The Coming Ice Age: Part IV CO2 Causing Cooling?

CO2 causes warming! CO2 causes cooling! What the hell is going on? The fact is that CO2 can do both. Thinking purely of the radiative impact, initially, CO2 causes a little cooling if a lot is added at once, then the warming impact catches up and over takes the cooling impact. It is kinda weird, but there is a pretty logical though a little complicated explanation.

The big thing is where is the energy coming from? Early when there is a rapid increase in CO2, the energy is coming from the sun until the surface temperature catches up. In the upper atmosphere, it is easier for CO2 to radiate to space than it is to the surface. Since a good portion of the incoming solar energy is absorbed by the atmosphere, a higher percentage of that atmospheric warming will be lost to space with a jump in CO2. The warming effect is happening just initially, the cooling wins out a little. Since there is a disruption of the outgoing energy flux, the surface temperature responds by warming until it reaches a new average temperature that is a little warmer and the atmospheric cooling and surface warming come into a new balance that is warmer if you only consider the radiative impact. Unfortunately, the world's climate system tends to be a little chaotic, so if you only consider radiation you miss the big picture.

In the first of the Coming Ice Age series, I emphasized the important role of water. Water vapor, only a part of the puzzle, is emphasized in the radiation impacts of CO2. In a warmer world the air can hold more water vapor, CO2 causes warming, more water vapor adds to the warming, so OH My God, we are in trouble!

If you only consider water vapor you are absolutely right. Clouds though are more than water vapor, they are condensed water droplets. Water reacts different than water vapor. So the cloud issue is one of the largest unknowns in the climate change debate.

The recent global not warming is likely due to cloud cover increase that causes more reflection of incoming energy than it does retention of out going energy. These changes in average cloud cover are likely associated with the longer term internal climate oscillations. The impact of these oscillations are considered trivial to long term climate because they should tend to average out. On very long time scales that is probably true. With more CO2 though, that can change in several ways.

The first is more radical internal climate variability. More water vapor in the atmosphere means more intense rain and snow events. So visions of snow in winter so rare that future children will be amazed, is totally bogus. Certain areas will have a lot more snow and a lot less snow with climate oscillations. Rain events will be a lot stronger and droughts a lot deeper. But stronger and deeper than what?

The rain and drought events so far are not exceptionally different than past recorded events and do not seem to be significant at all compared to thousand year events as best as we can tell. So while climate events will be more extreme, it is not easy at all to confidently predict how much more.

During the past 30 years of climate science, most of the period indicated warming that agreed very well with warming predicted by climate models geared to estimate the climate's sensitivity to increased CO2. For the past ten or so years, the climate appears to have shifted due to the change in one of the internal oscillations, the Pacific Decadal Oscillation (PDO) an now the sun is going into a quite mode, which the satellite era of science has never experienced. So there are a lot of questions that will get better answers.

Second, increased climate extremes during a general cooling internal oscillation is likely to cause more cooling, IF water in its solid state, snow and ice, increases albedo to a point where it amplifies the impact of the cooling. That possibility increases with a cooling PDO and quieter sun. Should another internal oscillation synchronize with the PDO and quiet sun, the possibility increases greatly.

Third, with less outgoing radiation from the surface due to increased albedo, the cooling effect of CO2 on incoming solar energy will be enhanced. That will result in more cooling or less warming if you like, due to atmospheric CO2.

So there is the potential of a lot of stuff happening with more CO2. The scientific community in my opinion is screwing up royally by stressing their certainty in one scenario, when the uncertainty of the various scenarios in more important.

The Coming Ice Age? Part III Is it the Sun?

The sun provides nearly all of the energy for our climate system. The energy in the Earth's core is small by comparison so it can be neglected in most cases. The impact of volcanic aerosols generated by that internal energy is not negligible. Large volcanic eruptions, especially near the equator, can cause significant cooling for a year or two by reflecting solar energy and by absorbing solar energy higher in the atmosphere where it is more easily radiated to space. These aerosols, primarily sulfur based, change the chemistry of the atmosphere as well. There is a complex interaction of albedo, radiation height, radiation type, radiation intensity and chemical processes that all impact climate. Like we really need more complexity, right? The last three of those variables combine to create the most uncertainty in my mind.

