In a Policy Forum, Andrew Baker and colleagues discuss the recent regulatory action in Florida that has enabled the world’s first international coral exchange. The exchange was done to bolster genetic diversity in declining elkhorn coral populations, enhancing their resilience to climate change and other environmental pressures. Expanding such efforts to other coral species and regions will require international collaboration and a reevaluation of current conservation laws, note the authors. Coral reefs are among the most climate-sensitive marine ecosystems, with prolonged heat stress causing increasingly frequent and devastating bleaching events. For example, the historic marine heatwave of 2023 delivered a particularly severe blow to staghorn and elkhorn coral populations across Florida and the Caribbean. To help preserve species and maintain ecosystem function, researchers are turning to assisted gene flow (AGF), a conservation strategy that introduces genetic material from healthier, nonlocal populations to restore genetic diversity and boost resilience.

Florida regulators recently approved the outplanting of elkhorn coral offspring bred from parents originating in both Florida and Honduras, which will be the first time internationally sourced coral offspring have been permitted for restoration on wild reefs anywhere in the world. According to Baker et al., while this landmark decision marks an important step in AGF efforts, further regulatory action is crucially needed to proactively expand efforts to other critically threatened sites and species. In order to achieve this, amendments to international conservation law, particularly the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), are required. Despite these hurdles, the authors argue that establishing shared regional coral nurseries and equitable genetic resource-sharing agreements, Caribbean nations can work together to safeguard and restore coral reef ecosystems. “Historically, the precautionary principle ‘take no action unless there is high certainty no harm will result’ was the basis for endangered species law and was appropriate in an age of relative environmental stability,” write the authors. “Windows of opportunity for effective large-scale implementation of AGF are closing rapidly; waiting until genetic rescue is ‘needed’ to save coral species on the brink of extinction may well be too late.”

As the climate becomes warmer on average, it makes intuitive sense that we will see more hot days and we've had predictions of this for some time. However, the duration of heatwaves — how many days in a row exceed a temperature that is unusually hot for a given region — can be very important for impacts on humans, livestock and ecosystems. Predicting how these durations will change under a long-term warming trend is more challenging because day-to-day temperatures are correlated — tomorrow's temperatures have a dependence on today's temperature. This study takes this effect into account, along with the warming seen in current and historical observations and projected for the future by climate models for a wide range of land regions. Not only do the heatwave durations increase, but each additional increment of warming causes a larger increase in the typical length of long heat waves. In other words, if the next decade brings as much large-scale warming as a previous decade, the additional increase in heatwave durations would be even larger than we've experienced so far.

A new study shows how extreme weather and power outages can impact socially vulnerable populations in counties near the U.S. Gulf Coast. The researchers also estimated the 10 counties most and least likely to have long-term power outages in the five states that border the Gulf.

Lightning has a greater impact on forests than previously thought. Researchers at the Technical University of Munich (TUM) have developed new model calculations that, for the first time, estimate the global influence of lightning on forest ecosystems. According to their findings, an estimated 320 million trees die each year due to lightning strikes. Tree losses caused by direct lightning-ignited wildfires are not included in these figures. In the future, lightning-induced tree mortality could rise due to an increase in flash frequency.