Climate

NASA’s James Hansen: “One sure bet is that this decade will be the warmest” on record

New analysis asks “Can people recognize changing climate?”

The country’s leading climatologist has a fascinating analysis on “Perceptions of Climate Change:  Can people recognize changing climate?”  Hansen had predicted as part of his famous 1988 testimony “that the perceptive person would notice that climate was changing by the early 21st century.”  He revisits that subject in this paper with his coauthor, Makiko Sato.

They also make a number of noteworthy predictions.  That the 2010s will be the warmest decade on record may be a surprise to the deniers and confusionists — like the discredited Dr. J. Scott Armstrong, a marketing professor at the Wharton School, who is testifying Thursday in front of the House Science committee (more on that later).  But it is obvious to anyone who follows the science.  Hansen and Sato also predict:

we believe that the system is moving toward a strong El Nino starting this summer. It’s not a sure bet, but it is probable.

They don’t say so here, but that would very likely make 2012 the hottest year on record, one that is every bit as overwhelmed by extreme weather as 2010 was.

This entire analysis of how climate change is recognized by the public, especially the American public, is quite important, so I will excerpt their piece at length below:

This past winter, for the second year in a row, seemed pretty extreme in both Europe and the United States. So this is a good time to check quantitatively how seasonal climate change is stacking up against expectations.

People’s perception of climate change may be the most important factor determining their willingness to accept the scientific conclusion that humans are causing global warming (or global climate disruption, as you please). It is hard to persuade people that they have lying eyes.

In the paper attached to my congressional testimony in 1988 (1) we asserted that the perceptive person would notice that climate was changing by the early 21st century. I used colored dice to illustrate how the frequency of unusually warm seasons was expected to change.

We considered three scenarios for future greenhouse gas amounts. Figure 1 shows that the real world so far is close to scenario B.

Sato1

Fig. 1. Update of Fig. 2 of Reference 1, scenarios A, B and C being climate forcings of greenhouse gases used in climate model simulations. The real world (red curve) has closely followed scenario B.

“There are two main reasons that greenhouse gas growth moved off the track of scenario A onto scenario B in the early 1990s, Hansen and Sato explain, “the growth of CFCs (chlorofluorocarbons) was greatly diminished by successive tightenings of the Montreal Protocol, (2) the growth of methane slowed sharply.”

Temporary aside: there are two main reasons that greenhouse gas growth moved off the track of scenario A onto scenario B in the early 1990s, as shown in Figure 2: (1) the growth of CFCs (chlorofluorocarbons) was greatly diminished by successive tightenings of the Montreal Protocol, (2) the growth of methane slowed sharply.

PERCEPTIONS OF CLIMATE CHANGE

Let’s start with this past winter, compare it with the last few winters, and then check whether the odds of warm seasons have changed as expected. Figure 3 shows the temperature anomaly for each of the past three months and the seasonal (Dec-Jan-Feb) mean anomaly.

Sato2

Fig. 3. Surface temperature anomalies in Northern Hemisphere winter 2010-2011 relative to 1951-1980 mean.

Hansen and Sato explain:

December was very warm in northeast Canada, about 10°C (about 15-20°F) warmer than baby-boomers’ climatology (1951-1980 mean). It was unusually cold in the eastern United States and especially in northern Eurasia. Hudson Bay and Baffin Bay (between Canada and Greenland) were essentially ice-free, the first recorded time that ice-free conditions lasted so long. Ice-free water is a huge potential source of heat to the atmosphere. When the water is ice-covered the air above the ice can sink to 10 or 20°C below zero, but ice-free water warms the air above. I speculated in a prior post that this energy source may have contributed to causing the long-wave patterns that pushed cold Arctic air into northern Eurasia. But before getting carried away with regional climate prediction, let’s compare the last few winters and summers.

Figure 4 shows the seasonal mean temperature anomalies for the prior three Northern Hemisphere winters and the mean for the past decade. Note that the Northern Hemisphere temperature anomaly pattern in 2010 (Dec 2009, Jan-Feb 2010) was very similar to 2011, including the unusually warm Hudson Bay region. The similarity occurred despite the opposite phases of the Southern Oscillation in the equatorial Pacific Ocean, 2010 having an El Ni±o and 2011 having a La Ni±a. But the strong patterns are averaged out in the mean anomaly for the first decade of this century. The decadal mean has widespread warming of about 1°C, but greater warming in the Arctic and less warming in the southern and western United States.

