0° Initiative

Today, I would like to recommend three books by Edward Osborne Wilson, who was an influential voice in the fields of biogeography (where Robert MacArthur and him conceived the widely applied thoery of island biogeography), evolutionary biology, sociobiology, conservation and others. The first book is "The Diversity of Life" from 1992, which gives an overview about the evolutionary mechanisms that shaped the diversity of life forms on this planet, the rising threat of species extinction by human expansion, as well as concrete examples for resolving this conflict by closer integration in space, time, energy, matter and information between the human and the natural world. In the second book, "Consilience: The Unity of Knowledge" from 1998, this integration of both spheres is discussed much more generally under the premise of developing a unifying perspective on the co-evolution of nature with its biodiversity in genes, species and ecosystems, and human biology, society, culture, arts, religion and science. While his personal perspective in this book is one of sociobiology, the underlying theme is a much broader encouraging call for bridging scientific disciplines and scales, to find a comprehensive perspective on both humans and nature, and to develop a common scientific story of how both shape each other. The third book, "Half-Earth: Our Planet's Fight for Life" from 2016, makes a much more direct argument for the necessity to put half the planet, continents and oceans, under some form of conservation management, to ensure the long-term coexistence of humans with the remaining life on Earth. At it's core, the book revolves around a fundamental ecological root-function-relationship between area and species richness, the concentration of biodiversity in specific regional hotspots, and the still superficial empirical cataloguing of global biodiversity. While this book has been criticized for its lack of concrete implementation strategies, previous work, such as "The Diversity of Life", outlined this aspect in more detail, be it by acknowledging co-evolved indigenous ecological knowledge, or 'scientifical' land-use practices that take species composition and ecosystem functions into account. Overall, a theme of Wilson's work is an attempt of a unified perspective on humans and nature, as a means to advance understanding, but also to outline a path of reconciliation of the two realms, which increasingly split apart throughout human history. Particularly after his death, some of his views and affiliations have met criticism and scrutinization. As such, Wilson certainly had some ambivalences, which are perhaps in some form inevitable when attempting his overarching tour de force that was his life. Still, with a critical mindset, his work provides a wealth of insights, as original as they are ambitious, and to anyone that is interested in the history of and mechanisms behind life on Earth, I recommend reading his books. #zerodegrees

According to Barnes et al. (2025), for much of the planet, regional warming could reach 2 °C until 2040, and 3 °C until 2070. To address the high uncertainties of classical climate models when simulating regional warming, they trained several Convolutional Neural Networks (CNN) on a range of Coupled Model Intercomparison Project 6 (CMIP6) models, which were parameterized with historical regional temperature data and assume a "worse-case" SSP3-7.0 (Shared Socio-Economic Pathway 3 / +7 W/m^2 warming) future emission scenario, characterized by geopolitical competition and a lack of global mitigation efforts. Likewise, they used spatial temperature data from the anomalous years 2023/24 as neural network input. Thus, their assessment could be regarded as a conservative, higher-bound worse-case. Nevertheless, while this averaging of averaging adds layers of intransparency on model projections, it works well for classical machine learning. Additionally, what might be regarded as pessimistic parameterization, can also be interpreted as rather realistic, given current developments. In any case, it is a further reminder that climate change mitigation and carbon dioxide removal should be taken very seriously. #zerodegrees https://lnkd.in/gXbQeB92

