I've taken this from the following blog, (link highlighted below). Are variances in the energy received from the sun are responsible for climate change? It sure looks like it.
It’s the Sun, stupid
The The United Nations’s IPCC Report comes out today so I thought I’d make a report too.
James Carville used to remind Clinton during the ‘92 campaign that “its the economy, stupid”.
I (and many others far smarter than I am) say that on the subject of Global Warming: “its the SUN, stupid”
Our earth is warmed by a gigantic nuclear fireball, millions of times the mass of earth and a mere 8.5 light-minutes away. One hundred and nine Earths would be required to fit across the Sun’s disk, and its interior could hold over 1.3 million Earths.
By the way, the sun has a total luminosity output of 386 YottaWatts thats 386,000,000,000,000,000,000,000,000 watts, but we only get a tiny portion of that.
You can’t just ignore that kind of power. Though it seems some prefer to, since it muddles the results they seek.
The total luminous energy output received by earth from the sun is 174 PETAWATTS (174,000,000,000,000,000) watts. Now lets just say the sun increases its output by 0.1% as its been measured to do. (And its gotten way more active this century.) That dumps an extra 174,000,000,000,000 watts into our atmosphere (174 trillion watts) 24/7.
Data source for graph: http://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/solar_variability/lean2000_irradiance.txt
Note: In the graph above, the low flatline from 1645-1715 is the Maunder Minimum, a period of virtually no sunspots, where the historical reports from the northern hemisphere tell a story of dramatic climate change: harsh winters, cools summers, crop failures, famine and disease.
From the abstract referenced above: “Estimated increases since 1675 are 0.7%, 0.2% and 0.07% in broad ultraviolet, visible/near infrared and infrared spectral bands, with a total irradiance increase of 0.2%. “
So its not just 0.1 %, it is 0.2% which translates to a 348 TeraWatts global irradiance increase.
Now lets put 348 trillion watts into perspective:
Hurricanes: the heat energy released by a hurricanes category 1-5 equals about 50 to 200 trillion watts or about the same amount of energy released by exploding a 10-megaton nuclear bomb every 20 minutes.
Katrina, released about 200 trillion watts over its life cycle.
Now imagine double that amount of extra energy being added to earth’s atmosphere every second by small increases in the suns output that have been documented to exist. Thats what the increase in solar irradiance is doing. Since 1675, after the depths of the Maunder Minimum, we’ve seen an increase in solar irradiance of about 2.5 watts per square meter.
Climate modelers say that the extra CO2 equates to a forcing of about 2 watts per square meter, which totals about 1.12 Petawatt (1,120,000,000,000,000 watts). The problem is, they can’t always recreate that reliably between all of the different models out there, with the positive and negative feedback mechanisms, and other variables involved. There’s disagreement on the total contribution. A lot of it. Nonetheless they seem all to agree that CO2 makes some contribution, and thats likely true. But compared to the sun, I beleive it’s minimal.
Now lets look at us: 13.5 TeraWatts is the average total power consumption of the human world in 2001.
Do you think we could change the planets atmospheric energy balance with that if we squeezed all the power we made that year together and shot it into our atmosphere ?
Whats very clear though, when you look at history, and the graph above, is that our earths atmosphere and resulting climate is extremely sensitive to variations in solar output. The sweet center point seems to be about 1365 watts per square meter of irradiance…what we consider as “normal” climate. Take 1.5 watts/sq. meter away, and we get significant cooling, harsh winters, cool summers, and increases in ice and glaciers. Add 1.5 watts,/sq. meter and we get hotter summers, mild winters, and melting of ice and glaciers.
Now irradiance aside, as it’s only one component, there’s also the suns dynamic magnetic field and solar wind, which modulates earths magnetic field, which modulates the number of cosmic rays that enter our atmosphere, which modulates the number of clouds that form, hence changing the net surface irradiance. Plots of changes in the suns magnetic field line up very well with climate change.
There’s growing sentiment that CO2 theory may very well be a red herring.
Yeah, its the sun, stupid.