Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. It helps in the fight against climate change by trying to reduce the CO2 levels in our atmosphere.
Popular techniques for carbon sequestration are reforestation and afforestation. They are both similar but slightly different:
- Reforestation is restoring forests on lands that were once forests but are no longer, because of deforestation for farming, commercial activities etc.
- Afforestation is creating forests on lands that were not previously forests. This could be repurposing land that was used for farming, or mining etc. into forest land.
We at AIMMS have started a new program, AIMMS Forest, to contribute to the fight against climate change.
We have partnered with One Tree Planted to support reforestation projects around the world and would like to invite you to join us by participating in this fun challenge.
For every person that solves the challenge using an AIMMS model, we will plant 20 trees 
! Share your solution by replying to this post (note: if you prefer to share your solution privately, you can also send or share your files with Jessica.Estenssoro@aimms.com). You will get a certificate in your name with the tree donation.
The challenge description is as follows:
(All data required is provided in this AIMMS project)
Area is available to plant trees in 4 different regions (provided in p_area(i_region)).
We have about 20 different types of trees which belong to 5 different families (provided in ep_treeFamily(i_tree)).
The tree families differ in the area required to plant a single tree that belongs to the family – each tree is planted in a square plot with a given length of side (provided in p_dimension(i_family)).
Not all families of trees can be planted in all regions. The families that are suitable for each region is provided in p_regionFamilies(i_region, i_family).
In addition to that, some families of trees cannot be planted in the same region as they will adversely affect each other’s growth. This data is provided in p_forbidden(i_family, j_family) – if this = 1, then those two families of trees cannot be planted in the same region.
The cost of planting each tree type ($) and the amount of carbon each tree recovers (Ton/year) is provided in p_cost(i_tree) and p_sequestration(i_tree).
Can you formulate a mathematical model to maximize the amount of CO2 recovered if there is a total budget of $400,000?
- What is the amount of CO2 recovered?
- How will your answer change if the budget is divided equally amongst the 4 different regions?
Where will your trees be planted?
To maximize the impact of our donations, One Tree Planted will allocate them to where they are needed most. Here are some examples:
- Peruvian Amazon: reforestation in the Western Arc of the Amazon Rainforest across the Loreto and Ucayali regions. This is one of the most biodiverse places on Earth and of critical importance for conservation.
- US, California: Post-fire reforestation of Edison Forestry land surrounding Shaver Lake. 3,000-acres burned in the 2020 Creek Fire.
Further reading
C. Vanlisuta and S. Prombanpong, A Mathematical Approach for Afforestation to Mitigate Climate Change, International Journal of Innovation, Management and Technology, Vol. 4, No. 1, February 2013
), decided to play a bit with the WebUI again.
. Let’s see if I solve this problem correctly.