I was interested to read this Physics Today article about how plants that are being affected by drought can actually change the composition of the atmosphere around them. When they are feeling the effects of drought, the plants close their stomata to decrease water loss. This reduces the amount of carbon dioxide that is used. It was even more interesting to read that the plants react differently to different carbon isotopes and can change the ratios of these different isotopes depending on the water stress. This is something that can now be incorporated into climate models, increasing their accuracy. You can read more at https://phys.org/news/2018-08-reaction-drought-composition-atmosphere.html.