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Obstacle 1 - The misconception that unsustainability is an uncertain forecasted possibility

Updated December 2021

Most publications on sustainability conclude that if humankind continues business as usual biosphere WILL collapse and this WILL have negative counter-effects on humankind. For example, the Summary for Policymakers of the IPCC report on Climate Change and Land (IPCC 2019) uses eleven times the term “will” referring to potential negative consequences of climate change. Similarly, the review of human impacts on biodiversity by Sage (2020) uses more than thirty times the term “will”.


Most of these worrying statements are based on forecastings by models at biosphere scale that make use of numerous assumptions and still have a considerable degree of uncertainty. Therefore, many decision-makers disregard them with skepticism, and the repeated calls for urgent sustainability action (e.g., Ripple et al. 2020, 2021) are failing to influence both decision-makers and general public. Some authors address unsustainability based on running facts, strong evidence (e.g., Bradshaw et al. 2021; Chure et al. 2021; Ripple et al. 2021) but they are the exception, not the rule.

The use of disputable forecasts of future calamities to call the attention on unsustainability is avoidable, because there already exists a huge amount of evidence on the PRESENT disintegration of the biosphere and on the ALREADY running negative counter-effects on humankind. This is not a forecasted possibility but a tangible reality as summarized in Table 1 and Figures 1 to 4.


The combination of factual data on present conditions with forecasted data is negative, because factual data and forecastings are put in the same level of reliability.

The report by IPCC (2021) separates present factual situation from forecastings, but factual situation is presented with a technical wording that -again- resembles uncertain forecastings, confuse everybody and convince nobody (likely, very likely, medium confidence, virtually certain, ...).

Table 1. Biosphere – main impacts of humankind on biosphere, their effects on biosphere and counter-effects on humankind. Evidence-based review of factual data from present times, forecasts are not included.

Table Biosphere diagnosis.JPG
CO2 emissions.jpg

Figure 1. Global Fossil CO2 Emissions and Surface Average Atmospheric CO2 concentration.

Schematic redrawn from Friedlingstein P, M Jones, M O’ al. (2019) Global Carbon Budget 2019. Earth Sys. Sci. Data 11:1783-1838.

Note: CO2 emissions decreased a bit in 2020 due to the COVID-19 crisis, but the atmospheric concentration continued to increase (WMO Press Release 23112020, 2020, )


Figure 2. Fertilizer production in the world in tons per year.


Land use for agriculture.JPG

Figure 3.  World use of land for agriculture versus time.

Redraw from: Ritchie H and M Roser (2019) Land Use. Published online at Retrieved from

Cancer in children.JPG

Figure 4. Incidence of cancer in children in the UK.

Data source: Cancer Research UK, accessed 03/2020


Bradshaw C, P Ehrlich, A Beattie et al. (2021) Underestimating the challenges of avoiding a ghastly future. Frontiers Conserv. Sci. 1:615419.

Chure G, R Banks, A Flamholz et al. (2021) The anthropocene by the numbers: a quantitative snapshot of humanity’s influence on the planet. preprint on arxiv 2021.

IPCC (2019a) Climate Change and Land. Intergovernmental Panel on Climate Change - Special Report. Approved Draft August7th.

IPCC (2021) Climate Change 2021 - The Physical Science Basis. Working Group I Contribution to the Sixth Assessment Report of the IPCC.  

Ripple W, C Wolf, T Newsome, P Barnard and W Moomaw (2020) World Scientists’ Warning of a Climate Emergency. BioScience 70(1):8–12. 

Ripple W, C Wolf, T Newsome et al. (2021) World Scientists' Warning of a Climate Emergency. Bioscience 71(9):894-898. 

Sage R (2020) Global change biology: A primer. Global Change Biol. 26(1):3-30.

Comments are welcome - write to 

R Pereyra wrote 14/1/2022

I think the report would benefit if you define unambiguously what you consider the holy grail of "sustainability" to be. I believe this to be of prime importance for two key reasons. 


Firstly, it would give everyone, including policy makers and governments, a fixed goal post to aim for when structuring practical measures in the 9 obstacles you identify to achieve it. I have heard as many definitions of "sustainability" as there are people with opinions on the topic, from primeval pre-agricultural hunter-gatherer societies vision, to post-industrial technological utopias. The former is historically wrong, as proven by the extinction of the American megafauna by Clovis hunter-gatherers. The latter is practically unachievable, as you yourself point out very eloquently (obstacle 6). Most of the alternatives in between those two extremes will partake of the same conceptual vices as one extreme or both. 


Secondly, The definition of "sustainability" cannot, and should not, be one of facts and figures alone, it must also be ethically compelling, and self-sufficiently so. Here I throw a challenge to you, because if we base our evolutionary future on metric tons of CO2, cubic kmts of freshwater, and billions of individuals on the planet, we are indeed doomed to failure.

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