15,000 scientists issue environmental 'warning' to humanity

Thousands of scientists from 184 countries have endorsed an open letter that outlines some of the Earth's most pressing environmental problems.

A red emergency light. (Caspar Benson/Getty)
A red emergency light. (Caspar Benson/Getty)

More than 15,000 scientists from 184 countries have issued a warning: Mankind must take immediate action to reverse the effects of climate change, deforestation and species extinction before it's too late.

The warning, issued by the Alliance of World Scientists and published in the journal Bioscience, comes on the 25th anniversary of a similar warning from the Union of Concerned Scientists that was titled “World Scientists' Warning to Humanity". The new letter, however, has 10 times as many scientists endorsing it.

“On the 25th anniversary of their call, we look back at their warning and evaluate the human response by exploring available time-series data," the paper reads. “Especially troubling is the current trajectory of potentially catastrophic climate change due to rising GHGs from burning fossil fuels (Hansen et al. 2013), deforestation (Keenan et al. 2015), and agricultural production—particularly from farming ruminants for meat consumption (Ripple et al. 2014). 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."


The paper outlines some of the world's most pressing environmental concerns, most of which have only worsened since 1992. They're summarized here:

A decline in freshwater availability – Per capita fresh water availability is less than half of the level of the 1960s. It is likely that climate change will have an overwhelming impact on the freshwater availability through alteration of the hydrologic cycle and water availability.

Unsustainable marine fisheries – In 1992, the total marine catch was at or above the maximum sustainable yield and fisheries were on the verge of collapse. Global catch rates have decreased, though fishing efforts are increasing.

Ocean dead zones – Coastal dead zones which are mainly caused by fertilizer runoff and fossil-fuel use, are killing large swaths of marine life. Dead zones with hypoxic, oxygen-depleted waters, are a significant stressor on marine systems and identified locations have dramatically increased since the 1960s, with more than 600 systems affected by 2010.

Forest losses – The world's forests are crucial for conserving carbon, biodiversity, and freshwater. Between 1990 and 2015, total forest area decreased from 4,128 to 3,999 million ha, a net loss of 129 million ha which is approximately the size of South Africa.

Dwindling biodiversity – The world's biodiversity is vanishing at an alarming rate and populations of vertebrate species are rapidly collapsing (World Wildlife Fund 2016). Collectively, global fish, amphibians, reptiles, birds, and mammals declined by 58% between 1970 and 2012.

Climate change – Global fossil-fuel carbon dioxide emissions have increased sharply since 1960. Relative to the 1951-1980 average, global average annual surface temperature, in parallel to CO2 emissions, has also rapidly risen as shown by 5-year mean temperature anomaly. The 10 warmest years in the 136-year record have occurred since 1998.

Population growth – Since 1992, the human population has increased by approximately 2 billion individuals, a 35% change. The world human population is unlikely to stop growing this century and there is a high likelihood that the world population will grow from 7.2 billon people now to between 9.6 and 12.3 billon by 2100.

It wasn't all awful news, however.

Now for some good news!
The Ozone Hole this year has been the smallest since 1988!https://t.co/8S7dDYW1c7
— Erik Solheim (@ErikSolheim) November 3, 2017

Your body’s full of stuff you no longer need. Here's a list.

Evolution doesn't clean up after itself very well.

Image source: Decade3d-anatomy online via Shutterstock
Surprising Science
  • An evolutionary biologist got people swapping ideas about our lingering vestigia.
  • Basically, this is the stuff that served some evolutionary purpose at some point, but now is kind of, well, extra.
  • Here are the six traits that inaugurated the fun.
Keep reading Show less

Godzilla vs. Kong: A morphologist chooses the real winner

Ultimately, this is a fight between a giant reptile and a giant primate.

Surprising Science

The 2021 film “Godzilla vs. Kong" pits the two most iconic movie monsters of all time against each other. And fans are now picking sides.

Keep reading Show less

How do you tell reality from a deepfake?

The more you see them, the better you get at spotting the signs.

ROB LEVER/AFP via Getty Images
Technology & Innovation
  • The number of deepfake videos online has been increasing at an estimated annual rate of about 900%.
  • Technology advances have made it increasingly easy to produce them, which has raised questions about how best to prevent malicious misuse.
  • It's been suggested that the best way to inoculate people against the danger of deepfakes is through exposure and raising awareness.
  • Keep reading Show less
    Surprising Science

    Ancient cave artists were getting high on hypoxia

    A new study says the reason cave paintings are in such remote caverns was the artists' search for transcendence.

    Quantcast