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Comments 551 to 600:

  1. Water vapor is the most powerful greenhouse gas

    Hello guys! I really appreciate that you collect arguments here and discuss about them. Because that is how science should be.

    Now to the topic: What I don't understand at the moment: How can water vapor be a reliable feedback loop for global warming?
    I understand that if the temperature gets hotter, more water can be absorbed by the atmosphere. To be accurate, for every degree (1 °C) of warming (at an operating point of 15°C on earth in average), the air can absorb circa 6% more water (see below for a derivation of this value (*1)). This means: If the global temperature increases by 1°C, the atmosphere can (but not must) hold 6% more water molecules. But when at the same time relative humidity drops by approximately 6%, we have the same amount of water molecules in the air than before the warming.

    Thus, to state this effect as a positive feedback loop, the total amount of water absorbed by air must be coupled only to temperature and no other effects (for example to random distributions due to other unknown or non-considered effects). But looking at meteorological stations, relative humidity changes quit a lot. As a rule of thumb, one can say that relative humidity is in the range of 80% (I looked up several meteorological stations, but this rule of thumb certainly will vary from station to station), but also when looking at the average relative humidity of one year at the same station, relative humidity fluctuates by approximately 10%-points (*2). This would compensate the impact of the increased saturation limit completely. So to me it seems that the feedback loop is just a mathematical model, which does not withstand empirical evidence by measurements of relative humidity.
    But you may prove me wrong. Are there any studies about the (global) relative humidity, which state that it indeed stays constant in average? To me it seems to be a very harsh and unrealistic criterion, that the relative humidity must not fluctuate more than 6% (otherwise this fluctuation would outweigh the feedback effect).
    So how can it be explained that the absolute amount of water in atmosphere is coupled only to temperature, and relative humidity stays constant over time and is not coupled to any other effects?

    (*1): One can calculate the saturation limit of water in air using the formula Rho = Ew / (Rw * T), Rho being the saturation limit [kg/m^3], Rw the specific gas constant of water (461.52 J/(kg * K)) and Ew the pressure for water/steam equilibrium, which is also a function of T, the temperature in Kelvin: Ew = 10^(A-B/(T-C))*1000, A = 7.2326; B = 1750.286; C = 38.1. Linearizing around 15°C (equals 288.15 Kelvin) yields a slope of 6% saturation limit change per 1°C change. When linearizing around an operation point of 0°C or 30°C instead of 15°C, the slope does not change much (only by 1%-point).
    Link 1
    Link 2

    (*2): For example I looked up the meteorological station of Hamburg, which has a nice graph of relative humidity over time. One can see that fluctuation is quite high, even averaged over one year. I also could not see a correlation to temperature at first glance. (Sorry, it's a German source, but you should be able to interpret the numbers nonetheless.)
    Link 3
    Link 4

    Moderator Response:

    [DB] Shortened links breaking page formatting.

  2. Climate change and wildfires – how do we know if there is a link?

    Phillipe@13 and nigelj@14 thanks for your encouragement. I will however, keep holding myself to a tightening standard, because we must. Fortunately in Minnesota 25% of our electricity is nuclear and over 20% is renewable, so driving an EV makes a lot of sense. We've communicated to our architect that low-carbon and low-energy impact is important. He seems to understand, and he even just bought an EV himself two weeks ago.

    Definitely agree about passive solar design.

    It's interesting that what really drove me to buy an EV was when I started writing at SkS about climate change. To me it was simply unacceptable to be writing about the urgent need for change and driving a gas hog. We still have one vehicle that burns gas, but we drive it very little. And our compact tractor burns diesel, but as soon as John Deere comes out with a compact electric tractor we will trade it in. This is one of the big problems is that it takes time to transition, even when one wants to.

    By the way, take a look at CarbonCure, which is an initiative to begin decreasing the carbon footprint of concrete.

    The other point here is to be an example. Hopefully, and I do me hopefully not certainly, as extreme weather events become more common place and more people are affected, more people will be open to the message of our need to reduce our carbon footprint. We have to set examples as soon as we can and as best as we can.

  3. Climate change and wildfires – how do we know if there is a link?

    Philippe Chantreau @13, I agree totally. Theres not much I can add, other than two points.

    1) Humanity is not programmed to think very long term in terms of problems that affect us well in the future, and future generations. We respond best to relatively short term immediate shocks.

    2)I agree government has indeed become very controlled by business lobby groups and the mega rich. I think its happened since the demise of trade unionism, and the rise of  market fundamentalism. That's not to say I idolise trade unions, because I dont,  but things seem to have swung to some sort of market fundamentalist extreme that has become absurd, but cracks are appearing and plenty of economists are now conceding its not working.

    Not all rich people have toxic intent, and many are philanthropists, but all it takes is a few extremist ideologues to exert considerable power in critical areas, like the Koch Brothers. Some families have more wealth than entire countries, and money is power.