The newly released Cern CLOUD report indicates that cosmic rays that increase in intensity during a solar minimum interact with the trace compounds in the atmosphere to create small particles that can "seed" clouds. These particle provide a surface making it easier form water molecules to condense. The particles created by cosmic ray interaction are smaller than required for efficient seeding of clouds. This process and the size of the particles present a statistical challenge for climate scientists.

Cosmic rays that penetrate the atmosphere increase as the solar energy decreases. If the cosmic rays increase cloud formation, the impact would amplify the change in solar energy which I have shown previously is on the order of 0.18 Watts/m^2. Albedo change provides a much greater change in solar energy absorbed, so more clouds would provide the umpf. By itself though, the change in cosmic rays doesn't appear to be that significant. Volcanic activity can amplify the cosmic ray impact by providing more feed stock for the chemical process. This increases the material and time for the cosmic rays to build bigger seed particles. With the volcanic aerosols more in the high atmosphere near the equator, more water vapor is available to form clouds around these particles.

This leads to a bit of a paradox, in order to trip the Earth system into an ice age, the Earth would have to be warmer than normal for there to be enough water vapor for a rapid change. Climate records show that climate is constantly changing with two set points, warm periods and ice ages. In either of those set point ranges there are minor warm periods and minor ice ages. The minor periods are primarily in the northern hemisphere where the percentage of land area to ocean area is higher. So these minor periods are "regional". With enough of the right conditions, these "regional" events have global impact.

This year's northern hemisphere weather shows how important the northern hemisphere is to global weather. Snowfall and spring precipitation pushed records thanks to the La Nina inspired change in weather patterns. The change is water vapor distribution has the potential to create snow pack deep enough and snow cover wide enough to increase albedo or reflectivity. The extent of the snow cover was not far enough south to have a major albedo impact this time. But imagine if you will, the snow that was in all lower 48 states, being a little heavier and lasting a little longer. The snow cover below latitude 45 has much greater impact on absorbed energy than the snow pack above latitude 50. The closer the snow gets to latitude 30 the much greater the impact becomes. So did we dodge a bullet? Maybe.

While the past year had a good amount of volcanic activity, most was above latitude 45 north or below the equator. This is not to imply that the volcano has to be located between the equator and latitude 45, but the aerosol cloud from the volcano impact the area between the equator and latitude 45 with the right mix of chemical compounds. The Laki volcano is located in Iceland near the arctic circle. When it erupted in 1783, it produced strong cooling dropping the average winter temperature in the US by nearly 5 degrees C. Thirty years later, Mount Tambora in Indonesia erupted causing a colder spring and summer. The location, timing and concentration of volcanic eruption greatly impact climate.

So how can these factors combine into the perfect storm? A large volcanic eruption with the impact of a Laki in the early spring, during a prolonged solar minimum during early transition to a cooling Pacific Decadal Oscillation with a strong La Nina could produce an increase in albedo of up to 5 percent in a very short period of time. If the volcanic climate cooling persists for two years approximately, we could tip into an ice age, minor or possibly major.

While I still have some work to do, somewhat surprisingly it looks like increased CO2 may provide enough water vapor increase to drive the cooling deeper than other wise. I will leave this with a link to a NASA animation of water vapor changes in 2005. If I can dig up the information for 2010 - 2011, the comparison may be interesting.

The Coming Ice Age? Part II

In my first post on the Coming Ice Age I gave some rough estimates of the changes of surface reflectivity and a rough range of temperatures that may correspond to those changes. I am not all that concerned with how exact those estimates are, just that there appears to be more range for cooling and some range for warming that is likely buffered by the response of the climate to the increased warming.

The reason is that the sun may be entering an new minimum cycle similar to the Dalton Maunder minimum, thought to cause the last little ice age. With global warming all the rage, though not as raging as it once was, the new minimum is seen by some to be proof that increased CO2 is not that big a deal maybe even a good thing.