Who should pay for climate change? The fair distribution of costs remains a highly contentious issue, intrinsically linked to global inequalities and historical responsibility, particularly regarding CO2 emissions. Historically, about 25 % of all fossil fuel emissions were produced by the US, followed by China (15 %), Russia (7 %), Germany (5 %), UK (5 %), Japan (4 %), India (4 %), and other industrialized nations, while many South American, African, Asian, and Oceanian nations did contribute only a small fraction (Map 1). In absolute terms (Map 2), this is particularly visible with Sub-Sahara Africa, where most countries produced a few 10 or 100 million tons, whereas the US, China and Russia emitted several 100 billion tons, a difference by a factor of 1000 or more! This changes when distributing yearly global emissions more fairly by global population share (Map 3). Here most industrialized nations should have emitted 10s of Gt of CO2, not 100s. The reverse is true for most others, particularly India and Africa. When comparing the difference between actual and allocated emissions (Map 4), this global divide becomes clearly visible. Of course this division is a bit more nuanced, as is evident in the ratio of historical to allocated emissions (Map 5). Here the Arabian states take the cake, having emitted 4-10 times more than their population would suggest, followed i.a. by the US (5x), Canada (4x), UK (3.6x), Australia (3.5x), Germany (3.5x), Russia (2.5x), and others. On the flip side, China is rather close to 1 (3/4), whereas countries like India (1/5), Pakistan (1/15), or Bangladesh (1/20) are far below, especially Sub-Saharan nations, with most between 1/10th and 1/100th! So who should pay for climate change? It is clear, that the actions of a relative minority shaped the reality for the majority. While the North has benefitted from abundance, much of the South has been excluded. In this context it seems only just to ask for equal rights to extract, burn, emit, exploit, that created much of the welfare the world rests on. While this view is economically logical, the tradeoff between emissions and growth is less acceptable by the year. When the paths of the past are turning into dead ends, privileges come with a moral and causal obligation to carry a fair share. While many attributions can be conceived, the fairest to agree and simplest to implement might be the emission shares of Map 1. However, as UN conferences show, even this might remain nothing but a phantasma of a just world. In a sense, who SHOULD pay might be irrelevant, and instead the real question is, who WILL pay. In that regard the division is between the insensible and the sensible, the irrational and the rational, the careless and the caring, the conservative and the courageous. The futures are open and it's up to us to make a wise choice. #zerodegrees ### Sources ### Our World in Data 2024: https://lnkd.in/dzffAnH2 https://lnkd.in/dM8X5-BA

According to a new study by Goessling et al. 2024, the recent global temperature increase during 2023 and 2024 of about 0.2 °C seems to be related to a sudden decrease in global albedo (reflectivity), specifically to a notable decrease in lower altitude cloud cover in the Northern Hemisphere and the Tropics. They speculate that this could be a result of internal variability, an unknown cloud feedback, or effects of aerosols. The latter might be related to coinciding emission regulations for shipping or the eruption of Hunga Tonga-Hunga Haʻapai. In contrast, alternative explanations like El-Nino or increased solar activity have been ruled out as main drivers. While disentangling the potential interactions and causes remains difficult, it is clear that existing climate models are incomplete and potentially significantly underestimate the sensitivity of Earth's climate. A hotter planet is approaching much faster than anticipated even by close observers a few years ago. Reality indeed waits for no-one. #zerodegrees https://lnkd.in/dwtZekdG

To Part 1: https://lnkd.in/d7Yn9zPX Well, of course Enhanced Weathering has also issues: 1. We would need to mine a lot. In 2020 about 17.3 Gt in metals and coal were extracted globally, which is about 36 % of the 48 Gt needed in the example. Of course there is substantial overburden, but, being complex mineral mixtures, not all are suitable for weathering. If this could make up for the 2.8-fold difference is unclear. 2. The assumed weathering rate of 1 kg/m² and year is also unrealistically high, especially when considering saturation through continued application. This could easily lower the effectiveness by an order of magnitude or more. 3. Only certain croplands with wet and warm climates (tropics) offer suitable conditions for fast weathering reactions. 4. Mineralizing croplands only confines the available area, and scaling beyond makes EW more costly. 5. By nature, mining waste has higher concentrations of toxic metals and compounds, with rather negative effects when entering the food chain. Reducing the dispersion or purifying the minerals limits scale and raises costs. 6. Excessive extraction and deposition has significant detrimental ecological effects. 7. Global extraction, processing, transportation and deposition infrastructure would have to grow considerably. 8. To create a net-negative CO2 balance, the underlying infrastructure needs to be fossil-fuel-free as well. 9. While leveraging potential synergies (fertilization), as with most CDR, EW relies on artificial CO2 markets with government control, and likely won't be self-sustaining. 10. While leveraging existing extraction and cultivation practices, it might also cement them, with less room for a true ecological rebirth. So it's not surprising that analyses, like from Beerling et al. 2020, estimate the CDR potential of EW to be around 0.5-2 GtCO2 per year, 15 times lower than the 30 GtCO2 in this illustration. Over 75 years this could still provide around 150 GtCO2 of removal. Still, while having potential, the future of EW might be supplemental, rather than focal, precisely because of its low-cost, low-tech approach to hard geochemical, ecological and economic limitations. #zerodegrees ### Sources ### (Enhanced) Weathering: https://lnkd.in/dNUakaYg https://lnkd.in/din98Xq4 Molecular weights: https://lnkd.in/dzBqBkYW Our World in Data 2024 - Croplands https://lnkd.in/d8Nf-bM Jasansky et al. 2023 - An open database on global coal and metal mine production https://lnkd.in/dNdRf7QC Beering et al. 2020 - Potential for large-scale CO2 removal via enhanced rock weathering with croplands https://lnkd.in/enukwSz

