Tag Archives: biodiversity

International Day for Biological Diversity, 22 May 2023

A moment of global agreement

Biological diversity (or biodiversity) means the variety of living things. It is a term that passed from conservation science into international law through the Convention on Biological Diversity (CBD). This was agreed at a UN conference in Rio in 1992, along with the conventions on climate change and desertification, and entered into legal force on 29 December 1993. Those were the heady days when peoples, experts and governments could agree on the need for urgent action to save nature and the human future. But in the years that followed goals and targets were repeatedly missed, and our global problems kept on getting worse.

A subtle but important idea

Meanwhile the word ‘biodiversity’ never really caught on as a way to promote public understanding. To make it make sense it often had to be translated into stories and pictures about endangered animals, plants and nature reserves. This gave the impression that biodiversity just meant ‘wildlife’. But it is in fact a different, deeper and more subtle idea about the nature of all living systems, which are involved in crises of global heating and climate change, desertification and water stress, and poverty and insecurity. So it’s worth going back to the very beginning to see what ‘biodiversity’ really means.

Immortal life

All living things (or organisms) share a common and continuous ancestry from the start of life on Earth nearly four billion years ago. Life as a whole is thus effectively immortal, even though all individual organisms eventually die. But if they have been able to cope in their own particular environment, they will have reproduced before dying. If so, then their offspring will keep their lineage going for another generation. Uncountable lineages since the beginning have thus struggled to continue, all competing to seed every new instant and environment with their own kind of life.

Diverse life

Under this pressure, the lineages of life spawned a near-infinity of different forms. Each made a living in its own way, and bred almost true until opportunity or necessity changed the rules of its existence. Then new forms arose by natural selection, time after time, rising and falling into extinction as changing environments dictated. All this creativity and intergenerational memory was made possible by complex molecules that stored, copied and passed on the information needed to make each organism in each place and time. These molecules are what we call genes and genetic material, the stuff of heredity and design information in living systems.

The Tree of Life

Now consider the myriad trillions of individual organisms and tens of millions of distinct lineages (or species) at any moment of Earth’s history, all living in intricate relationships with one another. Then you see the complexity and diversity of life on Earth, which we call biodiversity. Add the perspective of billions of years, with each species only lasting a short while before being replaced, and you have the immortal Tree of Life itself. This is a metaphor for something well beyond ordinary human understanding. A Tree rooted in the unimaginably distant past, bearing a shimmering, ever-changing canopy of life forms on the twigs and branches of its many tangled lineages

The Living World

And now add the curved surface of the Earth, oceans and atmosphere within which the Tree grows: the great planetary ecosystem that we call the living world or Biosphere. This unites all the subsystems and environments inhabited by every organism and species that lives on the planet today. These two visions of the Tree of Life and the Biosphere are useful and important, and should be taught from birth in all societies (as they are in some). The idea of the Tree tells us how we as organisms came into being, and that of the Biosphere tells us where and how we live as organisms among many others. The idea of biodiversity is integral to both.

Our divided minds

These concepts help to place us in the Universe. They also give us a context and reason for our existence, both as organisms and as conscious, social beings able to make informed and debated choices. These two aspects of being human are equally true. We have an animal existence shaped by heredity and evolutionary change, as well as individual consciousness shaped by culture and life-experience. But tensions within this double truth yield dilemmas, as well as enormous potential for cooperation and selfishness, which we often call good and evil.

Careless economics

People have recently gained access to fossil energy in the form of coal and petroleum, and combined its use with powerful new technologies. Thus we have built an economic system that has been allowed to operate almost regardless of the rules of ecological sustainability. Dire and dangerous consequences are now rampant: global heating from pollution that traps the Sun’s heat in the Biosphere; ecosystem degradation from over-exploitation and the expansion of settlements, infrastructure, plantations and farmlands; and mass extinction of non-human life forms from direct harm to natural ecosystems and from climate change.

The shedding of leaves

By these means we have blighted the Tree of Life, which is now shedding ‘leaves’ (species), ‘twigs’ (genera) and ‘branches’ (larger and deeper lineages) faster than at any time since the meteor strike that killed the non-avian dinosaurs 65 million years ago. And it is doing so much faster than at any other time in Earth’s history. This loss of biodiversity is rapidly degrading the integrity of the living systems that we depend upon. The blight is also undermining the stability of the oceans, Amazon, Arctic and other major Earth systems. The consequences if they tip into chaos are scarcely imaginable, but on present trends it could happen in this very century. Thus the blight threatens to end our comfort and prosperity, and quite possibly our existence.

A day to remind us …

Which brings us to the International Day for Biological Diversity. This was declared by the United Nations in 1994 to mark the CBD’s coming into force on 29 December. But in 2001 the date was changed to 22 May to avoid the distractions of mid-winter and year-end festivals. Its purpose is to remind us of the need to respect the Tree of Life and the Biosphere, of what we have been doing to them with our careless economic system, and of how we must regulate our behaviour to stay within the bounds of sustainability. In short, of the need to restore harmony with nature before everything tips into chaos.

And a day for celebration and commitment

In 2023, the International Day for Biological Diversity is a reminder of acute danger. But it can also allow for celebration that we are starting to recognise the threat, and to act on it. Many now remember that nature is the most valuable thing we have. We are living more gently within nature, and voting for better and greener governments. Our great task now is to restore ecosystems and peace with nature, and on this day we should think realistically about how to do so. In practice it can mean donating to wildlife trusts and community rewilding initiatives, or participating in actions to protect nature, or helping to build a sense of ecological reality among young and old. All such efforts are welcome, and all are vital for the Tree of Life and Biosphere.