    America has no limits on election campaign donations and spending, which means corporations and wealthy business lobbies dominate influence, and the public interest groups struggle to compete. Its hard to see how this changes and theres no organised public outcry, just simmering discontent. Problems like this tend to be solved at the 11th hour when it reaches a crisis point.

    New Zealand has some campaign spending limits and stronger climate policies than America, but I admit theres a long way for us to go.


  4. Climate change and wildfires – how do we know if there is a link?

    Evan @12, I think you are on the right path with your house. I design infrastructure. I dont want to be specific becuase I dont think discussion should be about peoples qualifications, however I know enough to comment on housing and you are on the right track. It would be damn near impossible to build a zero carbon home, so growing trees is a nice way of compensating. I dont see what more you could do.

    I suggest look into passive solar design, because this minimises heat loss and heat gain. It does require thermal mass, and normally a concrete floor  which is carbon intensive, but theres not much that could be done, unless you build a wooden floor overlaid  with natural stone, but this is probably unrealistic.

    But passive solar design can significantly reduce energy costs and sometimes all it takes is a little more glass facing the right way, some thermal mass in the floor as a heat sink, (this does mean not having carpet) good insulation etc, and so it doesn't have to cost significantly  more than a standard home. Of course I sense you have probably thought about all this anyway.

    But this all demonstrates a key point. Individuals cannot solve such a problem as carbon content of concrete. We are reliant on industry to reduce the carbon footprint of products, and to provide clean energy, pushed by government policy. Unfortunately theres a whole industry of climate denialism standing in the way of all this as PC points out.

  5. Pluto is warming

    I have seen no mention that Pluto was closer to the sun in 1988 than in 2002. In fact, according to the Wikipedia entry on Pluto, perihelion came on September 5, 1989. If it is true that, despite this, Pluto warmed up, this calls for further measurements — or a search of the literature for newer temperature measurements.

    Perhaps the following excerpt from  is overly simplistic: " At its warmest, when it is closest to the sun, Pluto can reach temperatures of minus 369 degrees Fahrenheit (minus 223 degrees Celsius)." Perhaps there is a delayed reaction as the planet continues to heat up due to being much closer to the sun than usual. Perhaps the increased temperature as Pluto approaches perihelion has atmospheric effects including a greenhouse effect. More discussion is needed!

  6. Philippe Chantreau at 03:11 AM on 19 August 2018
    Climate change and wildfires – how do we know if there is a link?

    Nigel, you don't see evidence of "huge change" because there isn't any. The depth of the denial and the strength of the entrenched interests are a perfect storm. From studying what happened in Europe in the 30s, I hold very little hope that people will wake up to the reality at hand, at least in the US, where they have been drilled ad-nauseam and where the critical thinking ability of the general population has gone down the tubes in the past 30 years. The propaganda means unleashed in the anglo-saxon world on the subject are simply staggering.

    This is a crisis that would require response on a global scale, global cooperation and a mobilization of the kind we have only experienced in large scale wars before. That turns out to be something impossible to muster for the current human animal. The emotional make up of the human simply has no provision for something like that. If we were attacked by aliens and could go at it with guns, there would be no problem, but this is different. It requires a truly, and almost exclusively cooperative effort. Worse yet, it requires us to exercise restraint in our pusrsuit of material goals, while the current economy is entirely based on frantic consumption of innumerable things that we don't really need and overconsumption of the ones we do need.

    What is hard for me to understand is the rapacity of the hyper rich, who are safe no matter what, but won't give up anything at all for the long term benefit of all. It's pretty obvious that is is even in their interest to do so. Of course most of them can be expected to die within the next 40 years, but still. I believe them, in fact. I believe that they're in a denial so profound as to be absolutely sincere. It is driven by emotion and mostly greed, but sincere nonetheless. 

    Evan, I wouldn't feel too guilty about your carbon footprint. No progress will be accomplished until coal fired power plants are displaced on a large scale. In fact, getting rid of coal burning completely and increasing transportation fuel efficiency standards for all vehicles (yes, even trucks) may be enough in the medium term to buy us time. The personal footprint argument is one used against honest folks by dishonest people; nobody can have an expectation that you'd have to live totally outside of norms, or expand all of your resources in an individual effort; that is not only unreasonable but stupid.

  7. One Planet Only Forever at 03:09 AM on 19 August 2018
    Climate change science comeback strategies

    Improving the awareness and understanding of more people regarding emergent truths is important. It is how humanity truly advances.

    Achieving all of the comeback strategies would be the best way to sustainably change a person's mind, help the person choose to accept the improved awareness and understanding of climate science. And that will happen if they were interested in learning to improve their awareness and understanding of the emergent truths of climate science, no self interests keep them from improving their understanding.

