Mathematical functions are useful in helping to ascertain the proper steps people need to take in order to address issues regarding rising global temperatures, climate change, ocean acidification, coastline erosion, and the like. The health of the natural environment and mathematics are intertwined on many levels, but the three most relevant are in terms of the basic foundations of global learning: global awareness, global perspective, and global engagement. Each of these sustainability-based principles is correlated with mathematics.
From a global perspective, exponential growth can be useful because it can offer insight into current usage rates of natural resources, as well as projected levels of said resources in the near, and potentially even far-off future. This is important because it can offer insight into levels of resources future generations will be able to draw from. We need mathematical models like those based on exponential growth and decay in order to accurately predict levels of resources for the next generation. For instance, predicting per capita levels of plastic produced per year allows one to measure the environmental impact the present population will have on the next.
As stated above, mathematics holds great value in a multitude of ways, particularly with regard to sustainability. Neither mathematics nor the environment can be taken into consideration without mention of the other.