© Julian Caldecott

Buying time to avoid Earth system breakdown

In this talk at the Edinburgh Climate Change Institute, Julian Caldecott warns of tipping points driven by global heating in the Arctic and other complex Earth systems. These systems have been under stress for decades, due to the heat-trapping effects of excess greenhouse gases. Using the case of the Arctic sea ice ‘death spiral’ since 1979, Julian explains how complex systems under this kind of stress tend to resist change before suddenly tipping into new forms. He then uses his knowledge of government climate aid programmes to show how being aware of mid-century deadlines can help us make better choices in mitigating climate change. Having a dated reference point would make it easier to calculate the true mitigation value of investments, thus helping to buy us time to build a safer and fairer world, one with peace with nature at its heart. But peace with nature needs ecosystem thinking, and this must quickly become normal if system change is to occur. Julian asks challenging questions about ‘business as usual’ climate aid, and offers new solutions in this most vital area of public policy.

Watch the video, or read more …

Some of the thinking in the talk is new and unorthodox. It treats Earth systems as complex and assumes that, like other complex systems, they can tip suddenly from one state to another after they have been under stress for a long time. Julian argues that just such a stress is the trapping of heat in the biosphere by greenhouse gases at a concentration in the air above 300 ppm CO2, which has been the case since about 1950. Its direct consequences include rising heat content of the world ocean and increasing global mean surface temperature (GMST). Its indirect consequences include declining polar sea ice volume, melting glaciers, marine and terrestrial heatwaves, weakening ocean currents and changing weather patterns that are often experienced as environmental chaos and usually described as climate change (CC).

The current 1.5 C goal, based on GMST, helps to focus public attention and mobilise action by governments. But it does not reflect the non-linear responses to be expected of a system as complex as the biosphere. The continuity of cause and effect over time, and the prospect of tipping points, challenge the realism of CC mitigation planning and investment assumptions. Improvements can be made by using an estimate of when Earth systems will, with current timing and heating trends, become irreversibly committed to transformational (‘tipping point’) change. This will pre-date the tipping point itself, so estimating when allows us to judge the effectiveness of CC mitigation investments in postponing it. Postponing tipping points is how we can buy ourselves time to make the changes needed for longer-term safety.

But such postponements may well become harder to do over time, as each system becomes steadily more inclined to transform itself. A relevant case is the ice-free Arctic Ocean, anticipated for September 2035 ± 5, which may already be unstoppable and could well drive a dangerous methane surge when it occurs. The mitigation value of delivering avoided net emissions would presumably decline in real terms as the commitment point is approached, either suddenly on its eve or more gradually in the preceding years. Uncertainties abound and call for precautionary thinking about the dates involved and the mitigation value of investments, including the unit value of mitigation returns on those investments. For these purposes, it is more realistic to reduce that value exponentially from now to the commitment point, rather than to assume a change from ‘valuable’ to ‘valueless’ the day before it.

Thus, a dated ‘deadline’ in mid century (2050 ± 10) might be chosen to represent the transformation commitment point of key Earth systems. This is based on the trajectory of change in sea ice minima in the Arctic Ocean, and on the rate and direction of change in other cryosphere (ice-world) and oceanic systems, and in major equatorial forest areas. Whatever the deadline chosen, precautionary investment plans would exponentially reduce the value of each expected mitigation unit as the deadline approaches. Such plans would therefore express all expected emission reductions not in tCO2e but in tCO2edmv, where ‘dmv’ stands for dated mitigation value. This would have the effect of valuing early net emission gains more highly than later ones. This is already in principle a common aim, but a standard metric would allow direct comparison of true cost-effectiveness between alternative investments in practice.

Julian tested the usefulness of this approach with data from projects funded by one EU member state in three developing countries, targeting: avoided deforestation; forest regrowth (also representing tree planting); wind farming (representing renewable energy, RE); and capacity building for economy-wide decarbonisation. Over 21 years with a constant 0.1 exponent used to depreciate mitigation value (such that 1 tCO2edmv in year 1 = 0.41 tCO2edmv in year 10 = 0.14 tCO2edmv in year 21), returns were estimated at 0.90 tCO2edmv/€ for capacity building, with least certainty; at 0.40 tCO2edmv/€ for avoided deforestation, with moderate certainty; at 0.05 tCO2edmv/€ for forest regeneration/planting, with moderate certainty; and at 0.01 tCO2edmv/€ for wind farming, with most certainty.

Among the cases with moderate to most certainty, the much higher mitigation returns from avoided deforestation than from RE and tree planting investments offer a key lesson to mitigation planners. Variation in the certainty of returns is an important factor in choosing the right mix of investments for each location, but so too are the varied co-benefits (biodiversity, adaptation, human rights, sustainable development, etc.) available from different investment strategies. And the biggest risk of all is that transformation commitment points in Earth systems cannot be postponed (or will not, due weak precaution and/or weak leadership).

This all suggests that a key starting point for justifying the expenditure of public mitigation funds lies the calculation of tCO2edmv/€. Once this is done, other factors such as expected co-benefits can be considered in detail. But the initial calculation would require an agreed deadline date (which could be moved by agreement later, if success is achieved), an agreed exponent for converting tCO2e into tCO2edmv, and attention to the comparative valuation of co-benefits for fine-tuning the justification of each investment.

Watch Julian’s talk and the Q&A afterwards here.