Meteorological Organization established the IPCC in 1988 to study human-induced climate change, its potential impacts, and options for mitigation and adaptation.