Scientists’ warning to humanity over health of planet

More than 16,000 scientists from 184 countries have published a second warning to humanity advising

In 1992, 1,700 independent scientists signed the “World Scientists’ Warning to Humanity.” The letter warned that “human beings and the natural world are on a collision course” and if environmental damage was not stopped, our future was at risk.

25 years on many scientists (and some politicians and others) believe that the world still faces major environmental challenges. So environmental scientist William Ripple and his colleagues created a new letter. Since it was published in the journal BioScience on Monday, hundreds more scientists have signed on.

The letter:


Twenty-five years ago, the Union of Concerned Scientists and more than 1700 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.”

In their manifesto, they showed that humans were on a collision course with the natural world. They expressed concern about current, impending, or potential damage on planet Earth involving ozone depletion, freshwater availability, marine life depletion, ocean dead zones, forest loss, biodiversity destruction, climate change, and continued human population growth.

They proclaimed that fundamental changes were urgently needed to avoid the consequences our present course would bring.

The authors of the 1992 declaration feared that humanity was pushing Earth’s ecosystems beyond their capacities to support the web of life. They described how we are fast approaching many of the limits of what the biosphere can tolerate without substantial and irreversible harm.

The scientists pleaded that we stabilize the human population, describing how our large numbers—swelled by another 2 billion people since 1992, a 35 percent increase—exert stresses on Earth that can overwhelm other efforts to realize a sustainable future.

They implored that we cut greenhouse gas (GHG) emissions and phase out fossil fuels, reduce deforestation, and reverse the trend of collapsing biodiversity.

On the twenty-fifth anniversary of their call, we look back at their warning and evaluate the human response by exploring available time-series data. 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 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.

Humanity is now being given a second notice, as illustrated by these alarming trends.

Trends over time for environmental issues identified in the 1992 scientists’ warning to humanity. The years before and after the 1992 scientists’ warning are shown as gray and black lines, respectively.

Panel (a) shows emissions of halogen source gases, which deplete stratospheric ozone, assuming a constant natural emission rate of 0.11 Mt CFC-11-equivalent per year.

In panel (c), marine catch has been going down since the mid-1990s, but at the same time, fishing effort has been going up (supplemental file S1).

The vertebrate abundance index in panel (f) has been adjusted for taxonomic and geographic bias but incorporates relatively little data from developing countries, where there are the fewest studies; between 1970 and 2012, vertebrates declined by 58 percent, with freshwater, marine, and terrestrial populations declining by 81, 36, and 35 percent, respectively (file S1).

Five-year means are shown in panel (h).

In panel (i), ruminant livestock consist of domestic cattle, sheep, goats, and buffaloes.

Note that y-axes do not start at zero, and it is important to inspect the data range when interpreting each graph. Percentage change, since 1992, for the variables in each panel are as follows:
(a) –68.1%; (b) –26.1%; (c) –6.4%; (d) +75.3%; (e) –2.8%; (f) –28.9%; (g) +62.1%; (h) +167.6%; and (i) humans:
+35.5%, ruminant livestock: +20.5%.

We are jeopardizing our future by not reining in our intense but geographically and demographically uneven material consumption and by not perceiving continued rapid population growth as a primary driver behind many ecological and even societal threats (Crist et al. 2017).

By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperilled biosphere.

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. 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.

The rapid global decline in ozone depleting substances shows that we can make positive change when we act decisively. We have also made advancements in reducing extreme poverty and hunger (www.worldbank.org). Other notable progress (which does not yet show up in the global data sets in figure 1) include the rapid decline in fertility rates in many regions attributable to investments in girls’ and women’s education (www.un.org/esa/population), the promising decline in the rate of deforestation in some regions, and the rapid growth in the renewable-energy sector.

We have learned much since 1992, but the advancement of urgently needed changes in environmental policy, human behavior, and global inequities is still far from sufficient. 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.

