Many people today think that what we humans are doing is not the cause of the global warming which Earth is experiencing. Can humans really be responsible for the extreme weather that is flooding our lands, destroying our homes and fields? Could Homo sapiens really be responsible for the melting arctic ice and the rising ocean levels? Could humans really change the pattern of the winds that have controlled the movements of warm and cold air around the globe?
In other words, could humans really change the environment so much that we actually permanently change the living conditions of the entire globe?
The evidence, though complex, strongly suggests that we can, and that we are.
If you think that human beings are too small, too ineffectual to accomplish anything this gigantic, think about the bacteria. About four billion years ago, bacteria developed the process of photosynthesis and began to excrete oxygen as their waste product. Atom by atom, they added oxygen to the environment. A billion and a half years later, oxygen was so plentiful that plants and animals totally dependent on this oxygen began to evolve. Eventually there was so much oxygen that plants and animals came out of the seas to start life on dry land.
If the relentless activity of single-celled bacteria can change the environment this radically, it’s not inconceivable that we humans can do it just as dramatically.
The evidence is that we are doing it.
The question is whether we will also be able to live with the new environment we are creating.