Solutions for a Livable Earth

Refreezing the Future  

As summer temperatures continue to rise every year, glaciers in Greenland and Antarctica are faster to melt and form puddles of water that accelerate ice loss. These pools, without sufficient time to refreeze overnight, contribute to rising sea levels and diminish ice’s crucial role in reflecting sunlight back into the atmosphere. 

Jaafar El-Awady, PhD, a professor in Mechanical Engineering at Johns Hopkins, along with colleagues across the University, are pioneering an innovative solution: ice nucleation proteins. These microscopic catalysts occur naturally in certain organisms and can accelerate the freezing process of water. When placed in melt pools, they can speed up the freezing process overnight “such that we can reduce the melting during the day,” El-Awady says. His team also plans to weigh the feasibility of cloud seeding—“basically dispersing these ice nucleation proteins into clouds over glaciers to induce snowfall”—as a scalable means of application. 

Preserving ice coverage would reinforce Earth’s natural cooling mechanism and create a positive feedback loop: More ice means more reflected sunlight, further cooling the planet and slowing melt. “If we’re able to increase ice mass,” he says, “then you’re going to actually start reversing the process of global warming.”  

The project, still in early stages, faces challenges. “Very detailed studies are still required to ensure these agents are not affecting the environment in a negative way,” El-Awady says. But with machine learning aiding the research, El-Awady is optimistic. “AI and machine learning will help almost every aspect of this problem,” he says, citing applications in designing more efficient proteins, predicting weather patterns, and modeling ice sheet mechanical behavior. 

In a warming world, El-Awady and his colleagues’ research offers some hope for a cooler future—not just a patch on the problem, but a way to potentially turn back the clock on ice loss.

Forecasting the Climate Exodus  

In the arid landscapes of southern Iraq, rising temperatures are pushing people northward in search of water and arable land. Meanwhile, in Mali, shifting rainfall patterns are altering traditional herding routes. These movements, seemingly disparate, are part of a global phenomenon that Paul Spiegel and colleagues at the Center for Humanitarian Health are working to anticipate and mitigate. 

Spiegel, director of the CHH and distinguished professor of the practice in International Health, has long studied conflict-driven displacement. Now, he’s turning his attention to a force that’s reshaping migration patterns worldwide: climate change.  

“Climate change will cause movement, but will also cause conflict that will then cause increases in death and movement,” explains Spiegel, MD, MPH ’96. To unravel these dynamics, Spiegel and his team hope to develop models that analyze decades of climate data, migration patterns, and health outcomes. 

This approach, which Spiegel refers to as “anticipatory action,” combines big data analysis with on-the-ground interviews of recent migrants to develop models that can predict future population movements, identify migration drivers, and help governments and aid organizations prepare for future population flows. 

In Iraq, this could mean designing climate-proof health systems that can accommodate significant population increases. In Mali, it might involve preparing health systems to tackle new disease vectors as both climate and human populations change. 

Spiegel acknowledges the challenges, particularly in conflict-affected areas where data may be piecemeal, but emphasizes the potential benefits, from updating infrastructure to implementing new protective measures in climate-stressed areas. “We don’t know if we will be successful,” he admits, “but it has to be attempted.” 

From ER to Earth 

During the chaotic early days of the COVID-19 pandemic, Johns Hopkins emergency medicine physician Chris Lemon found himself on the front lines. Exhausted after long shifts, Lemon, MD, would find himself scrolling through his phone, seeking distraction. As he pushed pandemic news aside, he encountered a cascade of troubling stories about floods, fires, and climate change. 

“During COVID, we felt incredibly vulnerable,” Lemon reflects. “It made me see how changes to our planet could similarly affect our health and safety.” This realization encouraged him to undertake a career transition—from full-time ER physician to champion for planetary health at the Johns Hopkins Institute for Planetary Health. 

Lemon now balances his ER duties with coursework, teaching health care providers to think about global environmental challenges by developing new curriculum and educational programs. He envisions a future where a patient’s environment is as crucial to diagnosis as their family history. 