    However, it may also be helpful to test if the person being deal with is interested in improving their awareness and understanding, improving as a human being. Comments in public (including public forums) can benefit bystanders, even if they do not change the mind of the person they are directed at.

    Pursuits of Human Improvement involve developing improved awareness and understanding based on the available evidence and choosing more helpful, less harmful, ways to act based on that constantly improved wisdom.

    A Good way to test a person's interest in improving their humanity is bringing up the UN Sustainable Development Goals and seeing how they respond. If they say that they like any aspect of the goals I use that as my way in to a deeper discussion. All of the goals need to be achieved for any of the goals to actually be achieved. And it is easy to explain how more aggressive corrective Climate Action makes it easier to achieve almost any of the other goals (and that a lack of action makes it harder to achieve them).

    For humanity to have the best possible future, Good Helpful Altruistic Reasoning has to govern and limit all human activity. It would be best if everyone self-governed responsibly.

    Everyone can be helped to improve their way of thinking about things. But, those who resist improving their awareness and understanding need to be identified and be kept from significantly affecting things until their developed high degree of harmful selfishness is helpfully corrected to being more helpfully altruistic.

    I think the following is a good way to make that point. It also addresses challenges about who decides what is good or acceptable. Many people mistakenly believe that any alternative opinion is 'equally valid - equally deserving of consideration'. That way of thinking leads to the belief that the emergent truths developed by improved awareness and understanding must be compromised 'out of consideration for people who prefer to believe other things'.

    I propose two choices for determining if what human action is acceptable or desired, and if a preferred belief needs to be corrected.

    A: Acceptable is - Doing no harm to others and not detrimental to developing a lasting improved future for humanity. Desired is - helping others and helping develop a sustainable future for humanity.
    B: Allow some people to enjoy their lives more by doing things that are understandably detrimental to achieving A, either delaying A or actually causing harm to other humans, and causing harm to other life may be understood to be harming other humans, especially the way that extinction of life forms almost certainly harms the ability of a robust diversity of future humans to sustainably fit into a robust diversity of life.

    A person who understands that A is the proper objective measure of acceptability and what should govern or limit desires can be helped to also understand the unacceptability of compromising A for B at any time in any way.

    This would lead a person to be more open to improved awareness of climate science and the importance of achieving all of the Sustainable Development Goals, especially the climate action goals (the sooner the better for the future of humanity).

    The major detractors of climate science try to prolong or increase the benefit that a portion of current day humanity can obtain from the burning of fossil fuels to the detriment of the entire future of humanity. They are not interested in increased awareness or understanding of the unacceptability of what they have developed a strong desire to personally benefit from. And they really dislike being corrected, or limited regarding their 'belief excused' actions.

    A conversation that includes the consideration how to help develop a sustainable better future for humanity can improve the awareness and understanding of a bystander, even if the conversation does not change the mind of the person directly engaged.

    If the conversation is private, no chance of bystanders learning from it, and I get a sense that the person does not care about the Sustainable Development Goals, I don't bother discussing the climate science. I briefly try to get them to change their mind regarding the future of humanity. And if that fails I express my disappointment about their lack of interest in becoming a more helpful person, and offer to help them if they are interested, then I move on.

    This is similar to what I learned to do as an engineer. My objective was to help people achieve a better result. I learned to test how interested the people I was dealing with were to improving their awareness and understanding of proper (ethical) engineering. I learned to find out if they genuinely wanted the work done properly to protect the public and the environment from the potentially harmful consequences of the desires of people who want something more profitable (faster or cheaper), or if they were simply interested in trying to impress people who wanted more benefit by getting things done faster and cheaper in the hopes that they could make more money that way.

  8. Climate change and wildfires – how do we know if there is a link?

    nigelj@11 very well stated. At least, I agree. Whether or not you like Al Gore, the name of his film "An Inconvenient Truth" was brilliant.

    I have worked hard to change my life to be consistent with our knowledge of Global Warming and Climate Change, but as you noted, it is really hard to do without. We are currently building a house, because we bought property 20 years ago with a 100-year old knock down house within which we've been living for 20 years. But we knew we could not live in forever because of the condition of the house. So I am very concerned about carbon expenditure to build a new house. We will put in geothermal and solar, and are making the house as small as possible, but still, it will have a carbon footprint. We are planning to plant fruit trees to compensate for the carbon emissions and get some fruit. Is that sufficient compensation for the carbon emissions to build the house?

    We sold our truck and bought an electric vehicle, which we drive about 25,000 miles/year, mainly because my wife volunteers at a rollerskating rink. We have no children of our own and she is amazing working with kids. Does working with kids and helping them grow up well justify the carbon expenditure (even EVs have a carbon footprint)? In some sense I open myself up to criticism in a blog like this because I think that one of the main ways I become motivated to change is when people comment on my degree of hypocrisy. i.e., I write about climate change but am I doing my part to justify my admonitions to others?