Sato3

Fig. 4. Surface temperature anomalies in the prior three Northern Hemisphere winters and the mean anomaly for the past decade.

For more on the Hudson Bay warming, see Canada sees staggering mildness as planet’s high-pressure record is “obliterated.”

Figure 5 shows seasonal temperature anomalies for the last three Northern Hemisphere summers and the mean anomaly for the past decade. The United States was about half a degree Celsius (about 1°F) warmer in summers of the past decade compared to 1951-1980. Europe was 1-2°C warmer, in what seems to be downwind extension of large warming in northern Africa.

Sato4

Fig. 5. Surface temperature anomalies in the last three Northern Hemisphere summers and the mean anomaly for the past decade.

THE ARCTIC OSCILLATION

There is one crucial thing that must be examined that affects northern hemisphere winters, the “Arctic oscillation,” which, as Wikipedia explain, “is an index (which varies over time with no particular periodicity) of the dominant pattern of non-seasonal sea-level pressure variations north of 20N latitude, and it is characterized by pressure anomalies of one sign in the Arctic with the opposite anomalies centered about 37-45N.”

Before betting any money on seasonal predictions, let’s look at one more piece of data. Figure 6 shows the Arctic oscillation index for Dec-Jan-Feb and Jun-Jul-Aug. When the AO index is negative Arctic surface pressure is high, which tends to cause cold air outbreaks, pushing Arctic air into middle latitudes. The AO index has high correlation (62%) with European winter temperature, and weaker but significant correlations for the United States (41%) and Japan (37%). The correlations are much weaker in the summer, as expected given the weaker latitudinal temperature gradient.

Sato5

Fig. 6. Arctic oscillation index (top row) for Dec-Jan-Feb and Jun-Jul-Aug, and corresponding seasonal mean temperature anomalies in the United States, Europe and Japan.

Both the United States and Europe were colder than the 1951-1980 mean during each of the last two winters. But note that, despite all the belly-aching that we heard from Europe, it was only a bit colder than climatology. There were many winters that were much colder in 1951-1980, and even a few in the 1980s. Memories seem to be short. Of the last 10 winters 8 of 10 have been warmer than the 1951-1980 mean in the United States, 8 of 10 in Japan, and 6 of 10 in Europe. In the summer it is 8 of 10 in the United States, 8 of 10 in Japan, and 10 of 10 in Europe. But let’s still hold off on any betting until we check on our climate dice of the 1980s.

In reference (1), in approximation of categories used by the then United States Weather Service, we defined the 10 warmest summers of the 30 in 1951-1980 as “hot”, the 10 coolest as “cold”, and the middle 10 as “normal”. Our climate simulations indicated that for greenhouse gas scenario B the frequency of “hot” summers would increase to about 60% in the first decade of the 21st century and 70% in the second decade. In other words, instead of two sides of the die being red, it was expected to become four red sides at about the present time.

EXTREME EVENTS

Now we can check the degree to which the real world has lived up to this expectation. The answer will vary from one place to another, so let’s make a global map for this past winter. Each gridbox will be colored red, white or blue, depending on how the local temperature this past winter compared with the categories established by the 1951-1980 climatology.

Figure 7 shows the result for the last four winters (summers in the Southern Hemisphere).

Sato6

Fig. 7. Dec-Jan-Feb “hot” and “cold” areas during the past four years, with hot and cold defined by the 1951-1980 climatology. Dark blue and black are areas of extreme cold and heat, extremes of a magnitude that occurred 2-3% of the time in the period of climatology

The extreme cases are important because those are the ones that have greatest practical implications, especially for nature. Species are adapted to climate of the past, so a change to more extreme climates can be detrimental, especially if it occurs so rapidly that species cannot migrate to stay within tolerable climatic conditions.

It also appears to be the case that people notice the extreme cases the most.

The numbers on the top of the maps are the percent of the area falling in the five categories: very cold, cold, normal, hot, very hot. In the period of climatology those numbers averaged 2%, 31%, 33%, 31%, 2%, rounded to the nearest percent.

Figure 7 reveals, for example, that the past two winters in Northern Europe both fell in the category of “cold” winters, but not extreme cold. The area hot or very hot (51-73%) far exceeded the area with cold or very cold conditions in all four years (14-27%).

