I think it can be fairly said that we are a people who believe in a better future. That the ideals of America are founded on building prosperity and expanding prospects — not only for ourselves, but for our fellows and for those generations that are to follow.

Americans have often been described as a ‘can-do’ kind of people. A people who will undertake any challenge to advance or protect our nation and to graciously extend her kind virtues to the huddled masses of a troubled world. Be it the freeing of slaves, the emancipation of women, the facing down of tyrannical dictators, the liberation of scientific inquiry, or the exploration of our Earth and the vast realm of space we have doggedly decided to march forward and on.

But today we are confronted by a new trouble. A trouble that was, in many ways, an unintended consequence of past progress. For as we industrialized, as a nation and as a global society, we also burned ancient carbon deposits long buried beneath the Earth. And so we expelled a great cloud of the most dangerous of gasses into the Earth’s atmosphere.

We didn’t know it so well at the time. But the carbon dioxide spewing from William Blake’s dark Satanic Mills was the same gas that in excess produced the worst and most horrific global die-offs in the great and deep, deep history of our Earth. Times of great mass extinction due to rising global heat that bear the infamous names — Permian, Triassic, Paleocene, Devonian and Ordovician. Blake, living today, would be terrified how right he was to call those mills Satanic. To learn what our scientists now have told us. But even then, he surely had an inkling. For the Bible itself warns — those who destroy the Earth shall be destroyed. And in 1808 the wanton destruction of the Earth and its airs by the pollution caused by fossil fuel burning was visibly evident if not so scientifically proven and explored as it is today.

Today, if we continue to burn fossil fuels as we have for the past 200 years or so, the world will again surely experience another such extinction. We already see the outliers of this crisis now — in the growing number of people bereft of land and home and livelihood as seas rose, or crops were destroyed by worsening storms and droughts, or lands and animals were lost to wildfires, or as reefs and fisheries were killed off by the warming, acidifying waters of our oceans. But what will come over the years and decades and centuries if we do not turn back from this horrid burning of fossil fuels and the dumping of their carbon into the atmosphere will be far, far worse.

What kind of world is this to make for our fellow human beings? What kind of future to leave for the generations that follow? Surely not the better one that we all work and hope for. Surely not one that honors the can-do, make the world a better place spirit of America.

But despite our worsening prospects and the dark and heavy clouds that now hang over the global climate, we have a window of opportunity in which to act. Our tools to confront climate change in the form of renewable energy systems like wind and solar and electrified transportation are growing more capable. And further innovation and change in our actions as people and nations can yet enable us to draw down the awful pall of heat trapping gasses that now hangs above us. These are things we can and must do if we are a moral people with any kind of vision, foresight and compassion.

This is our moment. The moment when we decide to make the choice to act and to save so many of the very precious things we all hold dear or to turn away from action and condemn each and every person and being now living or that will live to an age of terror and darkness the likes of which Earth has not seen in all of half a billion years.

So I’m asking you for your help. I’m asking you to make the choice to act. To join the People in their march for climate justice tomorrow. To support all the voices that are now speaking out. To lift your own voice to our growing chorus.

For the love of life and of all good things — we simply must act now.