    But I think your comments nigelj are well stated.

  9. Climate change and wildfires – how do we know if there is a link?

    Evan @10, that is not a rephrasing, it's more a total restructure of the question :) Still, its a good question.

    I think personal upfront experience of weather becoming more extreme has to motivate some degree of action. A slap in the face like this normally motivates change, yet I do not see much evidence of "huge change". There are at least three possible explanations:

    1) General reluctance to change well established habits (laziness)

    2) Climate change is a gradual thing.Frog being slowly boiled alive syndrome.

    3) I think this is the critical one. Fossil fuels are still the cheapest easiest fuel source for many people, and low carbon products are not common or attractively priced. Its human nature to buy the cheapest product that meets immediate needs, and somewhat irrational to do otherwise.

    I deplore battery chicken farming, but I still buy the damn things. I deplore single use plastic bags, and have managed to stop that but it took me a while to get there. I dont think Im a hugely lazy or irresponsible person. On the plus side I have a small fuel efficient car, but this was a relatively pain free decision to make.

    The answer to 3) should be carbon levy and dividend. This puts a price on carbon, and makes petrol unattractive, and low carbon alternatives more price competitive.

    The challenge is then how do we get this carbon fee and dividend policy? Not many people are crying out for it, and not many politicians support it, except for in a few places like British Columbia. I think the reason is over the last 40 years tax has been branded as evil, and as  theft and as the wrong sort of economic policy. Therefore we have made things difficult for ourselves, and I think its going to be hard work changing this mindset. But I try to remain an optimist on it.

  10. Climate change and wildfires – how do we know if there is a link?

    Perhaps I should ask the question another way. Polls say that a little over 50% of the people accept that humans contribute to global warming. Yet IMO far fewer than 50% of the general public are modifying their lives to acknowledge the reality of climate change. For people who already acknowledge climate change as real and our contribution as key, do these extreme weather events move them to start taking stronger action?

  11. Climate change and wildfires – how do we know if there is a link?

    Evan, I think people directly experiencing extreme weather first hand would mostly increase their acceptance of climate change science, especially warmists and fence sitters. I'm assuming here they are convinced the weather is getting more extreme or have seen data to that effect. Once the threat becomes real and perhaps painful, it clears the mind.

    I dont think it would harden anyones attitudes against climate science , unless they are really deep in conspiracy ideation and think its the government altering the weather, in order to bring on one world government . And yes, I have seen comments like this, but it cant be that many people.

    Of course even quite dramatic change probably won't increase acceptance among many of the denialists either, because they just rationalise it away with claims that climate changed before, the data is fake, its just weather. My guess is it would change maybe about half their minds at best. 

    Needs a poll or survey.

  12. Climate change and wildfires – how do we know if there is a link?

    nigelj @5

    That really seems to be the case.

    We had a fairly wet spring and early summer with few wildfires, we were well below the average until recently. The weather warmed up in early July and things dried out. Then we had a series of thunder storms come through that ignited a large number of wildfires. Over 400 in one outburst from what I recall.

    And now because smoke covers so much of the entire region, after the latest thunder storms it is very hard to detect new fires.

    2018 Wildfire season BC 

    "In fact, lightning has already sparked more than 1,300 wildfires in B.C. this year, which is more than any year since 2009. That number is likely to increase as the extended weather forecast calls for continued hot and dry conditions, with the risk of thunderstorms in some parts of the province."

  13. Climate change and wildfires – how do we know if there is a link?

    For those reading and writing comments here a question. Do you think people experiencing extreme climate-related events like wildfires, droughts, and floods firsthand increases their acceptance of climate science or hardens them against it? I'm not offering an opinion, just asking.

  14. Philippe Chantreau at 14:15 PM on 17 August 2018
    Climate change and wildfires – how do we know if there is a link?

    I think that's only part of the story Nigel. In BC, a major factor is the biotic stressors, many of which have been inked to climate change.

  15. Climate change and wildfires – how do we know if there is a link?

    Doug_C, @4, I might have part of the answer as to why Canada is experiencing more forest fires. Its related to more lightening strikes. Climate change is leading to thunderstorms moving northwards more into regions like Canada due to climate change according to this article.

    I was simply curious as to whether climate change would lead to more lightening strikes as a general rule, and  I did a google search, and came across that article. However it appears that its not certain that climate change would cause more lightening strikes for the planet as a whole. Some studies say it will and some don't. Here and here.

  16. Climate change and wildfires – how do we know if there is a link?

    It's sobering, my brother and his family were evacuated from our hometown for almost a month last year and he wasn't sure if there was going to be anything to go back to. He and his wife were the last car out heading north from that city with flames burning on both sides of the road.

    He's a 30 year veteran with BC Forest Service and has managed fire crews for years and has seen nothing like what is happening now.

    There were multiple fires started near where I live in mid July, hundreds of people a few kilometers to the north were evacuated and many homes burned. 

