Conflict, climate change and public health
University of Utah’s Andrew Linke is one of 128 contributors to the 2025 Lancet Countdown on health and climate change. Linke and colleagues focused on climate-related violence and community health.
University of Utah
image:
Annual number of months of extreme drought on average in 1951-1960(A) and 2024(B).
view moreCredit: Lancet Countdown 2025
The ninth 2025 global report of The Lancet on health and climate change was released on Oct. 29, 2025. The Lancet Countdown, an annual indicator report led by University College London and produced in strategic partnership with the World Health Organization (WHO), represents the work of 128 leading experts from 71 academic institutions and UN agencies globally. Published ahead of the 30th UN Conference of the Parties (COP), the report provides the most comprehensive assessment to date of the connections between climate change and health, including new metrics which record deaths from extreme heat and wildfire smoke, the coverage of urban blue spaces (rivers, lakes and coastlines), health adaptation funding and individual engagement with health and climate change.
Andrew Linke, associate professor in the School of Environment, Society & Sustainability at the University of Utah, co-authored a section of the study focused on how climate change and health intersect with armed conflict.
“It isn’t that the adverse effects of climate change cause violence directly, it’s that climate change is one part of a constellation of factors that contribute to cycles of political instability with impacts upon the provision of or access to healthcare,” Linke said.
Rural and primarily agricultural economies are the most susceptible to climate change and armed conflict, he continued. Structural conditions, including poverty, inequality and weak governance make for a potentially volatile society. Climate change adds pressure to an already fragile system; extreme heat, drought, flooding and shifting precipitation patterns reduce crop yields and raise food prices while lowering household incomes and disrupting livelihoods. These stressors affect the socioeconomic conditions on which health depends, especially in ethnically divided or areas with scarce resources.
The Lancet Countdown’s principal authors invited Linke to join the project last year after his talk at the Johns Hopkins University Bloomberg School of Public Health campus in Washington, DC. His presentation there focused on local-level population exposure to violent events worldwide, which can damage infrastructure like schools or healthcare facilities and reduce economic opportunities for communities.
“They thought my perspective could fill in a missing piece of the puzzle. Most of the Lancet Countdown explores how climate change influences population health directly due to things like mosquito-borne illness or extreme heat,” Linke said. “My contribution was more on the indirect effects of armed conflict and political instability amid climate change—what does population health look like with flood-damaged health clinics, disrupted transportation or disease exposure in refugee camps, for example?”
Managing social and economic changes is key to preventing climate-related conflict, the study concluded. Strengthening food systems boosts resilience, which can reduce malnutrition and food insecurity. If extreme weather events disrupt supply chains, ensuring emergency responses help all communities equally can lessen grievances and protect health care workers that often targeted when healthcare is limited.
The report concludes in an optimistic tone: “In a time of growing geopolitical volatility, strengthening multilateral cooperation and ensuring that the transition is not only green but also just might be essential to building peace in a climate-affected world.”
Linke’s piece is panel three in the 2025 Lancet Countdown on health and climate change. Find the full report online.
Adapted from a release by The Lancet.
Journal
The Lancet
Method of Research
Literature review
Subject of Research
Not applicable
Article Title
The 2025 report of the Lancet Countdown on health and climate change
Article Publication Date
28-Oct-2025
“State of the climate” 2025: Earth’s vital signs worsen, science shows options for livable future
Potsdam Institute for Climate Impact Research (PIK)
22 of the planet’s 34 vital signs are at record levels, with many of them continuing to trend sharply in the wrong direction. This is the message of the sixth issue of the annual “State of the climate” report. The report was prepared by an international coalition with contribution from the Potsdam Institute for Climate Impact Research (PIK) and led by Oregon State University scientists. Published today in BioScience, it cites global data from the Intergovernmental Panel on Climate Change (IPCC) in proposing “high-impact” strategies.
“The last few years have seen vital signs breaking their records by extraordinary margins, like surface temperature, ocean heat content, sea ice loss and fire-related tree cover loss,” says PIK Director Johan Rockström, a co-author of the report. “The accelerating climate crisis presents a range of deeply interconnected risks to the planet’s essential operating systems – from critical tipping elements such as the ocean current system AMOC, to the integrity of Earth’s living biosphere, to the stability of global water resources. But our report also shows how this unprecedented threat to the Earth system – and society – can be mitigated.”
The authors note that 2024 was the hottest year on record and likely the hottest in at least the last 125,000 years. “Climate mitigation strategies are available, cost-effective and urgently needed, and we can still limit warming if we act boldly and quickly,” said William Ripple, professor at Oregon State University and co-lead author. “But the window is closing. Without effective strategies, we will rapidly encounter escalating risks that threaten to overwhelm systems of peace, governance, and public and ecosystem health.”
