Category Archives: Biosphere

World Ocean(s) Day, 8 June 2023

Celebrating oceans

The world ocean encompasses all the bights, gulfs, seas, straits, bays, inlets and deep waters of the Atlantic, Pacific, Indian, Arctic and Southern oceans. With 97% of Earth’s 1.4 billion cubic kilometres of water, it covers 71% of our planet’s surface to a mean depth of 3.7 km, but with trenches up to three times deeper. World Ocean Day and World Oceans Day both sprang from the 1992 Earth Summit in Rio de Janeiro, Brazil. On 8 June they focus our attention on the key role of the oceans in the biosphere of our blue planet.

Two days in one

Ocean Day is the more activist version, especially engaging young people and partnerships with aquariums, zoos and museums. In 2022 it involved over 10,000 organisations and businesses in more than 15,000 ocean-themed events in 140 countries. Oceans Day is more official, linked to international treaties on the law of the sea, biodiversity, climate change and desertification. So between them, the two days in one respond to our emotional and intellectual fascination with the world ocean as the dominant feature of the biosphere. And in doing so they focus public concern on the need for governments to cooperate in saving this rich and beautiful living world.

Life in the world ocean

Almost all ocean life is sustained ultimately by the largest photosynthetic mechanism on Earth, the phytoplankton of the top hundred metres or so of sunlit water. This is mixed by currents, the daily vertical migrations of planktonic organisms, and the churning of whales. Its abundance is harvested directly or indirectly by a great diversity of jellies, corals, sponges and sea-fans, amongst many others, and by swarms of finned, tentacled, iridescent and scaled creatures. Once dead, these fall into a seething community of scavengers in the muddy silt of the abyss: brittle-stars, sea spiders, crabs, polychaete worms, nematodes, giant isopods, slime eels and sleeper sharks. And the accumulated nutrients of the sea bed are sometimes lifted back to the shallows by up-wellings that support areas of enormous biological productivity.

Traces of deep history

The oceans cradled life on Earth, and many of its basic designs (phyla) are only found in the sea. From the distribution of these and other marine organisms we can trace the effects of continental drift going back scores of millions of years. Thus there was once a huge equatorial Tethys Ocean, named for the ancient water goddess and consort of Oceanus. It lay between the northern continent of Laurasia (now Eurasia and North America) and the southern continent of Gondwanaland (now South America, Africa, Madagascar, India and Australia). It remained tropical as the continents wandered and collided, but was gradually squeezed by the moving lands. So it ended up as the Coral Triangle, reaching from Malaysia to the Philippines, Papua New Guinea and Indonesia. That region preserves the whole evolutionary record of a long and continuous history, and therefore has more marine species than any other.

The over-fished ocean

People have been harvesting the abundance of sea life since the early days of our lineage. We may even have taken up walking on two legs for wading and foraging in coastal waters. Later we made more and more effective traps and boats, in recent years powering unbreakable fishing nets and steel trawls through delicate and complex marine ecosystems. For all our knowledge of wildlife ecology and sustainable yields on land, where we can see what’s going on, we never really understood how sea-life should be harvested properly. The result is that life in the ocean is now much depleted, and can only really recover where people agree to take the pressure off and let it breed and grow again. These precautionary and no-take agreements are very hard to reach, and meanwhile there are other threats that are even harder to manage.

The polluted ocean

Everything we make and do on land can be picked up and carried by water downstream and into the sea. Run-off includes phosphates and nitrates from farmlands, and sewage from livestock and people. Biologically active, these wastes drive algal blooms that sap the oxygen from sea water, suffocating other life and creating multiplying dead zones. Diverse poisons add to the harm: insecticides from farms, waste chemicals dumped or leaked from industrial plants, and toxins leached from garbage land-fills. We even allow about 11 million tonnes of plastic wastes into the ocean each year, all with their own physical and chemical impacts. And finally, carbon dioxide from almost everything we do is making sea-water steadily more acidic, dissolving the shells and skeletons of marine organisms. As UN Secretary-General António Guterres says, we’ve been using nature and the world ocean like a toilet.

The heating ocean

Far more than air and the land surface, water takes a lot of energy to heat up and it holds that energy for a long time. By absorbing most of the extra heat trapped on Earth by carbon dioxide, methane and other greenhouse gases, the world ocean has protected us against its effects. This let us ignore or deny the underlying problem of global heating for too long, but the days of wilful ignorance are over. Since about 1970 average deep ocean temperatures have been rising, and those of surface waters are now accelerating upwards. And this changes everything: sea level as the ocean expands, the volume and direction of ocean currents, the timing and quantity of rainfall on land, and the frequency and destructive potential of storms that hit the coasts.

Action stations: this is not a drill!

World Ocean(s) Day is now deadly serious. We need to get a grip on sewage, chemical and plastic waste, our destructive treatment of marine ecosystems, and greenhouse gas emissions if we are to navigate this century without global catastrophe. The world ocean is too big and far too powerful to harm with impunity. We know what we should be doing with ever-greater clarity, but taken together our governments and businesses are doing far too little of it. Some are leading, and we should be applauding and rewarding them. Many others are lagging, influenced by polluters and other short-term interests, and we should be pressing them to do better. What hope there is lies with the millions of young people and dynamic institutions who support World Ocean(s) Day, and in the human capacity to restore peace with nature.

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.