    There have been very few smokeless days for a month and last year was the same for most of the summer.

    How we are supposed to treat this as normal is completely beyond me.

  17. Philippe Chantreau at 10:44 AM on 17 August 2018
    Climate change and wildfires – how do we know if there is a link?

    Thank you for reminding us of that Doug. Man made dorders matter little to physics. With all the noise made about the California fires, we tend to forget the extent of the BC fires. Over 1.2 million hectares burned and 65,000 evacuees in 2017. Current year shaping up to be as bad.

  18. Climate change and wildfires – how do we know if there is a link?

    Whatever is happening we are getting hammered for the second year in a row in western Canada.

    The new normal is going to be hugely expensive in terms of fighting fires, loss of property and loss of resouces like the forests themselves that are burning up.

    BC Wildfires Map

  19. Humans are pushing the Earth closer to a climate cliff

    Mal Adapted @16, agreed carbon fee and dividend has to be the central policy for all the reasons you have given eloquently and in detail here and over at RC. (Sad that you know who doesn't get it). And Michael Mann also thinks a carbon fee is a potential solution.

    Although we probably have to solve various environmental problems in parallel, and they tend to mutually help each other in many cases.

  20. Humans are pushing the Earth closer to a climate cliff

    nigelj @ 4

    Reducing CO2 levels does mean we need to change our economic model towards steady state. Or at the very least we need to develop a system that grows in sustainable ways, and perhaps in the services sector, rather than being based purely on maximising resource extraction until nothing is left.

    I agree that the global economy is up against multiple planetary boundaries, and must eventually become steady-state. AFAICT though, the specific problem of anthropogenic global warming is comparatively easy: we 'merely' need to replace fossil carbon with carbon-neutral energy sources. That's already underway, driven to an extent by market forces in response to piecemeal government regulations and subsidies to promote 'alternative' energy. Collective intervention on larger scales is needed to accelerate the transition, by internalizing more of the marginal climate change costs in global prices for fossil carbon. It's not that radical an idea. YMMV, but I've made no secret of my support for a US revenue-neutral Carbon Fee and Dividend with Border Adjustment Tariff.

    Once transferring fossil carbon to the climatically-active pool is no longer cost-effective, we'll have bought time to work on all the other problems.

  21. Humans are pushing the Earth closer to a climate cliff

    nigelj @ 4

    I firmly believe that we are already living far past what is sustainable for the environment over the long term.  We are consuming the world's resources far faster than is sustainable. Moving to adopting a steady-state economic model is imperative if we are ever to adapt to the restrictions that climate change and the enviroment as a whole imparts upon us.

    Will we be able to act in time and reduce CO2 sufficiently? I very much doubt it. Our brains and our sociities are just not set up right to make the logical deductions to arrive at the solutions we need to reach. I don't want to be a party pooper, but that's just the way I see it.

  22. Humans are pushing the Earth closer to a climate cliff

    Bob, if you want a closer statistical look at NA snow, try here and especially here. Note especially spring and summer trends. Couple of things to think about it. As the earth warms, the atmosphere holds more water. If the warm air goes somewhere cool (up, towards poles etc), then it rains or snows. If it is cold enough to snow, then likely snow volume will increase. Come spring, (which is happening earlier), then you have snow cover influenced by two constrasting factors - more than usual amounts of snow to melt against warmer than usual temperatures to do the melting. Extent of snow cover does affect albedo, but the climatic effect is not much in winter (especially in high latitudes) because duh, there isnt much sun. Snow persisting through summer is much more important. Indeed the transition to an ice age happens when orbital wobbles result in cold summers at 65N and a persistance of snow. Right now, we are having very hot summers not cold ones.

    Looking a real trends in NH snow cover (see here), I dont see anything encouraging at all. It is downward. Nor is there is anything unusual historically about two years of increasing snow cover.

  23. Climate change and wildfires – how do we know if there is a link?

    Informative article. Southern Australia has been experiencing a drought and high temperatures and serious bush fires recently, associated with persistent anticyclonic conditions. This is in the middle of Winter! 

    Drought conditions in southern Australia and the associated persistent anticyclones has been linked to climate change here.

  24. Humans are pushing the Earth closer to a climate cliff

    Bob Hoye @10

    We are not in a cooling trend in North America, globally we are in a warming state of climatic transition which results in a disruption of local weather patterns.

    You just have to look at the amount of heat that is constantly being added to the Earth's surface through the mechanism of radiative forcing from things like the massive emission of carbon dioxide by human activity.

    Fortunately we have a meter for that located on this very page.

    2.646 billion atomic bomb quivalent heat units have been added to the Earth since 1998 alone. Most of that absobed by the oceans in a band 30 degrees on both sides of the equator. A place where ice and snow cover is not growing.