Figure 8 shows results for Jun-Jul-Aug for each of the past four years. In both Jun-Jul-Aug and Dec-Jan-Feb it is apparent that the area falling in either the hot or very hot category totals 64-78% in agreement with our 1988 climate simulations.

Sato7

Fig. 8. Jun-Jul-Aug “hot” and “cold” areas during the past four years, with hot and cold defined by the 1951-1980 climatology. Dark blue and black are areas of extreme cold and heat, extremes of a magnitude that occurred 2-3% of the time in the period of climatology.

The perceptive person who is old enough should be able to recognize that the frequency of unusually mild winters is now much greater than it was in the period 1951-1980. But mild winters may not have much practical impact. So a return to one or two colder than average winters may affect the public’s perception of climate change. On the other hand, the huge increase in the area with extremely hot summers, from 2-3% in 1951-1980 to as much as 30-40 percent in recent years and most of the land area in 2010. If people cannot recognize that summers are becoming more extreme they may need to have their senses examined or their memories. Perhaps the people who do not recognize climate change are living in air conditioned environments, which are restricted mainly to one species.

Or perhaps they watch FoxNews (see “Greater exposure” to Fox News will lead to “increased misinformation” on policy issues, especially climate science).

BETS AND PREDICTIONS

O.K., now let’s see what bets we can make, starting with next winter: are Europe and the United States going to be unusually cold again? Sea ice cover is very low now, as low as it has been in the period of satellite data. If low sea ice cover has caused the climate disruption of recent winters, as some scientists have asserted, that should hold again next winter, right? And I suggested that the ice-free Hudson and Baffin Bays were related to cold Europe. But were the long waves (the jet stream waggles) where they were because Hudson Bay was ice-free, or was Hudson Bay ice-free because the chaotic jet stream waggles happened to be where they were, causing southerly winds over Hudson Bay? Given the high degree of chaos in the AO index (see Fig. 15 in reference 3), I would not bet anything on Europe or United States winter temperature. On the long run the tendency, as verified by Figure 6 above, is toward winters that are warmer than climatology, so that is the direction I would lean, but I usually only bet on sure things, or on almost sure things that people find surprising.

One sure bet is that this decade will be the warmest in [recorded] history. Yes, some scientists assert that there is decadal variability and the next decade or two could be cooler. How do we know they are wrong? Because, as we show in reference 4, the planet is now out of balance by about ¾ of a watt per square meter of Earth’s surface averaged over the solar cycle. It may not sound like much, but that is a lot of energy (in an interesting unit suggested in a colleague’s paper, Sarah Purkey and Greg Johnson?), the ¾ W/m2 corresponds, assuming a global populations of 7 billion, to every man, woman, and child on the planet running simultaneously 40 industrial strength 1400 watt hair dryers 24 hours a day 365 days a year). This energy is enough to cause the ocean to slowly warm and ice to melt all over the planet.

UPDATE:  In response to a query, Hansen emails me “I usually think of history as recorded human history — I believe most people do.”  As for volcanoes nulifying the “sure bet,” he writes me “A Pinatubo or Krakatau would not do it, so don’t worry about that.”

Sometimes it is interesting to make a bet that looks like it is high risk, but really isn’t. Such a bet can be offered at this point. The NOAA web pages giving weekly ENSO updates (http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf) predict a return to ENSO-neutral conditions by mid-summer with some models suggesting a modest El Nino to follow. We have been checking these forecasts weekly for the past several years, and have noted that the models almost invariably are biased toward weak changes. Based on subsurface ocean temperatures, the way these have progressed the past several months, and comparisons with development of prior El Ninos, we believe that the system is moving toward a strong El Nino starting this summer. It’s not a sure bet, but it is probable.

Finally, we can mention one other high probability bet, relevant to a Congressional hearing later this week. Dr. J. Scott Armstrong, a marketing professor at the Wharton School, University of Pennsylvania will testify about climate change to a committee of the House of Representatives. Armstrong, we are told, has made a bet that a prediction of no temperature change over a 10-year period starting in 2007 will prove more accurate than predictions of global warming. Observations (Figure 21 of Reference 3) show a linear warming rate over the past 50 years of 0.17°C per decade. Our climate model slows this down to about 0.15°C for the near future because of the change in GHG growth shown in Figure 2(b) above. That bet, warming of 0.15°C/decade would have a high probability of winning over a bet of no temperature change.

