Is there anything marshes can’t do? The recent heatwaves have shown the cooling properties provided by urban wetlands. I live in a tidal marsh on the River Roding & on hot days the temperatures have been noticeably cooler, not just in the marsh itself but also in the built up areas around it. The dark, wet ground (especially in tidal marshes where the water gets replenished twice a day) create huge areas of evaporation which effectively act as giant air conditioners for the city, helping to counteract the urban heat island effect. This is in addition to all their other benefits; providing flood reduction, carbon sequestration, rich & diverse habitats for ecology, birds & wildlife & human enjoyment & beauty etc etc. As our cities heat up, we desperately need to restore & create as many wetlands, ponds & marshes as possible, weaving these hard-working habitats into our urban fabric is not just a nice thing to have, but a necessity for both nature and human beings.