The Definitive Global Climate Change (aka Global Warming) Thread -- General Discussion and Questions

We hear a lot of talk about fiscal crises and balancing the national budget these days, never mind wrestling to balance our own family budgets. Given this attention to fiscal responsibility, I thought perhaps putting our climate change problem into fiscal terms might make it more understandable and meaningful for many people. What I am talking about is the Earth’s energy budget. We are currently importing more energy from the Sun than we are exporting to the rest of the universe. The imports come in the form of sunlight and the exports are a combination of light (reflected from the planet) and heat that is radiated in all directions. When the climate is stable, the energy budget is balanced. If we export more energy than we bring in, then the planet cools and ice ages occur. Conversely, if we import more energy than we export, the energy has to be stored somewhere as extra heat. Luckily for us, the Earth has a great storage tank called the oceans that soak up most of the extra energy and release it back to the atmosphere more slowly over time. This is a bit like the Strategic Petroleum Reserve that the United States maintains, just in case the flow of imported oil gets slowed down. The oceans act to moderate sudden climate changes by soaking up and releasing energy from the sun. This smoothes out temperature changes between day and night and between summer and winter. However, problems arise when energy fluxes remain out of balance for many years.

So let’s get back to the Earth’s energy budget. We currently import and average of 262 W/m² of the Sun’s energy across the planet and export roughly 261.15 W/m² of energy as reflected light or heat (Hansen et al. 2005). The amount of sunlight reflected increases or decreases with changes in the planet’s color. So, if we have more bright white clouds, snow and ice, then we reflect more of the sunlight. However, if the snow and ice melt or the clouds dissipate, we absorb more of the light because water, soil and vegetation are darker. The rate of heat export varies with the temperature of the planet. As the temperature rises, the heat release increases exponentially. This means that small increases in the Earth’s temperature result in larger amounts of energy being radiated out into space until a balance is reached. This is how the moon works. During the day, the surface heats up to a toasty 235 degrees Fahrenheit while at night the temperature drops to a mind numbing -243 degrees. Thankfully, our planet doesn’t have temperature extremes like the moon. The reason for this is that the atmosphere that envelops our planet slows down the rate of heat loss. In our financial analogy, it is like an export tax with some of the heat sent back to Earth. The atmosphere acts like the windows in your car. Sunlight gets in, but heat release is slowed down. The inside of your car doesn’t melt because, as the temperature inside rises, greater amounts of heat energy are released until the energy coming in and going out are balanced. This is why you’ve heard of global climate change being called the greenhouse effect. The analogy to a greenhouse isn’t perfect, but it does give the general idea of how certain gases, namely water vapor, carbon dioxide, methane and several others, act to slow down the rate of heat loss. Burning fossil fuels pumps more carbon dioxide into the atmosphere and strengthens the greenhouse effect, kind of like putting double-paned windows on your house to keep the heat in.

So, if you whipped out your calculators earlier, you could have calculated that the Earth has an energy imbalance of 0.85 W/m². How do we know this? We have had satellites in space for several decades now. We are able to measure the amount of sunlight reaching the Earth, and also measure the amount energy being released by it. So how bad is our energy balance problem? What seems to be a measly amount, at 0.85 W/m², is enough to permanently light 45 100W light bulbs on every football field sized area of the planet. That would be about 4.3 trillion light bulbs globally. Put another way, the Earth is currently storing an amount of energy equal to roughly 520 Hiroshima nuclear bomb blasts every single minute of every single hour of every single day all year long. We are gaining 29 times as much energy as all of humanity consumes for all purposes in a given year. This would be a great return on our investment if we wanted to heat the planet; the problem is that we don’t want to do this. To date, the planet has warmed by only 1.25 degrees because most of the heat has been soaked up by the deep oceans or expended melting glaciers and sea ice. This energy doesn’t disappear, it just get’s delayed before equalizing with the atmosphere. Because of time lags in the climate system, we can’t just stop this process whenever we want. If we could somehow stop all emissions of greenhouse gases today, the planet would still warm by another 1 degree because of what we have already set in motion. The planetary energy crisis is ominous. If we want to maintain a climate similar to the one we have today for our children and grandchildren, then the human race needs to achieve an 80% cut in global greenhouse gas emissions by 2020. This is a tall order by anyone’s measure, but this is one budget that we cannot afford to ignore.