Current satellite data on the sun is providing much better quality data of the impact of the change, but seems to ask more questions than it answers. The total solar power or insulation TSI only changes about 1 W/m^2 during a minimum out of 1366 watts/m^2 average. That is not enough to make much change without some amplification of its change. There are theories a plenty of things than may amplify the sun's impact. I will let those lay while I stick with my train of thought. Do remember that 1 W/m^2 would only be felt as about 0.18 W/m^2 at the surface where a full one degree change in surface temperature would require and estimated decrease of 3.7 W/m^2

A.A. Tsonis has a few studies where he determines there have been climate shifts due to natural climate oscillation that can synchronize in warm of cool phases. His papers indicate one started around the year 2000, before the current solar minimum started to show itself. That shift appears to most likely caused by the cool phase of the Pacific Decadal Oscillation (PDO). The PDO seems to cause some changes in the El Nino / La Nina timing and intensities. Dr. Roy Spencer with the University of Alabama at Huntsville (UAH) has noted that there has been a change in the percentage of cloud cover in the tropics which may be due to the PDO shift. A 1% can in cloud cover results in nearly 3 W/m^2 or about 0.8 degrees possible temperature change which will likely be less than 0.4 due to atmospheric water vapor.

Clouds have a few impacts on climate that can cool or warm things. Cloud top reflectivity is one pretty important impact. In the the original post my rough numbers indicate the range and impact of albedo or reflectivity change. Since the climate appears to have two rough set points, it takes a little push to move from one to the other. Leif Svalgard, who is a scientist studying the sun, does not think the drop in TSI due to a minimum is enough. I completely agree, but I don't think the required push is as much as many may think. Combining Tsonis' method of determining climate shifts with past climate history and the newer solar TSI reconstructions, there may be part of the push available. The synchronizing of the solar minimum with a cooling PDO.

With the PDO shift, average temperatures have leveled off. The solar minimum has started in sequence with the PDO shift and atmospheric temperatures are still pretty level but some cooling of sea surface temperatures seems be be happening. Not enough to ring any alarm bells, but a slight drop. The La Nina cycled to neutral, but instead of a new El Nino, indications are that there may be a new La Nina on the way.

The record temperatures of 1998 have been attributed to the "Super" El Nino of the same year. With our moist atmosphere, it is easier to warm with an El Nino than it is to cool with a La Nina. Temperatures in general show more rapid warming than cooling due to atmospheric moisture. So it is possible that the new La Nina if it is fairly strong, will cause a slight decrease in temperature, maybe a little more with the solar minimum. Not enough for me to say, "Ha! Its the sun and natural variability!" Possibly enough for me to say, "Watch out if the Atlantic Multi-decadal Oscillation synchronizes with the PDO AND solar!" Which has a pretty fair possibility of happening in the next few years.

If those natural variations all synchronize, the result will be more than expected cooling. How much? I have no clue. I doubt as much cooling as the little ice age, that should take a little more pushing. That is where the other theories come into play.

One I consider a player is the reduction in UV intensity. UV has been recently found to vary more than expected. Most consider UV to be a minor player. That same "most" also underestimate, in my opinion, the impact on the deep ocean of the shorter wave lengths of light from the sun, UV being one. So we may have a variety of small impacts synchronizing to create a major impact. Not out of the realm of possibility for a system with dual set points, which has some level of instability. Interesting times may be heading our way.

Should the minor factors synchronize, albedo can amplify the cooling more than it can the warming. We have a tendency for ice ages historically, why should this Holocene be particularly special?

To hypothesize is easy, to theorize is not, scientifically speaking. So it will take more research on my part to flesh out this hypothesis. Anyone reading that cares to join in is welcome to help.

The Coming Ice Age?

Climate changes on different time scales for different reasons. Ice ages or glacial periods are followed or led by warmer periods or interglacial periods. Pondering what causes these changes has been a pursuit of man since the first tree was found in a block of ice that is a glacier. I have proposed that the Earth has two temperature set points, one cold (ice ages) and one not so cold (warm interglacial periods), with water controlling the thermostat.

This is nothing new. I am sure there are many papers with similar ideas using a variety of triggers that starts the ball rolling. One question is how big the triggers have to be?

