2023 warmest year on record: U-M experts available

January 9, 2024
summer hot weather season high temperature thermometer with city view. Image credit: coffeekai, iStock


Last year was the planet’s warmest year on record by a wide margin, according to the European climate agency. University of Michigan experts are available to comment.

Jonathan T. Overpeck
Jonathan Overpeck

Jonathan Overpeck is an interdisciplinary climate scientist and dean of the School for Environment and Sustainability. He is an expert on climate and weather extremes, sea-level rise, the impacts of climate change and options for dealing with it. He served as a lead author on the authoritative Intergovernmental Panel on Climate Change 2007 and 2014 reports.

“Global temperature in 2023 blew the doors off previous records in many ways. A bigger jump in global warmth than ever before in the global thermometer record, more individual days—hundreds—breaking records than ever before, a warmer ocean than ever before,” he said.

“And the warming will continue to accelerate until we halt the burning of fossil fuels. This means continued worsening extreme heat and heat waves, but also many other worsening climate extremes driven by warmer temperatures. More severe droughts, more intense rainfall, more devastating hurricanes and bigger, more widespread wildfires.

“The list goes on and, increasingly, more and more people in the U.S. and around the world are experiencing the trauma these extremes bring to lives and livelihoods. The good news is that we know how to stop the mayhem, and that means replacing fossil fuels with the clean energy alternatives that also help clean up the air and save money.

“The big question right now is what will 2024 bring? The odds favor another exceptionally warm and extreme year of climate disaster. The on-going El Niño is helping to boost global temperature, but it’s important to remember that most of the heat humans trap with their emissions of greenhouse gases ends up in the ocean. This is why El Niños tend to release more ocean heat to the atmosphere than in the past.

“Ultimately, the global temperature records that are becoming more extreme by the decade are driven by human-caused global warming and the impact of this warming on the oceans and El Niño.”

Contact: overpeck@umich.edu

Sue Anne Bell
Sue Anne Bell

Sue Anne Bell is a nurse practitioner and an assistant professor at the School of Nursing. Her research focuses on the long-term impact of disasters and public health emergencies on health, particularly among older adults. She is clinically active in disaster response through the U.S. Department of Health and Human Services’ National Disaster Medical System, with over a dozen recent deployments including to the COVID-19 response, Hurricane Maria and California wildfires.

“Extreme heat affects communities, groups and individuals that already have extra needs to maintain their health and well-being during ‘normal’ times,” she said. “This underscores the importance of building strong and resilient health care systems.

“A strong infrastructure that provides access to healthcare during heat waves and associated power outages, along with a health care team knowledgeable and ready to care for heat-related illness, is fundamental to addressing current and future warming temperatures.”

Contact: sabell@umich.edu

Greg Keoleian
Greg Keoleian

Greg Keoleian is a professor at the School for Environment and Sustainability and co-director of the Center for Sustainable Systems. He is also co-director of MI Hydrogen, U-M’s hydrogen initiative. Keoleian has led more than 100 research studies, analyzing life-cycle energy, greenhouse gas emissions, and the costs of conventional and alternative vehicle technology, renewable energy technologies, buildings and infrastructure, consumer products and packaging, and a variety of food systems.

“We can all be alarmed by the news that 2023 was the warmest year on record,” he said. “Climate action is urgently needed to limit warming and the adverse climate impacts such as heat stress, flooding and droughts.

“Most importantly, everyone has a role to play in addressing the crisis. Action is needed by industry, governments, local communities, households and individuals to curb our use of fossil fuels and reduce greenhouse gas emissions.

“Examples of key climate solutions include increasing the share of renewable energy sources, electrification of vehicles and building heating and appliances, more utilization of public transit, increased energy efficiency and conservation, and diet shifts.”

Contact: gregak@umich.edu

Richard Rood
Richard Rood

Richard Rood is a professor emeritus of climate and space sciences and engineering at the College of Engineering and a professor emeritus at the School for Environment and Sustainability. He is an expert on U.S. weather modeling and can discuss the connection between weather, climate and society. He is also a co-principal investigator at the Great Lakes Integrated Sciences and Assessments, a federally funded partnership between U-M and Michigan State University.

“As soon as an El Niño watch was issued last spring, I expected 2023 to be the warmest year on record. This record is yet another affirmation that the planet is accumulating heat, and that the temperature is rising,” he said.

“Since the planet will continue to warm, I expect that in five to 10 years we will be leaving 2023’s record behind us. Because this record is consistent with what models and theory tell us should be happening, it stands as a verification point that our science-based understanding is basically correct.”

Open Climate

Contact: rbrood@umich.edu

Marie O'Neill
Marie O’Neill

Marie O’Neill is a professor of epidemiology and environmental health sciences at the School of Public Health. Her research includes the health effects of temperature extremes, air pollution and climate change on conditions such as mortality, asthma, hospital admissions and cardiovascular health. She also studies the intersection of environmental exposure assessment and socioeconomic influences on health.

She has worked for the U.S. Environmental Protection Agency, the Pan American Health Organization, in Mexico at the National Institute of Public Health and the National Center for Environmental Health as a Fulbright Scholar, and as a research fellow in environmental epidemiology at the Harvard School of Public Health. She was a Robert Wood Johnson Health and Society Scholar at University of Michigan from 2004 to 2006.

O’Neill analyzes the big picture of how climate change impacts cities and the people living in them and brings into focus the disparities that lead to more harm for vulnerable populations.

“This news is yet another wake up call about climate change,” she said. “We know that heat and extreme weather events have important effects on our health and communities. Especially in cities such as Detroit, where urban heat islands can amplify exposures, we know that people get ill or even die during heat waves, and that these effects are preventable.

“We also know that effects are unequal, and protecting those who are more vulnerable, including the elderly, the young and those with limited resources, is a social justice issue.

“We can both slow the pace of climate change by moving toward clean energy, and improve people’s immediate well-being by reducing the inequities that lead to vulnerability, including inadequate housing, health care and other social determinants of health.”

Contact: marieo@umich.edu

Julia Cole
Julia Cole

Julia Cole is an interdisciplinary paleoenvironmental scientist who has published more than 80 peer-reviewed studies on recent and rapid climate change. She is chair of the Department of Earth and Environmental Sciences, where she teaches on climate change, ocean science and science communication.

“Record-warm temperatures should come as no surprise, given the lack of meaningful steps to reduce greenhouse gases,” she said. “This past year, the tropical Pacific El Niño phenomenon has conspired with human factors to push temperatures to these record levels. During El Niño events, a large swath of the tropical Pacific warms and adds heat to the atmosphere.

“We can expect those conditions to persist for at least several more months, meaning that 2024 is also likely to be unusually warm. El Niño events bring additional climate extremes to many parts of the world. As climate warms, El Niño events appear to be strengthening, which adds to the heat, as well as to the growing risks of climate extremes.

“The reality is that we can expect a steady rise in temperature and ever greater risks of extremes until we get serious about reducing carbon emissions.”

Contact: colejul@umich.edu