“It’s about incorporating environmental factors into our standard health questions,” he explains. “Beyond asking, ‘Do you feel safe at home?’ we might ask, ‘Do you live near the Great Salt Lake?’ which is now exposing people to heavy metals as it recedes and creates dust.” Soon, asking if a patient lives near a pollution source could be as routine as inquiring about their smoking habits. 

Lemon believes health care providers have a central role in communicating these issues, and to train them, he and his colleagues are developing a clinical fellows program at Hopkins. This program aims to create a “super track” for clinicians to immerse themselves in planetary health concepts, allowing them to become pioneers in this field regardless of their specific medical specialty. 

“The med student who starts this semester is not going to be a boarded physician in the U.S. for at least seven years,” he says. “How do we retool our health care workforce to operate in this space? The problems are here now. We can’t wait any longer.” 

Appetite for Change 

At a Baltimore school cafeteria, students discard uneaten food. Across town, a grocer removes slightly blemished produce from shelves. These scenes, played out countless times across America, illustrate a pervasive food waste issue that Roni Neff and her team are tackling head-on. 

Neff, PhD, ’06, ScM, associate professor in Environmental Health and Engineering, and her colleague Kaitlyn Harper, PhD ’22, MS, assistant scientist in EHE, are studying solutions at multiple levels. In partnership with the World Wildlife Fund, they’re testing interventions in school cafeterias. “We’re measuring how much food students are throwing away and testing ‘share tables,’ where kids can leave unopened items for others to take,” Harper explains. 

Neff and Harper, along with Nicole Labruto, PhD, MA, assistant research professor in Anthropology at the Krieger School of Arts & Sciences, are also collaborating with workers at Albertsons grocery stores to reduce food waste and increase donations. They’ve created eye-catching posters with clear guidelines on what can be donated and even proposed in-store events where local food banks can connect with employees and customers.  

“These projects, and others we work on, are rooted in the idea that every food item in a landfill is the end result of a long list of missteps,” Neff says. “Rather than focusing on wasting food as an individual and blameworthy action, we want to find the system levers we can pull.” 

But the impact goes far beyond lost meals. Food waste is a significant contributor to climate change, accounting for about 8% of global greenhouse gas emissions. When food decomposes in landfills, it releases methane, a potent greenhouse gas, Neff points out. And that’s just the end of the story. “Consider all the resources—water, energy, labor—that went into producing that food in the first place,” she says. 

“Food waste is a systemic issue,” Neff says. “When we waste food, we’re not just missing an opportunity to feed others—we’re actively harming our planet.” 

The New Urbanism 

Cities are at a crossroads. As office buildings sit half-empty and malls struggle to attract visitors, urban planners face a crucial question: How can we reimagine these spaces to benefit both the economy and the environment? 

Seydina Fall, MBA, program director for real estate infrastructure at Johns Hopkins Carey Business School, believes the answer lies in sustainable urban development. “We’re clearly facing transition risk,” Fall explains, referring to the challenge of adapting urban spaces to meet new environmental regulations and changing societal needs. 

Fall’s solution centers on high-density, mixed-use zoning—a model where homes, offices, and amenities coexist within walkable distances. While not a new concept, Fall advocates for scaling up this approach using cutting-edge technology. “Can AI analyze population trends, income patterns, and consumer behavior to determine the best use for a piece of land?” 

Crucially, Fall sees technology as a means to enhance urban resilience—a city’s ability to withstand and recover from environmental challenges. By leveraging AI and other digital real estate innovations, cities can make more informed decisions about sustainable materials, energy-efficient designs, and adaptive reuse of existing structures. “Planetary health is very pro mixed-use,” he notes. 

Integral to this vision, however, are stakeholders with sometimes competing incentives: property owners hoping for an office space comeback, developers seeking profit, and environmentalists pushing for sustainability.  

“If you’re a long-term investor, it’s a no-brainer,” Fall argues, pointing out that buildings with sustainable features often have higher tenant retention and lower operational costs. “You need a 10–15-year investment period to really see accretion to your bottom line,” he adds.  

By demonstrating these long-term economic benefits, he aims to unite stakeholders behind creating sustainable, economically viable urban spaces. In Fall’s vision, economic growth and planetary health are complementary goals—all starting at the city level.