20,000 Scientists Underscore Alarm Over Changing Climate and Toxic Damage in “Warning Letter to Humanity”

The publishers of the letter now say that the letter is the sixth most-discussed piece of research since Altmetric records, which track publications’ impact, began. It has prompted speeches in the Israeli Knesset and Canada’s BC Legislature.” The Independent


Photo Credit: CBC News

My plan for today had been to tackle the great big silence, the massive absence of policy on toxics in the government of Canada’s new Bill C-69, a bill to reform the Canadian Environmental Protection Act, now in process through the House of Commons – a silence that is astounding, bewildering and frightening.

2But I have decided to postpone this installment in my mini-series on toxics, policy and politics by some days so that I can draw your attention to a document whose signatories have recently surpassed the 20,000 mark: – a warning letter from scientists to humanity. First issued last November, on the anniversary of an original warning letter sent 25 years ago, the new letter reports on how disastrously humankind has done in responding to threats, both climate and toxics related, that now put our species along with so many others at risk for the “sixth great extinction.”

If you like, you can download the letter here (pdf). I’m providing direct quotes – analysis, data points and solutions – from the letter, mostly verbatim, as it eloquently speaks for itself.

To begin, the scientists evaluate the progress – or, very seriously, lack of it – on most fronts since 1992, when the first group of scientists, including most of the then-living Nobel laureates called on humanity and its political leaders to take stock, and make radical changes.

On the twenty-fifth anniversary of the [original] 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 (figure 1, file S1). 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 (figure 1). 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. 

Here is “figure 1” and an explanation of the key data points – and reasons for alarm – from the letter.


These charts show steep acceleration in carbon dioxide emissions (we were up worldwide again last year), declining access to fresh water (think Cape Town, Saskatchewan, California), and endangered species and other dangers facing the globe. They imply that only if energy becomes  entirely sustainable, industry stops polluting, we give up the most harmful chemical products (e.g. plastics and chemical pesticides) limit both human and ruminant population growth can avert the catastrophes they describe.

The scientists explain the graphs this way: …

Ozone depletion, Figure 1a. During the 1970s, human-produced chemicals known as ozone-depleting substances, mainly chlorofluorocarbons, were rapidly depleting the ozone layer. In 1987, governments of the world came together and crafted the United Nations Montreal Protocol as a global attempt to address this issue. With protocol compliance, emissions of halogen source gases (ozone-depleting substances and natural sources) peaked in the late 1980s and since then they have significantly decreased (Figure 1a). Global ozone depletion is no longer increasing, and significant recovery of the ozone layer is expected to occur by the middle of this century (Hegglin et al. 2014).


Photo Credit: Permaculture Research Institute

Declining Freshwater availability, Figure 1b. Per capita freshwater availability is less than half of levels of the early 1960s (Figure 1b, AQUASTAT 2017) with many people around the world suffering from a lack of fresh clean water. This decrease in available water is nearly all due to the accelerated pace of human population growth.It is likely that climate change will have an overwhelming impact on the freshwater availability through alteration of the hydrologic cycle and water availability. Future water shortages will be detrimental to humans, affecting everything from drinking water, human health, sanitation, and the production of crops for food.Unsustainable marine fisheries,

Reconstructed Marine Catch, Figure 1c. In 1992, the total marine catch was at or above the maximum sustainable yield and fisheries were on the verge of collapse. Reconstructed time series data show that global marine fisheries catches peaked at 130 million tonnes in 1996 and has been declining ever since (Figure 1c). The declines happened despite increased industrial fishing efforts and despite developed countries expanding to fishing the waters of developing countries (Pauly & Zeller 2016, updated).


Photo Credit: UPI

Ocean dead zones, Figure 1d. 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 (Figure 1d, Diaz & Rosenberg 2008, updated). Forest loss,

Total Forest, Figure 1e. 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 (Figure 1e). Forest loss has been greatest in developing tropical countries where forests are now commonly converted to agriculture uses (FAO 2015). Dwindling biodiversity,

Vertebrate Species Abundance, Figure 1f. 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 (Figure 1f). Here, we display a diversity-weighted Living Planet Index that has been adjusted for taxonomic and geographic bias by accounting for the estimated number of species within biogeographical regions, and the relative species diversity within them. (McRae et al. 2017). Freshwater, marine, and terrestrial populations declined by 81%, 36%, and 35% respectively (McRae et al. 2017).


Endangered species                                                                                      Photo Credit:

Climate Change, Figure 1g, Figure 1h. Global fossil-fuel carbon dioxide emissions have increased sharply since 1960 (Figure 1g, Boden et al. 2017). 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 (Figure 1h, NASA’s Goddard Institute for Space Studies (GISS) 2017). The 10 warmest years in the 136-year record have occurred since 1998. The most recent year of data, 2016, ranks as the warmest on record. Temperature increases will likely cause a decline in the world’s major food crops, an increase in the intensity of major storms, and a substantial sea level rise inundating major population centers.