Given the forum guidelines I thought that a thread like this had to exist here. I'd be happy to get out and see th light of day (literally and figuratively!). I opened this thread in reponse to Chris' podcast. I've since been informed that there is an ongoing discussion on the subject matter up in the fresh air somewhere.

To answer your question I can give you a link to an excellent site for keeping track of a variety of climate change myths (http://www.skepticalscience.com/). This site discusses the "skeptic" arguments and provides the actual published science on the matter. It can get technical at times but does a good job of discussing the materials.

For me the main 'myth' I run into is that climate changes all the time, usually due to the sun, so we (humanity) can't possibly have any part in it. Skipping the math - first of all, just because climate responds to changes in the amount of solar energy that arrives at the planet doesn't mean that it can't be changed in other ways too. At its simplest, you have energy coming in (sunlight) and energy going out (heat). How can you tell if the increasing global temperature is caused by increased greenhouse gases trapping heat versus changing amounts of sunlight increasing the temperature? The easiest way is to realize that each will give you different types of temperature change. If the growing warmth were all due to increased amounts of solar energy we would expect temperatures to increase most during the day and during the summer when the sun is actually shining more brightly and for more hours per day. In the case of the greenhouse gasses that trap heat, you will get temperature increases year-round but they will be most apparent at night and during the winter when temperatures should drop quickly because the sun isn't shining or at least is only doing so fewer hours per day. The greenhouse gases act like a blanket that slows the rate at which heat escapes.

There is a lot of noise from one year to the next but globally this is the pattern we see. The planet is warming but it is warming most at night and during the winter. This is what makes heat waves increasingly deadly (e.g Europe 2003, Russia 2010). It doesn't cool down enough at night to let people recover enough to face the next scorching day. Those regions haven't been accustomed to such warmth don't have air conditioning in most homes. In Europe upwards of 30,000 people died, in Russia it was 50,000. This is a big part of why Europe is so active about addressing global climate change.

Thanks for touring the dungeon!

With regard to the rising minimum temperatures, Poet, sent a Washington Post link that had this quantification of the effect in the United States from NOAA's Climate Extremes Index.

In the last several decades, the prevalence of extremely warm low temperatures has overwhelmed extremely cold low temperatures. In 2011, 26.1% of the country experienced extremely warm low temperatures. The amount of country that experienced extremely cold low temperatures? Just 2.6%.

Hello Mirv,

You provide a lot to chew on! I am unsure which astrophysics you are referring to. The solar flux at the Earth has been increasing at a rate of about 10% every billion or so years as the Sun matures. No need to move the planet, just wait and we'll get that extra sunshine. The interesting thing is that the temperature range of the planet has been much more stable than would be expected if the temperature of the Earth system was a passive response to solar forcing.

I like your controversial commentary but it basically ends up in a question of value judgements, perfect for who, for how long? I was recently in New Hampshire and everyone was complaining about the lack of snow. They like to ski. As for me, I am quite happy not shoveling very much this winter. Throughout the period of life on this planet the response of the sense that things are too cold (or too warm), has been to get up and move (or propagate more efficiently in that direction if we are talking plants). Currently we are turning up the thermostat on the planet. Some people are going to be more comfy and others are going to be less comfortable. When I moved back from Brazil and visited some family, my wife turned up the thermostat one winter night and was quite comfortable. The rest of the house that was alseep under many blankets awoke very uncomfortable indeed! Some species will be winners, others will be losers - ultimately. The main problem is that we (humanity and the rest of life) all need to get from here to there.