Water, in its three stages controls the show. As a liquid it absorbs electromagnetic radiation only reflecting about 7% and as a solid it reflects about 95% and absorbs only about 5 percent. As a gas water vapor is great for moving heat around absorbing and giving off heat by conduction, latent heat or phase change and radiation. So to me, water runs the show.

At this point in time the earth and its atmosphere reflects about 30% of the solar energy the Earth system receives from the sun. During an ice age, more is reflected because there is more snow and ice. Even in an ice age, the water near the equator which receives the most solar energy does not freeze. If it did, the Earth would reflect too much of the solar energy and reach a snowball Earth tipping point. To recover from that, something catastrophic would be required to jump start the Earth which would mean that the fossils of critters that survived the ice age would be piled up in an easy to find layer and we would be taught about the remarkable recovery from the Shit Hit the Fan (SHF) era. There is evidence of some the Shit Nearly Hit the Fan eras, but some forms of life survived to start things anew.
Modern man is a product of the last SNHF era or recovery from the most recent ice age.

The reflectivity of the Earth, called albedo, which I can mix up absorptivity, is right now 30%, with most of that caused by clouds mainly in the tropics and sub tropics. Snow and ice at the poles and on top of mountain ranges contributes a small amount to the reflectivity because most of the snow is at the poles where solar radiation is much lower. The reflectivity cannot reduce much more. If all the snow and ice on the Earth melted, that may drop the reflectivity to 20% but all that water would produce more clouds so 25% is closer to the absolute minimum.

During an ice age the reflectivity increases, but it also has a maximum limit. This may be pretty hard to estimate. It is unlikely that the glaciers would expand to the tropics. The tropics are between 23.5 N and 23.5 S, the imaginary lines of the summer and winter equinoxes. Just for simplicity, I want to use 30 N and 30 S as my estimate tropical boundaries. Why? Because the sine of a 30 degree angle is one half. Since the Earth is pretty much a sphere, from equator to 30 N receives 50% of the solar energy of the northern hemisphere and the same thing from the equator to 30 degrees S. So 50% of all the energy the Earth receives is collected between 30 N and 30 S. If we assume that the cloud cover in this region remains about the same, we can assume that even during an ice age the Earth still absorbs 50% of the energy it absorbs in an interglacial period. Since the sun pumps out about the same amount of energy all the time, the worst case glacial albedo would 70/2 plus 30 equals 65 percent. So the range of albedo is in the ballpark of 25% minimum and 65% maximum, that means that the Earth can absorb between 75% and 35% of the solar energy available.

Since NASA has been kind enough to publish the solar energy available at the top of the atmosphere (toa) and we live on a pretty close to a sphere planet, the range of energy absorbed is 256 W/m^2 to 120 W/m^2. Power varies by the fourth root of the temperature, so while there is a big power difference, the temperature difference is not so big. So just using the fourth root, the apparent temperature at the toa would range from 2% more to about 16% less. This is based on the absolute temperature, which is about 255 K at the toa right now, so we have a rough range of 260 K to 214 K. While the average temperature of the surface depends on a bunch of stuff, a rough estimate for my purpose would be the same percentages of the 288K average surface temperature or 293K to 242 K as rough maximum average temperature ranges at the surface if albedo varies from 25% to 65 percent.

These are of course very rough numbers and not intended to be accurate enough to be useful for anything more than an illustration of the relative limits of climate change based on albedo change.

242 K is pretty cold. 274 K is zero degrees C and 242 is -32 degrees C or -26 degrees F. The temperature during the glacial periods is only estimated to be 6 degrees less or 282K. So why would my worst case be so much lower than 282K? Because of the location of the oceans.

The image above is an artist's conception of an Ice Age Earth from wikipedia. The northern hemisphere took the biggest hit because it has more land mass which doesn't benefit from the thermal mass of the ocean. So the 30N to 30S could be extend to 45N to 55S as to determine a more accurate maximum ice extent, or back calculating from the average temperature of the glacial period find that an albedo increase to 37% could produce that change. That would give us a more realistic maximum change albedo range of 25% to 40%.

While these are rough estimates, they show how lucky we are to live on a water world that has reasonable limits with our stable sun. Not that a new glacial period or 5 degrees of warming would be fun, but runaway conditions up or down are avoided thanks to the amount of water and where it is located.