Examples of diverse and effective steps humanity can take to transition to sustainability include the following (not in order of importance or
urgency):

(a) prioritizing the enactment of connected well-funded and well-managed reserves for a significant proportion of the world’s terrestrial, marine, freshwater, and aerial habitats;

(b) maintaining nature’s ecosystemservices by halting the conversion of forests, grasslands, and other native habitats;

(c) restoring native plant communities at large scales, particularly forest landscapes;

(d) rewilding regions with native species, especially apex predators, to restore ecological processes and dynamics;

(e) developing and adopting adequate policy instruments to remedy defaunation, the poaching crisis, and the exploitation and trade of threatened species;

(f) reducing food waste through education and better infrastructure;

(g) promoting dietary shifts towards mostly plant-based foods;

(h) further reducing fertility rates by ensuring that women and men have access to education and voluntary family-planning services, especially where such resources are still lacking;

(i) increasing outdoor nature education for children, as well as the overall engagement of society in the appreciation
of nature;

(j) divesting of monetary investments and purchases to encourage positive environmental change;

(k) devising and promoting new green technologies and massively adopting renewable energy sources while phasing
out subsidies to energy production through fossil fuels;

(l) revising our economy to reduce wealth inequality and ensure that prices, taxation, and incentive systems take into account the real costs which consumption patterns impose on our environment; and

(m) estimating a scientifically defensible, sustainable human population size for the long term while rallying nations and leaders to support that vital goal.

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 dayto-day lives and in our governing institutions, that Earth with all its life is our only home.

Full letter with supplemental files:

http://scientists.forestry.oregonstate.edu/sites/sw/files/Warning_article_with_supp_11-13-17.pdf

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31 Comments

  1. PDB

     /  November 27, 2017

    World population growth, especially in developing countries is the major problem;

    Even in developed countries the promotion of old fashioned ‘family planning’ is looked down upon as a human rights violation.

    • Alan Wilkinson

       /  November 27, 2017

      Is “developing countries” a euphemism?

      • PartisanZ

         /  November 27, 2017

        It’s not a euphemism at all, it’s just an incorrect name. The victors name for the vanquished.

        We could call them “exploited countries”, since all the “developed countries” exploited their populations and resources to become ‘developed’? They called this ‘trade’ because they traded in things like slaves, spices and minerals … So we could call them the ‘Traded Nations’ as opposed to the Trading Nations?

        I could go on for ages but I know how folks on here feel about posts longer than 3 lines …

        The developed countries who consider themselves responsible could call the developing countries “Our Responsibility”?

        Interesting too, perhaps, to contemplate the idea that within every post-colonial ‘developed country’ there is still a colonial (or colonized) ‘developing nation’ …?

        • David

           /  November 27, 2017

          “We could call them “exploited countries””

          You could, but you would be wrong. Their problem is that they have not been exploited enough.

      • Alan Wilkinson

         /  November 27, 2017

        My question is whether they truly are developing or merely stagnating or going backwards due to awful governance, ideology and policies.

        • PartisanZ

           /  November 27, 2017

          … or some form of collective PTSD from having been fucked-over so much for so long by so many …?

  2. Alan Wilkinson

     /  November 27, 2017

    Except that the alarmist predictions of 1992 resource depletion just like the Club of Rome Limits to Growth predictions of 1972 have turmed out to be crap.

    Engineers tend to have opinions more soundly based in reality than scientists. However the former are not necessarily reflected by their professional bodies which get taken over by political activisys.

  3. Zedd

     /  November 27, 2017

    I watched ‘Blue Planet’ (doco) last evening on TV; they showed the difference between large areas of the Great Barrier Reef, that have died in recent years, directly attributed to increased water temperature & CO2 (carbonic acid), breaking down the structure
    BUT I still hear the voices of C-C deniers & ‘scientists’ saying its all alarmist rhetoric; ‘Climate change is happening, but dont panic’ OR ‘its just part of a normal cycle’ (its all happened before), ie man made pollution is NOT the cause.. “WAKE UP !!” 😦

    The next great extinction is at the door & humanity may be the biggest group to die out.. if we just ‘act like ostriches’

    • Alan Wilkinson

       /  November 27, 2017

      The “next great extinction” already happened when Europeans encircled and colonised the world. There have been zero species extinctions in NZ in the last 100 years.

      • Zedd

         /  November 27, 2017

        more ‘facts’ from AW.. “yawn” 😀

        • Alan Wilkinson

           /  November 27, 2017

          Disappointed they contradict your desire to panic?

      • Fight4NZ

         /  November 27, 2017

        Except greater short tailed bat, bush wren, sth island piopio, SI snipe, narrow bodied skink, etc, etc

    • Zedd

       /  November 27, 2017

      btw; Ive been asked ‘what am I doing, to reduce emissions/pollution’: I dont own a car & use public transport. I take a shopping bag to the supermarket & dont get plastic shopping bags, I recycle as much as possible.

