Death from the Skies! by Ph. D. Philip Plait Page A

Is it caused by the Sun, and not by humans?
    A lot of noise has been made on this topic, but scientists actually do agree on this: the Sun is not the cause of the current temperature rise seen in the latter half of the twentieth century to today.
    This isn’t hard to show, actually. The amount of radiation from the Sun is measurable, and since the 1950s to today there has not been an increase in solar radiation. In other words, the Sun has not been getting brighter during the time when the Earth has been getting warmer. The amount of solar radiation has been quite steady since 1950, and is obviously not the cause of global warming. It’s clear to the overwhelming majority of scientists independently studying this phenomenon that it is human activity, our activity, that is behind the current sharp rise in global temperatures.
    This most basic fact has not stopped some people from claiming that many other planets are also experiencing global warming, and therefore the cause here on Earth cannot possibly be human-induced. The only thing linking all the planets is the Sun, they say, and therefore the Sun is causing this warming.
    However, this is nonsense. The claim is that Mars, Jupiter, Triton (a moon of Neptune), and even Pluto are warming. 20 However, each of these has separate causes, linked with the individual objects’ atmosphere and orbit, and any purported warming is not related to the Sun.
    And let’s be clear: these objects are much farther from the Sun than the Earth, and receive proportionately less heat. To warm up Pluto even one degree, the Sun would have to get so much brighter and hotter that it would be overwhelmingly obvious—in fact, the Earth would get totally fried. Since our own warming is less than a degree, it’s clear that the other planets’ warming must be due to some other source than the Sun.

SUNNY OUTLOOK
    We live on a small planet where a considerable number of factors have to align to make life hospitable. However, we live near a tempestuous star that will, inevitably, do what it can to disrupt that equilibrium. Ironically, too much solar activity can cause immediate and global damage, but too little can, in the long run, be just as bad. Like most things in the Universe, this is a delicate balance, and a swing to either side would be catastrophic.
    However, we have survived many small oscillations. The Little Ice Age came and went, with people taking it in stride—they really did skate on the Thames. Huge flares have wreaked havoc on our power grids, and with a little care, foresight, and a pile of money, we can avoid total disaster.
    As for the big swings . . . well, we’ll see. They may not happen for centuries or even millennia, and by then we may be able to take action. But the time to start thinking about it all is right now; and we are. Smart people are working on these very topics, and while it may take time to figure out all the angles, and there may be lots of arguments along the way, I think in the end we’ll figure a lot of this stuff out.
    In the meantime, I’ll still enjoy the occasional sunny afternoon . . . but I’ll also be mindful that over my shoulder, just an astronomical stone’s throw away, is a vast and mighty star. And it has a temper.

CHAPTER 3
    The Stellar Fury of Supernovae
    THE FIRST ONES TO NOTICE ARE PROFESSIONAL astronomers.
    Researchers at the Super-Kamiokande neutrino observatory in Japan are shocked when their detectors light up like Christmas trees. Such unprecedented readings prompt them to look for malfunctions in their hardware, because surely no astronomical event could generate so many of the ghostly subatomic particles—even the Sun, the brightest object in the sky, barely produces enough neutrinos to be picked up by their instruments. There would have to have been millions of neutrinos detected to register so strongly! Poring over their instruments, it takes them nearly two hours to figure out that the flood of neutrinos was indeed real,