What is the general potential of Enhanced Weathering (EW) for Carbon Dioxide Removal (CDR)? EW aims to artificially accellerate the chemical conversion of atmospheric CO2 into various forms of carbonate minerals. These processes occur naturally and are an essential component in Earth's long-term (100000+ years) geological carbon cycle. One approach pursued by some companies is to use mining residuals as additional mineral fertilizer for cropland farming. To get a rough idea of the global potential, let's look at some basics. EW involves three stages: 1. Dissolution of CO2 in water. 2. Carbonation of some mineral. 3. Precipitation of the carbonate. For example, let's look at the weathering of forsterite, a typical mineral that can be used for EW. First, CO2 reacts with water, creating carbonic acid: H2O + CO2 <-> H2CO3 (water + CO2 <-> carbonic acid) When this acid comes into contact with the forsterite (Mg2SiO4), magnesium metal ions (Mg) and hydrogen ions (H) basically swap partners (carbonation): Mg2SiO4 + 2 H2CO3 <-> 2 MgCO3 + H4SiO4 (forsterite + carbonic acid <-> magnesite + silicic acid) Lastly, when conditions are right, most of the magnesite will eventually precipitate from the solution, forming a solid mineral layer, thus storing the attached carbon atom in a solid form. How much carbon can be "solidified" this way? From the equations we can see that for each magnesium atom in the forsterite we bind 1 carbon atom in the magnesite, i.e. a 1-to-1 ratio. Of course the magnesium and carbon also have all those other elements attached. In other words, instead of spreading raw magnesium, we have to pay the extra mass cost in silicate (SiO4) that the magnesium comes with. More specifically, CO2 has a molecular weight of 44.01 g/mol, and forsterite (Mg2SiO4) of 140.69 g/mol. As 1 forsterite can convert 2 CO2 molecules, the conversion mass ratio is 141 / (2 * 44) ≈ 1.6, i.e. to bind 1 kg of CO2, one needs 1.6 kg of forsterite. Now, agricultural areas cover around 48 trillion m² globally. If one would spread 1 kg of forsterite per year on every m² of cropland, assuming all of the forsterite carbonizes, this would remove 48*10^12 kg / (10^3 kg * 10^9 * 1.6) ≈ 30 Gt of CO2 per year. Over 75 years, that would amount to 2250 GtCO2! This sounds fantastic, there's enough area, mining waste is cheap, industrial agriculture the norm, and the whole thing low tech. So climate change done and dusted? To Part 2: https://lnkd.in/dwPpgqfs #zerodegress

Here is something surprisingly unsurprising: Flood management by German government agencies does not include projections of climate change impacts on the water cycle. Any levee that is currently being planned and build is so far only modelled after historical floods. The year is almost 2025 and climate change has yet to seep into parts of German bureaucracy. #zerodegrees https://lnkd.in/dtsN-48A

The global water cycle is becoming more volatile. Continents have lost on average about 10 litres of freshwater per square meter in an abrupt decline around 2015, and have since not recovered (Rodell et al. 2024). Based on their graphs, the water regime might have shifted by about 1 standard deviation downwards! The authors attribute this to a series of droughts from 2015 onwards (particularly in South America), as well as larger temperature increases over land compared to oceans due to climate change, leading to a larger evaporation disparity, and accordingly less precipitation over the continents. It is clear, that Earth's climate changes quickly and with increasing instability. Be it mitigation or adaptation, the time of reactiveness is coming to an end. We need to finally take the future into account when planning our actions, or we will with absolute certainty fall far short of the new realities we have to face. #zerodegrees ### Sources ### https://lnkd.in/dTRNNUM4

