What caused the Little Ice Age?

[pete]

https://en.m.wikipedia.org/wiki/Little_Ice_Age

The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region.[2] It was not a true ice age of global extent.[3] The term was introduced into scientific literature by François E. Matthes in 1939.[4] The period has been conventionally defined as extending from the 16th to the 19th centuries,[5][6][7] but some experts prefer an alternative timespan from about 1300[8] to about 1850.[9][10][11]

[Shred]

Huge amounts of trees and other plant life took CO2 out of the atmosphere reducing the greenhouse effect most likely.

Problem in our era is that so much of the rainforests and other forests have been destroyed.

Even the airfield I fly from, was 100 years ago, a forest.

[pete]

Huge amounts of trees and other plant life took CO2 out of the atmosphere reducing the greenhouse effect most likely.

Problem in our era is that so much of the rainforests and other forests have been destroyed.

Even the airfield I fly from, was 100 years ago, a forest.

So the climate can drastically change without human intervention?

[Shred]

Yes, but deforestation, is an enormous factor.

The CFCs of the 1980's now banned internationally were a problem, the depletion of the Ozone layer was a problem, though it is recovering.
The problem now is deforestation and excessive CO2 levels.

We are constantly learning more about these changes affecting our environment, and scientists from the Polar Institute in Cambridge and The British Antarctic Survey have been at the leading edge of research in both the Arctic and the Antarctic, warning us of the greater dangers that lie ahead.

Let me quote from a letter I received only two weeks ago, from a British scientist on board a ship in the Antarctic Ocean: he wrote, “In the Polar Regions today, we are seeing what may be early signs of man-induced climatic change. Data coming in from Halley Bay and from instruments aboard the ship on which I am sailing show that we are entering a Spring Ozone depletion which is as deep as, if not deeper, than the depletion in the worst year to date. It completely reverses the recovery observed in 1988. The lowest recording aboard this ship is only 150 Dobson units for Ozone total content during September, compared with 300 for the same season in a normal year.” That of course is a very severe depletion.

He also reports on a significant thinning of the sea ice, and he writes that, in the Antarctic, “Our data confirm that the first-year ice, which forms the bulk of sea ice cover, is remarkably thin and so is probably unable to sustain significant atmospheric warming without melting. Sea ice, separates the ocean from the atmosphere over an area of more than 30 million square kilometres. It reflects most of the solar radiation falling on it, helping to cool the earth's surface. If this area were reduced, the warming of earth would be accelerated due to the extra absorption of radiation by the ocean.”

“The lesson of these Polar processes,” he goes on, “is that an environmental or climatic change produced by man may take on a self-sustaining or ‘runaway’ quality … and may be irreversible.” That is from the scientists who are doing work on the ship that is presently considering these matters.

These are sobering indications of what may happen and they led my correspondent to put forward the interesting idea of a World Polar Watch, amongst other initiatives, which will observe the world's climate system and allow us to understand how it works.

We also have new scientific evidence from an entirely different area, the Tropical Forests. Through their capacity to evaporate vast volumes of water vapour, and of gases and particles which assist the formation of clouds, the forests serve to keep their regions cool and moist by weaving a sunshade of white reflecting clouds and by bringing the rain that sustains them.

A recent study by our British Meteorological Office on the Amazon rainforest shows that large-scale deforestation may reduce rainfall and thus affect the climate directly. Past experience shows us that without trees there is no rain, and without rain there are no trees. [end p5]
THE SCOPE FOR INTERNATIONAL ACTION

Mr President, the evidence is there. The damage is being done. What do we, the International Community, do about it?

In some areas, the action required is primarily for individual nations or groups of nations to take.

I am thinking for example of action to deal with pollution of rivers—and many of us now see the fish back in rivers from which they had disappeared.

I am thinking of action to improve agricultural methods—good husbandry which ploughs back nourishment into the soil rather than the cut-and-burn which has damaged and degraded so much land in some parts of the world.

And I am thinking of the use of nuclear power which—despite the attitude of so-called greens—is the most environmentally safe form of energy.

But the problem of global climate change is one that affects us all and action will only be effective if it is taken at the international level.

It is no good squabbling over who is responsible or who should pay. Whole areas of our planet could be subject to drought and starvation if the pattern of rains and monsoons were to change as a result of the destruction of forests and the accumulation of greenhouse gases.

We have to look forward not backward and we shall only succeed in dealing with the problems through a vast international, co-operative effort.

https://www.margaretthatcher.org/document/107817

We cannot just drop everything as the "just stop oil" lot would like, and we cannot muddle on without there being consequences.
We have to replant the rainforests.
That means pressure on Bolivia, Brazil, Madagascar and Indonesia.

Another of the problems is that there are too many people on the planet, using too many resources having too many children, because in the past, with high infant mortality rates, large families were the only way to ensure survival of the family.
Traditions have remained the same whilst infant mortality has fallen.

The infants grow into adults, all the while using food and energy. And when forests are cleared for farms, that reduces global environmental absorption of CO2. When the adults burn fuel putting out CO2 that adds to it as well.

Thatcher was right about nuclear power.
It needs to be used to reduce industrial CO2 output.
Thorium would be the best form of nuclear power as it cannot be used to produce fissile material for thermonuclear bombs.

Humanity as a whole has to address global climate change.