Five megatrends present major global threats for planet Earth (1):
1. air pollution and climate change;
2. deforestation;
3. Species extinction;
4. Soil degradation;
5. Overpopulation.
Habitat size and numbers of species are systematically related. Physically larger species and those living at lower latitudes or in forests or oceans are more sensitive to reduction in habitat area (2). Conversion to "trivial" standardized ecosystems (e.g., monoculture following deforestation) effectively destroys habitat for the more diverse species that preceded the conversion. Even the simplest forms of agriculture affect diversity – through clearing/draining land, discouraging weeds and "pests", and encouraging just a limited set of domesticated plant and animal species (3). Co-extinctions are a form of habitat destruction (4). For example, as an estimated 87.5% of the world's flowering plant species are animal-pollinated their decline will have dramatic consequences on the flora (5).
Virtually all industrialized countries as well as many emerging countries are below the generation replacement threshold, but not all countries. Africa is the counter-example. Its demographic transition is only beginning. Mortality, which is the highest in the world, is declining. Fertility also: it is 4.5 children per woman on average in 2017 (more than 7 in Niger), compared to 5.5 twenty years earlier, 6.5 forty years ago. However the continent, with 1.13 billion people, could see its population quadruple by 2100 (6). See graph attached (7).
Strong national family planning programmes in various parts of the world jump-start a virtuous circle: fertility declines allowed more educational and other resources to be deployed per capita than otherwise would have been possible. In turn, relatively more educated girls and women are able to increase their economic value and societal status – allowing for even greater agency to access and use contraception. Unfortunately Africa has not had the same attention, resulting in slow, sometimes negligible, fertility declines. In a handful of countries, previous declines have stalled altogether and are reversing. Beyond unreliable supplies of contraceptives in many countries the greater obstacles to lower fertility are often male opposition to contraception, religious teachings, social norms, or misinformation about contraceptive options and their side-effects (8).
Therefore the question above arises.
References:
1. https://www.dw.com/cda/en/five-of-the-worlds-biggest-environmental-problems/a-35915705
2. Drakare S, Lennon J, Hillebrand H (2006). The imprint of the geographical, evolutionary and ecological context on species-area relationships. Ecology Letters 9:215–227.
3. https://www.crcpress.com/Natural-Resources---Technology-Economics--Policy/Aswathanarayana/p/book/9780415897914
4. Koh LP, Dunn RR, Sodhi NS, Colwell RK, Proctor HC, Smith VS (2004). Species Coextinctions and the Biodiversity Crisis. Science 305:1632–1634.
5. Ollerton J, Winfree R, Tarrant S (2011). "How many flowering plants are pollinated by animals? Oikos. 120: 321–326
6. Le monde (16.02.2019).
7. https://fabiusmaximus.com/2015/08/18/un-world-population-forecast-88453/
8. https://www.theguardian.com/global-development-professionals-network/2016/jan/11/population-growth-in-africa-grasping-the-scale-of-the-challenge
I agree that the word “cancer” is not quite appropriate. I use it as a metaphor in order to highlight the urgency of the issue. The consequences of the gradual colonization of the ecosystems of our planet by homo sapiens are similar to those of a cancer.
I would like to add that there is unfortunately the possibility of lack of control of the world population (cf. the graph on the world population projection in the field attached).
Of course, as for a cancer, the world population growth will be halted when most ecosystems are irreversibly deeply degraded.
I agree “there is nothing ‘necessary’ about humanity's continued existence” as I have never said otherwise.
“All that sense of urgency is all a figment of our imagination”. Could you argue your point?
“… that means becoming absolutely intolerant of those who are acting to accelerate our impending extinction”. I find this sentence ambiguous. What do you mean by “to accelerate our impeding extinction”?
Could you explicit what you mean by “what we normally take for granted”?
“Too many people simply refuse to act”. I suppose you mean “too many people simply refuse to act to try to reduce the five megatrends which present major global threats for planet Earth”?
Thank you for these clarifications.
However, I am still not sure to fully understand your point of view:
1. Could you explain what you mean exactly by the term “impeding extinction”?
2. Could you make explicit the new type of behavior you suggest?
I see my questions to you were unclear:
- by "impeding extinction" I suppose you mean "inescapable extinction" but your expression seems odd to a French speaker;
- actually, I fully agree that each human must minimising one's consumption. Now, it is easy to say it but the question is how to achieve such a goal?
The Question mentions "Five megatrends present major global threats for planet Earth".
As there are many different types of cancer, which is associated with humankind?
To Michael John McAleer:
• A given cancer is caused by the abnormal growth of a specific type of cells with the potential to invade or spread to other parts of the body.
• Homo sapiens is a species with the potential to invade or spread to most ecosystems of the Earth because of its uncontrolled growth.
Different cancers have different effects on different parts of the body.
Different cancers also have different survival rates.
Some cancers can be treated and cured, whereas others remain deadly.
To Chia-Lin Chang:
Indeed, I hope that the consequences won't be irreversible when humankind becomes wise enough to change its behaviour and thus, when the cancer is cured!
To Filippo Alnardo Salustri:
Again, I fully agree with near all your very relevant recommendations.
Actually, I think if everyone changes his behaviour then the game is won.
Unfortunatly:
- we have very little time;
- I doubt that the great majority of us is able to do it.
I agree that every single positive change is worth doing, no matter how small. However, I am doubtful as whether it goes far enough to avoid irreversible damages.
I would like to add that the impeding extinction of our species is not most likely, not even likely.
By contrast the extinction of larger species and those living at lower latitudes or in forests or oceans is not only very much likely but has already begun.
Dear Marc:
Not all cancers are curable.
Many of the negative impacts of humankind on the earth will be difficult to reverse.
Dear Chia-Lin,
It should not be taken literally the word "cancer" I use. I use it as a metaphore to highlight the dramatic biodiversity damages caused by the humankind increasing invasion of most ecosystems.
Indeed, I agree with you that irreversible damages, such as species extinctions, cannot be cured.
While US is the most polluter country in the world it is hotbed of climate change denial. Out of 23 big countries, only Saudi Arabia and Indonesia had higher proportion of doubters (The Guardian 8 May).
The fact that Donald Trump dares say "The whole climate crisis is not only Fake News, it's Fake Science" indeed reinforces the doubters' belief not only in US but also worldwide!
One can realize the insane irony of the situation as only our species is able to become aware of the drama for which we are responsible.
For sure, especially because leaders of large countries (e.g. US, Brazil, Indonesia) claim that there is no problem at all.
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