Category Archives: Tipping points

Fossil Fools Day, 2023

On this first day of April we celebrate foolishness. There is none greater than burning your own home because you like the pretty flames. It’s not even as clever as peeing in your pants to keep warm at the start of winter, as they say in the Nordic countries. So we throw more coal, peat, forests, petroleum and natural gas on the fire because it’s convenient right now. But the effects, as Al Gore and Greta Thunberg have pointed out, will be not just inconvenient but deadly.

Too many fires are making too much carbon dioxide too quickly. This traps the sun’s heat on Earth, warming the oceans and melting the ice of the poles. The Arctic is an ocean surrounded by land. In its bed are a trillion tonnes of frozen methane, which is already bubbling to the surface, and methane is much better at trapping heat than carbon dioxide. Moreover, in the frozen lands around about are another trillion tonnes of methane, held in frozen peat and organic soils. This is already leaking out as the ice lands melt and rot.

So what will happen when global heating pushes the Arctic beyond whatever tipping point keeps it in the deep freeze? Of course the answer is an immense pulse of methane. That’s the big show that could finish us off. Carbon dioxide is only the warm-up act. And when might that happen? All the signs suggest around the middle of this century. Are we ready for this, and do we even know what ‘being ready’ means? Are we even trying seriously to cut back on carbon dioxide emissions? We still churn out scores of billions of tonnes of the stuff every year, and save only a thousandth part of that. So the answers are: not yet!.

We seem inclined to keep putting things off. But with a mid-century deadline looming from the Arctic methane if nothing else, putting things off is really daft. Even if the sums are wrong and it’s really the 2080s rather than the 2050s when the Arctic methane hits the fan, that’s still not very long. We need to get a grip. And that means putting away the jester’s bladder and getting serious. So what to do instead of acting the Fossil Fool?

I could rattle off a list, but here are a couple. First, we should vote only for leaders who will tax carbon emissions radically and enable ferocious and fair investment in decarbonising our economies. And second, we should make sure that rewards from investment are highest when emissions are avoided soonest. With special merit points for those that also help protect and restore nature, and that promote human wellbeing and community solidarity. This would make working with local communities to prevent harm to all our remaining high carbon-density natural ecosystems the maximum top priority everywhere on Earth.

The simple fact in this emergency is that a tonne of emissions avoided now has much more survival value than a tonne of emissions avoided years from now. So that should be the starting point of all our policies, and it should shape all our efforts, incentives and disincentives. Any proposal to decarbonise anything should be met by the question: how much carbon saved how quickly? And be closely followed by another: and with what co-benefits?

These questions will lead not only to the best nature-based and community-based solutions, but to the best technological ones as well. The point is that every potential investment should be made to answer the same questions, so we can compare them. Talking up innovative and imaginative solutions is OK, but only if they are supported by evidence-based reasoning that lets us pick the most cost-effective ways to avoid global catastrophe. Survival value, precaution and co-benefits should be the watchwords. The time is over for Fossil Fool governments that fail to protect us, our children and the biosphere. No to more foolishness! Happy All-Fools Day.

New paper on biosphere tipping points and climate investment

My new paper ‘Implications of Earth system tipping pathways for climate change mitigation investment’ has now been published in the peer-reviewed journal Discover Sustainability. It can be freely downloaded here. In it, I explore some implications of an anticipated biosphere-wide tipping point (BTP) in the year 2050 ± 10, including:

that all climate change mitigation investments should be designed, chosen and judged against this hard and dated deadline, thus urgently prioritising early delivery of net GHG savings;
that deadline-compliant investments should aim transparently for optimum cost-effectiveness in their biophysical outcomes, especially net GHG emission savings but also biodiversity, ecosystem service and climate change adaptation co-benefits; and
that investors and markets should prefer actions that yield highly cost-effective biophysical returns, especially where valuable co-benefits are expected.

I explain how to do the necessary calculations, and I provide examples from recent mitigation aid portfolios to support a change of focus from financial to biophysical returns on investment. From these cases, key ways to prevent the BTP include protecting and restoring high carbon-density natural ecosystems, and improving choice awareness and building capacity to promote decarbonisation in all economic sectors.

Three urgent research priorities remain: (1) on the consequences of an Arctic Ocean imminently free of summer sea ice, and options for remedial action including the recapture of methane at large scale and high speed; (2) on testing a new dated mitigation value metric in justifying precautionary mitigation investments in multiple sectors and contexts; and (3) on integrating diverse co-benefit values (biodiversity, ecosystem services, adaptation, etc.) into mitigation investment decision making.

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.