When people first think of geoengineering, it’s easy to fall for the exotic-sounding stuff. The cloud seeding. The carbon capture. Terra-forming. But geoengineering exists on all scales, from your own back garden to that of the entire planet, and what matters is the boundaries within which that part of the scale operates.
Geoengineering can be defined at its most basic level as interactions and interventions with the Earth system. This encompasses subsurface geological engineering, environmental engineering and climate engineering, and on this blog, the term geoengineering covers all these aspects of Earth interactions.
We’ve been engineering our Earth for century upon century. Tilling the soil to create a fertile basis for agriculture is engineering our own environment. Building dams and aqueducts do the same – manipulate our environment to suit our own causes which we decide are important. Soil manipulation happens every day on small scales and large – from gardens to farms. In the past, one of the grandest soil engineering projects ever was undertaken by the inhabitants of the Amazon rainforest: they created a dark, organic-rich soil known as Terra Preta, on a large Amazon-basin-wide scale, and this nutrient filled soil played a huge part in facilitating crop growth within the forest.
Water management is a good example of geoengineering which comes with an inherent problem of scale as civilisations grow. Towns and cities, usually near rivers, develop with a manageable water supply for the most part, but as they grow larger, water and waste management systems have to be retrofitted around the pre-existing systems. This is why many older cities in Europe have huge issues with managing urban drainage in correlation with population growth, whereas more newly-developed cities in Asia are designed to accommodate such growth.
In Samsø, a small island in Denmark with a population of less than 4000, the entire energy supply is obtained by use of wind turbines on or around the island. This is an example of a regional-scale geoengineering solution.
In places like Turkey and Iceland, geoengineering is used on a nationwide scale to provide geothermal energy. And on a larger scale, petroleum companies use geoengineering technology globally to extract fossil fuels.
In the past century, there have been two main changes. The first is that technology has advanced to such a state whereby we are able to leave our own planet. This leads to a desire to construct what I consider the grandest scale of geoengineering, that which affects the Earth’s system as a whole. The gases emitted from the burning of fossil fuels like petroleum are an example, not of a specific desired outcome, but as a global side effect of the geoengineering technology used to extract fossil fuels from the ground.
What is interesting about this grandest scale is that, while it affects all smaller scales, there is no chance of the smaller scales of geoengineering affecting it. We can fertilise the soil in our backyards to combat the effects of, say, acid rain, but just for that particular patch in time and space. But if a geoengineering project were to neutralise the effects of acid rain (hypothetically), this would affect all small-scale patches of soil in that part of the world.
Equally, we could use cloud seeding on a regional scale to make the weather play nice for a specific event (like Beijing did for the 2008 Winter Olympics ceremony), but these localised effects would be dwarfed by a wider scheme like, if somebody managed to seed the stratosphere to the same extent as major historic volcanic eruptions. Something like that, if possible, would affect climate systems worldwide and not weather systems in a particular area for a limited period of time.
And furthermore, the side effects from a particular engineering method may not be important if you are only looking at the small scale. For instance, when petroleum geology was in its infancy, we were unable to foresee the potential problems this could cause for the entire world, as we did not realise how much demand and usage would increase over the centuries, and what this would do to the atmosphere. We only ever looked at the smaller scale.
The second main change that has occurred in the past century is that our understanding of the world has advanced to such a degree that we realise we are destroying it and its lifeforms, including ourselves. This, combined with the first, gives us the possibility of purposefully changing the climate, and adds a new cause to those which we have deigned important enough to warrant geoengineering in the past. Not only for human energy requirements, or comfort, or security, but for the maintenance of a steady state of the environment. The concept of using geoengineering for sustainability is not new – we have after all been using sustainable methods of agriculture in many locations worldwide. What is new is the combination of this plus technology.
Whether or not engineering on such a large scale would actually work or not, or whether it would be safe or not, or even whether we have the ability to accurately account for side effects, are questions for another time. For now, remember that problems arise because of scale, and scale needs to be considered in order to tackle environmental problems at their roots.