Twenty-five years ago, the Union of Concerned Scientists and more than 1,700 independent scientists, including the majority of living Nobel laureates in the sciences, signed the 1992 “World Scientists’ warning to humanity”. These concerned professionals called on humankind to curtail environmental destruction. In their manifesto, they showed that humans were on a collision course with the natural world. They proclaimed that fundamental changes were urgently needed to avoid the consequences our present course would bring.

On the 25th anniversary of their call, this paper, the “second notice”, looks back at the warning of 1992 and evaluates the human response by exploring available time-series data. It is underlined that, since 1992, with the exception of stabilizing the stratospheric ozone layer, humanity has failed to make sufficient progress in generally solving these foreseen environmental challenges, and alarmingly, most of them are getting far worse. Especially troubling is noted to be the current trajectory of potentially catastrophic climate change due to rising greenhouse gases from burning fossil fuels. So, humanity is now being given a second notice, as illustrated by these alarming trends.

The authors highlight that as most political leaders respond to pressure, scientists, media influencers, and lay citizens must insist that their governments take immediate action as a moral imperative to current and future generations of human and other life.

In the Epilogue, it is stated that the article has more than 15,000 signatories from all ends of the Earth. The leading authors state that this is the most scientists to ever co-sign and formally support a published journal article.

It is concluded that working together while respecting the diversity of people and opinions and the need for social justice around the world, we can make great progress for the sake of humanity and the planet on which we depend.

Spanish, Portuguese, and French versions of this article, as well as the full list of co-signatories can be found in the supplemental files in:

Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF and 15,364 scientist signatories from 184 countries (2017) World Scientists’ Warning to Humanity: A Second Notice. BioScience 67:1026-1028