      One of the biggest criticisms of ‘the Green Movement’ is that ‘its all talk & no action’.. well that maybe true with some, but not all, many are making an effort, even if others think ‘its just tokenism’. Regardless of the ‘nay-sayers’ every little bit does count. 🙂

      • Alan Wilkinson

         /  November 27, 2017

        Is an often mostly empty subsidised bus more efficient and less-polluting than a small modern car? A plastic milk bottle has as much plastic as 8 shopping bags.

        • PartisanZ

           /  November 27, 2017

          Ultimately its not about that though, is it? Its about: Why the bus at all? And: Why the plastic milk bottle? Its about the moneyed production-consumption paradigm?

          The best way to get milk to people who want it may have been the old-fashioned milkman? One person in one vehicle taking milk directly to the gate of a large community base and exchanging re-usable bottles?

          • Alan Wilkinson

             /  November 27, 2017

            An unnecessary daily trip which is eliminated when customers buy their milk at the same time as their other groceries. Probably its demise was the adoption of the household refrigerator.

          • High Flying Duck

             /  November 27, 2017

            That works if milk exists in a vacuum. But people don’t generally buy milk and nothing else.
            Bring back the milkman and the shopping trips still need to happen so you are not saving anything.
            The demise of the milkman was about improving efficiency.
            The issue is more about whole of life costs vs production costs.
            Plastic bottles are far cheaper to make than glass bottles, but only when you ignore the downstream disposal costs and impacts.
            We are finally (slowly) seeing society moving to a more complete cost structure, where the real costs including recycling and pollution mitigation are imposed at source.
            Pollution taxes, mitigation costs etc are beginning to be sheeted home to manufacturers.
            Once true costs are taken into consideration there may very well be a shift back to using more environmentally desirable materials as the overall costs are lower – like glass milk bottles over plastic.
            Electric cars may get a reality check as well as the environmental beginning of life and end of life costs of these have been somewhat swept under the carpet.
            It has been a weakness of the “free market” that many of the true costs involved in manufacturing and production are divested to the public purse, mainly as there was little cognisance of what those impacts were and limited means of imposing the costs back to the manufacturer.
            A truly free market will work better when these discrepancies are remedied.

            • PartisanZ

               /  November 27, 2017

              My Food Bag …

              There’s also consumer choice power and thankfully an element of decentralization remains too, regarding, for instance, the ‘downstream costs’ of driving further to the supermarket as opposed to walking (or driving a much shorter distance) to the local Superette (or Supermarket if you’re ‘lucky’ enough to live near one) … Probably mostly a rural problem … ..

            • PartisanZ

               /  November 27, 2017

              Makes me wonder why online shopping and home delivery isn’t used much more than it is … ?

            • High Flying Duck

               /  November 27, 2017

              I think people like to choose their own produce. But I believe online is growing.

            • Alan Wilkinson

               /  November 27, 2017

              The Countdown delivery truck passes through here every day and out the back road as well. I presume it has good patronage.

          • High Flying Duck

             /  November 27, 2017

            If you want something to get angry about, then how about the fact the supermarkets, at the same time as they are pontificating and virtue signalling on getting rid of plastic bags, are putting more and more unnecessary things on Styrofoam trays with glad wrap – like avocados, bananas and courgette’s!

            • PartisanZ

               /  November 27, 2017

              Don’t talk to me about supermarkets and “virtue” …

      • David

         /  November 27, 2017

        “I dont own a car & use public transport. I take a shopping bag to the supermarket & dont get plastic shopping bags, I recycle as much as possible.”

        None of these things make a significant difference.

  4. David

     /  November 27, 2017

    “estimating a scientifically defensible, sustainable human population size for the long term while rallying nations and leaders to support that vital goal.”

    PolPot was clearly ahead of his time.

    • PartisanZ

       /  November 27, 2017

      Ouch … a stinger of a cheap shot … Where’s my safe space!?

  5. Alan Wilkinson

     /  November 27, 2017

    That most rare of events – mainstream media publishing a sensible article on climate:
    http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=11948291

    In a hot climate plant grass and trees to absorb the sunlight, don’t spread bare bitumen surfaces to cook yourself.

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