last ice age
© HowStuffWorksIce sheet coverage during the last ice age
Excerpts:

"The sun has gone very quiet as it transitions to Solar Cycle 24.

"Since the current transition now exceeds 568 spotless days, it is becoming clear that sun has undergone a state change. It is now evident that the Grand Maxima state that has persisted during most of the 20th century has come to an abrupt end.

"(The sun) might (1) revert to the old solar cycles or (2) the sun might go even quieter into a "Dalton Minimum" or a Grand Minima such as the "Maunder Minimum". It is still a little early to predict which way it will swing. Each of these two possibilities holds a great threat to our nation.

"We are now at a crossroad. Two paths lie before us. Both are marked with a signpost that reads "Danger"! Down one path lies monstrous solar storms. Down the other path lies several decades of crushing cold temperatures and global famine."

"Climate change is primarily driven by nature. It has been true in the days of my father and his father and all those that came before us. Because of science, not junk science, we have slowly uncovered some of the fundamental mysteries of nature. Our Milky Way galaxy is awash with cosmic rays. These are high speed charged particles that originate from exploding stars.

"Because they are charged, their travel is strongly influenced by magnetic fields. Our sun produces a magnetic field wrapped in the solar winds that extends to the edges of our solar system. This field deflects many of the cosmic rays away from Earth. But when the sun goes quiet (minimal sunspots), this field collapses inward allowing high energy cosmic rays to penetrate deeper into our solar system.

As I say in Magnetic Reversals and Evolutionary Leaps, these same cosmic rays can lead to mutations and evolutionary leaps.

"As a result, far greater numbers collide with Earth and penetrate down into the lower atmosphere where they ionize small particles of moisture (humidity) forming them into water droplets that become clouds. Low level clouds reflect sunlight back into space. An increase in Earth's cloud cover produce a global drop in temperature.

"If the sun becomes quieter than the old solar cycles, producing more than 1028 spotless days, then we might slip into a Dalton Minimum or maybe even a Grand Minima such as the Maunder Minimum. This solar state will last for decades. Several solar scientist have predicted this will begin in Solar Cycle 25, about a decade from now. But a few have predicted this will occur now in Solar Cycle 24.

"A quiet sun will cause temperatures globally to take a nose-dive. We will experience temperatures that we have not seen in over 200 years, during the time of the early pioneers.

"Temperatures are already falling. Satellites provide generally the most accurate atmospheric temperature measurements covering the entire globe. From the peak year 1998, the lower Troposphere temperatures globally have fallen around 1/2 degree Celsius due to the quiet sun.

"This is despite the fact that during that same time period, atmospheric carbon dioxide (at Mauna Loa) has risen 5% from 367 ppm to 386 ppm. The main threat from a "Dalton Minimum" or "Maunder Minimum" event is famine and starvation (affecting millions or hundreds of millions worldwide) due to shortened growing seasons and harsher weather. In the past, in addition to great famines, this cold harsh weather has also lead to major epidemics.

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