The idea that warming the planet suddenly opens up a new continent (Antarctica) or makes much of Canada and Siberia now pleasantly warm is fine if someone wants to sit on their porch and enjoy the air but it isn't going to help anyone make a living there. Just because central Canada suddenly has a good temperature for growing corn will not make it Iowa. Without the soils you can't grow the crops. For most species the problem is the rate of change in the climate. I believe that you are right that we will have to try to help things along but we will be experimenting with the entire planet. We do not know how to build a functioning self contained ecosystem (see Biosphere 2).

My concern where we (humans) are concerned is that we have no idea of what we are setting ourselves up for. We have the idea that things will get a few degrees warmer, meh. Big deal, that happened since breakfast today already. This is not how it works though. We warm the planet and we effectively inject the climate system with steriods. A few places may actually get more stable climatically but most will see very different patterns of weather. We already are (hope to be able to show this well later this year). Also, climate systems are chaotic. Right now we are getting a gradual change in conditions but there is no guarantee that this will continue. Things can change abruptly and right now we have no idea of when, but there is some recent research that is looking for indicators of reaching such tipping points.

Your concern about ocean acidity is very astute. About half of the planet's carbon uptake for productivity is from phytoplankton in the world's oceans. Rising acidity messes wth their ability to form skeletons/shells. Osteoporosis for the masses. These are the base of the food chain in the oceans, soak up half the carbon dioxide and provide half of the annual oxygen production for all of us. Ecosystem services are important....

Hello Stan,

Thanks for the post. Having an honest assessment of the science is what I am aiming for. I'd like to assess what level people want this discussion at? As I see it we have everything from idle curiousity to well-informed posters. Some want a 'spare me the math' coverage and others want very detailed information. To the extent possible I'd like to provide materials at a level that works for most everyone. I do my best to demistify the science.

You ask for verifiable data, fair enough. In what form would that have to be? My stock and trade is peer reviewed publications. You throw out a lot of matter of fact conclusions that I am unaware of in the peer-reviewed literature. Which proxy data are you deriving your conclusions from? Tree rings, bore hole temperatures, sediment or ice cores? If you want the discussion that your post asks for then please repost your material with the same level of fidelity that you are requesting. I can then respond appropriately.

I can guarantee you that I don't have a policy agenda to push and I'd prefer it if the thread stayed more on the science and less on the political agendas of various ideologies. In case you are unaware of it, I'd like to point out that recently even the 'skeptical scientists', doing a detailed analysis addressing most of the supposed flaws in previous climate science have proven that the planet is warming in line with or even more rapidly than NASA, NOAA and the UK Met have indicated (BBC link)

Mark

Thanks for the thanks but no thanks are necessary. I've lurked long enough and benefited by the many posts here on the site that I felt it was time to give something back. My goal in discussing global warming here is to inform people of what climate change really means and what the science can and cannot tell us at this point. However, much like the theme of the rest of the site, I think we should prepare for what is likely to come - in this case, in terms of climate. The problem is that in most cases no one even knows what they need to prepare for.

To answer your main question, are we in a problem or a predicament. I am afraid to say that at this point we are in a predicament. However, the problem is that we can still influence the outcome so we don't get to throw up our hands and walk away. By way of analogy (true story - predicament), I once found myself falling head first down a cliff face (long story). I had the presence of mind to look where I was going and saw that due to the outward slope I would reconnect with mother Earth so at the last second I wrapped my arms around my head and tucked to take the impact on my shoulder instead of my face (managment!), two more bounces with a lot of spinning and 150 ft later, I managed to claw myself to a stop before things went completely vertical again. The combination of management and dumb luck allowed me to live to do more foolish things on other days.

The question is how are we going to manage this climate situation? Alas, I am somewhat pessimistic about concerted global action breaking out anytime soon. I feel the same way about the global economy at the moment too. This doesn't mean we cannot take personal action in much the same manner. Mike is moving to cooler climes. In my neck of the woods, the best action farmers can take can be summed up in two words - crop insurance.

