Dire warning

Aquarter of a century ago, more than 1,700 scientists wrote a joint letter about the dangers facing this planet. Sunday, 15,000 revisited the topic in a new letter. This is an edited version.

“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, penned the 1992 ‘World Scientists’ Warning to Humanity.’ These concerned professionals called on humankind to curtail environmental destruction and cautioned that ‘a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.’ …

“The authors of the 1992 declaration feared that humanity was pushing Earth’s ecosystems beyond their capacities to support the web of life. … The scientists pleaded that we stabilize the human population, describing how our large numbers — swelled by another 2 billion people since 1992, a 35 per cent increase — exert stresses on Earth that can overwhelm other efforts to realize a sustainable future. They implored that we cut greenhouse gas emissions and phase out fossil fuels, reduce deforestation and reverse the trend of collapsing biodiversity.

“On the 25th anniversary of their call, we look back at their warning and evaluate the human response… 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. … Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century. …

“As most political leaders respond to pressure, scientists, media influencers and lay citizens must insist that their governments take immediate action. … With a groundswell of organized grassroots efforts, dogged opposition can be overcome and political leaders compelled to do the right thing. It is also time to re-examine and change our individual behaviors, including limiting our own reproduction (ideally to replacement level at most) and drastically diminishing our per capita consumption of fossil fuels, meat and other resources…

“Sustainability transitions come about in diverse ways, and all require civil-society pressure and evidence-based advocacy, political leadership and a solid understanding of policy instruments, markets and other drivers.

“To prevent widespread misery and catastrophic biodiversity loss, humanity must practice a more environmentally sustainable alternative to business as usual. This prescription was well articulated by the world’s leading scientists 25 years ago, but in most respects, we have not heeded their warning. Soon it will be too late to shift course away from our failing trajectory, and time is running out. We must recognize, in our day-to-day lives and in our governing institutions, that Earth with all its life is our only home.”

How many warnings can we afford to ignore?