Does the fact that we're in a solar minimum lend credence to human-caused climate change?

Question

If we're currently in a solar minimum - a period of less solar activity and fewer spots - does that lend credence to the likelihood that global climate change is human-caused?
http://science.nasa.gov/science-news/science-at-nasa/2009/03sep_sunspots/

If not, what other factor than the sun or mankind might be a factor?

Answer 1

Yes. The fact that we've been at or near a solar cycle minimum for about 5 years, combined with the fact that we're in the midst of the hottest year ever recorded, pretty much rules out the Sun as a significant cause of the current global warming.

http://www.acrim.com/RESULTS/earth_obs_fig27.pdf



So does the fact that solar output hasn't increased in over 50 years.

http://www.mps.mpg.de/images/projekte/sun-climate/climate.gif



And the fact that no peer-reviewed study has attributed more than a small fraction of the recent warming to solar activity.

http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm



Of course as Paul noted, this fast amount of data won't stop some people from trying to blame the Sun, but those people are divorced from reality.



Other than anthropogenic activities, the only other explanation we seem to hear these days is the "magical natural cycles" argument, where people blame global warming on "natural cycles", but when asked to specify exactly what cycles are to blame, they go strangely silent or try to change the subject.

https://answersrip.com/question/index?qid=20090413224554AATtmFw



"It's not the Sun" isn't enough to tell us "it's CO2", but there's vast amounts of other evidence telling us that humans are causing global warming.

http://www.greenoptions.com/wiki/global-warming-and-climate-change-causes



*edit* jim wrongly claims "Your contention that we are in a solar minimum isn't totally correct."



Actually yes it is correct. We are in the midst of an 11-year solar cycle minimum. Maybe it's not the period you want to look at, but it most certainly is "a solar minimum" with respect to the 11-year cycle, if not the past several centuries. In fact it's even a minimum with respect to the past 50+ years. I'm rather curious how changes in solar activity 100 years ago are supposed to be impacting today's temperatures. I'll put it in simple terms - global warming has accelerated rapidly over the past 35 years. Solar activity has not increased on over 50 years. It's pretty simple to put 2 and 2 together and realize it's not the Sun causing the warming.



Jim then references a temperature graph which not only ends 80 years ago, as Jeff M notes, but failed to pass peer-review because it's so flawed. Here is some more accurate, up-to-date data:

http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html

Answer 2

The Industrial Revolution in the 19th century saw the large-scale use of fossil fuels for industrial activities. These industries created jobs and over the years, people moved from rural areas to the cities. This trend is continuing even today. More and more land that was covered with vegetation has been cleared to make way for houses. Natural resources are being used extensively for construction, industries, transport, and consumption. Consumerism (our increasing want for material things) has increased by leaps and bounds, creating mountains of waste. Also, our population has increased to an incredible extent. All this has contributed to a rise in greenhouse gases in the atmosphere. Fossil fuels such as oil, coal and natural gas supply most of the energy needed to run vehicles, generate electricity for industries, households, etc. The energy sector is responsible for about ¾ of the carbon dioxide emissions, 1/5 of the methane emissions and a large quantity of nitrous oxide. It also produces nitrogen oxides (NOx) and carbon monoxide (CO) which are not greenhouse gases but do have an influence on the chemical cycles in the atmosphere that produce or destroy greenhouse gases. There are a number of natural factors responsible for climate change. Some of the more prominent ones are continental drift, volcanoes, ocean currents, the earth's tilt, and comets and meteorites. Let's look at them in a little detail.

Answer 3

Recent temperature variations haven't been following the Sun's output closely for awhile now. However they still continue to claim that the Sun is the main driving force behind temperature variations. They look past all the evidence that points to an increase of CO2 in the atmosphere trapping more heat near the surface of the planet and the fact that human emissions are greater than what the atmospheric concentration is increasing by. I'm sure they'll continue to say it is the Sun regardless what gets put in front of their face.



JimZ: Just a question, why do you continue using the graph from Dr Spencer's site when it only goes up to approximately 1930, before WWII? Also, the graph on that wiki page clearly shows that there has been cooling for the last 50 years or so. Exactly how long do you claim heat in the oceans control temperatures on Earth?



JimZ 2: I am aware that the ocean stabilizes the temperature. I guess I should have made myself clearer. What I am basically asking is how long a time period do you attribute to this? It's been 50 years since the Sun's output began declining while air temperatures have continued to rise.



I'm also curious, given that the radiative trapping of radiation in the troposphere by CO2 and the greenhouse effect are pretty much fact, how much warming do you attribute to the rise of CO2 in the atmosphere?

