July 29, 2021

when humanity takes the risk of making the Earth unlivable


If you are prone to strong eco-anxiety, it is probably best to go your way. Collapsing glaciers, mega-fires, desertification, coral bleaching: the documentary Our Planet has its limits: the warning of science, released on Friday June 4 on Netflix, explores nothing less than the risk of destabilizing the entire planet, and therefore of making it unlivable for humanity.

This film, narrated by Sir David Attenborough, a British writer and naturalist, presents a concept described as “The most important scientific discovery of our time” : that of the planetary limits. In 2009, the Swede Johan Rockström, director of the Potsdam (Germany) Institute for Research on the Effects of Climate Change, and other scientists identified nine threshold limits that cannot be exceeded without endangering humanity. However, according to his work, updated in 2015, four of the nine planetary boundaries have now been crossed – climate, biosphere integrity, biodiversity and nutrients – and two are on the verge of being crossed. : fresh water and ocean acidification. Two limits could not be defined: new materials (steel, plastic, etc.) and air pollution.

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Swede Johan Rockström, director of the Potsdam Institute for Research on the Effects of Climate Change (Germany), in “Our planet has its limits: the warning of science” (2021), by Jon Clay.

In an educational and impactful way, the headliner of the documentary, Johan Rockström, explains how we have managed, in fifty years, to put ourselves outside the stable situation in which we have lived for 10,000 years. Human activities, and in particular the production and consumption of fossil fuels (coal, oil, gas), emit more and more greenhouse gases, increasing their concentration in the atmosphere. Cascading effects follow: we have warmed the Earth by more than 1 ° C since the pre-industrial era, the ice caps of Greenland and Antarctica are melting at an accelerated rate, extreme events are increasing, sea levels gets up.

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Johan Rockström, Potsdam Research Institute: “We have crossed danger zones and we are heading towards irreversible tipping points. As in a game of dominoes, there may be a chain reaction “

Not content with disrupting the climate machine, humanity is also responsible for the destruction of living things. To feed themselves, to build cities, to build infrastructures, humans have destroyed 20% of the Amazon, wiped out 68% of vertebrate populations or even disrupted the phosphorus and nitrogen cycle so much that dead zones are always more numerous. in lakes and oceans, due to excessive use of fertilizers and poor management of effluents from animal farms. “We have crossed danger zones and we are heading towards irreversible tipping points, prevails Johan Rockström. As in a game of dominoes, there is the risk of a chain reaction. ”

Shocking Images

The words are very substantiated while remaining digestible, with a lot of figures, shocking images, interviews with eminent scientists and special effects – too many. If this tour de force manages to perfectly popularize the planetary limits, the documentary leaves however unsatisfied as to the solutions to return to a state of stability of the planet. The avenues – already known – are sketched out too broadly: halving our greenhouse gas emissions every ten years to limit global warming to 1.5 ºC, eliminate all fossil fuels within thirty years , plant billions of trees, reduce animal protein consumption, waste and waste. “It is not too late for humanity to have a future”, assure Johan Rockström.

Finally, the only real touch of hope comes from the last of the planetary limits: the ozone layer, the destruction of which gave rise to concerted political action in the 1980s which made it possible to restore it. “It was really fantastic to see: the scientists sounded the alarm and the world took action”, enthuses David Attenborough. As scientists sound the alarm again, the question is whether the world will hear it in time.

“Our planet has its limits: the warning of science”, documentary by Jon Clay (EU, 2021, 74 min).