    Here in BC ice and snow cover is also not growing we are witnessing a rapid loss of alpine glaciers in British Columbia.

    Near total loss of glacial ice expected in BC, Alberta by 2100


    We did have greater than average snowfall here last winter resulting in much deeper snow packs. But this is duirng the winter months when insolation is at its minimum here. Snow falls here later in the year and melts sooner. 

    Resulting in a greater and greater occurance of catastrophic flooding.

    Record flooding in southern BC


    I see nothing to be encouraged about by the highly chaotic weather conditions we are being subjected to here in western NA or the increainsly catastrophics impacts of fossil fuel generated climate change.

    The Earth is not cooling based on almost all the evidence, it is warming at a rate that is overwhelming most natural mechanisms to adjust in a way that will mitigate catastrophic impacts like the loss of coral reef systems.

    Personally I have rarely seen the Sun in the last month and am glad that the large wildfire 3 kilometers to the north of my home has been put out. But much of this province is on fire with huge wildfire complexes that are joining together into incredible firestorms that cannot be fought. The same is happening right now in California. The smoke from BC reaches halfway across the continent and is causing unhealthy air conditions as far away as Manitoba.

    BC smoke blankets Southern Manitoba


    "Smoke from more than 500 wildfires burning in British Columbia has reached Manitoba prompting Environment and Climate Change Canada and Manitoba Health to issue a special air quality statement for the southern part of the province."

    Far from being encouraged, for many of us the experience is of being part of a very large scale and long term disaster movie where the conditions become increasingly hostile.

  25. Humans are pushing the Earth closer to a climate cliff

    While we continue to warm the atmosphere with CO2 emissions melting ice will continue. Basic physics. It may bounce around a bit from year to year but that is all.

  26. Humans are pushing the Earth closer to a climate cliff

    Bob Hoye @10, increasing snow and ice cover over two years is not a trend, or even change as such in any fundamental sense. It is weather and normal short term cyclical variation. Any increase in ice less than 10 years in duration can be dismissed as temporary natural variation. Read the IPCC reports.

    Remember the so called pause? The denialists were telling us the "warming trend" was over, this was "change", the models were wrong, an ice age was immenent. No I said, its natural variation and it will not last. It came to an end abruptly over the last 4 years in dramatic fashion. 

  27. Humans are pushing the Earth closer to a climate cliff

    The diagrams are illustrative and the part about ice or snow surface reflecting heat could be at an interesting juncture.

    The snow and ice cover for the Northern Hemisphere is published often. (I wish it was every day). Last year, the cover was above the high-side of the standard deviation band through the melt season of August and September. It remained above into October. And then for this year it was above begining in April. This begins the window of maximum energy being received at the Earth's surface. And the reflecting surface was greater than the year before.

    So far into this August, it has remained above the deviation band.

    While two seasons in a row does not constitute a trend, it represents a possible change. Particularly, with the Danish Met Institute's chart of temps "North of 80", which has been below the mean line through this melt season.

    Typically, this one gets below freezing at around the third week in August. And then when it is night all day there is little energy to reflect back into space.

    Over the two seasons, this is encouraging.

  28. Humans are pushing the Earth closer to a climate cliff

    ubrew12 @7: Wili's last quote from the OP:

    "What we are hoping for now is enough wisdom and will to at least stop short of going off these cliffs."

    You excluded "...and will" from your comment. Wisdom coupled with a will to act on it is absolutely necessary in mitigating and adapting to man-made climate change.

  29. Humans are pushing the Earth closer to a climate cliff

    If you're going to run into a brick wall and there's nothing you can do to prevent that, you need to prepare for the crash while applying the brakes. No matter when you apply the brakes the outcome will be better. But it does not mean you can avoid crashing.

    CO2 concentrations are accelerating upwards, not just going up. We can talk mightily about staying below 2C, but when we see that we are going over, it's time to prepare for what comes next, while we keep putting on the brakes.

    The problem is that our foot is still on the accelerator.

  30. Humans are pushing the Earth closer to a climate cliff

    wili@6: "What we are hoping for... is enough wisdom... to... stop short of going off these cliffs"  Jesus, friend.  Consider the words you just wrote.  'Enough wisdom' should have already stopped us well short of those cliffs.  Nope, not an alarmist, we'll muddle through.  But Earth's biodiversity is well and truly f000ed, and we should grant ourselves the right to say so.  We need to call out the fact that MAGA comes at a cost: the wholesale screwing of any part of this globe that isn't covered in MAGA.  No, if you're out there in the 'great unknown', you're not MAGA, you're a waste dump, as Turkey just found out.

  31. Humans are pushing the Earth closer to a climate cliff

    An important quotes from the full Guardian article: 

    "the time frames in the study suggest theres still much to be gained by keeping emissions under 2 degrees"

    "we don’t know how long they will take to tip"

    "it is far too late to avoid all climate change – it is already here.

