New research found that the century-old yardstick used across many industries to estimate air-conditioning and refrigeration energy demand — called cooling degree days — is missing something fundamental. The study reports a new, physics-based version of the metric — effective cooling degree days — that captures how temperature and humidity together impact the actual work a cooling system is required to do. Applying it across North America, they found that cooling efficiency has been quietly declining by 2–4% per decade since 1971, and that the old temperature-only metric misjudges how much cooling is required in different regions, overstating demand in some places and understating it in others.

As nations worldwide confront the urgent challenge of climate change, China's "Dual Carbon" goals prioritize significant decarbonization across all economic sectors. While industrial and energy sectors often receive primary attention, the agricultural sector, particularly livestock farming, represents a substantial source of potent greenhouse gases like methane (CH₄) and nitrous oxide (N₂O). Local governments in China have implemented stringent environmental regulations, such as "Livestock-Free Zones," to curb agricultural pollution. However, the overall effectiveness of these spatially targeted policies, especially regarding their potential to displace environmental burdens, remains a subject of considerable debate.

A recent study investigated the impacts of the "Livestock-Free Zone" policy in Guangdong Province, China's largest provincial economy. Researchers utilized county-level panel data from 2014 to 2023, employing a sophisticated combination of spatial Durbin models, continuous difference-in-differences models, and network analysis. This approach allowed for a precise quantification of the policy's local effects and any subsequent spatial spillover, addressing gaps in understanding policy-induced pollution transfers within land-intensive agricultural sectors and at subnational scales.

Methane (CH₄), a potent greenhouse gas, contributes significantly to climate forcing. While urban green infrastructure, such as green roofs, offers many environmental benefits, their capacity to mitigate CH₄ emissions has remained largely unexplored. New findings demonstrate that incorporating biochar, a carbon-rich material, into engineered green roof substrates substantially boosts their ability to absorb atmospheric methane. This discovery offers a promising avenue for strengthening climate resilience in urban environments.

Green Roofs: Beyond Aesthetics to Climate Action

Green roofs are gaining recognition for moderating building energy use, managing stormwater, and supporting urban biodiversity. They also act as important carbon sinks by storing carbon in vegetation and substrates. However, the exchange of non-CO₂ greenhouse gases, particularly CH₄, from these systems has received limited attention. Traditional green roof substrates, often rich in organic matter, can even promote localized CH₄ production. Quantifying and enhancing CH₄ exchange in these engineered systems is essential for maximizing their climate benefits.

A recent study uncovers the most comprehensive explanation to date for the unprecedented Arctic ozone event of March 2024, revealing new insights into the complex connections between tropical variability, atmospheric wave dynamics and polar ozone in a warming world.