Nearby supernovae could have affected life on Earth – Change Climate?

The surface of the Earth was bathed in life-damaging radiation from nearby supernovae on several different occasions over the past nine million years. That is the claim of an international team of astronomers, which has created a computer model that suggests that high-energy particles from the supernovae created ionizing radiation in Earth’s atmosphere that reached ground level. This influx of radiation, the astronomers say, potentially changed the course of the Earth’s climate and the evolution of life.

More details HERE. The part that interested me was the impact of cosmic rays on the climate, through increased cloud cover.

Climate change

The cosmic rays may have also changed Earth’s climate. The most recent batch of supernovae came just before Earth entered a series of ice ages, at the end of which paved the way for humans to emerge. One possible link between the supernovae and climate is that muons in the lower atmosphere affected cloud cover, thereby cooling the planet.
“When ionization takes place down in the troposphere, where all our weather occurs, what will that do to our weather and climate?” asks Melott. “I’m not going to claim it causes ice ages, but it’s a possibility that needs to be investigated.”
The next step, says Melott, is to scour the geological record, searching for any evidence that supernovae really did have an effect, while further refining the models describing the propagation of cosmic rays from supernovae through space.

A quiet sun reduces the influence of the magnetosphere on cosmic rays, thus more high energy cosmic rays reach the lower atmosphere producing more cloud cover and a cooler planet. Low sunspots could enhance the impact of a supernova.

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Blank Sun—Mini Ice Age?

Canada Free Press

Meteorologist and renowned sun-watcher Paul Dorian raised the alarm in his latest report: “for the second time this month the sun has gone completely blank.” The blank sun is a sign that the next solar minimum is approaching and there will be an increasing number of spotless days over the next few. “If history is any guide, it is safe to say that weak solar activity for a prolonged period of time can have a cooling impact on global temperatures in the troposphere which is the bottom most layer of Earth’s atmosphere—and where we all live,” says Dorian.

Mr. Dorian’s findings back research by professor Valentina Zharkova of Northumbria University, who warned that a predicted sharp decline in solar activity between 2020 and 2050 is a sign another ice age is coming.

A recent presentation by a team of European researchers indicates that reduced solar activity will lead to a mini ice age from 2030 to 2040. Another study of sunspots last year by Indian, Chinese and Japanese astronomers indicates that a new ice age could start as soon as 2020 and reach its depths by 2030 to 2040.

Details, including references  HERE.

 

A Cultural History of Climate

I am reading A Cultural History of Climate, by Wolfgang Behringer, after spotting it as one the reference used by Andy May is his Watts Up With That post on Climate and Human Civilization for the Past 4,000 Years. This a fascinating account of climate change’s impact on human history.

From the Amazon Book Review [edited]:

Global warming and the future of the climate is one of the greatest challenges of our time, but what do we know about climate variations 500 years ago, or 5000 years ago? How can we know anything at all about the history of weather? What impact has climate changes had on human prosperity and the spirit of invention?

In this major new book, Wolfgang Behringer introduces us to the latest historical research on the development of the earth’s climate. He focuses above all on the cultural reactions to climate change through the ages, showing how even minor modifications in the environment sometimes resulted in significant social, political and religious upheavals. By examining how our predecessors responded to climate changes, Behringer provides us with a fresh basis for thinking about how we might address the serious climatic challenges we face today.

I was struck by the variability in the climate even during the cold periods, including droughts, floods, extreme heat and cold as reported in the letters, journals, and sermons by those experiencing these conditions. These first-hand reports were chilling when you consider we are on the cusp of the Next Grand Minimum.

Little Ice Age Theory

By James A. Marusek, Retired U.S. Navy Physicist who is warning us of what is to come.

I. Introduction

General Discussion
The sun is undergoing a state change. It is possible that we may be at the cusp of the next Little Ice Age. For several centuries the relationship between periods of quiet sun and a prolonged brutal cold climate on Earth (referred to as Little Ice Ages) have been recognized. But the exact mechanisms behind this relationship have remained a mystery. We exist in an age of scientific enlightenment, equipped with modern tools to measure subtle changes with great precision. Therefore it is important to try and come to grips with these natural climatic drivers and mold the evolution of theories that describe the mechanisms behind Little Ice Ages.

The sun changes over time. There are decadal periods when the sun is very active magnetically, producing many sunspots. These periods are referred to as Solar Grand Maxima. And then there are periods when the sun is very weak producing few sunspot. These periods are called Solar Grand Minima. Solar Grand Minima correspond to dark cold glooming periods called Little Ice Ages. And there are states in-between. During most of the 20th century, the sun was in a Solar Grand Maxima. But that came to an abrupt end beginning in July 2000. The sun produced 6 massive explosions in rapid succession. Each of these explosions produced solar proton events with a proton flux greater than 10,000 pfu @ >10 MeV. These occurred in July 2000, November 2000, September 2001, two in November 2001, and a final one in October 2003. And there hasn’t been any of this magnitude since. Then the sun produced one of the weakest solar minimums since the Ap Index was first recorded (beginning in 1932). The current solar cycle (Solar Cycle 24) is very weak. Not quite weak enough to be called a Solar Grand Minima but very close. It is analogous to a period referred to as a ‘Dalton Minimum’.

As we transitioned from a Grand Solar Maxima, which typified the 20th century to a magnetically quiet solar period similar to a Dalton Minimum (~1798-1823 A.D.), it gave us the opportunity to observe the changes in solar parameters across this transition.

I propose two mechanisms primarily responsible for Little Ice Age climatic conditions. These two components are Cloud Theory and Wind Theory. At the core of Cloud Theory are galactic cosmic rays (GCRs) and at the core of Wind Theory are diamond dust ice crystals. During Little Ice Ages, there is an increase of low level clouds that cause a general global cooling and an alteration of the jet streams that drives cold air from upper latitudes deep into the mid latitude regions.

Little Ice Age conditions are defined not only by colder temperatures but also by a shift in the patterns of wind streams. They produce long-lasting locked wind stream patterns responsible for great floods and great droughts. They also affect the cycle of seasons producing great irregularity and crop failures. Altered wind streams impacts the development of massive storms and hurricanes. These Little Ice Age conditions in the past caused poor crop yields, famines, major epidemics, mass migration, war, and major political upheavals.

Read the full document HERE: Little_Ice_Age_Theory

Be sure to read Appendix A which catalogs the climate extremes during the Maunder Minimum.  We are on the cusp of a Grand Minimum, Dalton or Maunder type, only time will tell.