Overview

Hello people!!!

What have we learnt so far? We learnt that climate change is a fact, that we can declare ourselves guilty, and that we cannot continue on our current path if we do not want to find ourselves or our children living in a planet with such an extreme weather.

So, in this brief summary we are coming back to the original diagram. Sorry for repeating it but I find it very illustrative:

Source: TED video

We saw that environmental politics is a complicated topic, and studied the last agreement made. Therefore, we said mitigation is a complicated subject, because of the politics involved. Adaptation to some extent is inevitable.

Our main focus, therefore, was geoengineering. We studied solar radiation management and we saw that by partially blocking the sun, even if the amount of atmospheric CO2 doubles, we can return to pre-industrial temperatures. However, this is a big risk because of possible side effects, as a re-distribution of precipitation, possible increase of extreme climatic events, etc. Additionally, it has one major risk: once these techniques are implemented, if one does not want the weather to be like if would have been if geoengineering was not performed, then geoengineering can never stop.

We studied in less depth some of the existent carbon dioxide removal techniques, including ocean fertilisation and biochar. However, there are several other techniques being studied nowadays about possibilities of CDR and how they can change our future.

The following image show perfectly the most important geoengineering techniques, mixing both solar radiation management and carbon capture techniques. It shows the affordability, effectiveness in a coordinate system. It also shows the safety of each process, considering known and assumed consequences. Additionally, it considers how long would it take to make a change in the situation to be changed.

Scheme of the geoengineering techniques: Shepherd et al (2009)

But if there is one thing we learnt in the process is that plenty of solutions for climate change exist. But there are all new. Very few studies have been done to test the dangers of geoengineering, even though they are considered to be very important. Geoengineering nowadays is considered something that will have to be implemented. Therefore, we expect a large variety of studies on the dangers of the discussed techniques and others in the years to come.

I leave you with an example of how the world could be in the future. The power station in the picture below, called the Boundary Dam Power Station in Saskatchewan buries all its carbon emissions underground.

 Boundary Dam Power Station. Source: VOX

Goodbye!! I will see you soon!!

Happy new year! CDR Technique: Biochar!

Hello people!

This is my first 2015 post so I wanted to say:

HAPPY NEW YEAR!

I hope you had a good time with friends and family... 

But here we are again, trying to understand a little bit more about the new things being investigated about how to save the world. :)

Today we are going to discuss one technique, biochar.

Everyone knows plants use CO2 by photosynthesis. However when plants (and any other living organism) die, they return all the CO2 back to the atmosphere. So, a way of reducing the amount of CO2 in the atmosphere would be capturing this CO2 and avoiding it to return to the atmosphere. 

Clearly, it would be much better, instead of capturing this CO2, to stop emitting CO2 from fossil fuels to the atmosphere. However, we have discussed the political implications and complications of this, and therefore, anything that can reduce the amount of CO2 released must be considered. 

Let's discuss the process. Pyrolysis is an irreversible thermochemical decomposition with no or little oxygen, that transforms biomass into biofuel and charcoal (Shepherd et al, 2009). 

Biochar by pyrolysis. Source: Wikipedia by K.salo.85

So, this is great, because it produces energy from biomass (renewable energy), and it leaves charcoal behind. Therefore, it allows us to capture the C in this charcoal by burying it back in the soil. We would be eliminating the carbon that would have been released by the living organisms used in the process as biomass and, in the process, we would be producing energy! This process is synthesised in the following image:

Process of producing biochar and returning it to soil, by pyrolysis of biomass. Source: Lehman, 2007

I included that picture because it is a friendly representation of the process. However, it may seem like a perfect solution, and that this discovery could save the world. However, this picture does not show how much carbon would we be taking from the atmosphere and how much would we be giving back. So, what's the result? Woolf et at., 2010, found that by doing this process we could be reducing the emissions by 1.8 Gt of CO2 - C equivalent per year. This is, 12% of today's emissions. 

The following image shows the process in a less friendly way, but clearly shows the process of where is the emission of CO2 avoided and when it is not. However, it does not show the CO2 we would be preventing from being released into the atmosphere by the decomposition of plants and all biomass. 

Schematic representation of the process by Woolf et at., 2010.

It is interesting to read that Indians from the Amazones did bury charcoal into the soil. They did this, not to mitigate nor geoengineer climate, but for improving crop yields (Lean, 2008).

However, to do this at large scale, a lot of new technologies need to be created, and a risk analysis needs to be done. It is suspected that large amounts of biochar buried in the soil could generate chemichal problems but further studies on this topic have just started.

We hope in some time we will be able to understand the risks of doing this and transmit it to you!