The research team reviews high-impact groups of actions involving strategies around different sectors, including energy, nature and the global food system:
Energy: Renewable energy sources such as solar and wind have the potential to supply up to 70 percent of global electricity by 2050, the report notes. A rapid phaseout of fossil fuels would yield one of the largest contributions to climate mitigation.
Ecosystems: Protecting and restoring ecosystems such as forests, wetlands, mangroves and peatlands could remove or avoid around 10 gigatonnes of carbon dioxide emissions per year by 2050, which is equivalent to roughly 25 percent of current annual emissions, while also supporting biodiversity and water security.
Food systems: Reducing food loss and waste, which currently accounts for roughly 8 to 10 percent of global greenhouse gas emissions, and shifting toward more plant-rich diets can substantially lower emissions. These strategies also promote human health and food security, according to the report.
The report warns that every fraction of a degree of avoided warming matters for human and ecological well-being. Small reductions in temperature rise can significantly reduce the risk from extreme weather, biodiversity loss, food and water insecurity as well as risks posed from crossing major tipping points. The authors emphasise that delaying action will lock in higher costs and more severe impacts, while swift, coordinated measures can yield immediate benefits for communities and ecosystems worldwide.
Journal
BioScience
Method of Research
Literature review
Subject of Research
Not applicable
Article Title
The 2025 state of the climate report: a planet on the brink
Article Publication Date
29-Oct-2025
International scientists issue State of the Climate Report, highlight mitigation strategies
American Institute of Biological Sciences
image:
July 2025 Central Texas floods: Flooding of the Guadalupe River near Kerrville, Texas.
view moreCredit: USCG Heartland
A comprehensive new report published in the journal BioScience reveals that Earth's climate crisis is accelerating at an alarming rate, with 22 of 34 planetary vital signs now at record levels. The study, co-led by Dr. William J. Ripple of Oregon State University and Dr. Christopher Wolf of Terrestrial Ecosystems Research Associates, presents stark evidence that Earth is approaching climate chaos.
The vital signs tracked in the report represent key indicators of human activities and their associated climate responses, including energy consumption, greenhouse gas emissions and concentrations, global temperatures, ice sheet masses, ocean conditions, and extreme weather patterns. Together, these metrics provide a sweeping view of Earth's changing climate and its causes.
The report builds on a framework introduced by Ripple and colleagues in 2020, who “issued a declaration of a climate emergency that has garnered support from approximately 15,800 scientist signatories worldwide." The most recent data confirm that the planet experienced its hottest year on record in 2024, signaling what researchers call an "escalation of climate upheaval."
"So far, in 2025, atmospheric carbon dioxide is at a record level, likely worsened by a sudden drop in land carbon uptake partly due to El Niño and intense forest fires," the authors state. They caution that "a dangerous hothouse Earth trajectory may now be more likely due to accelerated warming, self-reinforcing feedbacks, and tipping points."
The report highlights cascading risks, including a potential collapse of the Atlantic Ocean meridional overturning circulation, which "could trigger abrupt and irreversible climate disruptions, including drastic shifts in regional weather patterns, intensified droughts and floods, and reduced agricultural productivity in key regions."
Despite the dire threats, the scientists emphasize that "Climate change mitigation strategies are available, cost effective, and urgently needed. From forest protection and renewables to plant-rich diets, we can still limit warming if we act boldly and quickly," they write. Additional strategies highlighted include reducing food loss and waste—which accounts for roughly 8-10% of global emissions—and restoring degraded ecosystems such as wetlands, peatlands, and mangroves. The report notes that "the cost of mitigating climate change is likely far lower than the global economic damages that climate-related impacts could cause."
The authors stress the power of collective action, noting that even in the face of looming climatic tipping points, "social tipping points can drive rapid change. Even small, sustained nonviolent movements can shift public norms and policy, highlighting a vital path forward amid political gridlock and ecological crisis." Unlocking the power of human action will require continued public engagement, say the authors. Importantly, they note that "despite majorities in nearly every country supporting strong climate action, most individuals believe they are in the minority."
Ripple, Wolf, and colleagues close their report by emphasizing that climate change is fundamentally an issue of justice. "We are disproportionately harming the vulnerable and marginalized—those least responsible for the crisis," the authors note. Yet they maintain that these harms can still be ameliorated through urgent action. "The future is still being written" through choices in policy, investment, and collective action.
The full report is available in BioScience.
Journal
BioScience
Article Title
The 2025 state of the climate report: a planet on the brink
Article Publication Date
29-Oct-2025
Climate report: Earth on dangerous path but rapid action can avert the worst outcomes
CORVALLIS, Ore. – 2024 was the hottest year on record and likely the hottest in at least 125,000 years, according to an annual report issued by an international coalition led by Oregon State University scientists.