I’ll discuss the Thursday hearing tomorrow, not so much because of Armstrong, who’s unscientific bet makes no sense,  but because the great fabricator, Berkeley’s Richard  Muller will be there.

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30 Responses to NASA’s James Hansen: “One sure bet is that this decade will be the warmest” on record

  1. rsmurf says:

    Most people may notice the climate changes but since they are so disconnected from the environment it is just a minor inconvenience. IE My electric bill was higher this summer, the rain ruined my cookout bla bla bla.
    When you are connected to the environment like someone like me who has a large vegetable garden it makes a difference and you notice. just the last four years went like this.

    1) drought… no rain had to water every day all year, plus a watering ban so garden size limited.
    2) next year FLOODS rained so much could not get into garden soggy, weeds overgrown
    3) sorta normal, temps rainfall…
    4) temps normal no rainfall for april may or june had to water every day
    5) this year 10+ degrees warmer than normal no rain have to water every day planted 2-4 weeks earlier than normal.

  2. Fascinating interview yesterday at CBA5 in Dhaka with Scientist Pablo Suarez, from the Red Cross/Red Crescent Climate Centre about their declaration in 07 that climate change was a humanitarian problem and mission to educate and engage in adaptation assistance at the community level. He talks about the awareness of people — from farmers in Ethiopia to bankers in developed countries who are too busy or too unconnected to find out what is causing the changes but know something is happening… This was also so interesting at COP16 where Mary Robinson and WEDO groups featured speakers who discussed their growing awarness that something was terribly wrong and how various groups (Ofxam, for example) would come into the community and explain … they would shift from praying to acting…

    Here’s the link, to OneClimate TVs live coverage”
    and to CGIAR’s coverage

  3. MarkB says:

    Deniers might get hysterical about the phrase “in history”. Hansen could have made that more clear, as in the historical instrumental record, although any thinking person could deduce that.

    [JR: Yes, I emailed him. Changed the headline.]

  4. amazes me lately how the xtreme weather in US parallels what is reported from LDCs … most specificially the intensity of precipitation being so destructive … flooding, massive snow storms, periods of unprecedented rainfall in Pacific NW…

  5. MarkB says:

    Minor grammatical issue this time with the headline

  6. dbmetzger says:

    Forecasters Predict “Barbecue Summer” for UK
    Independent meteorological company Positive Weather Solutions August will be a scorcher, but the Met Office, Great Britain’s national weather service, refuses to predict so far ahead. http://www.newslook.com/videos/300618-forecasters-predict-barbecue-summer-for-uk?autoplay=true

  7. GFW says:

    Acronym trouble here … is the LDC that Deborah uses “least developed countries”? I think it must be – a new TLA(*) for me.

    (*) Three Letter Acronym – the shortest autological acronym, ETLA being the next :-)

  8. Richard Brenne says:

    What hits you over the head like a 2 x 4 (something Jim has offered to do for free to anyone supporting the burning of more coal) about this is all the Arctic warming, sometimes up to 11.1 C (20 F) for entire regions for entire months, with all the lost ice and albedo effects and methane from the vegetation that had been frozen into permafrost and potential release of methane clathrates on the Arctic Ocean’s continental shelves that can mean.

    When will the best climate models incorporate these positive feedbacks?

    It’s nice Jim Hansen, who seems as virtuous as anyone I know about, shares his gambling habit with us.:) I’d consider him “the house” on these bets and put my money (or at least mouth) with his, in part because anyone who can ask for the century’s largest volcanic eruption (to test the accuracy of his climate models, which worked beautifully) and get it within months must have some fairly lofty connections.

    As rsmurf (#1) says, there are many factors influencing whether one would notice a change from 1951-1980 to now.

    1) They need to be old enough, or the one young person in the U.S. and similar cultures who cares what old people have to say.

    2) They need to be observant and/or a farmer, gardener, ice fisher, outdoor natural ice skater, ice climber, glacier climber, skier, backcountry skier, nature enthusiast, bird watcher, wildlife watcher, hunter, fisher, bird watcher, hiker, biker, backpacker, etc. Ideally they’d take dated photographs and keep calendar, log or diary records with exact dates.