    What we are hoping for now is enough wisdom and will to at least stop short of going off these cliffs"

  32. Humans are pushing the Earth closer to a climate cliff

    nigelj @1.

    I agree, there is a lot of reason to be concerned but this should motivate us not immoblize us.

    There are constant technological developments that give us options that didn't exist previously.

    Battery technology is rapidly maturing and with things like large scale redox flow batteries and solid state lithium metal batteries we can now plan electrical grids based almost entirely on intermittant sources of energy like wind and solar and can begin a phased movement to a transportation model based on electic power from those low carbon renewables.

    Three battery types in large scale grid storage


    Solid state lithium metal battery

  33. Humans are pushing the Earth closer to a climate cliff

    Reducing CO2 levels does mean we need to change our economic model towards steady state. Or at the very least we need to develop a system that grows in sustainable ways, and perhaps in the services sector,  rather than being based purely on maximising resource extraction until nothing is left.

    I think a steady state economy is inevitable sooner or later anyway. Take a look at gdp growth trends here and notice the falling trend over the last 40 years in developed countries, despite multiple tax cuts, a huge expansion of the money suppy, quantitiave easing, low interest rates, and endless stimulatory policies. I think anyone who believes high rates of gdp growth are possible in western countries anymore is delusional or will only achieve them very short term, and at the cost of huge debt levels and massive environmental damage.

    Developing countries are a different story. They have room to expand because of market demand for basic essentials of life. But they will reach a plateau eventually like western countries.

  34. Humans are pushing the Earth closer to a climate cliff

    With several nonlinear positive feedback loops potentially adding to global warming its going to be very difficult to predict the extent of warming we will see, or the size of any rise in sea level over the next 80 years. All the more reason for us to limit the amount of CO2 that we release into the atmosphere.

    It's not really a case of it being too late to do anything, as if we stopped CO2 output now it would have a sigificant effect on curtailing the amount of warming we will see. Given the human race's ability to obfuscate about our addiction to the fossil fuel drug that we have, it's more a case of us being unwilling to tackle the problem and to meaningfully reduce our CO2 output in the time we have before the positive feedback loops kick in.

    Reducing CO2 levels to the degree that we need to means that we will have to change our economic models from expansionist to steady-state Herman_Daly_thinkpiece. Something I don't think that politicians in most countries have the will to do yet alone the ability to achieve. 

  35. Humans are pushing the Earth closer to a climate cliff

    Through fossil CO2 emissions, people have driven a water vapor increase that triples the warming effect of the CO2 alone.   This should have served up an early warning that Earth's mysterious feedbacks won't magically resolve themselves in our favor, as we unnecessarily party our way through uncharted waters.

  36. Trump reignited his war with California, but his Tweet got burned

    Bob, you might also want to look at the graphs here to put 1930s in perspective with current temperatures. That the effects are so bad is due more to improvements in farming practise, irrigation and other technology.

  37. Trump reignited his war with California, but his Tweet got burned

    The charts dont tell all the story. The other side would be chart of $ investment in fire suppression and control. I think the forest service in US was created in 1930s in response to some big fires. If that hadnt resulted in change, then it would have been big waste of money. Much more interesting is change since 1970 when infrastructure for forest management is relatively constant but climate is changing.

    Fires are taking place despite huge increase in fire-fighting technology, investment and understanding on fire suppression. I would expect if temperatures increase, then the amount of investment is also going to have a dramatic increase.

  38. What does ‘mean’ actually mean?

    I really enjoyed Kevin's introductory statistics in the Climate Science Denial 101 course. Very stimulating.

  39. What does ‘mean’ actually mean?

    Kevin  Cowtan is very good  at explaining things and making it accessible. I only know part of this math but could get the general idea of where he was going. 

  40. Humans are pushing the Earth closer to a climate cliff

    The multiple tipping point  scenarios should have anyone worried, however the good news is the time frames in the study suggest theres still much to be gained by keeping emissions under 2 degrees. I get tired of the doom mongers claiming it's too late to do anything.

    However a study shows Antarcticas eastern glaciers are melting as well as the western glaciers, so are probably on the way towards a tipping point.

  41. What does ‘mean’ actually mean?

    A basic requirement for a good statistical analysis is that every member of the population being examined has an equal chance of being chosen in the sample you take.  In this case, each point of longitude/latitude would be the population.  Since sampling at such points around the poles is less likely, the various estimates have to be made with a single point near the poles being taken as the result for the points not sampled.  Not perfect but a pretty good first approximation. 

  42. Philippe Chantreau at 23:26 PM on 15 August 2018
    Trump reignited his war with California, but his Tweet got burned

    I wonder how that all looks if considering also British Columbia and Alaska. The past 2 years have been very bad in BC, all years since 2010 have had bad fire seasons. Limiting to the US is not very informative. The atmosphere doesn't care one bit about man drawn boundaries.