The likelihood of extreme events like droughts, floods, or storms changes non-linearly with ongoing climate change. Understanding how those likelihoods change is crucial for any adaptation measure. For instance, an extreme event with a probability of 2 % without warming might have a probabilty of 4 % with 1 °C warming, and 10 % with 2 °C warming. Part of the reason for this non-linear change can be demonstrated with the effects of transformations on probability functions. The most widely known such function is the Gaussian normal distribution. It occurs with astonishing frequency in almost all parts of nature and our daily lifes where randomness is involved. An example is shown in plot 1, displaying riverine water level fluctuations over a given period, say a year. As can be seen, the most probable water levels are also the average water level that can be observed. In contrast, extremely low or extremely high water levels are much more unlikely, due to the overall bell-shape. Two basic changes of such a distribution may occur (e.g. by climate change), that substantially change the probability of 'extreme' events. The first one (also plot 1) is a shift of the whole distribution. If one defines an extreme event as any event that exceeds a given threshold (here 2 original standard deviations), then a shift in probabilities (here 1 standard deviation), i.e. the distribution mean, increases the likelihood of the same event exponentially (here from 2 % to 16 %!), before then converging and leveling of again (plot 2). The curve in plot 2 is simply the result of shifting the original distribution over the chosen threshold level, and summing up all the area that exceeds the chosen level, which is nothing else, but the associated so-called cumulative distribution function. The second transformation is a change variability, i.e. a change in the range of events that can be observed (plot 3). For instance, in increase in variability from 1 to 2 standard deviations also corresponds to an disproportional increase from 2 to 16 % for the same example threshold. However, the overall effect of increased variability on the likelihood of extremes is, in contrast to shifts, mostly convergent (plot 4). With respect to climate change the question of course is, how exactly the related distributions are effected. However, the takeaway is that once such an effect can be assumed, the resulting expectations of what is considered 'extreme' cannot be simply extrapolated linearly from past experiences, as extremes can easily become disproportionally more frequent. It is vital for involved politicians, planners and the affected public to be aware of that, if resources are not to be wasted on insufficient public safety projects. #zerodegrees

How much CO2 will humanity emit overall? That's the burning question for Carbon Dioxide Removal (CDR). To gain some intuition about the magnitude of the task, here is a simple, albeit crude outline of potential requirements. Plot 1 shows all CO2 emissions so far, around 2600 Gt of CO2 in total. Assuming emissions peak now, 4 hypothetical future trajectories are shown, which equal 500 Gt - 2000 Gt. The shape of the curves is less important than total emissions, i.e. the area below each curve. A sharper decline implies a larger difference in area between left and right parts. Thus, a rough assessment of future emissions can simply be based on how symmetrical economic life cycles usually are throughout human history. After all, global CO2 emissions are just the cumulated result of many such life cycles. Plot 2 shows historical data about coal usage in the United Kingdom. By splitting each time series at its peak into a left and right part, one can calculate their ratio. The results are shown in plot 3. On average, there is a right / left ratio of .73. When applying this ratio to global CO2 emissions (assuming peaking), around 1900 Gt (.73 * 2600 Gt) of remaining emissions could be expected, as seen in plot 4. Plot 5 outlines the corresponding global temperature increase, a ballpark estimate for Earth's Equilibrium Climate Sensitivity (ECS), which describes how much temperature increases, when doubling CO2 concentrations, a logarithmic response, about 3 °C on doubling. By setting the pre-industrial amount (2100 Gt) to 0 °C, adding the expected total (4500 Gt), diminished by natural uptake (~ 55 % land/ocean, 45 % remainder), the result is 4125 Gt, or about 2.9 °C of total warming. What would this mean for CDR? Ocean uptake is mostly a reversible conversion into carbonic acid, a full reversal might not only have to remove 45 % of 4500 Gt (2025 Gt), but also about half of the (ocean) uptake as well, so in total maybe .75 * 4500 Gt = 3375 Gt. A partial reversal to 1.5 °C of warming might still require the removal of 1100 Gt (atmosphere) + 730 Gt (oceans, 1100 / .45 * .3) = 1830 Gt. This is not a rigorous prediction of total emissions. A peak now is highly unlikely, the data is coarse and the ECS curve simplistic (no tipping points). However, 2 of those biases lead to worse emissions/warming, not less! While highly debatable, an abrupt stop of emissions with 200 Gt of CDR for 1.5 °C (as by the IPCC) seems at least equally as otherworldly. It is not too much of a leap, that serious CDR strategies should plan for > 1000 Gt, better > 2000 Gt of removal. Of course this is extremely hard to swallow for everyone involved, but it might be the last opportunity to be more safe than sorry. #zerodegrees ### Sources ### Our World in Data 2024: https://lnkd.in/d-K56Crr Fouquet & Pearson 1998: A Thousand Years of Energy Use in the United Kingdom Skeptical Science 2024: https://lnkd.in/duXvJEwa