International Day of Forests, 2023

How we treat our forests is a measure of our relationship with nature, with each other, and with common sense. With nature because natural forests are key components in the web of life: rich with biodiversity and evolutionary and biophysical processes that sustain the living world. With each other, because natural forests are lived in by many indigenous peoples and also support vast downstream and nearby populations who rely on them for water, environmental security and essential harvests. And with common sense, because natural forests make landscapes, countries and the world as a whole both habitable and beautiful, so wrecking them is our loss.

We know all this, but the harm still being done to forests shows that we find it hard to regulate our collective treatment of them. This is usually because the bounty that forests offer is most appreciated locally and globally, but less so at intermediate levels where businesses and national governments operate. Here there are incentives with their own logic, which make it profitable in the short term to over-harvest catchment forests for their timber, to replace wetland forests with aquaculture ponds, or inland forests with plantations, mines or planned settlements.

Local and indigenous people are often too weak politically to protect themselves against these forces, yet wherever they are empowered over their forests they prefer to keep them intact. Meanwhile, the global community looks on with rising alarm, conscious that with every hectare of forest lost, another few hundred tonnes of greenhouse gases are released into the air. The days are long gone when a forest could be destroyed in Borneo or the Amazon without anyone caring on the other side of the world. Now we know that we all have to live with the consequences of global heating: floods, droughts, crop failures and high food prices, a list lengthening inexorably towards worldwide suffering, war and total system breakdown.

The story of our efforts to slow and halt forest degradation and loss is dominated by the interplay of these three levels of human society. Local people have strived for recognition and control of their lands and ecosystems. Businesses and governments have strived for short-term wealth. And global actors have strived to moderate short-term demands on forests, while not interfering in national decisions but not able to pay enough to cancel out perverse incentives. Yet this dialogue has yielded victories when different interests aligned around workable solutions.

These usually result from governments and global actors agreeing that local people should take charge of local forests for everyone’s benefit, and should be supported in doing so. Examples include the successes of Danish and Swiss support for indigenous land titling in Bolivia and community forest user groups in Nepal, and Danish support for community forest protection in the Harapan area of Sumatra and the Mbeliling area of Flores in Indonesia. There are many others, and not just in forests. The combination of local empowerment and environmental education works just as well for mangroves, fisheries, grasslands, bush-savannahs and other ecosystems wherever one cares to look, from the equator to the poles.

As well as being good for human rights, traditional lifeways, local well-being, biodiversity and landscape-scale ecosystem services, community forest initiatives are also cheap. Just for carbon, test calculations from Danish investments show that protecting high carbon-density natural ecosystems with community help has far higher climate change mitigation effectiveness per unit cost than renewable energy generation projects ever can. And the co-benefits of these initiatives are abundant, diverse, and full of promise for fair and sustainable wealth creation.

So while we struggle to head off global catastrophe later this century, we should be concentrating on the most cost-effective ways to change outcomes. And that means massively accelerating our investments in nature-based and community-based solutions in natural forests, but learning from past successes and doing it right. Adequate funding for local partnership-based protection over millions of hectares can offer certainty that billions of tonnes of carbon will not be released quickly. As a precaution during a life-or-death gamble with the living world, the need for this assurance should be shaping the regulations and market preferences that control the flow of all climate-relevant investment. With local people as genuine partners, encouraged and enabled by wise governments and advised and financed globally, conserving the world’s remaining natural forests is key to solving the triple crisis of climate, nature and poverty that faces us all. This offers us hope and purpose for the International Day of Forests, 2023.

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.

Ecology

Ecology is the science of living systems. As a science, it relies on the use of common standards of observation, analysis and collective criticism to build up reliable descriptions and explanations of reality. As biology, it assumes the engineering of organisms through evolutionary responses to design challenges imposed and opportunities offered by the real world. This makes biological thought very practical, and often to do with budgets, investments, costs and benefits that may be expressed and accounted in terms of energy, nutrients and surviving offspring. But being also concerned with systems, ecology focuses on describing the parts, their relationships, the things that connect them, and the properties that result from all the parts, relationships and connections being active within or upon each system.

Since every living system is connected to every other, an ecologist distinguishes them only as a matter of convenience, and has to remain alert to possible influences from abroad at all times. Here, ‘abroad’ means any kind of distance – spatial, but also sensory (that is, what can be detected using our human senses, as constrained by the expectations of our culture and the abilities shaped by our inherent aptitudes and training, and what other organisms can detect using their own senses, which may differ from ours) and instrumental (that is, what can be detected by the instruments we use, as constrained by the expectations of existing knowledge that are designed into the equipment, and which may simply be unable to detect something important). So while proceeding more-or-less within the boundaries of consilient science, this alertness to ‘abroad’ makes ecologists open to the phenomenological diversity that is inherent to anthropology, mythology, psychology and religion, and also to potential connections within and between systems that are invisible to human senses and current instruments.

At the same time, the systems approach requires an ecologist to think in terms of every system being part of a bigger system, in a connected sequence from the molecular to the global level, and with the characteristics of every level both influenced by and influencing every other level, over every imaginable scale of time and space. This is a way of thinking reminiscent of anthropology, since both have the same challenge of reconciling detail and pattern at all scales. Living systems include our own selves, families, communities, farms and dwellings, as well as the atmosphere, oceans, coasts, swamps, grasslands, soils, drylands and forests and all their non-human inhabitants, which make up the living world and every part of it. These are all systems, and climate change is a system-wide phenomenon, so we have no choice but to address it at a system-wide level. In doing so, since every part of the ecological story has to be supported by evidence and reason, the result in ecology is an edifice of systems knowledge that is reliable, vast and inclusive enough to make sense of climate change and help with the challenge of adaptation in all parts of the world and at all scales of human society and the ecosystems that sustain it.