Answer 4

Your contention that we are in a solar minimum isn't totally correct. We are simply living in a period of low solar activity based on the 11 year cycle. We are still living in the Modern Maximum.

http://en.wikipedia.org/wiki/Modern_Maximum

It never ceases to amaze me how most people think in very short time intervals.

This period of time corresponds with a time of generally high solar output and high sunspots. This has corresponded to a general warming over the last several hundred years since the Maunder Minimum. The climate typically doesn't (and hasn't) change that quickly. There is a lot of energy stored up in the ocean and elsewhere.



Here is a climate reconstruction using non tree rings.



http://www.drroyspencer.com/global-warming-background-articles/2000-years-of-global-temperatures/

Notice that we have warmed gradually over the last few hundred years. Those who look at such short time intervals are deluding themselves IMO. If the downturn is something else besides the typically downturn you get with the 11 year cycle, then it may take a while for it to manifest itself with cooler temperatures. El Ninyos may still be very warm. Climate doesn't proceed in a straight line.



Note: Jeff, what I said about the ocean stabilizing the climate isn't just my opinion. It is really pretty basic. Based on the CO2 versus temperature in ice core data, it taks a few hundred years for the ocean to begin to catch up to atmospheric trends. That is the lag time you have probably heard of. It is a wiki article so I wouldn't claim it is reliable in every way. It suffices to define what the Modern Maximum is. Just because it is October, doesn't mean warm temperatures are necessarily over. Similarly, just because the Modern Maximum seems to be waning, doesn't mean the warm trend has ended. Isn't that obvious or it is just me?

Answer 5

Sunspots are not a direct measurement of solar output, although solar activity is at a minimum too, and has been for quite a while now.



If you consider that 2010 is shaping up to be the warmest year on record in spite of this minimum, then yes, I would say it lends credence to AGW.

http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts+dSST.txt



But it's not as if this observation was needed in the first place. There are so many nails in the coffin of the "global warming is caused by the sun" theory already that another one is not really needed. It's like asking if the discovery of a new genetic mutation in a bacterium lends credence to evolution.

Answer 6

There are three physically proven facts: 1. Burning fossil fuel releases carbon dioxide. 2. The amount of carbon dioxide in air went up 40% in the last century (from 280 parts per million to 390 parts per million) and is still going up 2 ppm per year 3. When the amount of carbon dioxide in air goes up, the Earth warms.



For 30 years scientists have tried to understand the weird changes in the climate, the worse storms, increase in floods and droughts, dying forests. Working in sub zero temperatures to analyze gases in bubbles in ice; trekking across melting tundra in Siberia to measure methane gas escaping from the Earth; spelunking in caves and then counting the rings on stalactites; and, of course entering statistics in computer programs, the scientists are a hardy group of people.



When you put together all their research, there is just no other explanation that makes any sense at all. There is nothing else that affects the climate anywhere near as much as the excess carbon dioxide that is coming from the fossil fuel we are burning. To look for something else is like wearing a fur coat in the summer and looking for another reason why you are hot.



People who invested or worked in the fossil fuel industries should feel proud that they have contributed to the development of a fabulous, comfortable, fascinating culture. Cheap energy allowed the development of computers and ice core drills and satellite laser spectrometers that measure the changes in the climate. The oil economy made possible the invention of computers that give us predictions that are getting more accurate by the day.



Thanks to fossil fuels, we have developed excellent technology for getting energy from the sun, wind, waves, and deep earth. So, now it is time to take away Grandpa's keys; time to say syonara to fossil fuel and move into a new more profitable, sustainable, clean energy economy.



Climate science is new, it was really not clear before 1980. At first scientists thought it would happen fairly slowly. However more recent research on feedback mechanisms tells us it is happening pretty fast. (Feedback is like hotter air melting ice replaced by dark water or land that absorbs heat which then melts more ice and it continues.)



Climate scientists predict that if we don't make a modest investment now to change from burning fossil fuel to using clean energy that we will see sea level rise of 2 meters and temperature rise of 4 to 9o F by 2100.



More information at the US site:http://globalchange.gov

Grist Environmental News http://www.grist.org

Get active, send a letter a week to an official to get our government to stop spending our taxes to support the fossil fuel industry and instead give clean energy some support.

http://nrdc.org or http://greenpeace.org

Answer 7

● SOLAR MINIMUM



“If we're currently in a solar minimum - a period of less solar activity and fewer spots - does that lend credence to the likelihood that global climate change is human-caused?”



The sunspot cycle averages 11 years, typified by half the cycle showing increased sunspot numbers and half the cycle with decreasing numbers. We’re now on the cusp of entering cycle 24 but there was a stalling of a couple of years in which sunspot activity was very low.