All is not lost where the climate is concerned, however. Climate change is more and more of a concern globally due to the simple fact that more and more people are being negatively affected. Why did Europe get so forward thinking on climate change? In 2003, they had a major heatwave that killed 30,000 people. That will get your attention. Russia did a complete 180 degree in 2010 from claiming this global warming thing was an American hoax to wanting immediate action. In 2010, an historically unprecendented heatwave and associated fires led to the deaths of 50,000 (curiously, many of whom drowned after going swimming while innebriated). Australia recently passed a carbon tax. It seems 10 years of crushing drought, the Black Saturday fires in Victoria (2009) and flooding much of the northeast of the country (2011) got people motivated. I am not advocating any particular approach to this predicament but I do think that we may be reaching a critical mass of consciousness about the situation. One can always hope.

I am all for identifying and mitigating future problems and furthermore we are going to have to adapt in many ways but this still does not absolve us of our need to kick our fossil fuel addiction. Peak oil may have come already, peak natural gas and coal may follow but it won't just end, just look at the 'non conventional' fuels to date, shale gas and oil, tar sands. How long until mining methane clathrates starts sounding economically desirable? There is already plenty of work being done on the possibility.

Well I am probably rambling on too much and definitely too late!

Mark

I actually read Heinberg's book 'Blackout: Coal, Climate and the last energy crisis" last year. Definitely an important part of the peak energy discussion. With regard to the climate implications, first a few points to make.

1. The target of 2 degrees celsius warming is not a magic number. There is nothing that say that if we can hold that line that everything will work out alright. What it is, is the most conservative target where pretty much everyone working on the IPCC science summary could agree that anything higher would produce unimaginable societal consequences.

2. 450ppm CO2 does not equal 2 C of global warming - the science of climate change is continually evolving. Every year we get better paleoclimate data, more historical data and better understanding (or discovery) of feedbacks in the climate system. For those who don't know, feedbacks can be positive (meaning making things continue in the direction of change) or negative (meaning making things return toward their initial conditions). Almost everything we've discovered in the last decade shows we have underestimated the effects of greenhouse gas emissions.

3. Trying to achieve a global temperature increase of no more than 2C, when accounting for feedbacks, has led to shifting targets for CO2 levels. The most recent target has been placed at 350ppm, which is a problem since we are already at 392ppm and rising about 2ppm per year.

4. Peak energy - I have been trying to wrap my head around what this means for climate for the last year. In principle it means that we probably can't achieve the worst case scenarios of the IPCC(A2, A1F1) unless we find a new source of more fossil fuels (clathrates anyone?) or trigger more feebacks than we've already noticed. So the climate of 2100 and beyond may not be as extreme as the business as usual (BAU) scenarios. However, it has little to do with what we can already expect in the next 30-50 years.

5. Aerosols - atmospheric pollution is shielding us from much of global warming. This is one of the more underappreciated facts of climate science. At its simplest, all of the particulates we pump into the atmosphere act to make things a bit hazy like a fine shade cloth over the planet. This reflects a chunk of the sunlight and acts to cool the planet, shielding us from the full effects of greenhouse gas-related warming. What this means is that as we cut our emissions levels (whether through clean air acts or peak oil limitations) the rate of climate change will accelerate. We are stuck in a damned-if-you-do, more-damned-if-you don't situation. CO2 increases last 100+ years in the atmosphere while particulates last only weeks to months. Based on the existing literature, I have generally assumed that if we could suddenly stop all emissions tomorrow (think of the History Channel's 'Life after people') then the planet would double its warming within weeks. However, if the most recent work by Hansen et al. (December 2011 - see pdf here) is correct, then the situation is even more dire. We have bought the equivalent of sovereign negative energy bonds and we now have to either 1) keep printing more (polluting) at an ever less sustainable value, or default (pollute less) and face the true costs of our greenhouse gas-related energy retention debt.

For a more lucid and well referenced treatment of why 450 pmm is not a 'safe' target limit see this piece at Skeptical Science (link). In short, peak energy doesn't do anything to "solve the problem of global climate change", all it does is indicate more clearly when the final bill will come due unless we choose to default and pay the price (reduce energy use-related emissions) earlier. Just like you can't escape Student Loans" through bankruptcy in the US, this condition has no loop holes. The debt must be paid, the only question is how much of it will land on our children, grandchildren, great grandchildren and beyond.

