Wednesday, December 18, 2013

Dealing with Climate Deniers: Solar Variation 101

Global warming: a cause for the pause

After decades of intensifying warming, the rise in Earth's surface temperatures has slowed since the late 1990s— a seemingly mysterious pause used by climate science skeptics to argue that global warming isn't real.
But the mystery had a simple answer: the warming didn't go away. Instead, researchers found that much of ittook place in deep oceans, which are now warming 15 times faster than in the previous 10,000 years. (Anequatorial Pacific cooling trend also appears to have offset planetary warming trends, but it's expected to end soon.) The pause, it seems, is only a blip.

Changes in solar brightness are too weak to explain recent climate change.
- See more on Solar Variation

There is a lot of misinformation fog around the climate change issues, and most of it is being generated directly by the carbon-fuel corporations that fear a carbon-tax and future regulations to cap carbon-emissions or 
reparations for carbon pollution. Dealing with these climate change deniers is a full time job, they like to use normal variations in data to cast doubt on the general hypothesis that human actions are having a profound change on the Earths climate, and thus irreparably damaging our biosphere, including mass extinctions and potentially a global catastrophe.

One climate denier brought up some scientific data he claimed proved that the Earth was actually cooling rather than warming. He was listening to right-wing radio and learned that Solar Radiation has been declining over the last decade, according to the National Solar Observatory. But this information, when understood properly isn't enough to account for the massive warming trend across the planet, the melting of glaciers and tundra, or the warming of the seas. 

Both long-term and short-term variations in solar activity are hypothesized to affect global climate, but it has proven extremely challenging to directly quantify the link between solar variation and the earth's climate. The topic continues to be a subject of active study.
The Sun's radiation tends to vary over an 11 year sun-spot cycle due to a periodic flipping of the Sun's magnetic poles. Due to the plasma like fluid of compressed hydrogen and helium that makes up most of the Sun's mass, the magnetic field apparently winds faster at the Sun's equator than at its poles. Over an eleven year cycle, the magnetic fields get twisted up and eventually become chaotic, causing a peak in sun-spots, which are essentially solar storms on the surface of the Sun caused by magnetic effects. Each sun-spot is caused by holes in the plasma surface, and indicates mass ejections, and increases in cosmic rays, including "hard particles" and high energy radiation.

Other solar cycles may have climate effects over long periods of geologic time, but generally the Earth's climate is more greatly affected by other astronomic events such as the Earth's precession which causes ice to accumulate in the Northern Hemisphere over a 26,000 year cycle. 

Direct irradiance measurements at the top of the atmosphere have only been available during the last three cycles and are based on a composite of many different observing satellites. However, the correlation between irradiance measurements and other proxies of solar activity make it reasonable to estimate past solar activity over long periods of time.
Although we have been experiencing slightly lower solar irradiance over the last 11-year solar cycle, then over the last two for which we have good scientific data from satellites and observatories, the variation is extremely small. The Sun generally produces about 1366 watts per square meter (perpendicular to the Sun's surface at the radius of the Earth's orbit ~93,000,000 miles), but over the last decade that number had decreased by about one watt per meter square (about 0.1%).

The point of all this data is that while we still don't know enough about the Sun's radiation to predict the solar weather patterns and how they will effect the Earth's climate, as we collect more accurate data over time we get see that 
"over the past 20 years, all the trends in the Sun that could have had an influence on the Earth's climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures." In other words, the Earth is warming while the Sun has been dimmer than normal. So, the Sun is not causing global warming. 
What's more frighting is that, since humans have greatly increased global particulate pollution, both from carbon fuels (like China's smog problem) and from industrial farming techniques (slash and burn, forest fires, and plowing), we should have experienced a general decline in world temperatures due to this particulate 'sun-screen' in the upper atmosphere. Thus, if we clean our air quality up, we could see a dramatic increase in solar radiation at sea-level, which would be trapped by green-house gasses, like methane, water-vapor, and carbon-dioxide. If this happens, and Solar radiation returns to normal levels, we could see a serious spike in global temperatures. 

The mission of the 
National Solar Observatory is to advance knowledge of the Sun, both as an astronomical object and as the dominant external influence on Earth, by providing forefront observational opportunities to the research community. The mission includes the operation of cutting edge facilities, the continued development of advanced instrumentation both in-house and through partnerships, conducting solar research, and educational and public outreach. The National Solar Observatory is operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation, for the benefit of the astronomical community.

1 comment:

  1. I'm not sure how exactly this shows "flexibility", Scientific Facts are always open to new information. What FACTS are NEVER OPEN TO is opinion.

    I didn't even know we could measure the deep sea temperatures from thousands of years ago. Honestly, I don't know what evidence you would use to keep such records? There are no trees, corals don't go deep, there are volcanic vents and currents and seasonal changes that would change the temperature locally, so a few degrees of warming wouldn't seem to be noticeable.

    Water itself is a great heat sink, as it's density is so much greater than atmosphere, and given the great mass of the oceans, and the fact that the temperature in the deep darkness remains constantly at the freezing point due to the ice at the poles, and cold water being heavier than warm water, I can't imagine how heat from the planet's surface would reach the deep.

    That said, I already knew about GLOBAL DIMMING (the huge increase in particulate pollution due to industrial farming, coal burning, and the rise of third world) and figured that was keeping the temperature from rising globally, even while we experienced more severe climate change in the west after cleaning up our air pollution. Turns out I was wrong about the magnitude of that effect.

    What actually kept us from experiencing a more dramatic global warming shift over the last dozen years, even as GHGs poured into our atmosphere from melting permafrost rotting across Canada and Siberia, and methane hydrate crystals on the ocean floor bubbling to the surface from shallow water deposits in warming seas, and of course natural-gas released through fracking, was NOT just global dimming, but the accelerated melting of the glaciers and sea ice around the world.

    What we will now see in the next 20 years is a dramatic shift in surface temperatures as ocean temperature increases will push water-vapor into the atmosphere, and this will lead to super massive storms, the melting of the greenland ice-sheet, and mass extinctions. What should have taken 100 years, we will see in the next two decades. And even if we stop burning carbon-fuels today, it will not matter, it's too late.

    (the only positive thing that will come from this is that you Global Warming Deniers will disappear and start lying about something else for a change, perhaps the fact that you were all listening to the same AM radio propaganda stations)