From peak to trough of a Sunspot cycle the amount of energy emitted by the Sun (Total Solar Irradiance) varies by less than one thousandth from the mean. This is calculated be measuring the amount of incoming energy on a plane perpendicular to the Earth’s surface at the upper edge of the atmosphere. It’s measured in Watts per square metre per year and has a mean value of 1366W/m²/yr and a variation across a full sunspot cycle of ≈1.3W/m²/yr.

http://science.nasa.gov/media/medialibrary/2009/03/31/01apr_deepsolarminimum_resources/irradiance.jpg



From time to time there are extended periods of very low sunspot activity. Here’s a graph showing four minima in the last 1000 years http://en.wikipedia.org/wiki/File:Carbon14_with_activity_labels.svg and here’s the temperature graph for the last 1000 years http://www.globalwarmingart.com/wiki/File:1000_Year_Temperature_Comparison_png



You can see that there’s something of a correlation between the two, particularly if you look at the longer term trends – e.g. the decline in sunspots from c1100 to c1700 more or less corresponds with the decline in temps.



As a rough guide, a prolonged decline in sunspot numbers produces a temperature drop of 0.001°C per year, the relationship is inverse logarithmic and would tend to zero after a few thousand years.



Cycle 23 peaked just over 10 years ago and could have contributed ≈0.01°C to cooling http://solarb.msfc.nasa.gov/images/ssn_predict_hinode.gif



In at the peak of cycle 23 the average global temp had an anomalous value of 0.372°C* and today the anomaly is 0.475°C*. What we’ve seen therefore is warming of 0.103°C at a time when sunspot activity would have produced cooling of ≈0.01°C.



* The values are 30 year running means compiled from averages of all the global temperature records and expressed as anomalies against the 1961 to 1990 30 year base period mean. Using RA’s of less than 30 years shows more significant warming, as would using selective records.





● OTHER FACTORS



“If not, what other factor than the sun or mankind might be a factor?”



For all intents and purposes the Sun is the source of all heat on our planet, the contribution from direct heating, geothermal, friction, waves etc is tiny in comparison.



However, there exists on Earth a mechanism that allows for the retention of some of the heat energy and that is the Greenhouse Gases, without their insulative effect Earth would have no mechanism for retaining heat and would be so cold that life could not have evolved.



This insulating blanket traps a proportion of outgoing thermal radiation – the heat from the Sun being re-radiated outwards from Earth. The more greenhouse gases there are the greater the potential for heat to become trapped.



For many millions of years the concentration of greenhouse gases within the atmosphere varied between 180 and 290 parts per million by volume (ppmv). Our modern lifestyles have released significant quantities of these gases through industrial processes, burning of fossil fuels, agricultural practices etc and the consequence is that levels have now increased to 394ppmv, or about 40% in real terms.



With this significant increase of atmospheric greenhouse gases comes the inevitable realisation that more thermal radiation will become trapped thus leading to a gradual warming of the planet – manmade global warming.



Your question relates to solar cycles and these have a cyclicity of ≈11 years. In respect of the climate this is too short a period of time to derive ay conclusions due to the number of short-term influences that can affect the climate.



In short, we shouldn’t be drawing any conclusions based on changes that may have occurred during this relatively short period of decreased sunspot activity and instead we need to look at the longer term trends, ones of at least 30 years.

Answer 8

It makes it more difficult to blame the Sun, but plenty of people here manage anyway. You will probably be told that



you are looking at the wrong cycles or



that we don't understand all the cycles or



that we are coming out of a big ice age 10,000 years ago or



that we are coming out of a Little ice age 200 years ago or



that we have been cooling since 2005 (they used to say since 1998) or



that Watts says the results are distorted by the heat island effect or



that all the data come from very naughty scientists who can't be trusted or



that the warming for some particular 15 year period wasn't or statistically significant and therefore doesn't count or (the argument of last resort, which I'm beginning to see here),



that it's too late to do anything about it anyway

Answer 9

It might if these anti-science doomsday cultists like Hansen and Trev.. and Dan.. didn't suggests that we are headed for apocalyptic warming. The warming is only suggested by nearly brain dead activists like Hansen that corrupt data and people that think that less than a degree of manufactured warming is worth getting all freaked out about. They might as well do the world a favor and reduce the population right now. That level of ignorance shouldn't be passed on to future generations.

Answer 10

Hey monopoly, used to be my fav board game,

I dunno, sun feel about same to me, temps here in Hawaii bout the same all my life, so who knows, and who cares, nothing we can do about it anyway.