by Daniel Brouse
July 27, 2025
Air quality levels reached Code Red across parts of Philadelphia and the Jersey Shore last evening and today, prompting urgent health warnings for residents. The alert, triggered by unhealthy concentrations of fine particulate matter (PM2.5), was in effect from the southern tip of Long Beach Island to Sea Isle City, extending inland as far as Egg Harbor.
A Code Red Air Quality Alert means the air is considered “unhealthy for all individuals,” not just those with pre-existing conditions. Public health officials strongly advised everyone—especially children, the elderly, and those with asthma, heart, or lung conditions—to limit time outdoors, avoid strenuous activity, and stay inside with filtered air whenever possible.
“These pollutant particulates can penetrate deep into the lungs,” warned local air quality experts. “Even short-term exposure can cause inflammation, trigger asthma attacks, or worsen cardiovascular symptoms.”
Wildfire Smoke From Canada the Primary Cause
The spike in pollution was caused by smoke drifting south from ongoing wildfires in Canada. This marks another chapter in a growing trend of long-distance smoke events, as climate-fueled wildfires in the northern latitudes increasingly affect air quality thousands of miles away.
Temporary Relief from Incoming Rain
Conditions improved after midnight in a few areas, thanks to an incoming band of rain, which helped wash particulates out of the atmosphere. However, the reprieve was short-lived. Code Red conditions continued Sunday. With the Canadian wildfires still actively burning, experts warn that similar air quality alerts may return in the coming days depending on wind patterns and fire behavior.
A Growing Public Health Concern
Episodes like this are becoming more frequent and severe, highlighting how climate change and transboundary pollution are converging to impact public health. As wildfire seasons lengthen and intensify globally, the U.S. Northeast and Mid-Atlantic regions may continue to see deteriorating air quality even without local fires.
Public health officials encourage residents to check the AirNow.gov or local environmental agency websites for real-time air quality updates, and to consider investing in HEPA air purifiers or using MERV-13 filters in home HVAC systems to reduce indoor exposure.
Wildfires and Climate Change
Wildfires are becoming more intense, more frequent, and more destructive in climate-sensitive regions such as Canada, the U.S. West, Southern Europe, and Australia.
In fact, unprecedented events are now unfolding. In Canada, vast swaths of boreal forest and peatland are burning year-round. Once considered permanently frozen, Canadian peat permafrost has begun to smolder even beneath the snow, releasing immense quantities of carbon dioxide and methane. These fires, known as “zombie fires,” persist underground through the winter and reignite during spring and summer. This phenomenon marks a terrifying shift in the fire-climate feedback loop.
Wildfire behavior is now directly tied to a compounding set of climate-driven feedbacks. One such loop is: Drought → Fire → Dieback. During extended drought and extreme heat, trees close their stomata to conserve water, which reduces their CO₂ uptake and weakens their resilience. At the same time, warmer, drier conditions make forests more flammable. This leads to more frequent and intense fires, which kill trees and release the carbon they had stored. The Amazon rainforest, once the planet’s largest carbon sink, is now emitting more carbon than it absorbs.
Another underappreciated factor is ozone pollution, which results from fossil fuel combustion. Ground-level ozone damages plant tissues and further inhibits their ability to absorb CO₂, compounding forest dieback and undermining global carbon sinks.
Additionally, wildfires generate “brown carbon”—a class of light-absorbing organic particles. These airborne particulates can travel thousands of miles and settle on snow and ice in Greenland, Antarctica, and mountain glaciers. By darkening the surface, brown carbon reduces the reflectivity (albedo) of ice, accelerating melting. This leads to greater freshwater runoff, destabilizing ocean circulation patterns such as the Atlantic Meridional Overturning Circulation (AMOC), and further warming the poles.
This creates a cascading carbon feedback loop: drought and heat increase wildfires; wildfires kill forests and release stored carbon; ozone and pollution further weaken vegetation; and brown carbon accelerates ice melt. All of these processes contribute more greenhouse gases to the atmosphere, amplifying climate change and locking in even more fire, drought, and environmental collapse.
Drought → Fire → Dieback → Carbon Feedback
Drought stresses trees, increasing flammability and reducing CO2 uptake. Fires release stored carbon, turning the Amazon from a carbon sink into a carbon source. Brown carbon from wildfires darkens snow and ice globally, accelerating melt and AMOC slowdown, feeding back into the system.
Ignite a Domino Effect: Albedo, Brown Carbon, Permafrost Brouse and Mukherjee (2025)
Canadian Wildfires: Over the Tipping Point Brouse (2024)
Wildfires, Climate Change and Extreme Weather Events Brouse and Mukherjee (2024)