Mark

Mike,

I should be able to tell you more on that before too long. The preliminary Aussie regional future climate workup is a bit concerning due to the way the currents are moving. I dumped the materials on one of my grad students but as I recall the east side may have a substantial climate shift which could push the vegetation outside of its functional niche (in other words, there might be a type shift). Balmier but not necessarily good for the native vegetation. I got the climate reports on a confidential basis because they hadn't been officially released but this information came up in a public meeting, if the've done the official release I'll see if I can get you the link.

As a lifeboat location I'd say it's a bit of a mixed bag due to demographics (low population density) and economics (highly dependent on resource extraction) but you probably know more than I on that score. Climatically, I think that if you are taking the long-term view it probably gets better for agriculture over time. In the next 2-3 years, we should have a better handle on what the changes mean for the fire regimes and native vegetation in general (or we'll have to answer to a few funding agencies...). As for all locations, timing and the particular dystopian future scenario you envisage colors what one thinks. Personally, I love the place though I've only been there a few times. Given that it is the birthplace of permaculture there is a lot to like.

Cheers,

Mark

Thanks for a comprehensive post summing up our current dilemma, capped off with a question for the ages. Let's see what I can do with it...

First, let me say that I have no major differences of opinion with your assumptions other than that I think you are a bit optimistic about our population potential during the energy wind down, even without climate change. Various long term carrying capacity estimates have been made but are generally about 1 billion, though we've been eating our seed corn, so-to-speak, so that may still be an optimistic number. This doesn't mean we necessarily have to die off like flies. We could follow the inverted demographic pyramid of fewer children than adults in each generation to ramp down. Realistically, a rapid power down process means we cannot feed ourselves and do an even worse job of distributing food from places that can to places that can't.

Back to the climate question though. The, as if I didn't already have enough to worry about problem. You ask a good question because if you can't do anything about something (climate change) there is no point in worrying about it. The best individual and community response leaves a lot of room to cover since each person and community have a different host of abilities and problems. For myself, I feel I have the training and therefore obligation to try to make a difference at a global level through my research, and a more personal level through my students and interaction like this. That said, most people haven't chosen my path (probably wise). I won't throw out the normal platitudes of call your congressperson and buy green (whatever that means). Given the framing of your question and the basic preparation/resilience mindset of our community here, I will speak to why this might matter to your preparations and planning.

Things to take into account.

1. On average the temperature is going to go up - BUT we don't live in the average world. Average global temperature increase numbers are nice travel-sized descriptions of climate change but they tell you effectively nothing about the reality that you will experience. Peak oil etc probably means that we won't achieve the worst case scenarios of 5-6 C change in global temperature by 2100. What does that number even mean? Let's put it this way, since the depths of the last ice age until today we have warmed about 5 C. If we add another 5 C we are effectively punching the wayback machine for 30+ million years to before Antarctica had ice. The glaciers wouldn't respond all at once but it would be a fait accompli for an eventual 70 meters or so of sea level rise. Note, the current IPCC (2007) predictions are for 18-59 cm by 2100 but they are wrong and they knew they were wrong but they couldn't use data from after 2005 due to the rules (yes they exist), the common figure given now is 2m but with an uncomfortable possibility of up to 5 meters (pdf). Incidentally, just because the models end at 2100 doesn't mean the warming does. Planetary response times vary due to different components of the Earth system with about 40% of the temperature impact in a decade, reaching 60% by a century after the emissions. The other 40% will play out over a millennium or so. In the mean time what should you know/do? Realize that temperatures will go up but that night time temperatures will rise faster than daytime temperatures. This means heatwaves are more oppressive because you don't get to cool down at night. It also means higher dew points which equates to more time with wet leaves for your crops and a corresponding increased likelihood of disease.