  43. Trump reignited his war with California, but his Tweet got burned

    Well, the USDA has a chart for the contiguous states that begins in 1916 and records a huge peak in the mid-1930s. Of course, with that exceptional drought and heat.

    The "Great Falls Tribune" of July 23, 1933 records that the acreage being burned each year is at "41,000,000 each year". There is a scan of the actual story.

    The recent burn rate is about 20 percent of the highs clocked in the 1930s. Included was the number in many millions of board feet, but if I go back to the article, I'll lose what I've posted so far.

    The chart above, the very top one shows the very high numbers recorded in the 1930s, which heat and drought I hope never return.

    Bob Hoye

  44. Flaws of Lüdecke & Weiss

    This is pretty close to a submission that got trashed for many of the same (but not all) reasons at Climate of the Past

    Moderator Response:

    [PS] Link activated. Please use the Link button in the comments editor to create links yourself

  45. Trump reignited his war with California, but his Tweet got burned

    We can also let the past be our guide to the future, provided we understand the context of our modern era vs that of the past:

    "The data do suggest however that even modest increases in temperature and drought (relative to those being projected for the 21st century) are able to perturb the level of biomass burning as much as large-scale industrialized human impacts on fire.

    More dramatic increases in temperature or drought are likely to produce a response in fire regimes that are beyond those observed during the past 3,000 y."


    "Based on the fire data alone, the levels of burning during the 19th and 20th centuries are not anomalous; there were times (i.e., the LIA) when fire was as low as it has been over much of the 20th century, and times when it was as high as during the 1800s, as around 50 to 1 BCE. When climate is considered however, the past approximately 150 y (i.e., back to 1850) are remarkably anomalous. Although the current rate of biomass burning is not unusual (even allowing for post-1980 CE increases in burning such as in ref. 3), it is clearly out of equilibrium with the current climate.

    Our long-term perspective shows that the magnitude of the 20th century fire decline, while large, was matched by “natural” fire reduction during cold, moist intervals in the past (e.g., LIA). Current fire exclusion and suppression however, is taking place under conditions that are warmer and drier than those that occurred during the MCA, which calls into question their long-term efficacy."

    Marlon et al 2012 - Long-term perspective on wildfires in the western US
    doi: 10.1073/pnas.1112839109

    US Wildfires last 3,000 years

    Larger version of image

  46. Pollution is slowing the melting of Arctic sea ice, for now

    Yup, M.Sweet@4.

    But digging coal provides jobs! But at the cost of about 1 person for every seven job-years. The math: About 70,000 people have jobs directly mining coal. So 70,000 people work for a year, and 10,000 other people downwind die. Hire 700 more for a year, 100 people die.

    Two miners working for 35 years each, for 70 job-years, and 10 people die. And as a bonus, the Earth gets warmer!

  47. Trump reignited his war with California, but his Tweet got burned

    Bob @5 - no, accurate forest fire records are not available that far back.  In fact they're not very accurate prior to 1983 (see Zeke's post).

  48. wilddouglascounty at 00:06 AM on 15 August 2018
    Climate change science comeback strategies

    Regarding the first strategy, and addressing the "climate change has happened before without fossil fuels in the mix," I like to use the analogy that pretty much everyone can relate to: car troubles. If your car doesn't start, it could be for a whole host of reasons. This is because the car is a complex system with many inputs and outputs, so if the car is out of gas, has a dead battery, has run out of oil or coolant, or has a mechanical failure, it won't start.  In a similar fashion, the complexity of global climate has many inputs and outputs, so that in the past orbital dynamics, volcanic output and natural emissions/absorption of greenhouse gases have driven the observed changes. This time, we've definitively isolated the release of greenhouse gases at a rate that is faster than the earth systems can absorb it as the source of the changes we are observing.  You can ignore the science if you want, but it's kinda like ignoring your mechanic when he says that it's a dead battery and so you put more gas in the tank and expect the car to start. Furthermore, if your mechanic says that he replaced the battery so it should be fine and it still doesn't start, it's time to go to another mechanic.

  49. Trump reignited his war with California, but his Tweet got burned

    The charts are fascinating.

    The first chart of area burned runs from 1965 to recent.

    The second is of California's temperature history starts in 1895 and runs to recent.

    To be thorough and consistent, the comparison should include the history of area consumed by wildfire from the same approximate date. That is to say about 1895. It is available.

  50. Welcome to the Pliocene

    Just to clarify my rushed comment @18 where I said that sea level rise of 20 m would take thousands of years as ice melts slowly, but I mentioned periods of rapid sea level rise in apparent contradiction to this. The periods of rapid sea level rise appear to relate to very strong regional warming in critical areas of the Americas,  and destabilisation of glaciers causing their flow to speed up.

    Meltwater pulse 1a has its own wikipedia entry and it's quite good.

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