Ground Control to Major Tom : Earth Oddity or Mars Salvation?
07 November 2021 Cop26
Elon Musk is keen to have space explorers reaching the surface of Mars by 2026. Starship and Starbase are under construction and the man is on a mission. But is this whole idea only about scientific and technological prowess? Or is it a hedging strategy, since every year (barring 2020 and COVID-lockdowns) Earth Overshoot Day arrives earlier in the year? The problem’s initial conditions remain the same: we are 7.5bn human beings (and growing) on a planet that has been harvested and exploited in a very unsustainable manner (probably an understatement) for the past 150 years.
Saturday 6th was all about Nature whose role in trapping CO2 (natural sinks) has been documented by researchers. However, human activities are increasingly putting pressure on our natural carbon sinks.
- Oceans: since the Industrial Revolution, oceans have been able to absorb roughly 30% of global CO2 emissions. However, relentlessly rising emissions mean that the concentration of CO2 in oceans has increased significantly, leading to higher ocean acidity. The acidification of the oceans can have significant long-term consequences on marine food chains (and subsequently to humans) while reducing reef protection in the event of storms.
- Soils and plants: of all the CO2 stored in the biosphere, 80% is in soils, and 20% in plants. This ratio moves to 70%/30% in forests, and up to 50%/50% in tropical forests. No surprise then to see COP26 committing to end deforestation by 2030 despite the no-go from Indonesia (despite having made significant progress on deforestation since the early 2000s). In addition, we could face two risks that were under the radar at COP26:
- The Amazon forest has turned into a net CO2 emitter. Although this has been caused by human activity, it is paramount to reverse the course by allowing our best global carbon sink to perform its duty.
- Permafrost thawing: roughly 1,600 bn tonnes of CO2 are trapped in the Arctic permafrost. In the event of rising temperatures well-above 2°C degrees, up to 40% of total permafrost could thaw.
Is this all doom and gloom? The answer is no. First, the role of sustainable agriculture in achieving climate ambitions is better understood. According to the FAO, 9.3 bn tonnes of GHG (farm gate and related land use and land use change) can be attributed to the agricultural sector (2018 figures, or 17% of total GHG emissions). According to this same study, emissions at the farm gate have kept increasing since 2000 (+14% over 2000-18) while emissions related to land use and land use change (primarily deforestation) have decreased by 20% over the same period. It is thus no surprise that COP26 has established a sustainable agriculture agenda. The role of innovation (precision agriculture1, vertical farming) and a change in our feeding habits (plant based vs. meat-based) are, in our view, two powerful drivers of a more sustainable agriculture.
Second, we have gathered enough evidence about the role of biodiversity in restoring balance to natural ecosystems. In 1995, wolves were reintroduced to Yellowstone Park, resulting in an ecological phenomenon known as a trophic cascade (trophic, relating to feeding; cascade, passing on, or falling). This phenomenon displaced some ideas about how ecological health is restored, and that it is more than a few factors such as soil health and climate. In fact, over time, it became obvious that when we take big, influential creatures like wolves out of an ecosystem, we create an imbalance. In the case of Yellowstone, the absence of wolves meant that the elk population were not hunted, and not forced to move constantly. This meant they would overgraze on willow, particularly close to rivers where beaver populations then suffered as their main food source was closely grazed. With more willow in winter, beaver populations recovered and began to dam rivers and create pools, processes that are central to rivers, evening out seasonal runoff and even creating cooler pools for fish and songbirds.
When it comes to oceans, the case for ‘re-wilding’ is even more compelling, as human impacts are devastating ocean habitats faster than any other species. Industrial fishing is the key culprit and a claim by the controversial environmental documentary ‘Seaspiracy’ stated that if overfishing continues at the current rate, that oceans will be so overfished that fish species will be critically depleted by 2048, at which point it would be impossible to continue fishing. While such a claim has been met with scepticism and controversy, there is widespread agreement that fish stocks are massively depleted and this is causing significant changes in marine ecosystems. As the largest carbon sink on earth (thought to concentrate 50 times more carbon than the atmosphere) we need to be conscious that changes to marine life and ecosystems are critically affecting the ocean’s role in carbon capture, with rising sea temperatures and acidification happening at record levels. According to US researchers Worm and Hilborn (2009) there needs to be enforcement of the concept of ‘Maximum Sustainable Yields (MSY)’ in fishing. At the time of writing, around two-thirds of the world’s stocks were being fished beyond their MSY, and to make progress MSY’s need to be treated as limits on fishing, rather than targets. Evidence has suggested that reducing fishing rates and allowing overfished areas to recover has allowed ecosystems and ocean wildlife to bounce back in many regions.
The complexity of nature is bewildering and human actions can spark multitudes of events, of which very few are linear in effect. Instead, effects cascade, with complicated feedback loops making it almost impossible to predict the ecosystem outcome. Re-wilding is the way to mass restoration of ecosystems, ideally bringing back as many of the missing elements as we can and allowing ‘tamed’ areas to become wild. Other ways include letting hedgerows grow wild, restoring land previously grazed by livestock, rewetting peatlands and leaving patches of land unmanaged. In essence, the concept is to remove humans from the equation and allow nature to provide its own checks and balances, which it tends to do very successfully.
Nature is resilient and it will be around a lot longer than we will, and if we do cause the sixth mass extinction, the planet is likely to recover, and that’s more than we can say for ourselves. Unless we buy tickets to Mars to Elon’s other $100+bn venture.
1The application of modern information technologies to provide, process and analyse multisource data of high spatial and temporal resolution for decision making and operations in the management of crop production. Global Food Security, 2016.