As we start the new year, it is a time to reflect on the human footprint on our planet. All organisms on the planet are affected by their environment, and each organism in turn is affected by its environment. Humans are no different, but arguably we have had an outsized impact on the environment.

     In general, the natural environment affects the organism because it provides the living situation that the organism must try to survive in. The environment influences natural selection, based on who is fittest to survive in the particular environment. The organism affects the environment, because it is part of the ecosystem, and plays a role in it, such as prey, predator, photosynthesizer, etc.

     Humans have had a large effect on the environment. We have not been a species very long on this planet, compared to other species like sharks, liverworts and bacteria. However, in our short time on the planet, we have caused the current climate change of global warming that is having a severe impact on the planet.  

     Also, our population growth has impacted other species and the natural environment as we have crowded out much of nature with our developments and deforestation. We have also caused pollution, and introduced poisons such as pesticides. We have also introduced foreign species that have crowded out the native species in a particular area.

     In researching human population growth, it is clear that in the last few centuries, the human population has increased at a rapid rate. From Stone Age times through the Middle Ages, the human population stayed fairly constant, under one billion people. However, in modern times, the human population has increased sharply, to over 6 billion people.

     The United Nations estimates that the human population will soon reach 10 billion people. Around 90 million people are added each year, and our advancements with the Industrial Revolution and modern agriculture medicine have helped cause this explosion.

     According to the 2015 Revision of World Population Prospects, which is issued by the United Nations, the world population will reach 8.5 billion by 2030 and 9.7 billion by 2050, due mostly to growth in developing nations. By 2100, the population will be over 11 billion.

     Also, according to United Nation?s Key Findings, the growth rate has declined slightly in the last ten years to 1.18 percent annually, down from 1.24 percent annually.  Asia has the largest population, around 4 billion, but by 2100 it is projected to still be under 5 billion. The most striking data is about Africa. Africa has a population of around 1 billion, but is projected to reach 4 billion by 2100. Europe, Latin America and North America will all remain under 1 billion over this time period.

     I have trouble seeing what positive impact we have had on the health of the planet. Clearly the human spirit has brought great creativity, innovation and other advancements to the world, which we can celebrate. Hence, as we start the new year, it is worth reflecting on what we can do to try to use these talents of the human spirit to help our planet thrive and survive.

     I recommend the National Geographic "Human Footprint" DVD as an excellent documentary on this subject.

Sources:

https://www.amazon.com/Human-Footprint-Elizabeth-Vargas/dp/B00147F8WS

http://www.un.org/en/development/desa/population/

https://esa.un.org/unpd/wpp/Publications/Files/Key_Findings_WPP_2015.pdf