What is geoengineering you might ask? Well depends who you’re asking. Some call it climate intervention, others remediation. The bottom line, however, is that geoengineering is deliberate human intervention on a global scale to mitigate the effects of climate change. There are multiple techniques of geoengineering, I will cover two here.
First is Carbon Dioxide Removal (CDR), which is pretty much exactly what it sounds like. The strategy is to remove CO2 from the atmosphere and store it somewhere else. This is called sequestering. There are a couple options when it comes to CDR. The most logical and low-risk is to make a fundamental change in land use management. Trees naturally remove CO2 from the atmosphere, so if communities around the world gave preference to trees over development, we could take back some of the carbon dioxide we’ve released into the atmosphere. Sadly, it’s not that simple. First of all, trees take a long time to grow, and people are impatient. Additionally, in capitalistic societies (like the U.S) trees don’t make you rich, building more factories and developing real estate does.
The next type of CDR is air capture. This is the idea that we could build machines that extract CO2 from the atmosphere and then store it. Direct air capture has been proven to work effectively, taking in “dirty” air and pumping out “clean” air, but once again the story isn’t so simple. These machines would have to be huge. Like, ridiculously huge and unsightly (see below). Not to mention that they will use equally large amounts of energy, contributing to the related problem of energy usage.
There are many other suggested techniques of CDR, including biochar, and carbon capture storage, but I’m trying to keep this compact.
After CDR there is Ocean Iron Fertilization, an interesting idea first formed by John Martin that takes advantage of the natural system of the biological pump found in our oceans. The strategy is as follows: The ocean is filled with phytoplankton, which are tiny marine organisms that use photosynthesis to take in CO2 from the water (which is absorbed from the air) and break it down. The ability of phytoplankton to grow larger and break down CO2 is limited by iron, a mineral that arrives to the ocean as fine dust particles. Studies of arctic ice cores have shown that there is an inverse relationship between iron dust and CO2 in the atmosphere, leading scientists to believe that when there is more iron abundant in the oceans, phytoplankton bloom mightily and remove a fair amount of CO2 from the global atmosphere. So, scientists have gotten it in their head that if they dumped a whole bunch of iron in the oceans, they could trigger phytoplankton growth and subsequent CO2 removal. Seem to simple to be true? That’s cause it is. A few of these experiments have been carried out with very limited success. Plus there’s the issue that iron doesn’t just grow on trees, nor is it cheap to ship it to the middle of the ocean And thirdly, although the ocean is the largest sink of Carbon on our planet, it eventually releases it back into the atmosphere, making ocean fertilization a temporary fix.
There are other geoengineering techniques such as solar radiation management and stratospheric sulfate aerosols. All of these actions have their own benefits and each have serious drawbacks and potential consequences attached to them. I’ve mentioned some here, but this is a surface explanation, there are components which I have excluded for simplicity and brevity. In my opinion, these techniques should be approached with serious caution, because they are all reactionary, not preventative. If we allow the general public to believe that these technologies will solve the problems currently affecting Earth, it will be tragic. We need to continue to develop ideas to stop global warming in the first place, and maybe then geoengineering can be used as a complement. It is also important to note that these technologies would not spring up overnight – they require extensive planning, funds, and cooperation from many disciplines and governing bodies. Lastly, I just do not like the idea of man trying to tinker with global forces. When will we learn that the forces of nature are much stronger than us?