If we really wanted to increase global population we would be coming up with ways to use geoengineering to warm the planet.
CO2 won’t work. It might actually radiate more heat into space.
Changing albedo or amount of sun reflected would be best bet. Making more surfaces black might help melt some ice.
Probably best bet is messing with the oceans. Blocking or releasing ice bergs at strait narrows might help.
If a volcano blows we will need ways to remove the particles. The atmosphere has such a small effect compared to oceans it might be best to find ways to tilt the earth. If we could steer the planet or alter the gravity by steering in asteroids that would be ideal.
Cold has done serious damage in the past:
Scott A. Mandia
Professor – Physical Sciences
“Climate during the LIA had a huge impact on the health of Europeans. As mentioned earlier, dearth and famine killed millions and poor nutrition decreased the stature of the Vikings in Greenland and Iceland.”
That sounds bad. Mandy’s then says,
“Cool, wet summers led to outbreaks of an illness called St. Anthony’s Fire. Whole villages would suffer convulsions, hallucinations, gangrenous rotting of the extremities, and even death. Grain, if stored in cool, damp conditions, may develop a fungus known as ergot blight and also may ferment just enough to produce a drug similar to LSD. (In fact, some historians claim that the Salem, Massachusetts witch hysteria was the result of ergot blight.)”
Interesting thing about LSD and climate change. https://niflheimmedia.wordpress.com/2016/02/23/climate-change-military-propaganda-or-colonialism-2-0/
Malnutrition led to a weakened immunity to a variety of illnesses. In England, malnutrition aggravated an influenza epidemic of 1557-8 in which whole families died. In fact, during most of the 1550’s deaths outnumbered births (Lamb, 1995.) The Black Death (Bubonic Plague) was hastened by malnutrition all over Europe.
One might not expect a typically tropical disease such as malaria to be found during the LIA, but Reiter (2000) has shown that it was an important cause of illness and death in several parts of England. The English word for malaria was ague, a term that remained in common usage until the nineteenth century. Geoffrey Chaucer (1342-1400) wrote in the Nun’s Priest Tale:
You are so very choleric of complexion.
Beware the mounting sun and all dejection,
Nor get yourself with sudden humours hot;
For if you do, I dare well lay a groat
That you shall have the tertian fever’s pain,Or some ague that may well be your bane.
In sixteenth century England, many marshlands were notorious for their ague-stricken populations. William Shakespeare (1564-1616) mentioned ague in eight of his plays. Oliver Cromwell (1599-1658) died of ague in September 1658, which was one of the coldest years of the LIA.
Five indigenous species of mosquito are capable of transmitting malaria in England where they prefer the brackish water along river estuaries. The anaerobic bacterial flora of saline mud produces a strong sulfur odor that was widely believed to be the cause of agues in salt marsh areas (i.e. Shakespeare’s “unwholesome fens.”) The term malaria comes from the Italian term “mala aria” meaning “bad air.”