    3) They’d need to realize less than 1 per cent of homes and apartments in the U.S. had air conditioning in 1951, maybe 15 per cent had it in 1980 (when the U.S. consumed more AC than the rest of the world put together) and maybe 60 per cent (all guesses when I couldn’t find these stats) have it today.

    4) The efficiency of heat and insulation in homes and cars has also increased during that time.

    5) The percentage of time per capita spent outdoors has dropped dramatically with more time spent in homes that have more than doubled in size, in cars that have air conditioning, tinted windows, improved heat and heated seats, in offices rather than outside or in largely unheated factories and industrial workplaces, and in box stores and malls and downtowns connected with more tunnels and sky malls than ever before, all at an ever-increasing (to this point, I think we’re near the peak of all of this) rate.

    6) The number of observant people like farmers and gardeners and many of the other key activities has dropped in per capita percentages.

    So this isn’t necessarily the best thing to pin our hopes on, but fighting the war of awareness on every level, I’ve been speaking to gardening clubs, astronomy clubs, ski clubs and any other groups I can find of such observant people, and asking them what they’ve seen, if any of them have kept records (like planting and harvesting), and if they’d like to start.

    Lastly, here’s a post I wrote for CP last year about the Vancouver Winter (should have been Summer) Olympics that has a lot of such anecdotal observations about the world’s biggest outdoor speed skating races, ski racing, mountain climbing and the sport of bandy, that has retreated with consistent natural ice from most European nations:

    http://climateprogress.org/2010/02/13/winter-olympic-sports-vancouver-climate-change-global-warming-richard-brenne/

  9. Merrelyn Emery says:

    Yes, the personal perceptions are critical and lead to belief and action particularly when supplemented by non-commercial radio and TV (see Beliefs and Actions about Climate Change on http://www.sustainablefutureplanning.com.au).

    We use this in the community workshops where they first have to collectively list the changes they have seen take place on the planet in the last 5-10 years, analyze these and then work out the implications for their community, leading to plans for mitigation and adaptation. Changes lots of minds and totally bypasses the unproductive arguing about believers and deniers, ME

  10. Paul Sloane says:

    The warmup during the period from 2010-2019 will probably be considerably greater than 0.15 Celsius because of the following reasons.

    1.) Sulfur dioxide aerosols from ship plumes and coal burning plants in China and the United States will be reduced.

    2.) Decreasing ice cover over the Arctic Ocean will result in a considerable decrease in albedo over the high latitudes of the northern hemisphere.

    3.) Rapidly increasing coal/natural gas usage by Asia will result in a sharper rise in CO2 levels.

    4.) Methane levels are beginning to rise again.

    Paul A. Sloane

  11. Michael Tucker says:

    No, sorry but if it were not for the data record and the reports from NOAA, and NASA, and the NSIDC it would not be obvious to me that the planet is warming and climate is changing. Especially since all scientists have so far insisted that we cannot draw conclusions form a single summer heat wave and last summer was on the chilly side where I live. However, this past years weather news did provide very persuasive evidence of climate change, even though some “experts” could not agree on that conclusion, but news coverage does not really count as perception of climate change by my senses. So no I am not able to discern that climate has been changing with my senses alone especially since my experiences are accompanied by constant reminders that the current heat wave, or blizzard, or 100 year flood that I might be experiencing indicates nothing. So must I construct a memory record so I might, or might not, reach and anecdotal conclusion that the climate is changing? I have seen may reports on other blogs (sometimes this one) where the respondent reports that his current weather is not consistent with his interpretation of what climate change should bring.

    I really don’t think we want to rely on peoples memories. You know what they say about eye-witness accounts in court. In any case I’m sure the data records that you have included with this piece are much more reliable than my faulty memory and clearly indicate that the planet is warming and also clearly indicate that I am an unperceptive person.

    Meanwhile:
    The perceptive gardeners who post here say YES we see the climate changing.
    The radiacl extremist Republican owner of my local nursery says NO it is all a liberal hoax!
    The American farmers say it is not obvious to them.

    I wonder if Mrs Obama notices anything when she tends her garden?

  12. it appears as if the first El Niño occurred in 1986-1987, <a href="http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html"<NOAA/Story of…" and wondering if any research has been done regarding both El Nino and La Niña and parts of the ocean reaching carbon cap?