Population growth, Figure 1i. Since 1992, the human population has increased by approximately 2 billion individuals, a 35% change (Figure 1i, FAOSTAT 2017). 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 (Gerland et al. 2014). Like the change in human population, the domestic ruminant population, which has its own set of major environmental and climate impacts, has been increasing in recent decades to approximately 4 billion individuals on Earth (Figure 1i, FAOSTAT 2017).”

71-e1520963947938.pngPhoto Credit: Beef Magazine

What will it take to get us there? Green and equal governance – our greatest species challenge

 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.” – Letter of Warning to Humanity.

 To the scientists’ analysis, prescriptions (see sidebar) and the words of the above conclusion, I want to add one point, and to and underscore it as strongly as possible: Humans are brilliant at technology: the petrochemical technology that has reshaped the world and now threatens it; and – given a chance –the “beyond-petrochemical” technology that can be used to save the world. By contrast, however, it seems we are fundamentally challenged in our ability to govern ourselves, and therefore to control how we deploy technology, good or bad. In these most perilous times, we seem unable to regulate the capitalist market or the commanding branches of government to accelerate the shift to benign technologies – be it in energy, in manufacturing or in agriculture – remotely as fast as we need to in order to avert even worse planetary disaster than we are living through now.

“Technology is easy; politics is hard.” Jeremy Rifkin, The Biotech Century


Ministers meet in Kenya to prepare for environmental summit   Photo credit: UN Climate Programme

And so, many detailed prescriptions notwithstanding, it will only be in overcoming this challenge in governance capacity that we will save ourselves from ourselves. Because to achieve the “sustainability transitions” identified by the scientists in their letter, we will need governments – at all levels, in all jurisdictions – capable of leading these transitions. Market forces and voluntary guidelines or piecemeal, incremental change just won’t cut it. In the sidebar, you can find the entire list of “transitions” the scientist prescribe. Here let me just quote the final four that will make all the others possible.

Divesting of monetary investments and purchases to encourage positive environmental change; devising and promoting new green technologies and massively adopting renewable energy sources while phasing out subsidies to energy production through fossil fuels; revising our economy to reduce wealth inequality; incentive systems take into account the real costs which consumption patterns impose on our environment; and estimating a scientifically defensible, sustainable human population size for the long term while rallying nations and leaders to support that vital goal. 


Graphic Credit: United National Environment Programme http://web.unep.org/unepmap/introduction-environmental-governance-free-online-course-informea

 I hope you do read the whole list, and you might also be interested in reading more about solutions involving politicizing pollution on this website too:  

10This wonderful photo and quote remind us that real people have created the technologies and economies now wrecking havoc on every continent; so – through green and equitable governance – real people can remake technologies and economies. Market forces are not beyond human change; technologies are not autonomous. We are not helpless. We just need to focus on changing our governments to ones that are up to the job. Graphic Credit: Janhangir’s World Times

From The Independent: Some Context and History

20,000 scientists give dire warning about the future in ‘letter to humanity’ – and the world is listening

The paper is now one of the most discussed scientific works ever and has been signed by a huge number of experts

Andrew Griffin        March 7, 2018


 A dire warning to the world about its future, which predicts catastrophe for humanity, is continuing to gain momentum.

The letter – which was first released in November – has now been signed by around 20,000 scientists. And the world seems to be listening: it is now one of the most discussed pieces of scientific research ever, and its publishers claim it is now influencing policy.

The new letter was actually an update to an original warning sent from the Union of Concerned Scientists that was backed by 1,700 signatures 25 years ago. It said that the world had changed dramatically since that warning was issued – and almost entirely for the worse.

Mankind is still facing the existential threat of runaway consumption of limited resources by a rapidly growing population, they warned. And “scientists, media influencers and lay citizens” aren’t doing enough to fight against it, the letter read.

If the world doesn’t act soon, there will be catastrophic biodiversity loss and untold amounts of human misery, they wrote.


Cape Town almost out of water                                                   Photo Credit: The Independent

Now scientists have written a follow-up piece in which they argue scientists and economists need to switch their focus from encouraging growth to conserving the planet. “There are critical environmental limits to resource-dependent economic growth,” the authors state.

The original letter was signed by more than 15,000 scientists. But it has since been endorsed by a further 4,500 – taking the total to around 20,000 and giving further encouragement to scientists working to counteract the dangers highlighted in the letter.

The lead author of the warning letter and new response paper, ecology Professor William Ripple, from Oregon State University, said: “Our scientists’ warning to humanity has clearly struck a chord with both the global scientific community and the public.”

The publishers of the letter now say that the letter is the sixth most-discussed piece of research since Altmetric records, which track publications’ impact, began. It has prompted speeches in the Israeli Knesset and Canada’s BC Legislature.


Header Image Credit: DailyDot


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