How have humans affected the four spheres?

Human activities are impacting our environment and, in particular, the composition of the atmosphere, water, and plants. However, it is sometimes difficult to distinguish the "natural" signature from the one induced by industrial and urban activities. The latest analytical developments allow the fine and precise measurement of isotopic signatures of elements whose content or isotopic composition may be changed by modern industrial activities, such as the transition metals (Ni, Hg, Se, and Zn), lithium, and helium. This approach opens up original and new avenues of inquiry, including the determination of the sources of aerosols, of the elements carried by rivers, the effects of bioaccumulation, the phytoavailability of metals, and allows the refinement of the determination of anthropogenic fluxes.

preservation because he preserves part of the land and preserves means save

explanation:

i thinking chemical change