  13. Joan Savage says:

    This year the US Weather Service prediction maps show that the deep South, Great Plains region historically affected by the Dust Bowl, and the Southwest are all likely to have warmer than normal temperatures.

    http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.php

    As Hansen and Sato, and Romm are all careful about predictions, this year may or may not be a year that the record high temperatures set in the 1930s Dust Bowl era are overcome by higher records, but it does not look good.

  14. Joan Savage says:

    Deborah Phelan (#10)
    The records for El Niño, La Niña and the neutral phase of the ENSO cycle go back a lot farther.

    Here’s a convenient table:
    http://www.atmos.washington.edu/~mantua/TABLES2.html

  15. Barry says:

    It is not enough that people “notice” climate changing…they also need to feel this as a threat before they will want to act on it.

    One of the delayer memes is that warmer will be better. I think that is where the GOP and Watts of the world are going to try to triangulate their way towards.

    Extreme weather is the fulcrum that will move most people to want to act because it carries a threat and sense of losing control. That is the battle ground of the future for the hearts and minds of citizens in the wealthy world.

  16. Barry says:

    Michael Tucker (#11) says: “The American farmers say it is not obvious to them.”

    I’m not so sure that is true from what I’ve read. Many are very aware and concerned. It would be a good subject to explore and write about.

    Regardless, the farmers of the world that rely on rainfall and the climate knowledge of the past for growing crops definitely feel the climate changes and are hurting. We will hear lots more of their stories in coming years as they join the climate refugee masses.

  17. Joan Savage says:

    In the Dirty Thirties, a lot of topsoil blew away into the Atlantic Ocean, and on its way, sometimes darkened the skies over Washington, DC and New York. That got the East Coast people’s attention, even if failed crops hadn’t. Like watching a house slide down a slab of melting permafrost, the Black Blizzard was genuinely unusual.

    One of the basic predictions about carbon emissions-amplified climate change since at least the 1980s is that the weather will be more variable, less predictable. In my opinion that is sometimes a hard sell to get people to see, until the costs of preparing for skewed seasons, drought & overly wet conditions catch up with the urbanites economically. Maybe I’d call it the Uncertainty Blizzard.

  18. Michael Tucker says:

    Barry,

    I absolutely agree that what American farmers have to say “would be a good subject to explore!”

    Especially since many are located in decidedly red states and they continue to vote for science deniers.

  19. Aaron Lewis says:

    Last April, I was at a big funeral in North Central Kansas attended by a good number of farmers, whose families have held and farmed the same land since the mid 1920s. The all said that both temperature and precipitation was up in the last 50 years.

    In the days when the climate was (more) stable, El Nino was a big deal. Since 2007, I expect that global warming is a larger factor in the variability of global weather. For example, I see last summer’s warmth around Hudson’s Bay and the Russian Heatwave as both stemming from jet stream circulation driven by heat from the Gulf of Mexico and Caribbean. That southern loop of the jet stream was just plain weird.

    I think that history will see 2007 as one of the great milestones in AGW. The actual tipping point was a bit earlier, and became visible in the sea ice melt of 2007. Feedback from the change in summer albedo and additional moisture in the summer will accelerate Arctic warming, and in particular the melt of addition sea ice and the Greenland Ice Sheet. Moreover, loss of sea ice will allow wind driven circulation of the Arctic seas allowing additional heat transport into the Arctic from the North Atlantic. Yes, the decade 2007-2017 will be the warmest in man’s history. We will see weather that we have never seen before. We will see more snow in the winter and more heat in the summer, with more flooding in between. The El Nino effects will be small compared to the albedo and moisture over the North Pole feedback effects.

  20. Merrelyn Emery says:

    Different people notice different things and some more than others. It is only when you put them all in a room and get them to share their perceptions that they start to add up to a pattern that everybody can identify.

    Also people think and work differently when they are on their own and when they are in a group. When working in a group, the most common motivation is the positive future of the group or community – it does not have to be a threat.

    Climate change is a threat but even when people simply work together to improve their community, they take many of the actions that work to mitigate and adapt to CC anyway, e.g. clean energy, community gardens, ME

  21. Steve L says:

    Hmm, I thought the collapse of the Soviet Union (and the reduction in economic activity that resulted) had something to do with the slowdown of greenhouse gases in the ’90s.

    On another note, the graphs tend to be red, white, and blue … but the blue is declining. Does this mean that the US is becoming more like Canada? And if so, can someone (Inferno?) twist this into meaning that the US is getting colder?

