<p>In January, two new colleagues have joined the SIWA cluster, Dr. Rüdiger Grote and Dr. Harald Stelzer. Dr. Grote, from the Karlsruhe Institute of Technology, has joined the group of Dr. Tim Butler to work on modeling biogenic emissions from plants and considering feedbacks between vegetation and air pollution. This will support the research on urban transformation processes and their impacts on short-lived climate-forcing pollutants (SLCPs) with regional and global implications to air chemistry and climate. Dr.</p>