Concern for Earth
It would go a long way to caution and direct people in their use of the world that they would be better studied and known in the creation of it. For how could man find the confidence to abuse it, while they should see the Great Creator stare them in the face, in all and every part thereof? — William Penn, 1693
If an apple is dropped in the woods and forgotten, bugs and worms and small creatures will discover its sweetness. Some will feast, and use its sugar to better their lives. Some will start new families, even to hundreds and thousands. A few days later the apple and the families will be gone. It is up to the humans of our time, whether earth is treated as such a transient gift, or treated with greater care and kept. It falls to us to be among the first human generations to have this responsibility on a global scale.
In these times we see frequent reminders of changes in our planet that are due to our astonishing success as a species, risen from jungles and caves to live throughout the world and even to scatter space with works in steel. Life exists by changing the world, and in a balanced ecosystem each creature's changes support the whole, each creature's wastes support the ferment that maintains earth's richness. Our inventions as humans transcend that balance, giving us the power to break it, and thus the responsibility to maintain it. Many human inventions have upset earth's balance in various regions, raising threats to animals and peoples. One invention in particular puts all at risk, through its global impact on oceans, air and climate: fossil fuels. Following on humankind's defining tool fire, and our invention of the Steam Engine as a way to harness energy from burning carbon, we now live in a world where fossil fuel based energy is central to our culture. Even the inconvenient truth, learned a generation ago, that this fossil frenzy is risky in the long term, has not prevented a massive increase in its use.
Fossil fuels leave carbon (dioxide) in the air, which helps trap heat, warming the earth. Science rejects certainty, but the established principles of chemistry and physics squarely support that inference. And we need only check the thermometer, or Florida flooding records, or pictures then and now of vanishing glaciers and snowcaps, to confirm that earth is warming. Evidence points to anthropogenic (human-generated) causes for the current patterns of warming and climate changes around the world. The evidence can be summarized using this graph:
The blue line is a mere sketch, but it approximately follows human population, nearly flat and steady for eons, then suddenly and recently leaping up; doubling twice in the last 100 years. The blue line also parallels carbon burned worldwide, long small (when our only fuels were wood and animal oils), then suddenly spiking in the age of coal and petroleum. The blue line also closely matches measurements of carbon dioxide (CO2) levels in the atmosphere over the centuries (measurements from long ago are made using air trapped in glaciers, etc.). The correlation between those three trends (population, carbon burned, and carbon measured in air) builds support for the science involved. The blue line also parallels measurements of temperature, in both air and oceans, globally. The temperatures were fairly steady for most of human history, then recently going up, as carbon increased, and now rising sharply. All four of these "hockey stick" trends have a similar moment in history when they start to shoot up; this supports (but does not prove) the idea that they are related. Beyond that simplified minimalist account; science has a lot more to say. The 2018 United Nations Climate Report and the full 2018 IPCC report (Intergovernmental Panel on Climate Change) both underscore the worldwide scientific consensus on anthropogenic climate change. Here are some of the relevant graphs, with real data.