  22. Reginald Buckley Simms says:

    I am so scared. We need to unite as climate hawks and have a 1 million hawk march on the mall.

    To show our dedication to our cause that humans are the cause of climte disruption, we will all drink kool aid laced with cyanide in order to save the planet.

  23. Steve L says:

    Don’t be scared (and don’t feign it, either). Just try to pollute less and support initiatives that will most fairly make it easier for everyone to have a fulfilling life while not pushing other species closer to extinction and disrupting our ability to feed ourselves.

  24. George says:

    Remember that we also live in a mobile society. I recently saw a statistic which said that 75% of people in the US change their residence within a 5 year period. In my case, in the course of my life, I’ve lived in Wisconsin, Ohio, Missouri, Michigan, Minnesota, New Jersey, Massachusetts, and Connecticut. I can say with certainty that the climate in Missouri is different than in Minnesota. I can’t really say how the 1960’s in Missouri compared the following decades, since I haven’t lived in Missouri since the 1960’s. So where is my baseline for ‘personally’ observing climate change?

  25. Calamity Jean says:

    I’ve lived in Chicago IL for 30 years, and I have noticed a change. It doesn’t get cold enough to snow here until the beginning of December; when I first moved to Chicago snow at the end of October wasn’t terribly strange. It’s still cold in December and January, but by the middle of March it’s really springlike. It used to be a person couldn’t count on “shirtsleeve weather” until April.

    Winter weather now starts two to three weeks later than it did 30 years ago, and spring starts about a week or two earlier.

  26. Dr.A.Jagadeesh says:

    Yes. The symptoms are already felt.

    Dr.A.Jagadeesh Nellore(AP),India

  27. Marnie Gannon says:

    Here in Livingston, MT, we used to have bright, sunny and cold days during the
    winter. Regularly 20-30 below for weeks at a time when I moved here in 1988. In the last decade we are mostly overcast in the winter, but much warmer. If we go to
    -25 it will be just a day or two, but even that happens rarely. I miss the sun
    a lot. As a gardener, I noticed when I moved here from the damp California Central Coast, there were no earwigs, sowbugs, slugs and snails here. The winters were just too severe. Now we have them all, and lots of them!

  28. Larry Gilman says:

    If only Mr. Hansen could parse his own perceptions of the salvific potential of nuclear power as accurately as he parses public perceptions of climate change . . . I’ve heard him speak: his ideas are surprisingly crude on the “we need nuclear” question. He believes that “100% burnup” of wastes is around the corner, that new (unbuilt, untested) reactor architectures will fulfill all the promises of infallibility and low cost that have been made for all previous designs, and that we must deploy nukes to stop burning coal. The latter point may seem commonsensical to Mr. Hansen — but then, so does climate denialism on snowy days, to people who have drunk the Kool-Aid. (The coal-or-nukes choice offered by writers like Monbiot and assumed by Hansen, among others, is not real: viz. http://www.rmi.org/cms/Download.aspx?id=1138&file=E09-01_NuclPwrClimFixFolly1i09.pdf&title=Nuclear+Power%3a+Climate+Fix+or+Folly%3f .)

    Don’t get me wrong. Hansen’s a great guy doing great work. He’s put himself on the line in the fight against coal, repeatedly. But he can and does muff at least one big question.

  29. @Calamity,

    Chicago was colder still, 40 years ago.

    It was darned cold by the end of September and wont to snow in April, even once in the third week.

    But even in southern Illinois, where last year temperatures during October broke or nearly broke records for weeks (almost reaching 90 °F), I ran into people who were disconcerted when I said it was abnormal, as if this was something that they had not believed and did not want to hear.

  30. Alteredstory says:

    For Mike Tucker #11, here are links to the abstracts of a couple papers indicating changes in seasonal behavior in Massachusetts

    Whether or not weather in any individual season can be attributed to climate change (though I think increasingly it can be), there ARE changes occurring, and they’re being responded to by flora and fauna across the globe.

    http://www.esajournals.org/doi/abs/10.1890/07-0068.1

    http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2008.01619.x/abstract

    These are just a couple of many, many examples. You can also check out Early Spring, by Amy Seidl (http://www.amazon.com/Early-Spring-Ecologist-Children-Warming/dp/0807085847/ref=sr_1_20?s=books&ie=UTF8&qid=1301580089&sr=1-20)