Contrails in the blue sky remind us of daily air traffic – and its impact on the climate. However, the effect of contrails on the climate is still only partially understood. It is assumed that they have a predominantly warming effect. Researchers from Forschungszentrum Jülich and universities in Mainz, Cologne, and Wuppertal have now discovered: 80 per cent of all long-lived contrails do not form in cloudless skies, but within existing natural ice clouds, known as cirrus clouds. The climate impact of these embedded contrails has hardly been investigated to date. However, the study published in the journal Nature Communications provides new insights and could influence the planning of climate-optimized flight routes in the future.

A new monitoring method created by UC Irvine scientists provides a cost-effective method for cities to measure their greenhouse gas emissions. It involves sampling turfgrass, which is shown to be a reliable recorder of fossil carbon dioxide concentrations. Cities without expensive gas monitoring equipment may find the tool useful.

In many parts of the world, staple crops such as maize and wheat are dependent on rainfall recycled from land rather than oceans, making them more vulnerable to drought. Researchers at Stanford and the University of California San Diego identified a critical threshold in atmospheric moisture sources that could help predict and prevent future crop failures.