“Without effective strategies, we will rapidly encounter escalating risks that threaten to overwhelm systems of peace, governance, and public and ecosystem health,” said co-lead author William Ripple. “In short, we’ll be on the fast track to climate-driven chaos, a dangerous trajectory for humanity.”
Despite the sixth annual report’s ominous findings – 22 of the planet’s 34 vital signs are at record levels – Ripple stresses that “it’s not too late to limit the damage even if we miss the temperature mitigation goal set by the 2015 Paris Agreement,” an international treaty that set targets for reducing greenhouse gas emissions.
But with many vital signs, including greenhouse gas concentrations in the atmosphere, ocean acidity and ice mass, continuing to trend sharply in the wrong direction, the authors note that time is definitely of the essence.
“What’s urgently needed are effective climate mitigation and adaptation strategies, including ones that embed climate resilience into national defense and foreign policy frameworks,” said Ripple, distinguished professor in the OSU College of Forestry. “We also need grassroots movements advocating for a socially just phaseout of fossil fuels and limits on the fossil fuels industry’s financial and political influence.”
Published today in BioScience, “The 2025 state of the climate report: A planet on the brink” cites global data from the Intergovernmental Panel on Climate Change, a United Nations organization for assessing the science related to climate change, in proposing “high-impact” strategies, including:
Energy: Renewable energy sources such as solar and wind have the potential to supply up to 70% of global electricity by 2050, the report notes. A rapid phaseout of fossil fuels would yield one of the largest contributions to climate mitigation.
Ecosystems: Protecting and restoring ecosystems such as forests, wetlands, mangroves, and peatlands could remove or avoid around 10 gigatonnes of carbon dioxide emissions per year by 2050, which is equivalent to roughly 25% of current annual emissions, while also supporting biodiversity and water security.
Food systems: Reducing food loss and waste, which currently accounts for roughly 8-10% of global greenhouse gas emissions, and shifting toward more plant-rich diets can substantially lower emissions. These strategies also promote human health and food security, according to the report.
“The human enterprise is in a state of ecological overshoot where the Earth’s resources are being consumed faster than they can be replenished,” said co-lead author Christopher Wolf, a former OSU postdoctoral researcher who is now a scientist with Corvallis-based Terrestrial Ecosystems Research Associates, known as TERA. “Population, livestock, meat consumption and gross domestic product are all at record highs, with an additional 1.3 million humans and half a million ruminant livestock animals added every week.”
To address ecological overshoot, the report calls for equitable and transformative changes across many areas of society, including reducing overconsumption by the wealthy. Among the report’s other key elements:
- In 2024, fossil fuel energy consumption hit a record high. Combined solar and wind consumption also set a new record but was 31 times lower than fossil fuel energy consumption.
- Warming is accelerating, likely driven by reduced aerosol cooling, strong cloud feedbacks and declines in albedo, the reflection of sunlight back into space.
- Ocean heat content and wildfire-related tree cover loss are at all-time highs. By August 2025, the European Union’s wildfire season was already the most extensive on record, with more than 1 million hectares burned.
- Deadly and costly weather disasters surged in 2024 and 2025, with Texas flooding killing at least 135 people; Los Angeles wildfires causing damages in excess of $250 billion; and Typhoon Yagi killing more than 800 people in Southeast Asia.
- The Atlantic Meridional Ocean Overturning Circulation is weakening, threatening major climate disruptions.
- Social tipping points can drive rapid change. Sustained, nonviolent movements can shift public norms and policy in a positive direction.
The report warns that every fraction of a degree of avoided warming matters for human and ecological well-being. Small reductions in temperature rise can significantly reduce the risk of extreme weather, biodiversity loss, and food and water insecurity. The authors emphasize that delaying action will lock in higher costs and more severe impacts, while swift, coordinated measures can yield immediate benefits for communities and ecosystems worldwide.
“Climate mitigation strategies are available, cost effective and urgently needed, and we can still limit warming if we act boldly and quickly, but the window is closing,” Ripple said. “The cost of mitigating climate change is likely much, much smaller than the global economic damages that climate-related impacts could cause.”
In addition to Ripple and Wolf, the report’s other authors are Jillian Gregg of TERA; Michael Mann of the University of Pennsylvania; Johan Rockström and Nico Wunderling of the Potsdam Institute for Climate Impact Research; Chi Xu of Nanjing University; Sarah Perkins-Kirkpatrick of the Australian National University; Roberto Schaeffer of the Federal University of Rio de Janeiro; Wendy Broadgate of Future Earth Secretariat; Thomas Newsome of the University of Sydney; Emily Shuckburgh of the University of Cambridge; and Peter Gleick of the Pacific Institute.
Journal
BioScience
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
The 2025 state of the climate report: a planeton the brink
Article Publication Date
29-Oct-2025
