Briefing

Natural Geoengineering: terraforming Earth

Towards The Mainstream

With evidence mounting that the climate system and sea-level rises have passed tipping points and that we face irreversible, large-scale disruption, you might expect investment in geoengineering to be booming, or at least making headlines and capturing the imagination of the public and the scientific and policy communities.

Instead, headlines are dominated by the space adventures of Elon Musk, Jeff Bezos and Richard Branson.  The idea of terraforming Mars makes news.  Terraforming earth through reforestation does not.  The IPCC report that will be finalised in the next week to discuss the 1.5 target and solutions and amidst a growing sense of urgency, may change all this.

Academic Isolation

Investment in geoengineering, which might be seen, at least in theory, as the source of ‘emergency stops’ to runaway climate has barely increased.  This is in contrast with the worldwide increase in academic research in this area.  Even this remains fragmented.  In the US, there is no national geoengineering research programme, but rather a variety of individual and collaborative programmes.  In Europe, there are several national and multinational programmes like the German Research Foundation (DFG), established in 2012.

The roots of all this academic activity go back to Nobel prize-winning Paul Crutzen’s call to action in 2006, in which he argued that attempts to reduce emissions had been “grossly unsuccessful” and too little, too late.  He called for research into the potential impact of injecting sulphur particles into the stratosphere.  He called for the end of the “taboo” against feasibility studies.

Despite the growing sense of urgency and body of research, interest in policy circles and international studies on global governance, geoengineering has remained on the fringes of mainstream dialogue.  The voices of a small number of committed individuals argue with increasing urgency that we need a hedge against other, more gradualist approaches.

The broad narrative about geoengineering is that it adds to and may amplify systemic risk, with unquantifiable, unpredictable and barely imaginable potential consequences.  This frames how the future is understood and shapes how the wider community sees any initiative.  It acts as a barrier to inventive solutions.

Geo-Engineering in Context: technology rules

To put this in context, geoengineering comes in two broad flavours: solar radiation management (SRM) and carbon dioxide removal (CDR).  Simulations and feasibility studies are in the mix, but if we focus on practical solutions, a few promising pathways are emerging.  They are dominated by technology-centric thinking.

SRM includes ideas about reflective coverings of buildings and desert areas.  Both are high on the list of relatively simple options.  All are intended, in theory, to increase surface reflection.  The same principle can be applied to techniques to enhance the reflective effect of clouds, reducing the amount of sunlight that reaches the earth’s surface.  A variety of novel aerosols distributed in the stratosphere also work in the same way, as do giant sunshades in space.

CDR and particularly integrated ’Bioenergy with carbon capture and storage’ (BECCS) forms a key part of the earlier Intergovernmental Panel on Climate Change (IPCC) solutions.  The paradox is that one the one hand BECCS is one of the few ‘pathway’ technologies to reduce emissions and on the other, it surrounded by unknowns and is unproven.  Critics argue that science has overreached and been driven towards speculative, even fictional conclusions.

Techno-Culture and Natural Solutions

The deeper problem is that in a techno-centric culture, natural solutions, such as reforestation, do not capture the public imagination, or media attention.

Mass reforestation is a ‘natural pathway’.  Trees are the best, most easily implemented, lowest cost and lowest risk ‘geoengineering’ technology.

Amidst the radical thinking and risk-centric caution, this is hidden in plain sight.  Since agriculture, forestry and animal grazing make up about 25% of greenhouse gas emissions, natural solutions and better strategies for land management have the potential to deliver up to a third of the emission reduction targets called for by the Paris climate agreement .

What is curious is that having destroyed vast areas of rainforest, this simple strategy has not received as much attention as it might.  To put this in context, only about eight per cent of the South America Atlantic forest has survived years of exploitation.  The dominant narrative has been, for decades, that global forest cover has been systematically decimated, mainly by unregulated and unconstrained commercial exploitation.

Yet a recent study shows that from a global perspective, this narrative of decimation is not true.   Global forest loss over the last 35 years has been offset by new growth, particularly in previously barren areas, such as deserts, tundra, mountains and in cities.   In other words, the positive changes are regional, which means that local initiatives and policy changes at national levels can make a substantial difference.  According to a World Bank study, China’s US $ 100 billion ‘Grain-for-Green’ programme contributed to increasing forest area as a percentage of land area from about 17% in 1990 to 22.2% in 2015.

This does not mean, however, that this initiative, or others, are nearly enough.

Picture this scenario: over the next ten years, despite progress, fossil fuels continue to dominate; the promise of electric vehicles is only slowly realised; and emissions continue to rise, raising fears of catastrophic biosphere failures. At the same time radical technology-based options, such as BECCS and SRM geoengineering cannot be agreed by the international community, because the risk narrative holds sway.

In this scenario, large-scale global reforestation, through changes in land-use policies may emerge as a natural, low cost, low-risk solution to stabilising the climate, at least to some degree.  Coupled with fresh planting (afforestation) and draconian rules on deforestation, it may take off.

In any case, in a policy environment short of creative strategies against climate change, reforestation is a ‘win-win’ (see ‘Inventing the Big Hedge‘).  Whatever the future scenario, radical changes in land use and forestation at the local level can not only contribute to reducing global emissions but improve water management, deliver agricultural solutions and provide jobs.