World leaders from more than 190 countries have convened in Paris during the first two weeks of December for the long-awaited United Nations Climate Change Conference. Will the governments of the world finally pass a binding global treaty aimed at reducing the most dangerous impacts of global warming… or will they fail in this task?

Letters to the Future, a national project involving more than 40 alternative weeklies across the United States, set out to find activists, authors, artists, scientists and others willing to get creative and draft letters to future generations predicting the success or failure of the Paris talks—and what came after. Some participants were optimistic about what is to come; some not so much. We hereby present some of their visions of the future.

These words will bring you no solace and they bring no joy to me, but I feel that by way of confession I must say them nonetheless. I am sorry. Very, very sorry. As I think of the misery we have visited upon you and the coming generations, I mourn that you will never see a coral reef; never walk among majestic trees; never fish from a river that runs as cold as ice or lie among wildflowers as far as the eye can see.

To say that we have failed you is the biggest understatement of all time. It is not as if we did not see this coming. We did. Some of us rang the clarion bell, but too few of us joined in and even fewer paid any heed. For decades, we knew that the planet was warming and that the oceans were turning to acid. Yet we carried on as if all was well, smug in the knowledge that the Earth has seen such cycles before, and things basically turned out OK. Why should we risk our comfortable lives when scientists refused to speak in certainties?

Yet we forgot about time—that what in the past had taken millennia, we were undoing in decades. When scientists described the pending calamity as “probable” or ‘likely” or “almost certain,” that left some room for doubt, did it not? If they were not 100 percent certain that such things would come to pass and that it was within our ability to control them, why should we concern ourselves with those things that might happen long after we have gone? Now it is you who must suffer the consequences of our indolence.

In 2015, we had one final opportunity to get it right, but our collective misunderstanding of the scientists kept us from doing so. The inherent distrust that existed between nations kept us from doing so. Our selfishness and lack of regard for you, our own flesh and blood, kept us from doing so. So we did next to nothing. Too little, too late.

Do not blame our parents, or our grandparents or those who came before them. True, it was mostly they who set this wheel in motion, but they knew little of the consequences of their actions. We, however, have no excuse. We knew. We saw. We did nothing. I am so very, very sorry.

Farmer is a professor of cellular biology at the University of Georgia. Read more letters to the future here.