2. Weather is going to be a lot more variable. Climate chaos is one of the current buzz words (for example). Climate is average weather, if the climate changes it doesn't mean that everything shifts nicely in one direction or acts the same in each location or through time. In most places what this means is that 'unusual' events will become increasingly common. For eample, where I live we had our 'wettest ever year' just over a year ago. Now we have had just about the driest 6 months on reacord (actually 0.01 inches higher). On average the weather may be fine but your crops won't grow during the average year very often. The take home message is plant more and expect less. If you are a commercial farmer (at least in the US) take advantage of crop insurance. It is currently a federal subsidy that doesn't reflect actual increasing risks. If you are depending on 'the system' for food, expect volatility in prices or availability, especially if globalization stops and/or the economy crashes and regions depend on increasingly local supplies.

3. Major climate and weather events are likely to become more common. The graphic below isn't from scientists, it comes from the people (Munich Re) who insure the insurance companies! Supposedly the U.S. suffered 14 billion-dollar weather disasters last year (link). We aren't alone, the rest of the world is getting the same treatment or worse (just ask DTM about Queensland last year). Nowadays if we have an event like this they send in the troops with aid. If our world gets a lot more local then we have to help ourselves. How do you prepare? Build stronger, pick your sites carefully, store more longterm food supplies - meaning more than you already are doing.

4. We better understand why things work not just what worked in our plantings. The knowledge of things on a family farm which has been operated for generations will be eroded much as inflation erodes your savings if you simply keep doing what always worked in the past. A kid born in Vermont in 2000 could be buried in the climatic equivalent of today's South Carolina in 2080, even if he never left the farm. The apple orchard might be peaches with oranges getting increasing consideration. Growing zones will be changing a lot more. New things (plants, animals, diseases) will invade, existing vegetation will be increasingly stressed. Stressed vegetation gets sick/attacked much as you do when you are stressed.

The Mountain Pine Beetle (MPB) is currently on a spree across the west, attacking mostly lodgepole, ponderosa, sugar and white pines. It's not new but the synchronicity of outbreaks all over is. British Columbia has been particularly hard hit. Note that little thumb sticking out in Canada. The temperature warmed enough for the beetles to get over the Canadian Rockies. They've recently been confirmed to have developed a taste for Jack Pine. This means they can now spread across the boreal forest towards the Atlantic. The only thing slowing them down now is the extreme arctic cold that often covers the region.  The point being that bugs, disease and fire are nature's way of clearing the landscape of vegetation that is no longer suitable for a location. Normally changes lke this would play out over millennia, we are compressing it into decades. Ecosystems aren't designed to change this fast. What can you do? Mitigate change if you can, adapt if you cannot.

5. We are all promoted to ecosystem managers. Like it or not, we have collectively chosen to manage the entire planet's ecosystems. We haven't got a clue of how to build a functioning ecosystem but we are going to get a lot of on the job training in the coming centuries. If what normally grows in your region won't anymore and nothing else can get there quick enough, we will either have to select the 'winners' and work to get them established or face the consequences. We don't have a stellar record in this area so far (rabbits in Australia come to mind). The point here is that there is nothing inherently better or worse between today's climate or that of the distant future. We and especally our decendants, no longer live in either though. The problem will be traversing this period of climate transition. What can you do? Keep track of your local weather as it changes and keep an open mind about what you try to plant over time.

6. Some places will become drier, others wetter but everywhere a greater percentage of the rain will come down in intense events. As we warm the planet, the air takes up more water. Raindrops get bigger, erosion increases and gully washers become more common. If you've experienced a tropical downpour you know just how much water can come down very quickly. Getting a months worth of rain in a week is a very different event than getting it in an hour. Places that never used to flood will do so. Placid little streams may change character quickly. There is going to be a lot of work for bridge builders going forward (whether or not we'll have the materials is another question). If you have a rainwater storage system (good!), just make sure that you have as part of your design a spillover in case the rate or amount overwhelms your system so that the excess is channeled where you want it to go.

I could probably go on but I think I have said enough for the moment. On a cheerier note, just because we can't imagine how we will live in a world unlike what we know, this doesn't mean we can't. Once we stop trying to get back to the past, we will become a lot more innovative as we look forward. Our predicament brings problems a plenty crying out for solutions.