Fifty Fifty

Kunming-Montreal Agreement December 2022 (Cop15, target to protect 30% of nature by 2030)

… only by setting aside half the planet, or more, as natural habitat, can we save the living part of the environment and achieve the stabilization required for or own survival. E.O Wilson, Half-Earth (1929-2021)

Is 30×30 ambitious enough?
two-thirds of conservation scientists agree [1] that if we are to successfully address the twin existential crises of the climate and extinction emergencies it is imperative that we protect, conserve, and steward at least half of Earth’s lands and seas in a high-functioning, wild and intact state. This is iterated in the 2022 International Panel on Climate Change (IPCC) report stating that “conserving half may be necessary to restore the ability of natural ecosystems to cope with the damage wreaked on them.” [2]

What exactly is at stake if we fail to protect Earth’s biodiversity by not setting aside enough space for nature? Loss of biodiversity means not only that species of animals and plants are disappearing, but also that the food supply, health and security of humanity are at risk. In short: without biodiversity, no oxygen, no fresh water, no bees, no pollination, no food.

Protecting and conserving half does not mean that we have license to degrade the other half, nor does it mean the exclusion of people from living and working in the conserved half. We must prioritize the life cycle of plants and animals on at least half of the earth’s surface, how we do that is up to us to decide. Only the boundary is not set by us, but completely determined by the needs of nature. Why not set aside half the planet now, when it is ecologically better to do so, and work creatively within these boundaries to create a truly sustainable society? [3]

Not in 2050 but now
The rationalizations for why we cannot achieve Half, at least not now, center on political and economic concerns: it’s just not feasible in such a short time period. In actuality, it is likely far easier to achieve Half in the near-term than it is in the distant future. Because by 2050, we can expect that there will be 25 million kilometers of new paved roads globally – enough to encircle Earth 600 times. [4] Combined with a doubling of urban areas to accommodate the nine billion people that are anticipated to live in cities, it is reasonable to ask where space for nature will remain in 2050 if we do not act now.[5]

We now have (if only barely) a planet with about half of its nature intact.[6] When is it more feasible, economically and politically, to take action to protect Half? Is it really a choice we can afford to postpone to the future, if to reach Half in that future we will have to restore nature on a massive scale and cannot bring back the thousands of species of animals and plants that have become extinct by then?

In ecological terms, we are far more capable of achieving the Half target now than we will be in 2050. The consensus – 30×30 is an important milestone on the road to half. In addition, a major step forward would be to give nature its legal rights, as laid down in the constitution in Ecuador and also happened for the inland sea Mar Menor in Spain.

On the edge of the abyss
The most significant obstacle to achieving a healthier relationship with our wild planet is our own lack of ambition. Environmental ambition is not, and never has been, an easy choice. The alternative though is far more dire. At no point in life’s ancient history has nature been so fragmented and frayed. We are rapidly sailing over a precipice of planetary proportions, one that we have never crossed before, and one from which there is no guarantee we can climb back out.

Up till now the world is failing to address a castrophic biodiversity collapse that not only threatens to wipe out beloved species and invaluable genetic diversity but endangers humanity’s food supply, health and security.

Can we afford to wait for political will to catch up to science, even as the ecological fabric of our world disintegrates? [7]

A version of this article is published in Trouw 10 January 2023

  1. Woodley, S. et al. (2019.) Area-based conservation beyond 2020: A global survey of conservation scientists. Parks Vol. 25. 2 November 2019:
  2. (2022.) Climate change 2022: Impacts, adaptation and vulnerability. United Nations: sixth-assessment-report-working-group-ii/
  3. Dinerstein et al. (2020.) A global safety net to reverse biodiversity loss and stabilize Earth’s climate. ScienceAdvances. Vol 6, Issue 36:; Woodley, S. et al. (2019.) A review of evidence for area-based conservation targets for the Post-202 Global Biodiversity Framework. Parks. Vol 25, issue 2: wp-content/uploads/2019/10/Woodley-et-al-Targets-PARKS-25.2-proof-3.pdf; Locke, H. (2013.) Nature needs half: A necessary and hopeful agenda for protected areas. Parks. Vol 19, Issue 2: 19.2-Nature-needs-half.-A-necessary-and-hopeful-new-agenda-for-protected-areas.-Locke-pdf.pdf
  4. Dulac, J. (2013.) Global land transport infrastructure requirements: Estimating road and railway infrastructure capacity and costs to 2050. International Energy Agency, Paris.
  5. Global Alliance of Buildings and Construction. Status Report: 2018. United Nations Environment Programme:
  6. Dinerstein et al. (2017.) An ecoregion-based approach to protecting half the terrestrial realm. Vol 67, Issue 6:
  7. Is the status quo ambitious enough? Wild, COP15 briefing note