So, you have the dream of becoming Neanderthal again and want to recreate the glaciar period when that species lived and disappeared.
It’s simple: just use the physical laws.
Destroy most of rain forests, turning soil into desert sand.
You will not want that trees’ roots grab humidity in the soil, inhibiting the evaporation of big quantities of water.
Every time that it rains and, then, the sun comes and warms up the air (dry air insulation), the evaporation will start: a continuous convective flow will remove energy out of the system through the porous material (sand).
Repeat the process for several days, weeks, months or even years…
The inner core of Earth will become a huge freezer. Paradoxically, global warming will give a precious help to foster global freezing. Don’t you feel the chills already?
If you don’t believe this, just try at home to build the pot-in-pot refrigerator, also known as Zeer, “big jar”, in Arabic.
It is a refrigeration device which keeps food cool without electricity by using evaporative cooling. It’s a natural, cheap, easy-to-make refrigerator.
Evaporative cooling was used as early as the Old Kingdom of Egypt, around 2500 B.C. Frescos show servants fanning water jars, which would increase air flow around the porous jars and aid evaporation, cooling the contents.
Similar jars were used to keep water fresh in Portugal (“cântaros”) and Spain (“bojitos”).
The zeer is constructed by placing a clay pot within a larger clay pot with wet sand in between and a wet cloth on top. The space between the two pots, filled with sand, creates an insulating layer around the inner pot. The sand is then kept damp by adding water at regular intervals — generally twice a day — reducing the temperature within the inner pot. Seawater can be used to drive the cooling process. As the water evaporates from the sand, it pulls the heat out with it, cooling the inner pot. In a given system, as a gas flows over the wet surface, evaporation and condensation continuously occur to maintain steady-state conditions.
In order to sustain evaporation, there must be a draw of internal energy in the liquid, which would result in a temperature reduction. This cooling effect is known as evaporative cooling and is most effective in dry climates due to the lack of humidity in the air. Evaporative coolers tend to perform poorly or not at all in climates with high ambient humidity, since the water is not able to evaporate well under these conditions. This invention must be placed in a dry, ventilated space for the water to evaporate effectively towards the outside.
But notice that the curvature of the Earth is bigger than any known pot…